Method to address carbon incorporation in an interpoly oxide

• US 7,806,988 B2
• Filed: 09/28/2004
• Issued: 10/05/2010
• Est. Priority Date: 09/28/2004
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Rana, Niraj, Shea, Kevin R.
• Primary Examiner(s): Cleveland; Michael
• Assistant Examiner(s): BLAN, NICOLE R
• Application Number:
  US10/951,997
• Publication Number:
  US 20060065286A1
• Time in Patent Office: 2,198 Days
• Field of Search: 134/2, 134/3, 134/26, 134/27, 134/28, 134/30, 134/32, 134/33, 134/36, 134/39
• US Class Current: 134/28
• CPC Class Codes: B08B 3/08 the liquid having chemical or dissolving effect substances used, see the relevant classes
• CPC Class Codes: C23F 1/32 Alkaline compositions C23F1/42 takes precedence
• CPC Class Codes: C23F 4/00 Processes for removing metallic material from surfaces, not provided for in group C23F1/00 or C23F3/00
• CPC Class Codes: H01L 21/02063 the processing being the formation of vias or contact holes

Abstract

A method of removing a mask and addressing interfacial carbon chemisbored in a semiconductor wafer starts with placing the semiconductor wafer into a dry strip chamber. The dry stripping process is performed to remove the mask on the semiconductor wafer. The semiconductor wafer is then subjected to a cleaning solution to perform a cleaning process to remove particles on the surface of the semiconductor wafer and to address the interfacial carbon. The cleaning solution being either water containing ozone (O₃) and ammonia (NH₃), or a solution of hot phosphoric acid (H₃PO₄).

Claims

1. A method of removing interfacial carbon from a device structure formed on a semiconductor wafer, the method comprising:

providing the semiconductor wafer and device structure with interfacial carbon and a photoresist layer;

performing a dry stripping process to remove the photoresist layer on the device structure;

using a first cleaning solution to perform a first cleaning process to remove said interfacial carbon on or near a surface of the device structure, the first cleaning solution consisting of hot phosphoric acid (H₃PO₄);

using a second cleaning solution to perform a second cleaning process to remove residual first cleaning solution on the surface of the device structure, the second cleaning solution being DI water; and

spin-drying the semiconductor wafer.

2. The method of claim 1 wherein the semiconductor wafer is placed into a dry strip chamber to remove the photoresist layer on the device structure on the semiconductor wafer before performing the first and second cleaning processes.

3. The method of claim 2 wherein the dry stripping process is an ashing process using a plasma comprising oxygen or ozone to remove the photoresist layer on the device structure on the semiconductor wafer.

4. The method of claim 1 wherein the semiconductor wafer is placed on a rotator of a wet clean chamber to rotate the semiconductor wafer during the first and second cleaning processes.

5. The method of claim 1 wherein the first cleaning process utilizes a horizontal rotational rate of the semiconductor wafer that ranges from about 50 to about 2500 rpm, and has an approximate duration ranging from about 2 to about 20 minutes.

6. The method of claim 1 wherein the second cleaning process utilizes a horizontal rotational rate of the semiconductor wafer that ranges from about 50 to about 2500 rpm, and has an approximate duration ranging from about 20 to about 300 seconds.

7. The method of claim 1 wherein a horizontal rotational rate of the semiconductor wafer in the spin-drying process ranges from about 2000 to about 2500 rpm, and a duration of the spin-drying process ranges from about 10 to about 20 seconds.

8. The method of claim 1 wherein the wet cleaning chamber comprises a plurality of nozzles to spray the first and second solutions onto the surface of device structure on the semiconductor wafer in the first and second cleaning processes, respectively.

9. A method of removing a photoresist layer on a device structure formed on a semiconductor wafer, the method comprising:

performing a dry stripping process to remove the photoresist layer on the device structure;

horizontally rotating the semiconductor wafer and performing a wet cleaning process on the device structure, the wet cleaning process comprising;

using a first cleaning solution to perform a first cleaning process to remove particles on the surface of the device structure, the first cleaning solution consisting of hot phosphoric acid (H₃PO₄); and

using a second cleaning solution to perform a second cleaning process to remove the first cleaning solution employed in the first cleaning process, the second cleaning solution being DI water, and

spin-drying the semiconductor wafer.

