Plasma immersion ion implantation process using a capacitively couple plasma source having low dissociation and low minimum plasma voltage

• US 7,291,545 B2
• Filed: 11/21/2005
• Issued: 11/06/2007
• 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, Monroy, Gonzalo Antonio
• Primary Examiner(s): GHYKA, ALEXANDER G
• Application Number:
  US11/284,975
• Publication Number:
  US 20060073683A1
• Time in Patent Office: 715 Days
• Field of Search: 438510-514, 156/345.37
• US Class Current: 438/510
• 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: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H01J 37/32412 Plasma immersion ion implantation
• CPC Class Codes: H01L 21/2236 from or into a plasma phase

Abstract

A method of ion implanting a species in a workpiece to a selected ion implantation profile depth includes placing a workpiece having a semiconductor material on an electrostatic chuck in or near a processing region of a plasma reactor chamber and applying a chucking voltage to the electrostatic chuck. The method further includes introducing into the chamber a precursor gas including a species to be ion implanted in the workpiece and applying an RF bias to the electrostatic chuck, the RF bias having a bias level corresponding to the ion implantation profile depth.

Claims

1. A method of ion implanting a species in a workpiece to a selected ion implantation profile depth, comprising:

placing a workpiece comprising a semiconductor material on an electrostatic chuck in or near a processing region of a plasma reactor chamber;

applying a chucking voltage to said electrostatic chuck;

introducing into the chamber a precursor gas comprising a species to be ion implanted in said workpiece; and

applying an RF bias to said electrostatic chuck, said RF bias having a bias level corresponding to said ion implantation profile depth.

2. The method of claim 1 wherein the workpiece further comprises dielectric material.

3. The method of claim 2 wherein the semiconductor material is comprised in a deposited layer.

4. The method of claim 1 wherein the semiconductor material is amorphous.

5. The method of claim 1 wherein the semiconductor material is crystalline.

6. The method of claim 1 further comprising controlling the temperature of the workpiece.

7. The method of claim 1 further comprising depositing a material on said workpiece from said process gas during the step of ion implanting.

8. The method of claim 1 further comprising coupling a second source of RF power to the chamber.

9. The method of claim 1 further comprising performing the following step prior to placing the workpiece in the chamber:

forming a seasoning layer on interior surfaces of the chamber.

10. The method of claim 9 wherein the step of forming a seasoning layer on interior surfaces of the chamber comprises:

introducing a seasoning material precursor gas into the chamber; and

applying plasma source power to generate a plasma in the chamber.

11. The method of claim 10 wherein the seasoning material precursor gas comprises a hydrocarbon or a fluorocarbon.

12. The method of claim 10 wherein the seasoning material precursor gas comprises a hydride of silicon, germanium, boron, phosphorous or arsenic.

13. The method of claim 10 further comprising removing said seasoning layer after said species has been ion implanted into said workpiece.

14. The method of claim 13 wherein the step of removing the seasoning layer comprises:

introducing a seasoning material removing precursor gas into the chamber; and

generating a plasma in the chamber.

15. The method of claim 1 further comprising regulating the rate at which the workpiece is etched during the step of ion implantation.

16. The method of claim 7 further comprising regulating the rate at which the depositing of the material occurs.

17. The method of claim 16 further comprising regulating the rate at which the deposited material is etched during the step of ion implantation.

18. The method of claim 1 further comprising regulating an etch rate during ion implantation of at least one of:

(a) the workpiece, (b) material deposited on the workpiece during ion implantation, by controlling a temperature of said workpiece using said at least one of a heating or cooling apparatus of said electrostatic chuck.

19. The method of claim 1 further comprising adjusting the angular distribution of trajectories of ions near said workpiece by adjusting the pressure inside said chamber.

20. The method of claim 6 wherein the step of applying an RF bias to said electrostatic chuck comprises applying the RF bias to a chucking electrode of the electrostatic chuck.