Process and gas for treatment of semiconductor devices

• US 4,303,467 A
• Filed: 11/11/1977
• Issued: 12/01/1981
• Est. Priority Date: 11/11/1977
• Status: Expired due to Term

• Current Assignee: Branson International Plasma Corporation
• Original Assignee: Branson International Plasma Corporation
• Inventors: Bersin, Richard L., Scornavacca, Frank
• Primary Examiner(s): Powell, William A.
• Application Number:
  US05/850,713
• Time in Patent Office: 1,481 Days
• Field of Search: 204/164, 204/168-170, 204/192 E, 204/192 EC, 204/298, 156/643, 156/646, 156/656, 156/657, 156/659, 156/662, 156/664, 156/345, 156/653, 427/39, 252/79.1, 252/79.2, 252/79.3
• US Class Current: 438/720
• CPC Class Codes: C23F 4/00 Processes for removing metallic material from surfaces, not provided for in group C23F1/00 or C23F3/00
• CPC Class Codes: G03F 7/427 using plasma means only
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/31138 by dry-etching

Abstract

Gas plasma process and gas mixture useful for the removal of materials in the manufacture of semiconductor devices. Substrate wafers or other semiconductor devices are exposed to a gaseous plasma containing SiF₄ or SiF₄ and oxygen for a time sufficient to effect a desired removal of material from the wafer or device. The process and gas are particularly suitable for selective etching of Si₃ N₄ and the stripping of photoresist, as well as the etching of materials such as silicon and compounds containing silicon.

Claims

1. In a process for removing a material from a semiconductor device in a plasma reactor, the steps of:

introducing SiF₄ and oxygen gas into the reactor chamber, energizing the SiF₄ and oxygen gas to form a plasma, and exposing the material to the plasma for a time sufficient to remove a predetermined amount of the material.

2. The process of claim 1 wherein the material to be removed is photoresist and the gas contains on the order of 10 to 50 percent SiF₄ by volume.

3. In a process for removing a material consisting of or containing silicon from a semiconductor device in a plasma environment, the step of exposing the material to a gaseous plasma containing SiF₄ as a major constituent thereof for a time sufficient to remove a predetermined amount of the material.

4. In an etching process for selectively removing Si₃ N₄ from a semiconductor device in a plasma environment, the step of exposing the device to a gaseous plasma containing SiF₄ and no oxygen for a time sufficient to remove the Si₃ N₄.

5. In a process for removing photoresist from a semiconductor structure in a plasma environment, the step of exposing the photoresist to a gaseous plasma formed of a mixture of SiF₄ and at least 20 percent oxygen by volume for a time sufficient to remove the photoresist.

6. A gas for removing silicon or a silicon containing material from a semiconductor device in a plasma environment, comprising a mixture of SiF₄ and oxygen.

7. The gas of claim 6 wherein the mixture contains on the order of 2 to 20 percent oxygen by volume.

8. A gas for removing photoresist from a semiconductor structure in a plasma environment, comprising a mixture of SiF₄ and oxygen.

9. The gas of claim 8 wherein the mixture contains at least 50 percent oxygen by volume.

10. A plasm etching process for selectively removing a passivation and diffusion barrier material from a substrate comprising the steps of placing said substrate in a plasma environment, and exposing the substrate to a gas plasma consisting essentially of SiF₄ for a period of time sufficient to remove the desired amount of barrier material from the substrate.

11. A plasma etching process for etching a material selected from a silicon containing material, molybedenum and titanium, which process comprises placing the material in a plasma environment and then exposing the material to a gas plasma containing SiF₄ and oxygen for a sufficient period of time to obtain the desired etching of the material.

12. The process of claim 11 wherein the mixture contains about 2 to about 20% oxygen by volume.

13. A process for stripping a photoresist material from a semiconductor device which comprises placing said device in a plasma environment and exposing the device to a gas plasma mixture containing oxygen and at least 5% SiF₄ for a sufficient period of time to strip the desired amount of the photoresist material.

14. A composition useful as a gas plasma in a plasma etching process which consists of a mixture comprised of SiF₄ and oxygen.

15. The composition of claim 14 wherein the mixture contains about 2 to about 20% oxygen by volume.

16. The composition of claim 14 wherein the mixture contains at least 5% SiF₄ volume.

17. A gas mixture useful in a plasma etching process, which mixture consists essentially of SiF₄ and oxygen.