EP0421315A2
Expired / Lapsed
EP
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Method for selectively removing an insulating film
Assignee: Dainippon Screen Manufacturing Co Ltd
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Filing: 1990-10-01
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Granted: —
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Expires: 2010-10-01
Abstract
Abstract A method for selectively removing a desired insulating film from a wafer surface. The method includes the steps of: preparing vapor containing hydrogen fluoride and water; keeping a temperature of the wafer surface higher than a temperature of the vapor by a prescribed range; and supplying the vapor to the wafer surface. Due to the difference in responsiveness caused by the temperature difference of the range, only the desired film, for example, the native silicon oxide film formed on the silicon layer surface is selectively etched and removed by the hydrogen fluoride. It is not necessary to extremely reduce the water content in the reaction system or to accurately regulate the concentration of the hydrogen fluoride gas.
Inventors
- 👤 Masato Dainippon Screen Mfg. Co. Ltd. Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 09:41
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10P70/00; H10P70/20; H10P70/23
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
107 words
A method for selectively removing a first insulating film with respect to a second insulating film, said first and second insulating films being formed on a wafer surface, said method comprising the steps of: (a) preparing vapor containing hydrogen fluoride and water; (b) relatively keeping a temperature of said vapor higher than a temperature of said wafer surface by a prescribed range, said prescribed range being determined by said first insulating film and said second insulating film; and (c) applying said vapor to said wafer surface, whereby said first insulating film is selectively etched and removed with respect to said second insulating film by said hydrogen fluoride.
Claim 2
Independent Claim
107 words
A method for selectively removing a first insulating film with respect to a second insulating film, said first and second insulating films being formed on a wafer surface, said method comprising the steps of: (a) preparing vapor containing hydrogen fluoride and water; (b) relatively keeping a temperature of said vapor higher than a temperature of said wafer surface by a prescribed range, said prescribed range being determined by said first insulating film and said second insulating film; and (c) applying said vapor to said wafer surface, whereby said first insulating film is selectively etched and removed with respect to said second insulating film by said hydrogen fluoride.
Claim 3
Dependent Claim
39 words
The method in accordance with claim 1, wherein said first insulating film and said second insulating film are native silicon oxide film and thermal silicon dioxide film, respectively, and said prescribed range is from approximately 10°C to approximately 50°C.
Claim 4
Dependent Claim
38 words
The method in accordance with claim 1, wherein said first insulating film and thermal insulating film are CVD silicon dioxide film and thermal silicon dioxide film, respectively, and said prescribed range is from approximately 10°C to approximately 30°C.
Claim 5
Dependent Claim
37 words
The method in accordance with claim 1, wherein said first insulating film and said second insulating film are PSG film and thermal silicon dioxide film, respectively, and said prescribed range is from approximately 10°C to approximately 200°C.
Claim 6
Dependent Claim
37 words
The method in accordance with claim 1, wherein said first insulating film and said second insulating film are BPSG film and thermal silicon dioxide film, respectively, and said prescribed range is from approximately 10°C to approximately 150°C.
Claim 7
Dependent Claim
37 words
The method in accordance with claim 2, wherein said first insulating film and said second insulating film are PSG film and CVD silicon dioxide film, respectively, and said prescribed range is from approximately 15°C to approximately 200°C.
Claim 8
Dependent Claim
37 words
The method in accordance with claim 1, wherein said first insulating film and said second insulating film are BPSG film and CVD silicon dioxide film, respectively, and said prescribed range is from approximately 15°C to approximately 150°C.
Claim 9
Dependent Claim
39 words
The method in accordance with claim 1, wherein said first insulating film and said second insulating film are CVD silicon dioxide film and native silicon oxide film, respectively, and said prescribed range is from approximately 12°C to approximately 30°C.
Claim 10
Dependent Claim
37 words
The method in accordance with claim 1, wherein said first insulating film and said second insulating film are PSG film and native silicon oxide film, respectively, and said prescribed range is from approximately 12°C to approximately 200°C.
Claim 11
Dependent Claim
37 words
The method in accordance with claim 1, wherein said first insulating film and said second insulating film are BPSG film and native silicon oxide film, respectively, and said prescribed range is from approximately 12°C to approximately 150°C.
Claim 12
Dependent Claim
38 words
The method in accordance with claim 1, wherein said first insulating film and said second insulating film are SiN x film and thermal silicon dioxide film, respectively, and said prescribed range is from approximately 10°C to approximately 100°C.
Claim 13
Dependent Claim
36 words
The method in accordance with claim 1, wherein said first insulating film and said second insulating film are PSG film and SiN x film, respectively, and said prescribed range is from approximately 5°C to approximately 200°C.
Claim 14
Dependent Claim
36 words
The method in accordance with claim 1, wherein said first insulating film and said second insulating film are BPSG film and SiN x film, respectively, and said prescribed range is from approximately 5°C to approximately 150°C.
Claim 15
Dependent Claim
75 words
The method in accordance with claim 1, wherein said step (b) includes the steps of detecting the temperature of said vapor, detecting the temperature of said wafer surface, and changing the temperature of said vapor or the temperature of said wafer surface based on the detected temperature of said vapor and the detected temperature of said wafer surface to cause a temperature difference of said vapor and said wafer surface to be 15°C or more.
Claim 16
Dependent Claim
66 words
The method in accordance with claim 1, wherein said step (b) includes the steps of maintaining the temperature of said vapor at a predetermined constant temperature, detecting the temperature of said wafer surface, and maintaining the temperature of said silicon layer surface at a level higher than said constant temperature by 15°C or more, in response to the detection of the temperature of said wafer surface.
Claim 17
Dependent Claim
32 words
The method in accordance with claim 1, wherein said step (a) includes the steps of preparing hydrogen fluoride gas, preparing water vapor, and mixing said hydrogen fluoride gas and said water vapor.
Claim 18
Dependent Claim
29 words
The method in accordance with claim 1, wherein said step (a) includes the steps of preparing hydrogen fluoride aqueous solution, and heating and evaporating said hydrogen fluoride aqueous solution.
Claim 19
Dependent Claim
40 words
The method in accordance with claim 1 further comprising the step of placing a wafer having said wafer surface in a chamber isolated from external air, wherein said step (c) includes the step of introducing said vapor into said chamber.
Claim 20
Dependent Claim
34 words
The method in accordance with claim 18, further comprising the step of applying ultraviolet to said wafer surface of said wafer placed in said chamber, whereby organic impurities are removed from said wafer surface.
Claim 21
Dependent Claim
40 words
The method in accordance with claim 18, further comprising the step of purging said chamber by a gas inert to at least said chamber and said surface of said wafer, prior to the introduction of said vapor into said chamber.
Claim 22
Dependent Claim
47 words
The method in accordance with claim 18, wherein a part of said chamber is formed by quartz glass, said method further comprising the step of keeping a surface temperature of said quartz glass in said chamber higher than the temperature of said vapor by 20°C or more.
Claim 23
Dependent Claim
36 words
The method in accordance with claim 18, further comprising the step of purging said chamber by a gas inert to at least said chamber and said wafer after the introduction of said vapor into said chamber.
References Cited (Backward Citations)
No citation records indexed.
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