DE102004004858A1 - Implements for simultaneously coating number of wafers during semiconductor manufacture by deposition from gas phase, i.e. chemical vapour deposition (CVD), or compressing chemical vapour deposition (LPCVD) as well as gas injector - Google Patents

Abstract

Implement contains process chamber (Tp) with vertical jacket tube (TL) forming reaction chamber (R). In jacket tube is fitted holder (C) with stacked positions for horizontal holding of wafers (S1-n). Gas injector (I) supplies process gas into reaction chamber. Gas injector and/or opening region (O) in jacket tube extend vertically along holder and are so arranged that process gas stay, its flow velocity, pressure and/or other parameters are similarly adapted. Independent claims are included for gas injector and its manufacture.

Description

contraption for coating substrate wafers, gas supply device and method for their production.

The The present invention relates to a simultaneous coating apparatus a plurality of wafers during semiconductor production by means of vapor deposition (CVD, Chemical Vapor Deposition), especially at low pressure (LPCVD, Low Pressure Chemical Vapor Deposition). Furthermore, the invention relates a gas injection device for this device and a method for producing the gas injection device.

Coating process, in which different materials from the gas or vapor phase on surfaces are deposited by substrates found in semiconductor manufacturing diverse applications. As a rule, very high demands are placed on the quality or homogeneity of the process produced layers (layer thickness, conformity, etc.), because certain deviations of the layer properties, the functionality the associated Semiconductor structures undesirable impair can. This applies in particular to the production of highly integrated circuits (IC), because these are usually very sensitive due to their fine structure sizes respond to any deviation from the intended structure. Often, therefore, suffice relatively small layer variations to semiconductor chips for the intended Use unusable. Because of the semiconductor industry prevailing trend to ever higher Integration densities will continue in the future as well The need to continue the coating process continues optimize.

Next typical single-wafer reactors, which gives very good results can be achieved in the coating of individual wafers, come too so-called batch reactors for use. This becomes simultaneous Processed a plurality of wafers parallel to each other in a batch are arranged. As for the mass production of the Semiconductor industry regularly on a particularly high throughput is required, are already coating systems with a capacity of up to 200 wafers. In addition to horizontal coating systems, in which the wafers are arranged side by side on a horizontal support are so-called vertical vertical reactors (vertical batch reactor) used in which the wafers in a vertical stack on top of each other are arranged. These take over the horizontally arranged Reactors significantly less space.

When Particularly difficult turns in conventional batch reactors, uniform conditions for all To create wafers inside the reactor. Conditioned by their the Geometry, a reactor chamber regularly has local areas in which other physical conditions prevail than in the remainder of the reactor chamber. However, if the physical parameters such. B. the distribution, the Pressure or the composition of the process gas along the stack can vary also deviations in the generated layers can be observed. These hang typically from the position of the respective wafer within the plant from, in particular between the first and the last Wafer of a stack distinct differences in the layer thickness or the layer quality can be observed. Such deviations from the norm may be for a relative high committee rate.

Of the As used herein, "process gas" includes both gaseous and vaporous materials. Likewise, microgranulated powders and combinations of vorgenanten substances possible.

To be able to distribute the process gas better within the reactor sees EP 0491393 B1 a gas inlet device with a gas inlet tube extending along the holding device which has a plurality of gas injection openings arranged at different heights.

Out JP 04308086 A Furthermore, an LPCVD coating system with a vertical processing chamber for coating a plurality of wafers is known, which are arranged one above the other in a holding device. To improve the homogeneity of the layers produced, it is proposed to arrange a plurality of gas inlet systems uniformly along the circumference of the process chamber.

The The object of the invention is an improved coating system to disposal to deliver. It is another object of the invention an improved Gas injection system and a method for its production disposal to deliver.

These The object is achieved by a device for coating substrate slices according to claim 1, a gas injection device according to claim 13 and a method according to claim 15 solved. Further advantageous embodiments are in the dependent claims specified.

According to the invention, an apparatus for coating substrate disks is provided, which comprises a vertical process chamber, a casing pipe arranged vertically within the process chamber and a concentrically arranged within the casing tube holding means. The holding device, for its part, has substantially stack-shaped superimposed positions for receiving substrate wafers, wherein the receiving positions hold the substrate wafers substantially horizontally. Furthermore, the device comprises a gas injection device for supplying a process gas into a reaction space bounded by the jacket tube. In the jacket tube an opening area is formed, which serves as an outlet for the spent process gas from the reaction space. According to the invention, it is provided that the gas injection device and / or the opening region extend along the holding device. It is further provided that the spatial arrangement and configuration of the gas injection device and / or the opening region are optimized in order to adjust the throughput, the residence time, the flow velocity, the pressure and / or a further physical parameter of the process gas in the region of the pickup positions. By matching these special conditions for all positions, positional differences in the generated layers within a batch can be minimized, thereby increasing the overall yield of the respective semiconductor products.

