Patent US6015477A successfully refreshed from Google Patents.
US6015477A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Point-of-use ammonia purification for electronic component manufacture
Assignee: LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
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Filing: 1998-05-22
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Granted: 2000-01-18
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Expires: 2018-05-22
Abstract
Abstract Highly purified ammonia for use in processes for the production of high-precision electronic components is prepared on-site by drawing ammonia vapor from a liquid ammonia reservoir, passing the vapor through a filter capable of filtering out particles of less than 0.005 micron in size, and scrubbing the filtered vapor in a high-pH aqueous scrubber.
Inventors
- 👤 Joe G. Hoffman
- 👤 R. Scot Clark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:16
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/04; H10P72/0402; H10P72/0404; C; C01; C01B; C01B7/00; C01B7/01; C01B7/07; C01B7/0706; C01B7/0712; C01B7/0731; C01B7/19; C01B7/191; C01B7/195; C01B7/196; C01B7/197; C01B7/198; C01C; C01C1/00; C01C1/02; C01C1/024; C01C1/16; C01C1/162; Y; Y10; Y10S; Y10S203/00; Y10S203/17
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
59 words
A method for the preparation of ultra-high-purity ammonia, said method comprising: (a) drawing ammonia gas from a vapor space above liquid ammonia in an ammonia-containing reservoir; (b) passing said ammonia gas through a scrubber whereby said ammonia gas is contacted with an aqueous solution of ammonia in deionized water; and (c) recovering said ammonia gas emerging from said scrubber.
Claim 2
Independent Claim
59 words
A method for the preparation of ultra-high-purity ammonia, said method comprising: (a) drawing ammonia gas from a vapor space above liquid ammonia in an ammonia-containing reservoir; (b) passing said ammonia gas through a scrubber whereby said ammonia gas is contacted with an aqueous solution of ammonia in deionized water; and (c) recovering said ammonia gas emerging from said scrubber.
Claim 3
Dependent Claim
20 words
The method according to claim 1, further comprising purifying the ammonia gas in a distillation unit downstream from said scrubber.
Claim 4
Dependent Claim
19 words
The method according to claim 1, further comprising introducing the recovered ammonia gas into a chemical vapor deposition system.
Claim 5
Dependent Claim
20 words
The method according to claim 3, further comprising purifying the ammonia gas in a distillation unit downstream from said scrubber.
Claim 6
Dependent Claim
24 words
The method according to claim 4, further comprising dehydrating the ammonia gas emerging from said scrubber prior to said purification in said distillation unit.
Claim 7
Dependent Claim
24 words
The method according to claim 4, further comprising dissolving said ammonia gas emerging from said scrubber in purified water to form an aqueous solution.
Claim 8
Dependent Claim
16 words
The method according to claim 6, further comprising combining said aqueous solution with aqueous hydrogen peroxide.
Claim 9
Dependent Claim
22 words
The method according to claim 1, further comprising bubbling said ammonia gas emerging from said scrubber into an aqueous hydrogen peroxide solution.
Claim 10
Dependent Claim
21 words
The method according to claim 1, wherein the ammonia produced has less than 100 parts per trillion of any metallic impurity.
Claim 11
Dependent Claim
24 words
The method according to claim 1, further comprising directly applying the ammonia or an aqueous solution formed from the ammonia to a semiconductor substrate.
References Cited (Backward Citations)
DE268230C
Cited
GB830188A
Cited
US3383173A
Cited
US3679549A
Cited
US3745748A
Cited
US3869313A
Cited
US4075306A
Cited
US4287162A
Cited
US4917123A
Cited
US4899767A
Cited
US4645516A
Cited
US4778532A
Cited
JPS6259522A
Cited
US4953694A
Cited
JPS62213127A
Cited
US4940134A
Cited
JPS62253772A
Cited
JPS62264280A
Cited
US5164049A
Cited
US4828660A
Cited
US4855023A
Cited
JPS63152603A
Cited
US4892625A
Cited
US4756899A
Cited
US4929435A
Cited
JPS63283027A
Cited
JPS6476420A
Cited
US4929312A
Cited
US4952386A
Cited
US4980032A
Cited
US5288333A
Cited
US5512142A
Cited
US5445714A
Cited
US4985228A
Cited
WO1992016306A2
Cited
US5242468A
Cited
US5346557A
Cited
US5362469A
Cited
US5500098A
Cited
US5496778A
Cited
US5755934A
Cited
US5558688A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-01-17 | 2003-07-19 | 2004-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-01-17 | 2007-07-19 | 2008-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-01-17 | 2011-07-19 | 2012-01-18 | $7700.00 | Window Closed / Lapsed |