METHOD OF MAKING RESISTOR THIN FILMS BY REACTIVE SPUTTERING FROM A COMPOSITE SOURCE

• US 3,763,026 A
• Filed: 09/24/1971
• Issued: 10/02/1973
• Est. Priority Date: 12/22/1969
• Status: Expired due to Term

• Current Assignee: Linus F. Cordes
• Original Assignee: Linus F. Cordes
• Inventors: Cordes, Linus F.
• Primary Examiner(s): Mack, John H.
• Assistant Examiner(s): Valentine, D. R.
• Application Number:
  US05/183,688
• Time in Patent Office: 739 Days
• Field of Search: 204/192
• US Class Current: 204/192.21
• CPC Class Codes: C23C 14/0036 Reactive sputtering
• CPC Class Codes: H01C 17/12 by sputtering
• CPC Class Codes: H10N 97/00 Electric solid-state thin-film or thick-film devices, not otherwise provided for

Abstract

A method of making high resistivity thin film resistors by reactively sputtering a composite source onto a substrate is described. The composite source comprises a first material selected from the group consisting of chromium, silicon, beryllium, aluminum and magnesium and a second material selected from the group consisting of molybdenum, tantalum, tungsten, gold, silver, platinum, osmium and iridium. In the presence of a reactive gas such as nitrogen, the first materials form a high resistivity nitride on the substrate and the second materials either form a low resistivity nitride on the substrate or are non-reactive with the nitrogen and remain in their elemental states. The resulting thin films have resistivities ranging between the high resistivity nitrides and the low resistivity nitrides depending upon the composition of the composite source.

Claims

2. The method of claim 1 wheRein said reactive gas is nitrogen and said first material forms a high resistivity nitride and said second material is nonreactive with said nitrogen.

3. The method of claim 1 wherein said reactive gas is maintained at a pressure of from 0.5 X 10 3 torr to 150 X 10 3 torr.

4. The method of claim 1 wherein said source and said substrate are in substantially parallel relationship and separated from each other by at least 2 centimeters.

5. The method of claim 1 wherein the step of reactively sputtering comprises:

bombarding said source with positive ions to liberate free atoms therefrom, at least some of said atoms reacting with said gas to form a resistance film on said substrate, said film characterized by a high resistivity per square and a low temperature coefficient of resistivity.

6. The method of claim 1 wherein said source is formed by mixing powders selected from said groups of said first and second materials and compressing said powders to form said composite structure.

7. The method of claim 1 wherein said substrate comprises a semiconductor body having an insulating layer over a major surface thereof on which said film is deposited.

8. The method of claim 1 wherein said thin film is greater than approximately 100 A thick.