EP0276774A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Composition for use in the processing of semiconductor materials and method for its preparation and use
Assignee: Micro Image Technology Ltd
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Filing: 1988-01-22
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Granted: —
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Expires: 2008-01-22
Abstract
Abstract A storable semiconductor cleaning solution consists essentially of sulphuric acid at a concentration of from 30% to 70% and hydrogen peroxide at a concentration of from 1% to 20% preferably also containing a pentavalent phosphorus sequestrant and tin ions. The solution is produced by diluting concentrated sulphuric acid, ageing the diluted acid until it reaches a temperature below 30°C and introducing the hydrogen peroxide, preferably having a concentration of at least 70% by weight, into the aged acid and equilibrating the resulting solution. The cleaning solutions can be stored for an extended period at ambient temperature and can be used to clean semiconductors, and with suitable precautions aluminised semiconductors, at temperatures below 100°C.
Inventors
- 👤 David John Lapham
- 👤 Geoffrey Hitchmough
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 03:14
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/20; H10P70/10; H10P70/15; C; C11; C11D; C11D2111/00; C11D2111/10; C11D2111/14; C11D2111/22; Y; Y10; Y10S; Y10S438/00; Y10S438/906
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
29 words
A storable semiconductor cleaning solution consisting essentially of water, sulphuric acid at from 30% to 70% concentration by weight and hydrogen peroxide at from 1% to 20% by weight.
Claim 2
Dependent Claim
29 words
A storable semiconductor cleaning solution consisting essentially of water, sulphuric acid at from 30% to 70% concentration by weight and hydrogen peroxide at from 1% to 20% by weight.
Claim 3
Dependent Claim
23 words
A cleaning solution as claimed in claim 1 wherein the sulphuric acid is at a concentration of not more than 65% by weight.
Claim 4
Dependent Claim
25 words
A cleaning solution as claimed in claim 1 or 2 wherein the hydrogen peroxide is at a concentration of not more than 17% by weight.
Claim 5
Dependent Claim
13 words
A cleaning solution as claimed in any preceding claim also containing a sequestrant.
Claim 6
Dependent Claim
15 words
A cleaning solution as claimed in claim 4 containing at least 0.1% of the sequestrant.
Claim 7
Dependent Claim
18 words
A cleaning solution as claimed in claim 4 or 5 wherein the sequestrant is a pentavalent phosphorus compound.
Claim 8
Dependent Claim
13 words
A cleaning solution as claimed in any preceding claim also containing tin ions.
Claim 9
Dependent Claim
23 words
A cleaning solution as claimed in claim 7 containing at least 0.02 ppm by weight of a soluble tin compound expressed as Sn.
Claim 10
Dependent Claim
23 words
A cleaning solution as claimed in any preceding claim containing not more than 0.2 ppm of a soluble tin compound expressed as Sn.
Claim 11
Dependent Claim
18 words
A cleaning solution as claimed in any preceding claim containing less than 0.5 wt % of the sequestrant.
Claim 12
Dependent Claim
56 words
A process for the production of a cleaning solution as claimed in any preceding claim comprising diluting sulphuric acid by the addition of water, ageing the diluted acid until its temperature has dropped to below 30°C, introducing the hydrogen peroxide into the aged sulphuric acid while maintaining its temperature below 30°C, and equilibrating the resulting solution.
Claim 13
Dependent Claim
25 words
a process as claimed in claim 11 wherein the concentration of the hydrogen peroxide added to the diluted acid is at least 30% by weight.
Claim 14
Dependent Claim
25 words
A process as claimed in claim 11 wherein the concentration of the hydrogen peroxide added to the diluted acid is at least 65% by weight.
Claim 15
Dependent Claim
21 words
A process as claimed in claim 11 wherein the diluted acid has a concentration of not more than 80% by weight.
Claim 16
Independent Claim
23 words
A method of cleaning a semiconductor comprising contacting it with a cleaning solution as claimed in any one of claims 1 to 10.
Claim 17
Independent Claim
26 words
A method of cleaning a semiconductor comprising contacting it with a cleaning solution produced by the process claimed in any one of claims 11 to 14.
Claim 18
Dependent Claim
23 words
A method as claimed in claim 15 or 16 wherein the cleaning solution has a temperature of from ambient temperature to below 100°C.
References Cited (Backward Citations)
No citation records indexed.
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