A particularly advantageous embodiment of the device according to the invention provides that the jacket tube is closed gas-tight in its upper region by means of a lid and the opening region is formed substantially on a side opposite the gas injection device side of the holding device in the jacket tube to a substantially horizontal flow of the process gas within of the reaction space, in particular in the region of the receiving positions. The advantage here is that the process gas flows substantially horizontally past the receiving positions, whereby a more effective and more uniform coating of the substrate wafers housed therein can be achieved. In particular, the advantages of the single-wafer reactor principle are thereby transferred to a vertical reactor furnace, whereby the quality of the layers produced increases. Among other things, the radial homogeneity of the layers produced on a substrate wafer can be significantly improved. Furthermore, a horizontal flow also allows a better removal of the spent process gas. Since the mass transfer between the substrate wafers (S ₁ -S _n ) now takes place actively and not only by convection processes, the residence time of the process gas in the deposition zones is lower overall. As a result, exhaust gases from the by-products of the chemical reaction are also increasingly transported away from the reaction space. Since the reaction chamber otherwise remaining exhaust gases can have a negative effect on the desired deposition reaction, expressed an improved removal of these gases in particular in a higher quality of the produce layers. Another advantage is that the design of the invention can be easily applied to existing vertical reactor ovens without having to make a costly and costly redesign. Likewise, a transfer of this concept to other reactor types is possible.

A further advantageous embodiment of the Invention provides that the opening area of the Jacket tube is substantially vertical along the entire holding device extends and a vertically along the holding device extending opening in the Casing tube has. By a suitable selection of the opening can be the horizontal flow the process gas in a particularly advantageous manner as desired shape.

According to one advantageous embodiment of the Invention is provided that the vertically along the holding device extending opening in Upper area of the jacket tube is wider than in the lower area of the jacket tube. By this constructive feature can inter alia a typical pressure drop of the process gas in the upper part of the Reaction chamber can be compensated.

A further advantageous embodiment of the Invention is also seen in that the opening area a plurality of vertical comprises openings arranged in the jacket tube along the holding device. The advantage here is that by a suitable embodiment the opening areas the profile of the horizontal flow can be determined individually. In particular, you can by a suitable shape, number and / or arrangement of the openings the aerodynamic conditions in the separation zones of the intake positions independently matched by their relative position within the holding device become.

In a further advantageous embodiment of the invention is provided that an opening arranged in an upper region of the jacket tube is larger as an opening in a lower region of the jacket tube. This is possible as well as the typical pressure decrease of the process gas in the upper area of the reaction space compensate.

Furthermore, an advantageous embodiment of the invention provides that the gas injection device extends substantially vertically along the holding device and is designed to distribute the process gas uniformly along the entire holding device into the reaction space. With the help of a running along the holding device gas injection device can be a achieve even horizontal flow of the process gas particularly effective.

According to one further advantageous embodiment The invention provides that the gas injection device at least two tubular injection lines which is substantially vertical between the casing pipe and the holding device run side by side and each have an injection opening in have a different height, wherein the injection lines have a common gas supply line and wherein each of the two injection lines from the gas supply line up to their respective injection opening for the process gas in each case Same effective distance and / or the same flow resistance having. Particularly advantageous is that using the injection lines the same amount of process gas under identical conditions in different heights the holding device can be dispensed.

Further is in an advantageous embodiment the invention provides that each injection line each one essentially vertical first section, a bent second Section and a substantially vertically duri fenden third Section has, which has the associated injection port. The advantage here is that all injection lines substantially identical flow characteristics for the Have process gas. In particular, this structure enables a gas injection device with several identical injection ports, each in different Heights arranged are, with each injection port independently from their respective height can deliver the same amount of process gas into the reaction space.

A further advantageous embodiment of the Invention also provides that the injection lines from in Essentially identical tubes exist, each in a different Height around Bent 180 ° are. By using identical tubes, each bent 180 °, can be ensured that each injection line for the process gas represents the same effective distance and / or the same flow resistance having.

In a further advantageous embodiment of the invention is provided that the device is a CVD and in particular a LPCVD coating system is.

According to the invention, it is provided the gas injection device consists of at least two substantially identical pipes to produce, with a common gas supply line connected and then in each case different longitudinal sections bent by 180 ° become. By means of this method, the gas injection devices according to the invention can be achieved especially easy to make.

in the The invention will be explained in more detail with reference to drawings. It demonstrate:

1a and 1b two sectional views through a conventional CVD coating system with a vertical process chamber.

2a and 2 B two sectional views through a CVD coating system according to the invention with a vertical process chamber.

3a - 3f six possible embodiments of the opening region according to the invention in the jacket tube of the coating system according to the invention.

4a - 4d a manufacturing process according to the invention for a gas injection device of a coating system according to the invention.

The 1a and 1b schematically show a conventional CVD coating machine, wherein 1a a vertical and 1b represent a horizontal cross section through the reactor chamber. The CVD system is designed as a so-called vertical furnace furnace (vertical furnace reactor). Such a vertical reactor furnace is z. B. off EP 0491393 B1 known.

