CN100473497C

CN100473497C - Method for monitoring termination detecting state

Info

Publication number: CN100473497C
Application number: CNB2006100292471A
Authority: CN
Inventors: 王海军; 王贝易; 程晓华; 赵正元
Original assignee: Shanghai Hua Hong NEC Electronics Co Ltd
Current assignee: Shanghai Huahong Grace Semiconductor Manufacturing Corp
Priority date: 2006-07-21
Filing date: 2006-07-21
Publication date: 2009-04-01
Anticipated expiration: 2026-07-21
Also published as: CN101108471A

Abstract

The invention discloses a monitoring method of destination test situation, which adopts pre-generated polished section with same structure of products as testing plate. Before producing milling product needing terminal testing, adopts the terminal testing procedure to test the terminal of testing plate, thus achieving monitoring the terminal test is or not under the normal situation. The invention can test the milling terminal accurately and ensure the qualification rate of product. The invention not only can be used as the terminal test method using optics theory, but also can be used for monitoring terminal test method by temperature changes and current intensity.

Description

Method for supervising to termination detecting state

Technical field

The present invention relates to the detection method in a kind of semiconductor fabrication process, particularly relate to a kind of in chemical mechanical planarization process the method for supervising to termination detecting state.

Background technology

In semiconductor fabrication process, the end point determination of chemical mechanical planarization process has the characteristic of process stabilizing, because after being ground to new medium, can realize that according to the end point determination program terminal point detects, so be not subjected to the variable effect of cephacoria; Help the maintenance of system program.

At present at shallow trench isolation from (STI) technology, tungsten grinds (W-PLUG) technology and copper and grinds technologies such as (Cu-CMP) and all utilized end-point detection method.

For example, shallow trench isolation from manufacture craft, chemically mechanical polishing (CMP) is generally had suffered the silica of filling out with removing peace.For satisfying the requirement to silicon nitride and the control of silica amount of grinding, CMP technology need adopt end point determination to control milling time usually.

In the tungsten process of lapping, must remove the tungsten of product surface, require insulating barrier that good flatness and minimum depression are arranged simultaneously.This technology also needs to utilize end-point detection method.

For relating to multi-layer transparent or translucent dielectric CMP technology, the method that detects the catoptrical interference strength variation of different medium interfaces is the most commonly used, as AppliedMaterials ' ISRM EPD system (the optical end point checking system of company of Applied Materials).

But,, do not have a good method for the status detection of end-point detection method own.Because a variety of causes breaks down (intake in as detection window etc.), can not correctly detect grinding endpoint when end point determination itself.This is very dangerous for production line, causes product to be ground to the maximum time of program setting easily, and the product yield reduces, and is serious, product rejection.

Summary of the invention

Technical problem to be solved by this invention provides a kind of method for supervising to termination detecting state, and it can be correct detects grinding endpoint, guarantees the qualification rate of product.

For solving the problems of the technologies described above, the present invention is achieved by the following technical solution the method for supervising of termination detecting state:

Need in production before the grinding technics product of end point determination, at first generating a kind of and grinding technics product has the mating plate of film medium between identical layer, as the whether normal test pieces of monitoring termination detecting state, grind this mating plate, whether be in normal condition with the end point determination itself that detects chemically mechanical polishing; When state just often, again the grinding technics product is ground, when state is undesired, then check board.

Adopt method of the present invention, owing to the interference that does not have pattern as the mating plate of test pieces, therefore the detected optical signalling change intensity of easier embodiment is monitored the purpose whether end point determination is in normal condition thereby reach.

Adopt method of the present invention; the state of monitoring end point determination that can be clearly, the state of the current board of grasp that can be relieved helps ensureing product safety; also significantly reduced the cost (as grinding pad and corresponding human cost, the downtime of board) of consumables associated therewith.And help manufacturing department's personnel operation (only needs move the program of an end point determination).

Description of drawings

The present invention is further detailed explanation below in conjunction with accompanying drawing and the specific embodiment:

Fig. 1 is the method for supervising process chart of the present invention to termination detecting state;

Fig. 2 is the resolution chart of end point determination when undesired;

Fig. 3 end point determination resolution chart just often.

The specific embodiment

In present production process of semiconductor, it is very important to guarantee that end-point detecting system is in normal condition.

The present invention has the mating plate of same structure as test pieces by generating in advance with the grinding technics product that needs to produce, need in production before the grinding technics product of end point determination, utilize the end point determination program the same to detect the terminal point of this mating plate with the grinding technics product, because mating plate does not have pattern, so the detected optical signalling change intensity of easier embodiment.Thereby reach the purpose whether the monitoring end point determination is in normal condition.

Flow chart shown in Figure 1 has specifically described the method for the present invention of utilizing, and how to realize the whether normal process of end point determination of monitoring chemical mechanical polishing.

When a collection of product arrival, when needing to grind, whether normal, if undesired, then check board if at first detecting board speed; If normal, whether then further detecting the board terminal point, to detect state normal, if undesired, then checks board, if normal, abrasive product then.

In chemically mechanical polishing (CMP) end point determination, when light incides the film that is superimposed with certain angle, produce reflection from each interface.Catoptrical angle and intensity are relevant with membranous characteristic and thickness, and can interfere mutually.Its Strength Changes of the interference light that is produced can reflect the variation of the membranous and thickness that is detected.Membranous difference is big more, and this variation is obvious more, as from the metal to the silica.

But owing to artificial reason (the end point determination function is not opened in engineer's maloperation), board does not just carry out end point determination at all, or owing to the reason of board, the end point determination equipment fault, the variation of endpoint detection is not really strong, causes omission or flase drop easily.By generating the mating plate that same structure is arranged with the grinding technics product that needs to produce in advance, need in production before the grinding technics product of end point determination, utilize grinding and the end point determination program the same to grind and detect the terminal point of test pieces with the grinding technics product, because this mating plate does not have pattern, so the detected optical signalling change intensity of easier embodiment.Thereby reach the purpose whether the monitoring end point determination is in normal condition.

Interlayer structure as the mating plate of test pieces can be multiple different interlayer matter, as tungsten and boron-phosphorosilicate glass (BPSG), and silicon nitride and FSG (fluorine silex glass) etc.

The method of monitoring chemical mechanical grinding endpoint of the present invention not only can be used to monitor the end-point detection method that utilizes optical principle, can also be used to monitor the end-point detection method that utilizes variations in temperature, current strength to change.

In Fig. 2,3, abscissa is a milling time, and the result shows identical end point determination program, when end point determination is undesired, grabs less than terminal point (referring to Fig. 2); And work as end point determination just often, can catch terminal point (referring to Fig. 3).

Claims

1, a kind of method for supervising to termination detecting state, it is characterized in that: need in production before the grinding technics product of end point determination, at first generating a kind of and grinding technics product has the mating plate of film medium between identical layer, as the whether normal test pieces of monitoring termination detecting state, grind this mating plate, whether be in normal condition with the end point determination itself that detects chemically mechanical polishing; When state just often, again the grinding technics product is ground, when state is undesired, then check board.

2, the method for supervising to termination detecting state according to claim 1 is characterized in that: the interlayer structure of described test pieces is multiple different interlayer matter, is tungsten and boron-phosphorosilicate glass or silicon nitride and fluorine silex glass.