Method for cleaning elements in vacuum chamber and apparatus for processing substrates

• US 8,206,513 B2
• Filed: 06/02/2008
• Issued: 06/26/2012
• Est. Priority Date: 08/25/2003
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Moriya, Tsuyoshi, Nagaike, Hiroshi, Nakayama, Hiroyuki
• Primary Examiner(s): Kornakov, Michael
• Assistant Examiner(s): BLAN, NICOLE R
• Application Number:
  US12/131,803
• Publication Number:
  US 20080245387A1
• Time in Patent Office: 1,485 Days
• Field of Search: None
• US Class Current: 134/21
• CPC Class Codes: B08B 3/12 by sonic or ultrasonic vibrations washing or rinsing machines for crockery or tableware using sonic or ultrasonic waves A47L15/13; of natural teeth, of prostheses using ultrasonic techniques similar to those used for natural teeth A61C17/20; application of ultrasonic vibrations to chemical, physical or physico-chemical processes in general B01J19/10
• CPC Class Codes: H01J 37/32862 In situ cleaning of vessels and/or internal parts
• CPC Class Codes: H01L 21/67028 for cleaning followed by drying, rinsing, stripping, blasting or the like
• CPC Class Codes: H01L 21/6831 using electrostatic chucks

Abstract

To clean an element in a vacuum chamber by causing particles sticking to the element to scatter, the present invention uses a means for applying a voltage to the element and causing the particles to scatter by utilizing Maxwell'"'"'s stress, a means for electrically charging the particles and causing the particles to scatter by utilizing the Coulomb force, a means for introducing a gas into the vacuum chamber and causing the particles sticking to the element to scatter by causing a gas shock wave to hit the element, a means for heating the element and causing the particles to scatter by utilizing the thermal stress and thermophoretic force, or a means for causing the particles to scatter by applying mechanical vibrations to the element. The thus scattered particles are removed by carrying them in a gas flow in a relatively high pressure atmosphere.

Claims

1. An element cleaning method for scattering particles sticking to an element in a process chamber and removing the particles by using a gas flow, comprising:

evacuating the process chamber to reduce a pressure in the process chamber to a first pressure;

introducing a large amount of gas at a higher pressure than the first pressure and in a short time to generate a gas shock wave above the element;

propagating the shock wave to the element to scatter the particles sticking to the element;

setting the pressure in the process chamber to a second pressure higher than the first pressure; and

carrying away the scattered particles by using a flow of the gas introduced into the chamber while under the second pressure to remove the scattered particles,

wherein the first pressure is not more than 1.3×

10<sup>−

2</sup> Pa and the second pressure is not less than 1.3×

10³ Pa.

2. The element cleaning method as claimed in claim 1, wherein the element is a stage for mounting thereon a substrate to be processed.

3. The element cleaning method as claimed in claim 2, wherein the introducing includes introducing the gas through a showerhead provided in the process chamber and the propagating includes having the shock wave from the showerhead hit an entire surface of the stage.

4. The element cleaning method as claimed in claim 1, wherein the introducing includes introducing the gas through a gas inlet pipe provided in the process chamber.

5. The element cleaning method as claimed in claim 1, wherein the introducing includes introducing the gas a plurality of times in succession.

6. The element cleaning method as claimed in claim 1, further comprising:

heating the element to maintain the element at a high temperature; and

applying a voltage to the element so as to scatter the particles due to Maxwell'"'"'s stress based on a permittivity difference between the element and the particles, wherein the introducing and the applying are performed simultaneously or successively.

7. The element cleaning method as claimed in claim 6, further comprising:

coating the element with a material having a larger permittivity than the particles.

8. The element cleaning method as claimed in claim 6, wherein the applying includes applying an AC voltage.

9. The element cleaning method as claimed in claim 1, wherein the introduced gas has the higher pressure approximately equal to atmospheric pressure.

10. The element cleaning method as claimed in claim 1, further comprising:

applying ultrasonic or mechanical vibrations to the element.

11. The element cleaning method as claimed in claim 1, wherein the shock wave is generated by a rising rate of pressure of the introduction of the gas above a predetermined rate.

12. The element cleaning method as claimed in claim 1, further comprising scattering the particle by at least one of the following (a) to (c):

(a) charging the particles on the element and applying a voltage of the same polarity as the charged particles to the element;

(b) controlling a temperature of the element to use thermal stress and thermophoretic force; and

(c) applying ultrasonic or mechanical vibrations to the element.

13. The element cleaning method as claimed in claim 1, wherein the introducing includes introducing the gas through a showerhead provided in the process chamber.