The coating system shown here is preferably provided for operation as a typical low-pressure batch reactor (LPCVD batch reactor) and operates at a reduced pressure. It consists essentially of two nested cylindrical tubes, namely a vertical process chamber (T _P ) and provided within the process chamber (T _P ) jacket tube (T _L ), a so-called liner, which is also formed vertically. Both tubes (T _L , T _P ) are preferably arranged concentrically around a central holding device (C), the so-called 'boat', which is designed to accommodate a multiplicity of substrate wafers (S ₁ -S _n ). For this purpose, the holding device has a plurality of receiving positions (C ₁ -C _n ), which are preferably designed to keep the substrate wafers (S ₁ -S _n ) horizontal. Each recording position (C ₁ -C _n ) is assigned in each case to a deposition zone (Z ₁ -Z _n ) in which a deposition reaction of the process gas takes place and in the process material onto a substrate wafer (S ₁ ) arranged in the respective pickup position (C ₁ -C _n ) -S _n ) is deposited. The deposition zone (Z ₁ -Z _n ) of a receiving position (C ₁ -C _n ) is preferably by a Space region immediately above a in the respective recording position (C ₁ -C _n ) arranged substrate wafer (S ₁ -S _n ) formed.

The process chamber (T _P ) is further surrounded by a typical heater, which serves to control the temperature inside the coating plant (not shown here).

In the present case, the process chamber (T _P ) and the jacket tube (T _L ) essentially consist in each case of a vertical hollow tube with a circular horizontal cross-sectional area which rests gas-tight on a respective concentric ring (B ₁ , B ₂ ) of a horizontally arranged base flange (B) and it can be releasably connected to this. Alternatively, process and / or jacket tube (T _P , T _L ) also be welded to the base flange (B). While the process chamber (T _P ) is closed in its upper region by means of a slightly curved cover (T), the jacket tube (T _L ), which preferably extends to just below the ceiling of the process chamber (T _P ), is in its upper region (FIG. T _L ') open. The walls of the process chamber (T _P ), the jacket tube (T _L ) and the base flange (B) form a flow channel for a process gas (G) flowing into the reaction space (R). The flow of the process gas (G) is in 1a indicated by arrows.

The base flange (B) has a transfer port (B _O ) formed inside the inner one of the two concentric rings (B ₁ ). Via this opening (B _O ), the CVD reactor can be loaded and unloaded with a holding device (C) equipped with substrate disks (S ₁ -S _n ). The transfer opening (B _O ) is preferably closed gas-tight by means of a flange cover (B _D ). This closure (B _D ) also serves as a support for the holding device (C), which is rotatably mounted about its vertical center axis on the flange cover (B _D ).

Of the Base flange (B) also has a gas outlet opening (A), which with a Suction device (not shown here) is coupled to the CVD chamber to keep at a reduced pressure. Furthermore, the base flange (B) also one or more raw gas inlet openings, through the lines a gas supply system are introduced into the CVD chamber.

• – eine externe Gasversorgungseinrichtung (hier nicht dargestellt), in der das Prozessgas bzw. einzelne Komponenten des Prozessgases bereitgestellt werden,
• – eine Gaszufuhreinrichtung (hier lediglich angedeutet), über die die gasförmigen Stoffe aus der Gasversorgungseinrichtung zum CVD-Reaktor transportiert und dabei gegebenenfalls miteinander vermischt werden, sowie
• – eine innerhalb der CDV-Kammer angeordnete Gasinjektionseinrichtung (I) zum Verteilen des Prozessgases (G) bzw. seiner Komponenten innerhalb der Reaktionskammer (R).

The gas supply system of a typical CVD plant can usually be assigned three different functions:

• An external gas supply device (not shown here) in which the process gas or individual components of the process gas are provided,
• - A gas supply means (only indicated here), via which the gaseous substances are transported from the gas supply device to the CVD reactor and thereby optionally mixed together, and
• - A disposed within the CDV chamber gas injection device (I) for distributing the process gas (G) or its components within the reaction chamber (R).

In the simplest case of a conventional vertical CVD reactor, the gas injection device (I) consists only of a pipe socket (not shown here) arranged in a lower region of the reaction chamber (R), through which the process gas (G) controls the reaction chamber more or less controlled (R) is delivered. The process gas (G) then flows through the reaction space (R) in a substantially through the inner wall of the jacket tube (T _L ) and the holding device (C) flow channel defined vertically upward. The disadvantage here is in particular that the substrate wafers (S ₁ -S _n ) in the upper and in the lower region of the holding device (C) are exposed to a modified gas composition. Without a suitable gas injection device (I) therefore regularly show serious differences in thickness between the deposited or grown layers of Substratschei ben (S ₁ -S _n ) of the upper and lower receiving positions (C ₁ -C _n ). In addition to a lower layer growth, a decrease in the quality of the layers produced due to the incorporation of by-products of the deposition reaction can also be observed in the substrate slices (S ₁ -S _n ) in the upper absorption positions (C ₁ -C _n ).

