Claims
- 1. A method of making a semiconductor device comprising the steps of: forming a plurality of first aluminum conductors overlying selected portions of a first dielectric layer overlying portion of a semiconductor substrate, said first aluminum conductors having exposed top and side surfaces,
- characterized by the further step of selectively depositing a metal on said exposed top and side surfaces of said first aluminum conductors to form encapsulated bimetallic structures, wherein said metal has a hardness greater than that of said aluminum conductors;
- and comprising the further step of subjecting said encapsulated bimetallic structures to a subsequent processing step that tends to promote the growth of hillocks on said first aluminum conductors, whereby the deposited metal suppresses the growth of said hillocks on said top and side surfaces of said first aluminum conductors.
- 2. The method of claim 1 wherein said metal is selected from the group consisting of tungsten, molybdenum, tantalum, and titanium.
- 3. The method of claim 1 wherein said metal is tungsten.
- 4. The method of claim 3 wherein said tungsten is deposited by selective chemical vapor deposition.
- 5. The method of claim 4 wherein said chemical vapor deposition uses a mixture of WF.sub.6 and H.sub.2.
- 6. The method of claim 1 wherein said subsequent processing step that tends to promote the growth of hillocks is heating to a temperature in excess of 350 degrees C.
- 7. The method of claim 1 comprising the step of forming a second dielectric layer overlying said first dielectric layer and encapsulated bimetallic structures, with said second dielectric layer having openings exposing some of said bimetallic structures; forming a plurality of second aluminum conductors overlying selected portions of said second dielectric layer; said second aluminum conductors having exposed top and side surfaces,
- characterized by the further step of selectively depositing a metal on said exposed surfaces of said second aluminum conductors to form encapsulated bimetallic structures, wherein said metal has a hardness greater than that of said second aluminum conductors, whereby the formation of hillocks on the top and side surfaces of said second aluminum conductors is suppressed.
Parent Case Info
This application is a continuation of application Ser. No. 07/581,241, filed on Sep. 7, 1990, which is a continuation of Ser. No. 06/892,389 filed on Jul. 31, 1986 both abandoned.
US Referenced Citations (23)
Foreign Referenced Citations (7)
Number |
Date |
Country |
3194 |
Jan 1976 |
JPX |
17143 |
Sep 1984 |
JPX |
220919 |
Dec 1984 |
JPX |
157237 |
Aug 1985 |
JPX |
8801102 |
Feb 1988 |
WOX |
1196834 |
Jul 1970 |
GBX |
1330720 |
Sep 1973 |
GBX |
Non-Patent Literature Citations (4)
Entry |
Shiono Y "Method for Producing a Semiconductor Device" English Translation of Japanese Patent 157237 (Aug. 1985). |
Eliot K. Broadbent et al. "Selective Tungsten Processing by Low Pressure CVD" Solid State Technology Dec. 1985, p. 51-59. |
H. Exrol, H. S. Lehmen, F. Turene and R. Valletta "Molybdenum Deposition Process" IBM Technical Disclosure Bulletin, vol. 13, No. 5, Oct. 1970 p. 1298. |
J. M. Shaw and J. A. Amick "Vapor-Deposited Tungsten as a Metallization and Interconnection Material for Silicon Device" RCA Review vol. 31, No. 2, Jun. 1970 pp. 306-316. |
Continuations (2)
|
Number |
Date |
Country |
Parent |
581241 |
Sep 1990 |
|
Parent |
892389 |
Jul 1986 |
|