Plasma immersion ion implantation process

• US 7,288,491 B2
• Filed: 01/28/2005
• Issued: 10/30/2007
• Est. Priority Date: 08/11/2000
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Ramaswamy, Kartik, Hanawa, Hiroji, Collins, Kenneth S., Nguyen, Andrew, Al-Bayati, Amir, Gallo, Biagio
• Primary Examiner(s): DEO, DUY VU NGUYEN
• Application Number:
  US11/046,562
• Publication Number:
  US 20050191827A1
• Time in Patent Office: 1,005 Days
• Field of Search: None
• US Class Current: 438/780
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01L 21/67109 mainly by convection
• CPC Class Codes: H01L 21/6831 using electrostatic chucks

Abstract

One method of performing plasma immersion ion implantation on a workpiece in a plasma reactor chamber includes initially depositing a seasoning film on the interior surfaces of the plasma reactor chamber before the workpiece is introduced, by introducing a seasoning film precursor gas into the chamber and generating a plasma within the chamber, performing plasma immersion ion implantation on the workpiece by introducing an implant species precursor gas into the chamber and generating a plasma, and then removing the workpiece from the chamber and removing the seasoning film from the chamber interior surfaces.

Claims

1. A method of performing plasma immersion ion implantation on a workpiece in a plasma reactor chamber, comprising:

prior to placing the workpiece in the plasma reactor chamber, depositing a seasoning film on the interior surfaces of the plasma reactor chamber by introducing a seasoning film precursor gas into the chamber and generating a plasma within the chamber;

placing the workpiece on a workpiece support in the chamber; and

performing plasma immersion ion implantation on the workpiece by introducing an implant species precursor gas into the chamber and generating a plasma;

removing the workpiece from the chamber; and

removing the seasoning film from the chamber interior surfaces, wherein one of;

(a) said implant species precursor gas comprises a fluoride of a dopant species, said seasoning film precursor gas comprises a fluorocarbon gas and said seasoning film comprises a fluorocarbon polymer, or

(b) said implant species precursor gas comprises a hydride of a dopant species, said seasoning film precursor gas comprises a hydrocarbon gas and said seasoning film comprises a hydrocarbon polymer.

2. The method of claim 1 further comprising:

after the step of removing said workpiece from the chamber and before the step of removing said seasoning film, placing an other workpiece on the workpiece support in the chamber and performing plasma ion immersion on the other workpiece and removing the other workpiece from the chamber.

3. The method of claim 1 further comprising:

separately controlling a temperature of the chamber interior walls and a temperature of the wafer support, and holding the temperature of the chamber walls and of the wafer support at constant levels during the steps of depositing the seasoning film, performing plasma immersion ion implantation and removing the seasoning film.

4. The method of the claim 3 wherein the temperature of the chamber walls is held below a deposition threshold temperature and the temperature of the wafer support is held at a sufficiently low temperature to enable temperature control of the workpiece during ion implantation, the temperature at which the chamber walls are held and the temperature at which the wafer support is held being sufficiently high to permit removal of the seasoning film during the removal step.

5. The method of claim 4 wherein said seasoning film comprises a fluorocarbon polymer, the chamber wall temperature is held within a range of 20 to 80 degrees C. and the wafer support temperature is held within a range of 0 to 40 degrees C.

6. The method of claim 4 wherein said seasoning film comprises a hydrocarbon polymer, the chamber wall temperature is held within a range of 20 to 80 degrees C. and the wafer support temperature is held within a range of 20 to 60 degrees C.

7. A method of performing plasma immersion ion implantation on a workpiece in a plasma reactor chamber, comprising:

prior to placing the workpiece in the plasma reactor chamber, depositing a seasoning film on the interior surfaces of the plasma reactor chamber by introducing a seasoning film precursor gas into the chamber and generating a plasma within the chamber;

placing the workpiece on a workpiece support in the chamber;

performing plasma immersion ion implantation on the workpiece by introducing an implant species precursor gas into the chamber and generating a plasma;

removing the workpiece from the chamber;

removing the seasoning film from the chamber interior surfaces; and

wherein said implant precursor species comprises a fluorine-containing gas, said seasoning film precursor gas comprises a fluorocarbon gas and said seasoning film comprises a fluorocarbon polymer.