Around Counteract these negative effects are therefore measures necessary, the one opposite this simple solution improved distribution of the process gas (G) within the reaction space (R) allow.

The in the 1a and 1b For this purpose, a conventional gas injection device (I) already has a gas injection device (I ') which consists of a vertical injection line extending between the jacket tube (T _L ) and the holding device (C) over the entire height of the holding device (C). By means of the injection line (I '), which is typically formed from a quartz tube, the process gas (G) can be released in the reaction space (R) in the immediate vicinity of the substrate wafers (S ₁ -S _n ). As in 1a In the present case, a plurality of injection holes (I _O ') formed at different height portions of the quartz tube (I') provide better distribution of the process gas (G) within the reaction space (R). With their help, the process gas (G) can be injected at different heights of the holding device (C). In this case, the number and the distribution of the holes (I _O ') vary arbitrarily.

That in the 1a and 1b The conventional concept shown above already shows an improvement in the homogeneity of the layers produced compared to the simple concept described above, in which the process gas (G) is supplied without a corresponding injection line only in the lower region of the reaction space (R). This is particularly due to a more favorable distribution of the process gas (G), which is achieved by injecting the process gas (G) at different heights of the holding device (C). However, a homogeneous distribution of the process gas (G) over the entire height of the holding device (C) is also extremely difficult with the aid of this method, so that position-dependent differences in thickness can also be detected in the layers produced.

It proves to be particularly problematic in the distribution of the process gas (G) with the aid of several injection openings (I _O ') that the amount of process gas (G) emerging from an injection opening (I _O ') is not the same at all injection openings (I _O ') , The amount of gas delivered in a multi-hole injection line (I ') in particular depends on the position in addition to the gas pressure in the interior of the injection line (I') in the region of the respective injection hole (I _O ') or its ratio to the gas pressure in the reaction space (R) of the respective injection hole (I _O ') on the injection line (I'). In a typical multi-hole injection line (I '), the gas pressure prevailing in the interior of the injection line (I') at the level of an injection opening (I _O ') drops all the more as this injection opening (I _O ') is removed from the gas inlet or the more injection holes (I _O ') are located between the respective injection opening (I _O ') and the gas supply line. For this reason, at the in 1a shown, vertically along the holding device (C) extending multi-hole injection line (I ') from an injection port (I _O ') exiting gas amount with the height of the respective injection port (I _O ') from.

In order to achieve that exactly the desired amount of process gas (G) is delivered at each level, it is conventionally provided to vary the size or the number of injection holes (I _O ') depending on the height. However, this method is limited because the size of the injection holes (I _O ') is limited by the width of the injection line (I').

Furthermore, it is also evident that a certain gas injection profile, ie the ratio of the gas quantity flowing out of the injection openings (I _O '), can hardly be realized with the aid of the conventional method. As soon as z. B. changes the pressure ratio between the interior of the injection line (I ') and the reaction space (R), the gas injection profile can change.

In order nevertheless to ensure that the holes (I _O ') of a multi-hole injection line (I') each deliver a certain amount of process gas (G) independent of the respective pressure, the gas pressure inside the injection line (I ') would have to increase in such a way that the process gas (G) flowing out of the holes (I _O ') reaches supersonic speed. Only above this critical speed is a direct dependence of the amount of gas emerging from the prevailing within the respective injection line (I ') gas pressure practically no longer exist.

However, the use of the supersonic principle has practical disadvantages. In order for the process gas (G) to be able to leave the injection openings (I _O ') at supersonic speed, ie the flow of the process gas (G) through the injection openings (I _O ') becomes supercritical, an extremely high gas pressure within the respective injection line (I ') necessary. However, such a high gas pressure favors the undesired deposition of gaseous material in the interior of the injection lines (I '). Depending on the composition of the process gas used (G), the increase in gas pressure can also increase the risk of particle formation within the injection lines (I '). Both effects can greatly impair the functionality of the coating system.

Therefore, many conventional coating plants usually work with a significantly lower gas pressure at which the process gas (G) with subsonic speed from the injection ports (I _O ') emerges. As a result, the typical pressure drop of the process gas (G) in the upper region of the reaction chamber is also evident in these coating systems.

To compensate for this undesirable effect, the size of the injection openings (I _O ') in the longitudinal axis of the injection lines (I') can be adjusted accordingly, so that the holes (I _O ') become larger with the distance to the inlet of the injection line (I'). However, the size of the injection openings (I _O ') by the dimensions of the respective injection line (I') is limited.

In order to counteract the problematic decrease in pressure in the upper region of the reaction space (R), the temperature in this region is also increased. Due to the increase in temperature, the deposition rate also increases in the affected regions, as a result of which the layer thickness difference described above between the upper and the lower region of the holding device (C) can also be reduced. However, this method comes at the expense of the temperature budget of the processed substrate slices. Since in this case the upper substrate wafers (S ₁ -S _n ) are more thermally stressed as the lower ones, the application of this method is limited to substrates that have no limited thermal budget. Thus, this method can be used only conditionally in highly integrated semiconductor structures. Their production usually requires a large number of complex steps, which in any case strain the temperature budget of the semiconductor structures.

