US3654694A - Method for bonding contacts to and forming alloy sites on silicone carbide - Google Patents

Method for bonding contacts to and forming alloy sites on silicone carbide Download PDF

Info

Publication number
US3654694A
US3654694A US819832A US3654694DA US3654694A US 3654694 A US3654694 A US 3654694A US 819832 A US819832 A US 819832A US 3654694D A US3654694D A US 3654694DA US 3654694 A US3654694 A US 3654694A
Authority
US
United States
Prior art keywords
silicon
specimen
alloy
lead
heating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US819832A
Inventor
Howard L Dunlap
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Raytheon Co
Original Assignee
Hughes Aircraft Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hughes Aircraft Co filed Critical Hughes Aircraft Co
Application granted granted Critical
Publication of US3654694A publication Critical patent/US3654694A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/0445—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising crystalline silicon carbide
    • H01L21/048—Making electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S228/00—Metal fusion bonding
    • Y10S228/903—Metal to nonmetal
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S228/00—Metal fusion bonding
    • Y10S228/904—Wire bonding

Definitions

  • the present invention relates to a method for making bonded electrical contacts on silicon carbide.
  • silicon carbide whose melting point is approximately 2,700 C. and which is relatively insoluble in most substances.
  • the fabrication of semiconductor devices utilizing silicon carbide has presented difficulties.
  • One serious problem is the difficulty in forming electrical contacts to precise locations or sites on a silicon carbide sample with ease and without producing a poor contact.
  • Existing processes have not satisfactorily overcome these problems.
  • a silicon carbide wafer with a pellet of material placed at the desired contact site, is placed in a furnace and heated to approximately 2,000 C. to form an alloy site and thereafter cooled. After properly made alloy sites are formed, a wire lead is attached to the wafer at the site.
  • the pellet might be improperly or inaccurately placed or accidentally moved and, therefore, the contact site would not be located where desired.
  • Jigs have been utilized to hold the pellet in place but are cumbersome and are still liable to accidental movement or to imprecise placement. Even when proper alloy sites are formed, the high temperatures required can adversely affect the silicon carbide wafer or cause undesired penetration thereof by the material of pellet. This penetration damages the wafer and may even make it useless for its intended purpose.
  • the present invention overcomes these and other problems by providing a method which can be carried out under atmospheric conditions in a low temperature environment to secure a wire lead to silicon carbide, to form alloy sites, and the like.
  • a pulse of heat is utilized simultaneously to form an alloy of silicon and metal from the lead at their eutectic temperature and to cause adhesion of the alloy and the lead to the silicon carbide sample or specimen.
  • a nail head bonder having a heated tip is preferably utilized in the practice of the present invention and the wire to be bonded to the silicon carbide sample is threaded through the tip.
  • the wire is equipped with a bead.
  • a small particle of silicon, used as a wetting agent, is placed on the substrate at the point or site where the contact is to be made.
  • an alloy is formed from the bead and the silicon at the eutectic temperature thereof.
  • the tem perature is approximately 370 C.
  • the silicon carbide sample is heated, for example, to approximately 100 C., in order to prevent heat flow out of the bead-silicon-silicon carbide interface area.
  • the silicon carbide sample is heated, for example, to approximately 100 C., in order to prevent heat flow out of the bead-silicon-silicon carbide interface area.
  • the present inventive method when a nail head bonder is utilized, some correlation is required between the wire used, the temperature of the bonder tip, the wetting agent, and the substrate surface.
  • the tip temperature must not be allowed to approach the melting point of the wire; otherwise, the wire would melt within the tip.
  • the quantity of silicon and the size of metal bead must be such that the eutectic ratio of silicon to the metal permits formation of the alloy only at interface and not within the bonder tip.
  • the eutectic ratio is 31 atomic percent of silicon to gold.
  • the silicon used as a wetting agent may be placed on the silicon carbide sample manually or by any other method and, in most cases when great accuracy is required, the silicon can be applied as a pad by a conventional evaporation process or sputtering process in conjunction with photo masking methods.
  • the use of the present invention does not cause the substrate to enter into the eutectic condition, thereby avoiding penetration of the substrate.
  • the wire may be used in a variety of ways such as a mechanical hold-down device or as electrical contacts to silicon carbide of sufficiently low carrier concentration, in the realm of 10 carriers per cubic centimeter, or as alloy sites.
