PREVENTION OF INVERSION OF P-TYPE SEMICONDUCTOR MATERIAL DURING RF SPUTTERING OF QUARTZ

• US 3,616,403 A
• Filed: 10/25/1968
• Issued: 10/26/1971
• Est. Priority Date: 10/25/1968
• Status: Expired due to Term

• Current Assignee: Joseph S. Logan, Robert H. Collins
• Original Assignee: Joseph S. Logan, Robert H. Collins
• Inventors: Collins, Robert H., Logan, Joseph S.
• Primary Examiner(s): Williams, Howard S.
• Assistant Examiner(s): Kanter, Sidney S.
• Application Number:
  US04/770,477
• Time in Patent Office: 1,096 Days
• Field of Search: 204/192
• US Class Current: 204/192.22
• CPC Class Codes: C23C 14/10 Glass or silica
• CPC Class Codes: H01J 37/34 operating with cathodic sputtering H01J37/36 takes precedence ; methods of cathodic sputtering C23C14/34
• CPC Class Codes: H01L 23/291 Oxides or nitrides or carbides, e.g. ceramics, glass
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

Method for preventing inversion of semiconductor surfaces during RF sputtering of dielectrics by maintaining a low flat band charge level at the semiconductor interface. The flat band charge level is controlled by rigidly maintaining various parameters of the sputtering system such as target purity, and RF power density, in conjunction with the presence of a thin layer of phosphosilicate glass on the semiconductor which is supported on a dielectric material in floating mode.

Claims

2. The method of claim 1 wherein the positive impurity ion density of said target is of the order of 1 X 1017 ions per cm.3.

3. The method of claim 1 wherein said power density is maintained in the range of 15 to 20 watts per square inch.

4. The method of claim 1 wherein said phosphosilicate glass layer thickness is in the range of 650 to 3,000 A. thick.

5. A method of claim 1 wherein said layer of phosphosilicate glass is at least 1,000 A. thick.

6. The method of claims 1, 2, 3, 4, or 5, wherein said semiconductor is primarily silicon and said target is primarily silicon dioxide.