As explained above, let yourself a reliable one Compensation of position-dependent layer thickness differences not reach with the help of the known methods.

Therefore In the following measures according to the invention are described, with their Help a more even distribution the process gas within the reaction chamber (R) and thus in particular a better compensation of the position-dependent layer thickness differences can be achieved.

The 2a and 2 B schematically show the structure of a coating apparatus according to the invention, wherein in 2a a vertical and in 2 B a horizontal cross-section through the reactor chamber is shown. The CVD system according to the invention has a similar structure, as in the 1a and 1b already shown vertical reactor furnace. A vertical process chamber (T _P ) and a jacket tube (T _L ) arranged within the process chamber (T _P ) are likewise provided, which also preferably concentrically has a central holding device (C) for receiving a multiplicity of substrate wafers (S ₁ -S _n ). encloses.

in the Difference to the conventional one vertical reactor furnace has the coating device according to the invention however, two inventive concepts on, which individually, as well as in combination with each other uniformity the generated layers over improve the entire holding device (C). It is advantageous here in particular, that the inventive concepts are easy on already apply existing vertical reactor furnaces leave without a costly and costly redesign to have to. As well can also be a transfer of these concepts to other than the reactor types shown here take place.

In order to improve the uniformity of the layers produced over the entire holding device (C), the first concept according to the invention is intended to change the direction of the flow channel within the reaction space (R) by simple structural measures on the jacket tube (T _L ). For this purpose, an opening region (0) is formed laterally in the jacket tube (T _L ), which preferably extends along the entire height of the holding device (C). This opening area (0) is preferably on one of the gas injection device (I) opposite side of the holding device (C) is arranged to a horizontal gas flow over the in the receiving positions (C ₁ -C _n ) usually arranged substrate wafers (S ₁ -S _n ) to reach. Furthermore, the jacket tube (T _L ) is closed in its upper region. As in 2a is shown, the completion of the jacket tube (T _L ), for example, by a cover (T) take place, which is welded to the wall of the jacket tube (T _L ). Alternatively, however, other constructions are possible, such. B. one with the upper wall of the process chamber (T _P ) gas-tight or firmly connected jacket tube (T _L ). The flow of the process gas (G) within the reactor is in 2a indicated by arrows.

The opening area (O) may have one or more openings (O ₁ , O ₂ ). Its geometric arrangement and / or its design is optimized to provide the same conditions for a deposition reaction of the process gas (G) in the deposition zones (Z ₁ -Z _n ) of the receiving positions (C ₁ -C _n ). In this case, provision is made in particular to match certain physical parameters of the process gas (G) in the deposition zones (Z ₁ -Z _n ) of all recording positions (C ₁ -C _n ). Suitable parameters for this are, in particular, those variables whose change has a measurable influence on the deposition reaction of the process gas (G) and thus on the growth rate of the layers produced. These are above all the throughput, the residence time, the flow velocity or the pressure of the process gas (G). Furthermore, other physical parameters of the process gas (G) can be taken into account, such. B. its temperature or the concentration or the degree of mixing of its components.

Preferably, by means of the number, the size, the shape and / or the arrangement of the openings (O ₁ , O ₂ ), the flow of the process gas (G) is influenced such that (S ₁ -S ₄ ) during each coating process on each substrate wafer the same amount of process gas (G) flows past. For example, using a relatively small orifice diameter in certain areas of the reaction space (R), the process gas (G) can accumulate in these areas, thereby reducing the velocity of the process gas (G) in these areas. At the same time, more process gas (G) flows into other areas of the reaction space (R), which in turn can change the rate of deposition in these areas.

In order to more specifically control the flow of the process gas (G) by means of the opening region (O) formed in the jacket tube (T _L ), provision can be made be to arrange the opening area (O) of the jacket tube (T _L ) and the holding device (C) very close to each other. For example, this can jacket tube (T _L ) and holding device (C) in contrast to the in the 2a and 2 B variant shown to be eccentric to each other, wherein the holding device (C) is displaced in the direction of the opening portion (O). Furthermore, the jacket tube (T _L ) in the region of its opening area (O) can also be formed on the contours of the holding device (C).

In order to achieve a better uniformity of the layers produced over the entire holding device (C), the second inventive concept provides for an improved gas injection device (I). The gas injection device (I) according to the invention preferably has at least two injection lines (I ₁ -I ₄ ), by means of which the process gas (G) can be injected into the reaction space (R) at different heights of the holding device (C). In this case, the injection lines (I ₁ -I ₄ ) originate from a common gas supply line (I _Z ), wherein their arrangement and / or their configuration are optimized in the deposition zones (Z ₁ -Z _n ) of the receiving positions (C ₁ -C _n ) to create the same conditions for the deposition reaction of the process gas (G). In this case, provision is made in particular to match certain physical parameters of the process gas (G) in the deposition zones (Z ₁ -Z _n ) of all recording positions (C ₁ -C _n ). As already described above, parameters which can be used in particular are parameters which can be used to influence the deposition reaction of the process gas (G) and thus the growth rate of the layers produced on the substrate wafers (S ₁ -S _n ). These are above all the throughput, the dwell time, the flow rate and / or the pressure of the process gas (G). Furthermore, other physical parameters of the process gas (G) can be taken into account, such. B. its temperature or the concentration or the degree of mixing of its components.