  • the wire lead is removed and the wafer is heated to a sufiiciently high temperature to permit penetration of the wafer by the molten metal.
  • this alloying operation into the substrate can be efiected without the need for jigs to locate the defined site.
  • the contact can be removed mechanically, electronically, or chemically and reapplied, if needed or desired, without changing the characteristics of the silicon carbide sample because no penetration thereof has occurred.
  • Mechanical removal can be effected by cutting, electronic by ion or electron beam machining, and chemically by such reagents as aqua regia.
  • an object of the present invention to provide a method for forming bonded contacts on silicon carbide samples.
  • Another object is the provision of a simple, yet accurate, method for making such silicon carbide contacts.
  • Another object is to provide such a method whereby the silicon carbide sample is not deleteriously affected by the formed contact.
  • Another object is to provide a method whereby a contact on silicon carbide, after having been made, may be removed and relocated to another position on the sample.
  • FIGURE depicts a preferred apparatus for carrying out the present invention.
  • a nail head bonder 10 is provided with a tip 12 which is adapted to be heated.
  • a feeder hole 14 is provided in tip 12 so that a wire 16 may be threaded and fed therethrough from bonder 10.
  • a bead 18 terminates wire 16 and is generally formed by a prior use of the bonder.
  • a silicon carbide wafer or sample 20 is shown placed on a work surface 22 and a pad or particle of silicon 24 is placed on the sample in readiness for formation and bonding of the contact.
  • An electrical coil 26 is placed adjacent to sample 20 in order to heat the sample; however, other suitable heating means may be utilized.
  • the wafer may have already undergone prior processing, such as by ion implantation or thin layer diffusion.
  • a silicon chip in the form of a flake was placed on the sample.
  • a gold wire of 1 mil thickness having a bead of approximately 2 mil diameter had been extended from the bonder tip from a prior use of the bonder.
  • the silicon carbide wafer was heated to approximately C. and the bead of gold was brought into contact with the silicon chip and pressed thereto. Heat was applied by the tip and, at the eutectic temperature of gold and silicon, which was estimated at approximately 370 C., an alloy was formed to bond the gold wire to the silicon carbide wafer.
  • a method for forming a bonded electrical contact of a gold wire lead to a silicon carbide crystal without the need of special holding fixtures comprising the steps of:
  • a method as in claim 1 further including the step of heating the crystal.
  • a method as in claim 1 further including the step of utilizing a nail head bonder having a heating tip for supplying a heat pulse to accomplish said heating step.
  • a method of forming bonded electrical contacts of wire leads to a silicon carbide specimen without the use of special holding fixtures comprising the steps of:
  • a method of fabricating a bonded electrical contact between a wire lead and a silicon carbide specimen comprising the step of forming an alloy of the lead material and silicon on the specimen at the site thereon where the contact is to be made, said forming step being performed under ambient atmospheric conditions at a temperature sufficient to form the alloy and, consequently, to bond the lead to the specimen.
  • a method as in claim 5 including the step of utilizing predoped silicon.
  • a method as in claim 5 including the step of utilizing a photo masked specimen.
  • said forming step comprises the steps of placing silicon on the specimen, locating an end of the lead on the silicon, and heating the lead and the silicon to the eutectic temperature thereof.
  • a method as in claim 8 wherein said placing step consists of the steps selected from the methods of sputtering, evaporation and manually positioning the silicon on the specimen.
  • a method as in claim 8 wherein said heating step comprises the step of utilizing a nail head bonder having a wire lead feed and a heating tip for supplying a heat pulse to the silicon particle and an end of the wire lead.
  • a method as in claim 5 further comprising the step of heating the specimen.
  • a method as in claim 5 further comprising the step of pressing the alloy to the specimen.
  • a method as in claim 8 further comprising the step of forming a bead of the wire at the end thereof.
  • a method for bonding gold to a silicon carbide wafer at a specified site thereon including the steps of placing silicon on the wafer at the site,
  • a method as in claim 15 including the step of forming a silicon-gold utectic ratio of 31 atomic percent of silicon.
  • a method as in claim 15 further including the step of removing the bond from the wafer.
  • a method of forming alloy sites on a metal silicon carbide specimen comprising the steps of forming on the specimen at each of the sites an alloy of the metal and silicon at the eutectic temperature thereof under ambient atmospheric conditions and further heating the specimen sufficiently to cause penetration of the wafer by the alloy and to form a bond therebetween.

