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US6284580B1
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Method for manufacturing a MOS transistor having multi-layered gate oxide
Assignee: Lapis Semiconductor Co Ltd
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Filing: 2000-06-09
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Granted: 2001-09-04
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Expires: 2020-06-09
Abstract
Abstract In a pretreatment process, a silicon oxide film ( 13 ) with nitrogen content is formed on a semiconductor substrate ( 10 ). In a segregation process executing heat treatment in an inert gas atmosphere, a silicon nitride layer ( 14 ) segregates out at the interface of the silicon substrate ( 10 ) and the silicon oxide film ( 13 ). In a high dielectric film forming process, the unnecessary silicon oxide film ( 13 ) on the silicon nitride layer ( 14 ) is removed, a high dielectric oxide layer ( 15 ) is formed on the exposed silicon nitride layer ( 14 ). Whereby, a gate electrode ( 16 ) consisting of the silicon nitride layer ( 14 ) and the high dielectric oxide layer ( 15 ) is formed.
Inventors
- 👤 Shinobu Takehiro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:00
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/0134; H10D64/01344; H10D64/60; H10D64/66; H10D64/68; H10D64/681; H10D64/685; H10D64/691; H10D64/693; H10D64/01342
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
170 words
A method for manufacturing a MOS transistor having a gate oxide film formed on an active region of a silicon semiconductor substrate, said gate oxide film consisting of a silicon nitride layer for inhibiting the penetration of oxygen into the silicon substrate and a high dielectric oxide layer with higher dielectric constant than the dielectric constant of said silicon nitride layer, comprising the steps of: pretreatment for forming a silicon oxide film with nitrogen atoms on said active region; segregation for causing a silicon nitride layer to segregate out at an interface between said silicon substrate and said silicon oxide film by heat-treating the pretreated silicon substrate in an inert gas atmosphere; forming a high dielectric film by removing the unnecessary silicon oxide film on the silicon nitride layer to expose a segregated silicon nitride layer and depositing a high dielectric oxide layer on the exposed silicon nitride layer; and forming a gate on said gate oxide film consisting of said silicon nitride layer and said high dielectric oxide layer.
Claim 2
Independent Claim
170 words
A method for manufacturing a MOS transistor having a gate oxide film formed on an active region of a silicon semiconductor substrate, said gate oxide film consisting of a silicon nitride layer for inhibiting the penetration of oxygen into the silicon substrate and a high dielectric oxide layer with higher dielectric constant than the dielectric constant of said silicon nitride layer, comprising the steps of: pretreatment for forming a silicon oxide film with nitrogen atoms on said active region; segregation for causing a silicon nitride layer to segregate out at an interface between said silicon substrate and said silicon oxide film by heat-treating the pretreated silicon substrate in an inert gas atmosphere; forming a high dielectric film by removing the unnecessary silicon oxide film on the silicon nitride layer to expose a segregated silicon nitride layer and depositing a high dielectric oxide layer on the exposed silicon nitride layer; and forming a gate on said gate oxide film consisting of said silicon nitride layer and said high dielectric oxide layer.
Claim 3
Dependent Claim
24 words
A method set forth in claim 1 , wherein the formation of said high dielectric oxide layer is done in an oxygen gas atmosphere.
Claim 4
Dependent Claim
25 words
A method set forth in claim 1 , wherein said pretreatment step is to carry out an annealing process in an atmosphere of nitrogen oxide.
Claim 5
Dependent Claim
36 words
A method set forth in claim 1 , wherein said pretreatment step comprises the steps of nitrogen ion implantation for introducing nitrogen content into said active region, and heat treatment for forming said silicon oxide film.
Claim 6
Dependent Claim
20 words
A method set forth in claim 1 , wherein said segregation step comprises an annealing process by rapid thermal annealing.
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) | 2004-09-03 | 2005-03-05 | 2005-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-09-03 | 2009-03-05 | 2009-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-09-03 | 2013-03-05 | 2013-09-04 | $7700.00 | Window Closed / Lapsed |