Ion source cleaning in semiconductor processing systems

• US 9,991,095 B2
• Filed: 08/12/2009
• Issued: 06/05/2018
• Est. Priority Date: 02/11/2008
• Status: Active Grant

• Current Assignee: Entegris Incorporated
• Original Assignee: Entegris Incorporated
• Inventors: Sweeney, Joseph D., Yedave, Sharad N., Byl, Oleg, Kaim, Robert, Eldridge, David, Feng, Lin, Bishop, Steven E., Olander, W. Karl, Tang, Ying
• Primary Examiner(s): Murata, Austin
• Application Number:
  US13/201,188
• Publication Number:
  US 20120058252A1
• Time in Patent Office: 3,219 Days
• Field of Search: 134 31, 250426, 250424, 250423
• CPC Class Codes: C23C 14/48 Ion implantation
• CPC Class Codes: C23C 14/54 Controlling or regulating the coating process
• CPC Class Codes: C23C 14/564 Means for minimising impurities in the coating chamber such as dust, moisture, residual gases
• CPC Class Codes: H01J 2237/082 Electron beam
• CPC Class Codes: H01J 2237/22 Treatment of data mixing signals H01J2237/24495
• CPC Class Codes: H01J 37/08 Ion sources; Ion guns
• CPC Class Codes: H01J 37/16 Vessels; Containers
• CPC Class Codes: H01J 37/18 Vacuum locks ; Means for obtaining or maintaining the desired pressure within the vessel vacuum locks for electron-beam tubes in general H01J29/865
• CPC Class Codes: H01J 37/3171 for ion implantation plasma immersion ion implantation H01J37/32412

Abstract

Cleaning of an ion implantation system or components thereof, utilizing temperature and/or a reactive cleaning reagent enabling growth/etching of the cathode in an indirectly heated cathode for an ion implantation system by monitoring the cathode bias power and taking corrective action depending upon compared values to etch or regrow the cathode.

Claims

1. A method of controlling the condition of an indirectly heated cathode source in an ion implantation system comprising:

detecting a decrease in power usage of the indirectly heated cathode by determining power usage for the indirectly heated cathode source by measuring cathode bias power at a predetermined time and comparing the power usage at the predetermined time to initial power; and

regrowing the indirectly heated cathode by flowing a fluorinated gas in a plasma condition over the indirectly heated cathode, wherein the fluorinated gas comprises XeF₂.

2. The method of claim 1 further comprising:

detecting an increase in a power usage of the indirectly heated cathode by

i) determining power usage from the indirectly heated cathode source by measuring cathode bias power at an additional predetermined time; and

ii) comparing the power usage at the additional predetermined time to initial power; and

etching the indirectly heated cathode.

3. The method of claim 2 wherein the etching includes operating the indirectly heated cathode under conditions of low to moderate temperature sufficient for etching.

4. The method of claim 3, wherein the low to moderate temperature is from about room temperature up to about 2000°

C.

5. The method of claim 1 wherein the regrowing includes operating the indirectly heated cathode under conditions of high temperature sufficient for metal deposition to occur.

6. The method of claim 5, wherein the high temperature sufficient for metal deposition to occur is greater than 2000°

C.

7. The method of claim 1, wherein the fluorinated gas comprises N₂F₄.