Abstract

An alloy of silicon and metal (e.g., gold) formed at the eutectic temperature thereof permits the formation of a bonded contact of the metal (e.g., gold) to silicon carbide. Such a contact is useful for securing a wire to the silicon carbide, for forming alloy sites thereon, etc. A nail head bonder with a threadable heated tip may be utilized in the use of this method.

Description

United States Patent Dunlap [45] Apr. 11, 1972 54 METHOD FOR BONDING CONTACTS 3,028,663 4/1962 lverson et a1 ..29/472.9 ux TO AND FORMING ALLOY SITES 0N 3,075,282 1/1963 McConville ..29/590 UX 3,091,849 6/1963 Cohen ..29/472.9 SILICONE cARBIDE 3,228,104 1/ 1966 Emeis ..29/472.9 X [72] Inventor: Howard L. Dunlap, Granada Hills, Calif. 3,298,093 1/1967 Cohen ..29/590 X 3,316,628 5/1967 Lang, Jr ..29/473.1 X [73] "8" Alma Culver CIY, 3,397,451 8/1968 Avedissian m1... ..29/589 Cahf- 3,341,938 9/1967 Hoppe el al ..29/589 x [22] Filed; APR 23 9 3,492,719 2/1970 Zeitman et a1 ..29/473.1 X
1 PP N041 819,832 Primary Examiner-John F. Campbell Assistant Examiner-Ronald J. Shore 152 0.8. CL ..29/587,29/473.1, 29/504 Mme-14am Haskell and [51] Int. Cl. ..B0lj 17/00, H0l15/04,H0117/60, A T
H0119/08, H011 11/02, H011 11/04, H01115/08 [57] ABSTR C [58] Field 61 Search ..29/472.9, 473.1, 589, 590, An alloy of silicon and metal 8- g formed t e eutec- 29/621 504 537 tic temperature thereof permits the formation of a bonded contact of the metal (e.g., gold) to silicon carbide. Such a con- R f tact is useful for securing a wire to the silicon carbide, for [56] e erences cued forming alloy sites thereon, etc. A nail head bonder with 21 UNITED STATES PATENTS threadable heated tip may be utilized in the use of this th d. 2,918,396 12/1959 Hall ..29/472.9 ux me 0 2,937,324 5/1960 Kroko ..29/472.9 UX 18 Claims, 1 Drawing Figure g ,I /Z M 0- /3 4:47 Pan/98 .Sadec' METHOD FOR BONDING CONTACTS TO AND FORMING ALLOY SITES ON SILICONE CARBIDE The invention described herein was made in the performance of work under a NASA contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 U.S.C. 2457).
The present invention relates to a method for making bonded electrical contacts on silicon carbide.
With the increasing need to utilize semiconductor devices in high temperature environments, materials, which will satisfactorily function without deterioration at high temperatures, have been required. One such material is silicon carbide, whose melting point is approximately 2,700 C. and which is relatively insoluble in most substances. The fabrication of semiconductor devices utilizing silicon carbide, however, has presented difficulties. One serious problem is the difficulty in forming electrical contacts to precise locations or sites on a silicon carbide sample with ease and without producing a poor contact. Existing processes have not satisfactorily overcome these problems.
In one prior process, a silicon carbide wafer, with a pellet of material placed at the desired contact site, is placed in a furnace and heated to approximately 2,000 C. to form an alloy site and thereafter cooled. After properly made alloy sites are formed, a wire lead is attached to the wafer at the site. However, the pellet might be improperly or inaccurately placed or accidentally moved and, therefore, the contact site would not be located where desired. Jigs have been utilized to hold the pellet in place but are cumbersome and are still liable to accidental movement or to imprecise placement. Even when proper alloy sites are formed, the high temperatures required can adversely affect the silicon carbide wafer or cause undesired penetration thereof by the material of pellet. This penetration damages the wafer and may even make it useless for its intended purpose.
The present invention overcomes these and other problems by providing a method which can be carried out under atmospheric conditions in a low temperature environment to secure a wire lead to silicon carbide, to form alloy sites, and the like. A pulse of heat is utilized simultaneously to form an alloy of silicon and metal from the lead at their eutectic temperature and to cause adhesion of the alloy and the lead to the silicon carbide sample or specimen.
A nail head bonder having a heated tip is preferably utilized in the practice of the present invention and the wire to be bonded to the silicon carbide sample is threaded through the tip. From a prior use of the bonder, the wire is equipped with a bead. A small particle of silicon, used as a wetting agent, is placed on the substrate at the point or site where the contact is to be made. When a pulse of heat is produced by the bonder tip, an alloy is formed from the bead and the silicon at the eutectic temperature thereof. For a gold-silicon alloy, the tem perature is approximately 370 C. In addition, the silicon carbide sample is heated, for example, to approximately 100 C., in order to prevent heat flow out of the bead-silicon-silicon carbide interface area. Once the molten alloy is formed, the surface of the silicon carbide is wetted and affixation of the wire to the silicon carbide occurs.