8. A method of performing plasma immersion ion implantation on a workpiece in a plasma reactor chamber, comprising:

prior to placing the workpiece in the plasma reactor chamber, depositing a seasoning film on the interior surfaces of the plasma reactor chamber by introducing a seasoning film precursor gas into the chamber and generating a plasma within the chamber;

placing the workpiece on a workpiece support in the chamber; and

performing plasma immersion ion implantation on the workpiece by introducing an implant species precursor gas into the chamber and generating a plasma;

removing the workpiece from the chamber; and

removing the seasoning film from the chamber interior surfaces;

wherein said implant species precursor gas comprises a fluoride or hydride of a dopant, and wherein the step of performing plasma immersion ion implantation further comprises;

minimizing deposition on said workpiece of material derived from the implant species precursor gas.

9. The method of claim 8 wherein the step of minimizing deposition on said workpiece comprises:

holding said workpiece at a temperature above a deposition threshold temperature.

10. The method of claim 9 where in the step of minimizing deposition on said workpiece further comprises:

introducing a dilution gas into the chamber during plasma immersion ion implantation.

11. The method of claim 10 wherein said dilution gas comprises at least one of:

(a) a hydrogen-containing gas, (b) a nitrogen-containing gas, (c) an oxygen-containing gas, (d) a fluorine-containing gas, (e) helium, (f) neon, (g) argon, (h) xenon.

12. The method of claim 8 wherein the step of performing plasma immersion ion implantation further comprises:

minimizing etching of the workpiece by etchant species derived from the implant species precursor gas.

13. The method of claim 12 wherein the steps of minimizing deposition and minimizing etching are carried out by holding the temperature of the workpiece within a temperature range that is above a workpiece deposition threshold temperature and below a workpiece etch threshold temperature.

14. A method of performing plasma immersion ion implantation on a workpiece in a plasma reactor chamber, comprising:

prior to placing the workpiece in the plasma reactor chamber, depositing a seasoning film on the interior surfaces of the plasma reactor chamber by introducing a seasoning film precursor gas into the chamber and generating a plasma within the chamber;

placing the workpiece on a workpiece support in the chamber; and

performing plasma immersion ion implantation on the workpiece by introducing an implant species precursor gas into the chamber and generating a plasma;

removing the workpiece from the chamber; and

removing the seasoning film from the chamber interior surfaces;

wherein said implant species precursor gas comprises a fluoride or hydride of a dopant, and wherein the step of performing plasma immersion ion implantation further comprises;

minimizing etching of said workpiece of material derived from the implant species precursor gas.

15. The method of claim 14 wherein the steps of minimizing minimizing etching is carried out by holding the temperature of the workpiece below a workpiece etch threshold temperature.

16. A method of processing a workpiece in a plasma reactor chamber, comprising:

prior to placing the workpiece in the plasma reactor chamber, depositing an elastic cushioning film on the wafer-support surface of a wafer support within the chamber by introducing an elastic material precursor gas into the chamber and generating a plasma within the chamber;

placing the workpiece on the elastic cushioning film a workpiece support in the chamber; and

introducing a workpiece processing gas into the chamber and processing the workpiece in the chamber;

removing the workpiece from the chamber; and

removing the elastic cushioning film from the wafer support.

17. The method of claim 16 further comprising:

after the step of removing said workpiece from the chamber and before the step of removing the elastic cushioning film, placing an other workpiece on the elastic cushioning film and processing the other workpiece in the chamber, and removing the other workpiece from the chamber.

18. The method of claim 16 wherein said elastic material precursor gas comprises one of (a) a fluorocarbon gas, (b) a hydrocarbon gas, (c) a fluoro-hydrocarbon gas, and wherein said elastic cushioning layer comprises a polymer.

19. The method of claim 16 further comprising:

prior to depositing said elastic cushioning film, providing a generally uninterrupted continuous polished surface as the workpiece support surface of the wafer support.

20. The method of claim 19 further comprising controlling the temperature of the workpiece by applying a sufficiently large electrostatic workpiece-clamping voltage to attain a desired workpiece temperature.

21. The method of claim 16 wherein said workpiece process gas comprises a fluorine-containing gas, said elastic material precursor gas comprises a fluorocarbon gas and said cushioning film comprises a fluorocarbon polymer.

22. The method of claim 16 wherein said workpiece process gas comprises a hydrogen containing gas, said elastic material precursor gas comprises a hydrocarbon gas and said cushioning film comprises a hydrocarbon polymer.