IP Library Granted Patent US 8,741,066
Granted Patent B2
US 8,741,066 · App. 12/070,620 · Granted Jun 3, 2014

Method for cleaning substrates utilizing surface passivation and/or oxide layer growth to protect from pitting

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Quick Facts
Patent No.
US 8,741,066
App. No.
12/070,620
Granted
Jun 3, 2014
Kind
B2
Abstract

A process/method for cleaning wafers that eliminates and/or reduces pitting caused by standard clean 1 by performing a pre-etch and then passivating the wafer surface prior to the application of the standard clean 1. The process/method may be especially useful for advanced front end of line post-CPM cleaning. In one embodiment, the invention is a method of processing a substrate comprising: a) providing at least one substrate; b) etching a surface of the substrate by applying an etching solution; c) passivating the etched surface of the substrate by applying ozone; and d) cleaning the passivated surface of the substrate by applying an aqueous solution comprising ammonium hydroxide and hydrogen peroxide.

Claims (32)

1. A method of processing a substrate comprising:

a) providing at least one substrate;

b)performing a chemical mechanical polish to the substrate;

c) etching a surface of the substrate by applying an aqueous etching solution comprising hydroflouric acid and hydrochloric acid;

d) passivating the etched surface of the substrate by applying ozone subsequent to step c) and prior to step e); and

e) cleaning the passivated surface of the substrate by applying an aqueous solution comprising ammonium hydroxide and hydrogen peroxide.

2. The method of claim 1 further comprising:

f) etching the cleaned surface of the substrate;

g) passivating the etched surface of the substrate b applying ozone; and

h) drying the passivated surface of the substrate.

3. The method of claim 2 further comprising:

rinsing the etched surface of the substrate subsequent to step c) but prior to step e);

rinsing the cleaned surface of the substrate subsequent to step e) but prior to step f) while applying megasonic energy; and

rinsing the etched surface of the substrate subsequent to step e) but prior to step h).

4. The method of claim 1 wherein the aqueous solution applied in step e) is standard-clean 1 (SC1) having a ratio of ammonium hydroxide to hydrogen peroxide to water of about 1:2:30.

5. The method of claim 1 wherein step e) comprises applying megasonic energy during the application of the aqueous solution.

6. The method of claim 1 wherein step d) is accomplished by applying ozone gas to the surface of the substrate or applying an ozonated liquid to the surface of the substrate.

7. The method of claim 1 wherein the aqueous solution comprising hydroflouric acid and hydrochloric acid has a ratio of hydroflouric acid to hydrochloric acid to water of about 1:2:200.

8. The method of claim 1 wherein step c) is performed for 4-6 minutes, step d) is performed for 7-9 minutes, and step e) is performed for 9-11 minutes.

9. The method of claim 1 wherein step d) is accomplished by applying an ozonated deionized water to the surface of the substrate at an ambient temperature, and wherein the etching solution of step c) is applied at a temperature of 22-26 degrees Celsius, and wherein the aqueous solution of step e) is applied at a temperature of 60-70 degrees Celsius.

10. The method of claim 1 wherein steps c) through e) are carried out as a batch immersion process or as a single-substrate non-immersion process.

11. A post-CMP semiconductor wafer cleaning method comprising:

a) performing a chemical mechanical polish to at least one surface of at least one semiconductor wafer;

b) etching the surface of the wafer by applying an etching solution comprising hydroflouric acid and hydrochloric acid;

c) rinsing the etched surface of the wafer;

d) passivating the rinsed surface of the wafer by applying ozonated deionized water, wherein step d) is performed subsequent to step c) and prior to step e);

e) cleaning the passivated surface of the wafer by applying: a standard-clean 1 solution while applying megasonic energy;

f) rinsing the cleaned surface of the wafer while applying megasonic energy;

g) etching the rinsed surface of the wafer by applying an etching solution;

h) passivating the rinsed surface of the wafer by applying ozonated deionized water; and

i) drying the rinsed surface of the wafer;

wherein step b) is performed subsequent to step a).