In the use of the present inventive method, when a nail head bonder is utilized, some correlation is required between the wire used, the temperature of the bonder tip, the wetting agent, and the substrate surface. The tip temperature must not be allowed to approach the melting point of the wire; otherwise, the wire would melt within the tip. The quantity of silicon and the size of metal bead must be such that the eutectic ratio of silicon to the metal permits formation of the alloy only at interface and not within the bonder tip. For a gold-silicon alloy, the eutectic ratio is 31 atomic percent of silicon to gold. Regardless of whether a nail head bonder is used, the interface temperature at the silicon carbide sample cannot be below the eutectic temperature of the wire and wetting agent. Once the proper parameters have been obtained, the wire may be easily placed at any specific desired site on the silicon carbide sample with a high degree of accuracy.
The silicon used as a wetting agent may be placed on the silicon carbide sample manually or by any other method and, in most cases when great accuracy is required, the silicon can be applied as a pad by a conventional evaporation process or sputtering process in conjunction with photo masking methods.
The use of the present invention does not cause the substrate to enter into the eutectic condition, thereby avoiding penetration of the substrate. After the wire has been fixed in position, it may be used in a variety of ways such as a mechanical hold-down device or as electrical contacts to silicon carbide of sufficiently low carrier concentration, in the realm of 10 carriers per cubic centimeter, or as alloy sites. In the latter use the wire lead is removed and the wafer is heated to a sufiiciently high temperature to permit penetration of the wafer by the molten metal. For this use as an alloy site, if the wetting agent has been predoped or if multilayers of materials have been applied, this alloying operation into the substrate can be efiected without the need for jigs to locate the defined site. In addition, except for alloy sites, once the contact has been formed, it can be removed mechanically, electronically, or chemically and reapplied, if needed or desired, without changing the characteristics of the silicon carbide sample because no penetration thereof has occurred. Mechanical removal can be effected by cutting, electronic by ion or electron beam machining, and chemically by such reagents as aqua regia.
It is, therefore, an object of the present invention to provide a method for forming bonded contacts on silicon carbide samples.
Another object is the provision of a simple, yet accurate, method for making such silicon carbide contacts.
Another object is to provide such a method whereby the silicon carbide sample is not deleteriously affected by the formed contact.
Another object is to provide a method whereby a contact on silicon carbide, after having been made, may be removed and relocated to another position on the sample.
Other aims and objects as well as a more complete understanding of the present invention will appear from the following explanation of exemplary embodiments and the accompanying drawing thereof, in which:
The FIGURE depicts a preferred apparatus for carrying out the present invention.
Accordingly, a nail head bonder 10 is provided with a tip 12 which is adapted to be heated. A feeder hole 14 is provided in tip 12 so that a wire 16 may be threaded and fed therethrough from bonder 10. A bead 18 terminates wire 16 and is generally formed by a prior use of the bonder. A silicon carbide wafer or sample 20 is shown placed on a work surface 22 and a pad or particle of silicon 24 is placed on the sample in readiness for formation and bonding of the contact. An electrical coil 26 is placed adjacent to sample 20 in order to heat the sample; however, other suitable heating means may be utilized.
In operation, when it is desired to join wire 16 to sample 20, bead 18 is placed in contact with pad 24 and a pulse of heat, formed by bonder l0 and tip 12, produces an alloy between bead l8 and pad 24 at their eutectic temperature. Upon cooling of the alloy, a bond exists between wire 16 and sample 20.
