Methods and apparatus for cleaning semiconductor wafers

Patent metadata

Field	Value
Publication number	US-10020208-B2
Application number	US-201715418309-A
Country	US
Kind code	B2
Filing date	Jan 27, 2017
Priority date	Dec 12, 2008
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

A method for cleaning semiconductor substrate using ultra/mega sonic device comprising holding a semiconductor substrate by using a chuck, positioning a ultra/mega sonic device adjacent to the semiconductor substrate, injecting chemical liquid on the semiconductor substrate and gap between the semiconductor substrate and the ultra/mega sonic device, changing gap between the semiconductor substrate and the ultra/mega sonic device for each rotation of the chuck during the cleaning process. The gap can be increased or reduced by 0.5 /N for each rotation of the chuck, where λ is wavelength of ultra/mega sonic wave, N is an integer number between 2 and 1000. The gap is varied in the range of 0.5λn during the cleaning process, where λ is wavelength of ultra/mega sonic wave, and n is an integer number starting from 1.

First claim

What is claimed is:

1. A method for cleaning a semiconductor substrate using an ultra/mega sonic device, comprising:
holding a semiconductor substrate by using a chuck, the chuck connected to a motor;
positioning the ultra/mega sonic device adjacent to the semiconductor substrate;
executing a cleaning process using a control unit, the cleaning process including injecting a chemical liquid onto the semiconductor substrate and into a gap between the semiconductor substrate and the ultra/mega sonic device using at least one nozzle, applying an ultra/mega sonic wave to the cleaning liquid using the ultra/mega sonic device, and changing the gap between the semiconductor substrate and the ultra/mega sonic device, and
wherein the control unit controls the speed of the chuck and changes the gap between the semiconductor substrate and the ultra/mega sonic device based on a value of a wavelength of the ultra/mega sonic wave in the cleaning liquid and rotation of the chuck, and
wherein during the cleaning process the control unit is configured to adjust the gap between the semiconductor substrate and the ultra/mega sonic device for each rotation of the chuck by 0.5λ/N until a total change of the gap is 0.5nλ to provide a uniform power density application of the ultra/mega sonic device to the entire semiconductor substrate, wherein λ is the wavelength of the ultra/mega sonic wave, N is an integer number between 2 to 1000, and n is an integer number starting from 1.

2. The method of claim 1 , wherein the gap is changed by moving the ultra/mega sonic device in a direction vertical to the semiconductor substrate.

3. The method of claim 1 , wherein the gap is changed by moving the chuck in a direction vertical to the ultra/mega sonic device.

4. The method of claim 1 , wherein the ultra/mega sonic device is positioned adjacent to a front side of the semiconductor substrate.

5. The method of claim 1 , wherein the ultra/mega sonic device is positioned adjacent to a back side of the semiconductor substrate.

6. The method of claim 5 , wherein the chemical liquid is injected to a front side of the semiconductor substrate by a first nozzle of the at least one nozzle placed adjacent to the front side of the semiconductor wafer, and the chemical liquid is injected to a back side of the semiconductor substrate by a second nozzle of the at least one nozzle placed adjacent to the back side of the semiconductor substrate.

7. The method of claim 1 , wherein sonic frequencies of the ultra/mega sonic device are dual frequencies.

8. The method of claim 7 , wherein the dual frequencies comprises a high frequency f1 and a low frequency f2, and f1=Mf2, where M is an integer number starting from 2.

9. The method of claim 6 , wherein the chemical liquid is injected simultaneously on the front side and back side of the semiconductor wafer by the first nozzle and the second nozzle, respectively.

10. A method for cleaning a semiconductor substrate using an ultra/mega sonic device, comprising:
holding a semiconductor substrate by using a chuck, the chuck connected to a motor;
positioning the ultra/mega sonic device adjacent to the semiconductor substrate;
executing a cleaning process using a control unit, the cleaning process including injecting a chemical liquid onto the semiconductor substrate and into a gap between the semiconductor substrate and the ultra/mega sonic device using at least one nozzle, applying an ultra/mega sonic wave to the cleaning liquid using the ultra/mega sonic device, and changing the gap between the semiconductor substrate and the ultra/mega sonic device, and
wherein the control unit controls the speed of the chuck and changes the gap between the semiconductor substrate and the ultra/mega sonic device based on a value of a wavelength of the ultra/mega sonic wave in the cleaning liquid and rotation of the chuck, and
wherein during the cleaning process the control unit is configured to adjust the gap between the semiconductor substrate and the ultra/mega sonic device for each rotation of the chuck by 0.5λ/N to provide a uniform power density application of the ultra/mega sonic device to the entire semiconductor substrate, wherein λ is the wavelength of the ultra/mega sonic wave, and N is an integer number between 2 to 1000.

11. The method of claim 10 , wherein the gap is changed by moving the ultra/mega sonic device in a direction vertical to the semiconductor substrate.

12. The method of claim 10 , wherein the gap is changed by moving the chuck in a direction vertical to the ultra/mega sonic device.

13. The method of claim 10 wherein the ultra/mega sonic device is positioned adjacent to a front side of the semiconductor substrate.

14. The method of claim 10 , wherein the ultra/mega sonic device is positioned adjacent to a back side of the semiconductor substrate.

15. The method of claim 14 , wherein the chemical liquid is injected to a front side of the semiconductor substrate by a first nozzle of the at least one nozzle placed adjacent to the front side of the semiconductor wafer, and the chemical liquid is injected to a back side of the semiconductor substrate by a second nozzle of the at least one nozzle placed adjacent to the back side of the semiconductor substrate.

16. The method of claim 10 , wherein the gap is varied in the range of 0.5λn during the cleaning process, where n is an integer number starting from 1.

17. The method of claim 10 , wherein sonic frequencies of the ultra/mega sonic device are dual frequencies.

Assignees

• Acm Research Shanghai Inc

Inventors

• Wang Jian
• Nuch Sunny Voha
• Xie Liangzhi
• Wu Junping
• Jia Zhaowei
• Huang Yunwen
• Gao Zhifeng
• Wang Hui

Classifications

• H10P72/0424

  using mainly spraying means, e.g. nozzles · CPC title

• H10P72/0404

  for general liquid treatment, e.g. etching followed by cleaning · CPC title

• H10P70/234

  the processing being the formation of vias or contact holes · CPC title

• H10P72/0414 Primary

  using mainly spraying means, e.g. nozzles · CPC title

• H10P50/00 Primary

  Etching of wafers, substrates or parts of devices · CPC title