Furthermore, the gas injection device (I) can also comprise a plurality of mutually independent groups of injection lines (I ₁ -I ₄ ) or single injection lines (I ₁ -I ₄ ) fed by respective different gas supply lines (I _Z ). As a result, coating processes can be realized in which z. B. different components of the process gas (G) are mixed only immediately before the deposition reaction.

The following are in the 3a - 3f by way of example, six possible designs for an opening region (O) extending vertically along the longitudinal axis of the jacket tube (T _L ) of the coating device according to the invention are shown. All representations correspond in each case to a vertical cross section of the jacket tube (T _L ) along the route AA 2a ,

The 3a to 3d first show four different concepts for opening areas (O), each having a plurality of openings (O ₂ ) in the jacket tube (T _L ), while the 3e and 3f each opening areas (O) with a single opening (O ₁ ) in the jacket tube (T _L ) show. The number, the size, the shape and the arrangement of the openings (O ₂ ) can vary depending on the application. As a result, the profile of the horizontal flow of the process gas (G) within the reaction space (R) can be designed individually.

As in 3a 1, the first design provides an opening area (O) with eight identical openings (O ₂ ) formed inside the jacket tube (T _L ). The circular openings (O ₂ ) are arranged on a vertical axis and extend equidistant from each other along the entire casing tube (T _L ).

3b and 3c show two variations of the in 3a shown opening area (O), wherein here also a plurality of identical openings (O ₂ ) in each case the same distance from one another along the entire jacket tube (T _L ) are arranged. In contrast to 3a However, the openings (O ₂ ) of these variations have elliptical or slot-shaped profiles.

Another variant of the inventive concept is described in 3d clear. Here are five circular openings (O ₂ ) are provided, in which the diameter increases continuously with the height, in contrast to the previous designs. Therefore, the top opening (O ₂ ) is much larger than the bottom one. It can also be seen from this figure that the distance between two immediately adjacent openings (O ₂ ) can also be changed in order to achieve a suitable design.

Since the size of an opening also increases the amount of gas flowing through this opening, a possible decrease in the pressure of the process gas (G) in the upper region of the reaction space can be achieved by enlarging the openings (O ₂ ) in the upper region of the jacket tube (T _L ) Counteract (R). This pressure decrease, which occurs undesirably, frequently leads to altered conditions in the affected regions of the reaction space (R) and thus to the disadvantages of conventional vertical batch reactors already discussed above. Thus, in particular by means of an asymmetric opening area (O), as z. In 3d is shown, an altered flow of the process gas (G) in the reaction space (R) can be achieved, the pressure drop of the process gas (G) in the upper part of the reaction space (R) counteracts and thus contributes to the uniformity of the generated layers over the entire holding device.

3e shows, however, an opening area (O) with only a single opening (O ₁ ), which extends uniformly along the jacket tube (T _L ). By means of a uniformly along the holding device (C) extending opening (O ₁ ), a homogeneous horizontal flow behavior of the process gas (G) through the reaction space (R) is optimally supported. This becomes particularly noticeable in combination with a suitable gas injection device (I).

Also the in 3f shown opening area (O) has only a single opening (O ₁ ), which extends along the jacket tube (T _L ). In contrast to the previous design, however, the width of the opening (O ₁ ) increases continuously with the height, so that the opening (O ₁ ) is wider in its upper region than in its lower region. As a result, in turn, more gas can flow through in the upper region of the opening (0 ₁ ) than in its lower region. Even with a single opening (O ₁ ), which has a suitable profile, it is therefore possible to counteract a possible pressure decrease of the process gas in the upper region of the reaction space (R).

in the The following is an example of the gas injection device according to the invention (I) and the method according to the invention described for their preparation.

A basic motivation of the present invention is to provide homogeneous conditions for the deposition reaction within the reaction space (R), in particular in all deposition zones (Z ₁ -Z _n ) of the receiving positions (C ₁ -C _n ), to obtain comparable results independently of the respective To reach position of the substrate wafers (S ₁ -S _n ) within the holding device (C). The structural measures presented here can therefore contribute to improving the homogeneity of the layers produced, both individually and in combination with each other.

Make it clear 4a to 4d First, the inventive method for producing a gas injection device (I) in the context of the invention. For this purpose, at least two substantially identical thin tubes (I ₁ -I ₄ ) are first provided, one end of each tube (I ₁ -I ₄ ) being open and the other end each having an injection opening (I _O ). As material for the tubes (I ₁ -I ₄ ), quartz is preferably used in the present example. Due to its good processing properties, its thermal properties and its chemical stability, quartz is particularly suitable as a material for the gas injection device. However, other suitable materials are also possible in principle.

