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
•
Filing: 1998-05-22
•
Granted: 2000-01-18
•
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 03:09
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.
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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 |