CLEANING METHOD FOR SEMICONDUCTOR DEVICE FABRICATION

• US 20150000704A1
• Filed: 09/18/2014
• Published: 01/01/2015
• Est. Priority Date: 02/01/2013
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Yeh, Ming-Hsi, Wu, Sung-Hsun, Jang, Syun-Ming, Chou, Bo-Wei, Chen, Chao-Cheng
• Granted Patent: US 10,005,990 B2
• Time in Patent Office: Days
• US Class Current: 134/19
• CPC Class Codes: C11D 2111/22 Electronic devices, e.g. PCBs or semiconductors
• CPC Class Codes: C11D 3/3947 Liquid compositions
• CPC Class Codes: C11D 7/06 Hydroxides
• CPC Class Codes: C11D 7/08 Acids
• CPC Class Codes: H01L 21/02057 Cleaning during device manufacture
• CPC Class Codes: H01L 21/67051 using mainly spraying means, e.g. nozzles

Abstract

A method of cleaning a substrate such as semiconductor substrate for IC fabrication is described that includes cleaning the semiconductor substrate with a first mixture of ozone and one of an acid and a base, followed by a second mixture of ozone and the other one of the acid and the base. The cleaning mixtures may further include de-ionized water. In an embodiment, the mixture is sprayed onto a heated substrate surface. The acid may be HF; the base may be NH₄OH.

Claims

1. A method, comprising:

providing a semiconductor substrate;

performing a first cleaning of the semiconductor substrate with a first cleaning mixture including ozone, one of an acid and a base, and water;

rinsing the semiconductor substrate after the first cleaning; and

after the rinsing, performing a second cleaning of the semiconductor substrate with a second cleaning mixture including ozone, water, and the other one of an acid and a base.

2. The method of claim 1, wherein the first cleaning mixture includes the acid, wherein the acid includes HF.

3. The method of claim 2, wherein the second cleaning mixture includes the base, wherein the base includes NH₄OH.

4. The method of claim 1, wherein the first cleaning mixture includes the base, wherein the base includes NH₄OH.

5. The method of claim 4, wherein the second cleaning mixture includes the acid, wherein the acid includes HF.

6. The method of claim 1, wherein the first cleaning and the second cleaning further includes heating a backside of the semiconductor substrate while the first and second cleaning mixtures are incident the semiconductor substrate.

7. The method of claim 1, further comprising:

rinsing the semiconductor substrate after the second cleaning.

8. The method of claim 1, further comprising:

after the second cleaning, performing the first cleaning again using the first chemical mixture.

9. A method of cleaning a semiconductor substrate, comprising:

providing a first cleaning solution including HF, ozone and water onto a surface of the semiconductor substrate;

rinsing the semiconductor substrate after the providing the first cleaning solution;

providing a second cleaning solution including NH₄OH, ozone and water onto the surface of the semiconductor substrate after the rinsing.

10. The method of claim 9, further comprising:

heating a backside of the semiconductor substrate, the backside opposing the surface of the semiconductor substrate, during the providing the first cleaning solution and the providing the second cleaning solution.

11. The method of claim 9, wherein the providing the first cleaning solution has a duration of approximately 30 seconds and the providing the second cleaning solution has a duration of approximately 60 seconds.

12. The method of claim 9, wherein the providing the first cleaning solution further comprises providing at least one of a NH₄F and a surfactant.

13. The method of claim 9, further comprising:

after providing the second cleaning solution, providing a second occurrence of the first cleaning solution including HF, ozone and water onto the surface of the semiconductor substrate;

thereafter, providing a second occurrence of the second cleaning solution including NH₄OH, ozone and water onto the surface of the semiconductor substrate.

14. The method of claim 9, wherein the providing the first cleaning solution including HF, ozone and water includes providing between approximately 1% and approximately 500 parts per million (ppm) of HF and providing between approximately 500 and 1 ppm of ozone.

15. The method of claim 9, wherein the providing the second cleaning solution including NH₄OH, ozone and water includes providing between approximately 10% and approximately 0.01% of NH₄OH and providing between approximately 500 and 1 ppm of ozone.

16. A method of fabricating a semiconductor device, comprising:

forming a first feature on a surface of a semiconductor wafer;

spraying a first cleaning mixture onto the first feature on the surface, wherein the first cleaning mixture includes ozone and HF; and

after stopping the spraying of the first cleaning mixture, spraying a second cleaning mixture on the first feature on the surface, wherein the second cleaning mixture includes ozone and NH₄OH and wherein the spraying the second cleaning mixture is in-situ with spraying the first cleaning mixture.

17. The method of claim 16, further comprising:

heating the semiconductor wafer to a first temperature during the spraying the first cleaning mixture; and

heating the semiconductor wafer to a second temperature during the spraying the second cleaning mixture, wherein the second temperature is different the first temperature.

18. The method of claim 17, wherein the heating the semiconductor wafer is performed by heating a backside of the semiconductor wafer, wherein the surface is an opposing frontside of the semiconductor wafer.

19. The method of claim 16, the first cleaning mixture includes between approximately 1% and approximately 500 parts per million (ppm) of HF and between approximately 500 and 1 ppm of ozone

20. The method of claim 16, wherein the second cleaning mixture includes between approximately 10% and approximately 0.01% of NH₄OH and between approximately 500 and 1 ppm of ozone.