EXAMPLE A silicon carbide specimen of crystal quality, with designated sites at which contacts were to be made, was placed in readiness for bonding of a gold wire. The wafer may have already undergone prior processing, such as by ion implantation or thin layer diffusion. A silicon chip in the form of a flake was placed on the sample. A gold wire of 1 mil thickness having a bead of approximately 2 mil diameter had been extended from the bonder tip from a prior use of the bonder. The silicon carbide wafer was heated to approximately C. and the bead of gold was brought into contact with the silicon chip and pressed thereto. Heat was applied by the tip and, at the eutectic temperature of gold and silicon, which was estimated at approximately 370 C., an alloy was formed to bond the gold wire to the silicon carbide wafer.
Testing of the bonded contact thereby made showed that no discemable penetration of the wafer occurred, that the bond was mechanically strong, and that electronic noise was not present. The contact was made at the precise site desired.
Although the invention has been described with reference to particular embodiments thereof, it should be realized that various changes and modifications may be made therein without departing from the spirit and scope of the invention.
What is claimed is:
l. A method for forming a bonded electrical contact of a gold wire lead to a silicon carbide crystal without the need of special holding fixtures comprising the steps of:
placing silicon on the crystal,
placing the wire lead in contact with the silicon, and
heating the wire lead and the silicon in an ambient atmospheric environment to a temperature sufficient to form a gold-silicon alloy at the eutectic temperature to bond the lead to the crystal.
2. A method as in claim 1 further including the step of heating the crystal.
3. A method as in claim 1 further including the step of utilizing a nail head bonder having a heating tip for supplying a heat pulse to accomplish said heating step.
4. A method of forming bonded electrical contacts of wire leads to a silicon carbide specimen without the use of special holding fixtures comprising the steps of:
placing silicon on the silicon carbide specimen at the sites where the contacts are to be made,
placing the leads in contact with the silicon at the sites, and
forming an alloy of the silicon and the material of the lead on the specimen at each site to bond the lead to the specimen in an ambient atmosphere.
5. A method of fabricating a bonded electrical contact between a wire lead and a silicon carbide specimen comprising the step of forming an alloy of the lead material and silicon on the specimen at the site thereon where the contact is to be made, said forming step being performed under ambient atmospheric conditions at a temperature sufficient to form the alloy and, consequently, to bond the lead to the specimen.
6. A method as in claim 5 including the step of utilizing predoped silicon.
7. A method as in claim 5 including the step of utilizing a photo masked specimen.
8. A method as in claim 5 wherein said forming step comprises the steps of placing silicon on the specimen, locating an end of the lead on the silicon, and heating the lead and the silicon to the eutectic temperature thereof.
9. A method as in claim 8 wherein said placing step includes the step of attaching the silicon particle to the specimen.
10. A method as in claim 8 wherein said placing step consists of the steps selected from the methods of sputtering, evaporation and manually positioning the silicon on the specimen.
11. A method as in claim 8 wherein said heating step comprises the step of utilizing a nail head bonder having a wire lead feed and a heating tip for supplying a heat pulse to the silicon particle and an end of the wire lead.
12. A method as in claim 5 further comprising the step of heating the specimen.
13. A method as in claim 5 further comprising the step of pressing the alloy to the specimen.
14. A method as in claim 8 further comprising the step of forming a bead of the wire at the end thereof.
15. A method for bonding gold to a silicon carbide wafer at a specified site thereon including the steps of placing silicon on the wafer at the site,
placing the gold on the silicon,
heating the wafer to approximately 100 C., and
heating the silicon and gold bead to their eutectic temperature to form a bond between the gold and the wafer under ambient atmospheric conditions. 16. A method as in claim 15 including the step of forming a silicon-gold utectic ratio of 31 atomic percent of silicon.
17. A method as in claim 15 further including the step of removing the bond from the wafer.
18. A method of forming alloy sites on a metal silicon carbide specimen comprising the steps of forming on the specimen at each of the sites an alloy of the metal and silicon at the eutectic temperature thereof under ambient atmospheric conditions and further heating the specimen sufficiently to cause penetration of the wafer by the alloy and to form a bond therebetween.