Assignments (15)
CHANGE OF NAME Recorded May 26, 2022
From: NAURA AKRION INC.
To: AKRION TECHNOLOGIES INC.
Reel/Frame 060201/0991 →
TERMINATION AND RELEASE OF TRADEMARK AND PATENT SECURITY AGREEMENT RECORDED AT REEL 21744/FRAME 0209 AND REEL 21731/FRAME 0608 Recorded Jan 19, 2018
From: PNC BANK, NATIONAL ASSOCIATION
To: WAFER HOLDINGS, INC.
Reel/Frame 045097/0070 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 19, 2018
From: AKRION SYSTEMS LLC
To: NAURA AKRION INC.
Reel/Frame 045097/0140 →
TERMINATION AND RELEASE OF TRADEMARK AND PATENT SECURITY AGREEMENT RECORDED AT REEL 23220/FRAME 0423 Recorded Jan 19, 2018
From: BHC INTERIM FUNDING II, L.P.
To: AKRION SYSTEMS LLC
Reel/Frame 045102/0189 →
TERMINATION AND RELEASE OF TRADEMARK AND PATENT SECURITY AGREEMENT RECORDED AT REEL 22973/FRAME 0811 Recorded Jan 19, 2018
From: PNC BANK, NATIONAL ASSOCIATION
To: AKRION SYSTEMS LLC
Reel/Frame 045102/0288 →
TERMINATION AND RELEASE OF TRADEMARK AND PATENT SECURITY AGREEMENT RECORDED AT REEL 021731/FRAME 0718 Recorded Jan 19, 2018
From: BHC INTERIM FUNDING II, L.P.
To: WAFER HOLDINGS, INC.
Reel/Frame 045103/0624 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 1, 2012
From: KASHKOUSH, ISMAIL; NOLAN, THOMAS; NEMETH, DENNIS; NOVAK, RICHARD
To: AKRION SYSTEMS, LLC
Reel/Frame 029223/0624 →
SECURITY AGREEMENT Recorded Sep 14, 2009
From: AKRION SYSTEMS LLC
To: BHC INTERIM FUNDING II, L.P.
Reel/Frame 023220/0423 →
SECURITY AGREEMENT Recorded Jul 20, 2009
From: AKRION SYSTEMS, LLC
To: PNC BANK, NATIONAL ASSOCIATION
Reel/Frame 022973/0811 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 17, 2009
From: WAFER HOLDINGS, INC.; AKRION TECHNOLOGIES, INC.
To: AKRION SYSTEMS LLC
Reel/Frame 022824/0970 →
SECURITY AGREEMENT Recorded Oct 27, 2008
From: WAFER HOLDINGS, INC.
To: PNC BANK, NATIONAL ASSOCIATION
Reel/Frame 021731/0608 →
SECURITY AGREEMENT Recorded Oct 27, 2008
From: WAFER HOLDINGS, INC.
To: BHC INTERIM FUNDING II, L.P.
Reel/Frame 021731/0718 →
SECURITY AGREEMENT Recorded Oct 27, 2008
From: WAFER HOLDINGS, INC.
To: PNC BANK, NATIONAL ASSOCIATION
Reel/Frame 021744/0209 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 10, 2008
From: PNC BANK, NATIONAL ASSOCIATION; BHC INTERIM FUNDING II, L.P.; AKRION, INC.; GOLDFINGER TECHNOLOGIES, LLC; AKRION TECHNOLOGIES, INC.; SCP SERVICES, INC. (F/K/A AKRION SCP ACQUISITION CORP.)
To: WAFER HOLDINGS, INC.
Reel/Frame 021658/0928 →
SECURITY AGREEMENT Recorded Sep 1, 2008
From: AKRION TECHNOLOGIES, INC.
To: SUNRISE CAPITAL PARTNERS, L.P.
Reel/Frame 021462/0283 →