US5399520A
Expired / Lapsed
US
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Method for the formation of field oxide film in semiconductor device
Assignee: SK Hynix Inc
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Filing: 1994-03-30
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Granted: 1995-03-21
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Expires: 2014-03-30
Abstract
Abstract There are disclosed methods for the formation of field oxide film in a semiconductor device. By the methods, a field oxide film which plays a role of insulation for the separation of device, is formed in a trench formed in a semiconductor substrate. In the methods, an oxide-nitride film is utilized as an oxidation protective film which prevents a pad oxide film and the side well of the trench from being oxidized. As a result, the bird's beak is reduced, which allows to secure the active region more large. In addition, the methods make the field oxide film smooth. Furthermore, increasing the threshold voltage of a field, the field oxide film is superior in punchthrough characteristics. Accordingly, the methods can be applied to fabricate highly integrated semiconductor devices.
Inventors
- 👤 Se A. Jang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:49
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/61; H10P50/00; H10P50/20; H10P50/28; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/012; H10W10/0121; H10W10/10; H10W10/13; Y; Y10; Y10S; Y10S148/00; Y10S148/05
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
192 words
A method for the formation of field oxide film in a semiconductor device, comprising the steps of: covering a semiconductor substrate with a pad oxide film; annealing said pad oxide film, so as to form a first oxide-nitride film; overlaying said first oxide-nitride film with a polysilicon film and a first nitride film, in due order; etching said first nitride film and said polysilicon film to form a hole exposing a predetermined portion of said first oxide-nitride film, and depositing a second nitride film entirely over the resulting structure; subjecting said second nitride film to etch back, so as to form a spacer nitride film at either side wall of said hole, and applying an etch process to said predetermined portion, so as to form a trench in said semiconductor substrate, said spacer nitride film and said first nitride film serving as an etch mask; annealing said trench to grow a second oxide-nitride film from both the bottom and the side wall of said trench; and removing only the second oxide-nitride film formed on the bottom of said trench by use of etching, and forming a field oxide film in said trench.
Claim 2
Independent Claim
192 words
A method for the formation of field oxide film in a semiconductor device, comprising the steps of: covering a semiconductor substrate with a pad oxide film; annealing said pad oxide film, so as to form a first oxide-nitride film; overlaying said first oxide-nitride film with a polysilicon film and a first nitride film, in due order; etching said first nitride film and said polysilicon film to form a hole exposing a predetermined portion of said first oxide-nitride film, and depositing a second nitride film entirely over the resulting structure; subjecting said second nitride film to etch back, so as to form a spacer nitride film at either side wall of said hole, and applying an etch process to said predetermined portion, so as to form a trench in said semiconductor substrate, said spacer nitride film and said first nitride film serving as an etch mask; annealing said trench to grow a second oxide-nitride film from both the bottom and the side wall of said trench; and removing only the second oxide-nitride film formed on the bottom of said trench by use of etching, and forming a field oxide film in said trench.
Claim 3
Dependent Claim
24 words
A method according to claim 1, wherein said pad oxide film formed on said semiconductor substrate is approximately 50 to approximately 200 Å thick.
Claim 4
Dependent Claim
44 words
A method according to claim 1, wherein each of said first oxide-nitride film and said second oxide-nitride film is formed in thicknesses ranging from approximately 50 to approximately 100 Å in an atmosphere of ammonia (NH 3 ) or nitrous oxide (N 2 O).
Claim 5
Dependent Claim
21 words
A method according to claim 1, wherein said trench is formed in depths ranging from approximately 500 to approximately 1,000 Å.
Claim 6
Independent Claim
177 words
A method for the formation of field oxide film in a semiconductor device, comprising the steps of: forming a pad oxide film, a polysilicon film and a first nitride film on a semiconductor substrate, in due order; etching said first nitride film and said polysilicon film, to form a hole exposing a predetermined portion of said pad oxide film covering said semiconductor substrate, and depositing a second nitride film entirely over the resulting structure; subjecting said second nitride film to etch back, so as to form a spacer nitride film at either side wall of said hole, and applying an etch process to said predetermined portion, so as to form a trench in said semiconductor substrate, said spacer nitride film and said first nitride film serving as an etch mask; annealing said trench to grow a second oxide-nitride film from both the bottom and the side wall of said trench; and removing only the second oxide-nitride film formed on the bottom of said trench by use of etching, and forming a field oxide film in said trench.
Claim 7
Independent Claim
177 words
A method for the formation of field oxide film in a semiconductor device, comprising the steps of: forming a pad oxide film, a polysilicon film and a first nitride film on a semiconductor substrate, in due order; etching said first nitride film and said polysilicon film, to form a hole exposing a predetermined portion of said pad oxide film covering said semiconductor substrate, and depositing a second nitride film entirely over the resulting structure; subjecting said second nitride film to etch back, so as to form a spacer nitride film at either side wall of said hole, and applying an etch process to said predetermined portion, so as to form a trench in said semiconductor substrate, said spacer nitride film and said first nitride film serving as an etch mask; annealing said trench to grow a second oxide-nitride film from both the bottom and the side wall of said trench; and removing only the second oxide-nitride film formed on the bottom of said trench by use of etching, and forming a field oxide film in said trench.
Claim 8
Dependent Claim
23 words
A method according to claim 5, wherein said pad oxide film is formed in thicknesses ranging from approximately 50 to approximately 200 Å.
Claim 9
Dependent Claim
22 words
A method according to claim 5, wherein said trench formed in said semiconductor device is approximately 500 to approximately 1,000 Å deep.
Claim 10
Dependent Claim
36 words
A method according to claim 5, wherein said oxide-nitride film is formed in thicknesses ranging from approximately 50 to approximately 100 Å in an atmosphere of ammonia (NH 3 ) or nitrous oxide (N 2 O).
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