Claims (18)

1. A method for forming a bonded electrical contact of a gold wire lead to a silicon carbide crystal without the need of special holding fixtures comprising the steps of: placing silicon on the crystal, placing the wire lead in contact with the silicon, and heating the wire lead and the silicon in an ambient atmospheric environment to a temperature sufficient to form a gold-silicon alloy at the eutectic temperature to bond the lead to the crystal.
2. A method as in claim 1 further including the step of heating the crystal.
3. A method as in claim 1 further including the step of utilizing a nail head bonder having a heating tip for supplying a heat pulse to accomplish said heating step.
4. A method of forming bonded electrical contacts of wire leads to a silicon carbide specimen without the use of special holding fixtures comprising the steps of: placing silicon on the silicon carbide specimen at the sites where the contacts are to be made, placing the leads in contact with the silicon at the sites, and forming an alloy of the silicon and the material of the lead on the specimen at each site to bond the lead to the specimen in an ambient atmosphere.
5. A method of fabricating a bonded electrical contact between a wire lead and a silicon carbide specimen comprising the step of forming an alloy of the lead material and silicon on the specimen at the site thereon where the contact is to be made, said forming step being performed under ambient atmospheric conditions at a temperaturE sufficient to form the alloy and, consequently, to bond the lead to the specimen.
6. A method as in claim 5 including the step of utilizing pre-doped silicon.
7. A method as in claim 5 including the step of utilizing a photo masked specimen.
8. A method as in claim 5 wherein said forming step comprises the steps of placing silicon on the specimen, locating an end of the lead on the silicon, and heating the lead and the silicon to the eutectic temperature thereof.
9. A method as in claim 8 wherein said placing step includes the step of attaching the silicon particle to the specimen.
10. A method as in claim 8 wherein said placing step consists of the steps selected from the methods of sputtering, evaporation and manually positioning the silicon on the specimen.
11. A method as in claim 8 wherein said heating step comprises the step of utilizing a nail head bonder having a wire lead feed and a heating tip for supplying a heat pulse to the silicon particle and an end of the wire lead.
12. A method as in claim 5 further comprising the step of heating the specimen.
13. A method as in claim 5 further comprising the step of pressing the alloy to the specimen.
14. A method as in claim 8 further comprising the step of forming a bead of the wire at the end thereof.
15. A method for bonding gold to a silicon carbide wafer at a specified site thereon including the steps of placing silicon on the wafer at the site, placing the gold on the silicon, heating the wafer to approximately 100* C., and heating the silicon and gold bead to their eutectic temperature to form a bond between the gold and the wafer under ambient atmospheric conditions.
16. A method as in claim 15 including the step of forming a silicon-gold utectic ratio of 31 atomic percent of silicon.
17. A method as in claim 15 further including the step of removing the bond from the wafer.
18. A method of forming alloy sites on a metal silicon carbide specimen comprising the steps of forming on the specimen at each of the sites an alloy of the metal and silicon at the eutectic temperature thereof under ambient atmospheric conditions and further heating the specimen sufficiently to cause penetration of the wafer by the alloy and to form a bond therebetween.
US819832A 1969-04-28 1969-04-28 Method for bonding contacts to and forming alloy sites on silicone carbide Expired - Lifetime US3654694A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US81983269A 1969-04-28 1969-04-28

Publications (1)

Publication Number Publication Date
US3654694A true US3654694A (en) 1972-04-11

Family

ID=25229196

Family Applications (1)

Application Number Title Priority Date Filing Date
US819832A Expired - Lifetime US3654694A (en) 1969-04-28 1969-04-28 Method for bonding contacts to and forming alloy sites on silicone carbide

Country Status (1)

Country Link
US (1) US3654694A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3813759A (en) * 1971-09-09 1974-06-04 English Electric Co Ltd Method of brazing
US6001724A (en) * 1996-01-29 1999-12-14 Micron Technology, Inc. Method for forming bumps on a semiconductor die using applied voltage pulses to an aluminum wire
US7132356B1 (en) * 1999-12-15 2006-11-07 Pace Benedict G Interconnection method

