US5650015A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dry method for cleaning semiconductor substrate
Assignee: Taiyo Nippon Sanso Corp
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Filing: 1995-07-20
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Granted: 1997-07-22
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Expires: 2015-07-20
Abstract
Abstract A method is presented for cleaning of metallic surface contaminants from the surfaces of semiconductor substrate in semiconductor device manufacturing. The method is a dry method and avoids many of the problems introduced by the conventional wet method of cleaning while achieving a level of cleanliness better than the wet method. The method involves halogenizing the contaminants by exposing the wafers to a gas containing a halogen gas to form halogenized compounds of the contaminants. This is followed by a process of exposing the halogenized compounds to a gas containing beta -diketone so as to convert the halogenized compounds to beta -diketone complexes to enable highly efficient removal of the metallic surface contaminants by vaporization.
Inventors
- 👤 Ichizo Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:32
CPC Classifications
H; H10; H10P; H10P52/00; H10P70/00; H10P70/10; H10P70/12; C; C23; C23F; C23F1/00; C23F1/10; C23F1/12
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
143 words
A method for dry removal of metallic surface contaminants from surfaces of semiconductor substrate, comprising the steps of: halogenizing said metallic surface contaminants by exposing the surfaces to a gas consisting essentially of a gaseous halogen so as to form halogen compounds of said metallic surface contaminants, whereby only said metallic surface contaminants are halogenized in-situ without damaging said semiconductor substrate due to effects of chemical etching and other side reactions; and exposing the surfaces having halogenized metallic surface contaminants to a gas containing β-diketone so as to form β-diketone complexes incorporating metals of said metallic surface contaminants and remove said β-diketone complexes from the surfaces by vaporization, residual metallic impurity level on said semiconductor substrate after exposure being on the order of 10 10 atoms/cm 2 , wherein said halogenizing and exposing are performed at temperatures within the range of 150°˜350° C.
Claim 2
Independent Claim
143 words
A method for dry removal of metallic surface contaminants from surfaces of semiconductor substrate, comprising the steps of: halogenizing said metallic surface contaminants by exposing the surfaces to a gas consisting essentially of a gaseous halogen so as to form halogen compounds of said metallic surface contaminants, whereby only said metallic surface contaminants are halogenized in-situ without damaging said semiconductor substrate due to effects of chemical etching and other side reactions; and exposing the surfaces having halogenized metallic surface contaminants to a gas containing β-diketone so as to form β-diketone complexes incorporating metals of said metallic surface contaminants and remove said β-diketone complexes from the surfaces by vaporization, residual metallic impurity level on said semiconductor substrate after exposure being on the order of 10 10 atoms/cm 2 , wherein said halogenizing and exposing are performed at temperatures within the range of 150°˜350° C.
Claim 3
Dependent Claim
20 words
A method as claimed in claim 1, wherein said β-diketone is selected from a group consisting of acetylacetone and dipivaloylmethane.
Claim 4
Dependent Claim
14 words
A method as claimed in claim 1, wherein said gaseous halogen is gaseous chlorine.
Claim 5
Dependent Claim
30 words
A method as claimed in claim 1, wherein said metallic surface contaminants comprise at least one metal selected from the group consisting of Na, Fe, Al, Cu, Cr and Ni.
Claim 6
Dependent Claim
28 words
A method as claimed in claim 4, wherein residual metallic impurity level on the semiconductor substrate after exposure is on the order of 10 10 atoms/cm 2 .
Claim 7
Dependent Claim
16 words
A method as claimed in claim 1, wherein said gaseous halogen is gaseous fluorine or bromine.
Claim 8
Dependent Claim
21 words
A method as claimed in claim 1 wherein said halogenizing and exposing are performed at a temperature of about 200° C.
Claim 9
Dependent Claim
21 words
A method as claimed in claim 3, wherein said halogenizing and exposing are performed at a temperature of about 180° C.
Claim 10
Dependent Claim
21 words
A method as claimed in claim 6, wherein said halogenizing and exposing are performed at a temperature of about 230° C.
Claim 11
Dependent Claim
21 words
A method as claimed in claim 1, wherein said halogenizing and exposing are performed at a pressure of about 760 Torr.
Claim 12
Dependent Claim
26 words
A method as claimed in claim 1, wherein said gases consisting essentially of said gaseous halogen and containing said β-diketone each include an inert carrier gas.
Claim 13
Dependent Claim
16 words
A method as claimed in claim 11, wherein said inert carrier gas is argon or helium.
Claim 14
Dependent Claim
29 words
A method as claimed in claim 11, additionally comprising the step of bubbling said inert carrier gas through a bottle containing liquid β-diketone to form said gas containing β-diketone.
Claim 15
Dependent Claim
28 words
A method as claimed in claim 1, wherein said gas consisting essentially of gaseous halogen also includes at least one of an inert carrier gas and said β-diketone.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-07-21 | 2001-01-20 | 2001-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-07-21 | 2005-01-20 | 2005-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-07-21 | 2009-01-20 | 2009-07-22 | $7700.00 | Window Closed / Lapsed |