The number of tubes used (I ₁ -I ₄ ) may vary depending on the application, in which case the production of a gas injection device (I) with a total of four injection lines (I ₁ -I ₄ ) is shown by way of example. This number already enables a good distribution of the process gas (G) within the reaction space (R) of an LPCVD reactor 2a ,

The respectively one injection opening (I _O ) having ends of the quartz tubes (I ₁ -I ₄ ) are preferably completely closed. Here, relatively small holes are used as injection openings (I _O ), which in the case of all injection lines (I ₁ -I ₄ ) are each identically formed inside the tube wall in an end section of the tubes (I ₁ -I ₄ ). Alternatively, wholly or partially open ends of the quartz tubes (I ₁ -I ₄ ) can also serve directly as injection openings (I _O ).

In the next method step of the method according to the invention, the quartz tubes (I ₁ -I ₄ ) are connected with their open ends to a gas supply line (I _Z ), which is preferably likewise designed as a quartz tube. Since the gas supply line (I _Z ), through which the process gas is supplied and distributed to the individual injection lines (I ₁ -I ₄ ), the quartz tube (I _Z ) has a sufficiently large cross-section. It is provided to connect all four quartz tubes (I ₁ -I ₄ ) with the gas supply line (I _Z ) in such a way that the process gas flowing through the gas supply line (I _Z ) is evenly distributed to all injection lines (I ₁ -I ₄ ). 4a shows the four already connected to the gas supply line (I _Z ) quartz tubes (I ₁ -I ₄ ). In the present example, the parallel running quartz tubes (I ₁ -I ₄ ) are arranged side by side to achieve the lowest possible installation depth. However, in principle, other parallel arrangements of the quartz tubes (I ₁ -I ₄ ) may be provided. Furthermore, arrangements are also conceivable which deviate from a parallel arrangement of the quartz tubes (I ₁ -I ₄ ).

In the following, the initially identical quartz tubes (I ₁ -I ₄ ) are bent in respectively different sections of their longitudinal axis ( 4b to 4d ). This is preferably carried out in a known manner at a high temperature. For this purpose, the straight quartz tubes (I ₁ -I ₄ )) are heated locally in succession and then bent by 180 °.

Alternatively, however, it is also possible first to bend the quartz tubes (I ₁ -I ₄ ) into the intended shape and then to connect them to the gas supply line (I _Z ). Further, another alternative is also Method of preparation for the gas injection device (I) described here conceivable.

As in 4d is shown, the gas injection device (I) produced in this case has four injection lines (I ₁ -I ₄ ), each with an injection opening (I _O ) in each case at different heights. In the present example, the injection openings (I _O ) in the vertical direction are preferably arranged equidistant from each other. However, it is also possible to provide different vertical distances of the injection ports (I _O ) in order to ensure that, for. B. to make the injection profile as desired. Since all injection lines (I ₁ -I ₄ ) have the same length, the same diameter and a respective kinked portion, and also the injection openings (I _O ) are each identically formed in the same end region of the injection lines (I ₁ -I ₄ ) have all injection lines (I ₁ -I ₄ ) preferably have identical aerodynamic properties. In particular, they represent the same flow resistance or the same effective travel distance for the process gas (G) flowing through them. Therefore, the amount of process gas exiting through each of the injection openings (I _O ) is also the same for all injection lines (I ₁ -I ₄ ). Due to the identical aerodynamic conditions, unlike a conventional gas injection device (I '), the quantitative ratio of the injected process gas (G) does not change with the gas pressure prevailing in the interior of the injection lines (I ₁ -I ₄ ).

The The above description represents the application of the inventive concept exemplified by an LPCVD coating system. However, it is within the meaning of the invention, this concept also on any Coating method, such. Plasma enhanced CVD coating processes, apply.

The in the claims, The description and drawings disclosed features of the invention can essential both individually and in combination for the invention be.

S ₁ -S _n

substrate wafer

C ₁ -C _n

pickup position

Z ₁ -Z _n

separation zone

C

holder

T _L

casing pipe

T _P

process chamber

T

cover of the jacket tube

T _L '

upper Area of the jacket pipe

B

base flange

B _O

transfer opening

B _D

flange the transfer opening

B ₁ , B ₂

concentric ring

I

Gas injection device

I ₁ -I _n

injection line

I _O

injection port

I '

conventional injection line

I _O '

conventional injection port

I _Z

Gas supply line

I _I -I _III

sections the injection line

R

reaction chamber

G

process gas

0

opening area in the jacket tube

O ₁ , O ₂

openings of the opening area

I _Z

Gas supply line

A

gas outlet

Claims (15)