10. The method of claim 9 wherein the dry stripping process is an ashing process.

11. The method of claim 10 wherein the ashing process uses a plasma comprising oxygen or ozone to remove the photoresist layer on the device structure on the semiconductor wafer.

12. The method of claim 9 wherein the first cleaning process utilizes a horizontal rotational rate of the semiconductor wafer that ranges from about 50 to about 2500 rpm and has an approximate duration ranging from about 2 to about 20 minutes.

13. The method of claim 9 wherein a horizontal rotational rate of the semiconductor in the second cleaning process ranges from about 50 to about 2500 rpm, and a duration of the second cleaning process ranges from about 20 to about 300 seconds.

14. The method of claim 9 wherein a horizontal rotational rate of the semiconductor wafer in the spin-drying process ranges from about 2000 to about 2500 rpm, and a duration of the spin-drying process ranges from about 10 to about 20 seconds.

15. A method of processing a wafer, the method comprising:

providing a wafer having a device structure with a polysilicon surface layer covered by amorphous carbon, thereby contaminating the polysilicon surface layer with interfacial carbon;

dry stripping the polysilicon surface layer;

washing the wafer with a solution consisting of hot phosphoric acid (H₃PO₄); and

rinsing the wafer.

16. The method of claim 15 wherein the washing of the wafer has a duration in the range from about 2 to about 20 minutes.

17. The method of claim 15 wherein the washing of the wafer comprises heating the solution of hot phosphoric acid (H₃PO₄) to a temperature in the range from about 160°

C. to about 180°

C.

18. The method of claim 15, wherein the rinsing of the wafer comprises wetting the wafer with deionized water.

19. The method of claim 15 wherein the rinsing of the wafer comprises immersing the wafer in a cascade overflow of a deionized water and ozone solution.

20. The method of claim 15 wherein the washing comprises immersing the wafer in a bath of the hot phosphoric acid for about 8 to about 12 minutes, said bath of hot phosphoric acid having a temperature of between about 160°

C. to about 180°

C.

21. A method of manufacturing an electronic device, in which a device structure formed on a substrate is placed inside a process chamber and a surface of the substrate is subjected to a treatment comprising:

performing a dry stripping process to remove a mask layer on the device structure formed on the substrate;

horizontally rotating the substrate and performing a wet cleaning process on the device structure formed on the substrate, the wet cleaning process comprising;

using a first cleaning solution to perform a first cleaning process to remove particles on the surface of the device structure, the first cleaning solution consisting of hot phosphoric acid (H₃PO₄);

using a second cleaning solution to perform a second cleaning process to remove a first cleaning solution employed in the first cleaning process, the second cleaning solution being DI water;

using a third cleaning solution to perform an optional third cleaning process to remove particles on the surface of the semiconductor wafer; and

using a fourth cleaning solution to perform an optional fourth cleaning process to remove a residual third cleaning solution employed in the third cleaning process if the optional third cleaning process is performed, the fourth cleaning solution being DI water; and

spin-drying the device structure.

22. The method as claimed in claim 21, wherein the first, second, third, and fourth cleaning solutions are provided onto the surface of the substrate by spraying the cleaning solutions from at least one nozzle onto the surface of the device structure.

23. The method as claimed in claim 21, wherein at least the first cleaning solution is heated.

24. The method of claim 21 wherein a horizontal rotational rate of the semiconductor wafer in the third cleaning process ranges from about 500 to about 2500 rpm, and a duration of the third cleaning process ranges from about 5 to about 40 seconds.

25. The method of claim 21 wherein a horizontal rotational rate of the semiconductor wafer in the fourth cleaning process ranges from about 500 to about 2500 rpm, and a duration of the fourth cleaning process ranges from about 5 to about 40 seconds.

26. The method of claim 21 wherein a horizontal rotational rate of the semiconductor wafer in the spin-drying process ranges from about 2000 to about 2500 rpm, and a duration of the spin-drying process ranges from about 10 to about 20 seconds.

27. The method of claim 21 wherein the third cleaning solution is a standard cleaning solution (SC-1).

28. The method of claim 21 wherein the third cleaning solution is a 5:

1;

1 solution of water, hydrogen peroxide (H₂O₂), and ammonium hydroxide (NH₄OH).