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2918396A (en) * 1957-08-16 1959-12-22 Gen Electric Silicon carbide semiconductor devices and method of preparation thereof
US2937324A (en) * 1959-02-05 1960-05-17 Westinghouse Electric Corp Silicon carbide rectifier
US3028663A (en) * 1958-02-03 1962-04-10 Bell Telephone Labor Inc Method for applying a gold-silver contact onto silicon and germanium semiconductors and article
US3075282A (en) * 1959-07-24 1963-01-29 Bell Telephone Labor Inc Semiconductor device contact
US3091849A (en) * 1959-09-14 1963-06-04 Pacific Semiconductors Inc Method of bonding materials
US3228104A (en) * 1961-04-19 1966-01-11 Siemens Ag Method of attaching an electric connection to a semiconductor device
US3298093A (en) * 1963-04-30 1967-01-17 Hughes Aircraft Co Bonding process
US3316628A (en) * 1964-12-30 1967-05-02 United Aircraft Corp Bonding of semiconductor devices to substrates
US3341938A (en) * 1964-05-06 1967-09-19 Siemens Ag Method of producing selenium midget rectifiers
US3397451A (en) * 1966-04-06 1968-08-20 Western Electric Co Sequential wire and articlebonding methods
US3492719A (en) * 1967-03-10 1970-02-03 Westinghouse Electric Corp Evaporated metal contacts for the fabrication of silicon carbide devices

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2918396A (en) * 1957-08-16 1959-12-22 Gen Electric Silicon carbide semiconductor devices and method of preparation thereof
US3028663A (en) * 1958-02-03 1962-04-10 Bell Telephone Labor Inc Method for applying a gold-silver contact onto silicon and germanium semiconductors and article
US2937324A (en) * 1959-02-05 1960-05-17 Westinghouse Electric Corp Silicon carbide rectifier
US3075282A (en) * 1959-07-24 1963-01-29 Bell Telephone Labor Inc Semiconductor device contact
US3091849A (en) * 1959-09-14 1963-06-04 Pacific Semiconductors Inc Method of bonding materials
US3228104A (en) * 1961-04-19 1966-01-11 Siemens Ag Method of attaching an electric connection to a semiconductor device
US3298093A (en) * 1963-04-30 1967-01-17 Hughes Aircraft Co Bonding process
US3341938A (en) * 1964-05-06 1967-09-19 Siemens Ag Method of producing selenium midget rectifiers
US3316628A (en) * 1964-12-30 1967-05-02 United Aircraft Corp Bonding of semiconductor devices to substrates
US3397451A (en) * 1966-04-06 1968-08-20 Western Electric Co Sequential wire and articlebonding methods
US3492719A (en) * 1967-03-10 1970-02-03 Westinghouse Electric Corp Evaporated metal contacts for the fabrication of silicon carbide devices

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3813759A (en) * 1971-09-09 1974-06-04 English Electric Co Ltd Method of brazing
US6001724A (en) * 1996-01-29 1999-12-14 Micron Technology, Inc. Method for forming bumps on a semiconductor die using applied voltage pulses to an aluminum wire
US7132356B1 (en) * 1999-12-15 2006-11-07 Pace Benedict G Interconnection method

Similar Documents

Publication Publication Date Title
US11508694B2 (en) Chip assembly
US3006067A (en) Thermo-compression bonding of metal to semiconductors, and the like
US3724068A (en) Semiconductor chip packaging apparatus and method
US3200490A (en) Method of forming ohmic bonds to a germanium-coated silicon body with eutectic alloyforming materials
US3125803A (en) Terminals
US3380155A (en) Production of contact pads for semiconductors
FR2365209A1 (en) PROCESS FOR THE ASSEMBLY OF MICRO-PLATES OF INTEGRATED CIRCUITS ON A SUBSTRATE AND INSTALLATION FOR ITS IMPLEMENTATION
JPH07226416A (en) Semiconductor chip package and its preparation
US4142662A (en) Method of bonding microelectronic chips
US3316628A (en) Bonding of semiconductor devices to substrates
US4545840A (en) Process for controlling thickness of die attach adhesive
US2825667A (en) Methods of making surface alloyed semiconductor devices
US3470611A (en) Semiconductor device assembly method
US3566207A (en) Silicon-to-gold bonded structure and method of making the same
US3654694A (en) Method for bonding contacts to and forming alloy sites on silicone carbide
JP3971456B2 (en) Mounting SiC die and SiC die mounting method
CA2000838A1 (en) Method of soldering semiconductor substrate on supporting plate
US3273979A (en) Semiconductive devices
JPH11163006A (en) Method for bonding pellet
US4810671A (en) Process for bonding die to substrate using a gold/silicon seed
US2986481A (en) Method of making semiconductor devices
US3188251A (en) Method for making semiconductor junction devices
US3065534A (en) Method of joining a semiconductor to a conductor
US4040169A (en) Method of fabricating an array of semiconductor devices
US4659006A (en) Method of bonding a die to a substrate