Device for coating of substrate wafers (S ₁ -S _n) having a process chamber (T _P), a bearing provided in the process chamber (T _P) vertically disposed tubular casing (T _L), forming a reaction space (R), one in the tubular casing (T _L ) arranged holding device (C), the stacked stacked positions (C ₁ -C _n ) for the horizontal recording of substrate wafers (S ₁ -S _n ), and with a gas injection device (I) for supplying a process gas (G) in the Reaction space (R), wherein in the jacket tube (T _L ) an opening region (O) is formed, which serves as an outlet for the spent process gas (G) from the reaction space (R), characterized in that the gas injection device (I) and / or the opening area (O) extend vertically along the holding device (C), wherein the spatial arrangement and configuration of the gas injection device (I) and / or the opening area (O) are optimized to the throughput, the residence time He, the flow velocity, the pressure and / or another physical parameter of the process gas (G) in the range of recording positions (C ₁ -C _n ) to match. Apparatus according to claim 1, characterized in that the jacket tube (T _L ) in its upper region with a cover (T) is gas-tight, and that the opening portion (O) substantially on one of the gas injection device (I) opposite side of the holding device ( C) in the jacket tube (T _L ) is formed in order to achieve a substantially horizontal flow of the process gas (G) within the reaction onsraums (R). Apparatus according to claim 2, characterized in that the opening region (O) has a substantially vertically along the holding device (C) extending opening (O ₁ ) in the jacket tube (T _L ). Apparatus according to claim 3, characterized in that the vertically along the holding device (C) extending opening (O ₁ ) in the above Ren region (T _L ') of the jacket tube (T _L ) is wider than in the lower region (T _L '') of the jacket tube (T _L ). Apparatus according to claim 2, characterized in that the opening region (O) of the jacket tube (T _L ) extends substantially vertically along the entire holding device (C) and a plurality of substantially vertically along the holding device (C) arranged openings (O ₂ ) in Casing tube (T _L ) includes. Apparatus according to claim 5, characterized in that in an upper region (T _L ') of the jacket tube (T _L ) arranged opening (O ₂ ) is greater than one in a lower region (T _L '') of the jacket tube (T _L ) arranged opening (O ₂ ). Device according to one of claims 2 to 6, characterized in that the shape, the number and / or the arrangement of the openings (O ₁ , O ₂ ) are optimized to the aerodynamic conditions in the region of the receiving positions (C ₁ -C _n ) regardless of their relative position within the holding device (C). Device according to one of the preceding claims, characterized in that the gas injection device (I) is substantially vertical extends and is formed along the holding device (C), around the process gas (G) evenly along the entire holding device (C) in the reaction space (R) to distribute. Device according to one of the preceding claims, characterized in that the gas injection device (I) at least two tubular injection lines (I ₁ -I ₄ ), which extend substantially vertically between the jacket tube (T _L ) and the holding device (C) side by side and respectively an injection opening (I _O ) having a different height, wherein the injection lines (I ₁ -I ₄ ) have a common gas supply line (I _Z ) and wherein each of the two injection line (I ₁ -I ₄ ) from the gas supply line (I _Z ) up to their respective injection opening (I _O ) for the process gas (G) has the same effective distance and / or the same flow resistance. Apparatus according to claim 9, characterized in that each injection line (I ₁ -I ₄ ) each have a substantially vertical first portion (I _I ), a subsequent bent second portion (I _II ) and a substantially vertically extending third portion (I _III ) having the associated injection port (I _O ). Apparatus according to claim 9 or 10, characterized in that the injection lines (I ₁ -I _k ) each consist of a tube which is bent in each case at a different height by 180 °. Device according to one of the preceding claims, characterized characterized in that the device is a CVD, in particular a LPCVD coating system is. Gas injection device for a device for coating substrate wafers (S ₁ -S _n ) according to one of the preceding claims, characterized in that the gas injection device (I) comprises at least two tubular injection lines (I ₁ -I ₄ ) having a common gas supply line (I _Z ) and are substantially parallel to each other, and each having an injection port (I _O ) at a different level, wherein all the injection line (I ₁ - I ₄ ) from the gas supply line (I _Z ) to their injection ports (I _O ) for a process gas (G) flowing through the injection lines (I ₁ -I ₄ ) represent the same effective distance and / or have the same flow resistance. Gas injection device according to claim 13, characterized in that the injection lines (I ₁ -I ₄ ) have the same overall length and the same cross section, but bend in different areas in each case by 180 °, so that their injection openings (I _O ) in each case different longitudinal sections are located. Method for producing a gas injection device according to claim 13 or 14, characterized by the following steps: - providing at least two substantially identical tubes (I ₁ -I _k ) each having an open end and an injection opening (I _O ), - connecting the open ends of the tubes (I ₁ -I _k ) with an open end of a gas supply line (I _Z ), so that the tubes (I ₁ -I _k ) originate together from the gas supply line (I _Z ) and run parallel to each other, - bending a first tube (I ₁ -I _k ) by 180 ° in a first longitudinal section, - bending the other tubes (I ₁ -I _k ) by 180 ° in each case a different longitudinal section.