US5683933A
Expired / Lapsed
US
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Method of fabricating a semiconductor device
Assignee: Nippon Precision Circuits Inc
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Filing: 1996-06-17
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Granted: 1997-11-04
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Expires: 2016-06-17
Abstract
Abstract To minimize error in size and form a thick oxide layer as field insulating means in a narrow isolation region, a method of fabricating a semiconductor device is carried out as followings. A polysilicon layer 3 is formed on a silicon substrate 1. A silicon nitride layer 5 is then formed on the polysilicon layer 3. Thereafter, an aperture 7 is formed in the silicon nitride layer 5 and reaches the polysilicon layer. A silicon layer 9 is formed in the aperture 7 by epitaxial growth technique. The silicon layer 9 is selectively oxidized to form an oxide layer 10 as field insulating means. The silicon nitride layer 5 and a portion of the polysilicon layer 3 which was left unoxidized are removed. This makes it possible to form the desired thick oxide layer as field insulating means in a narrow region.
Inventors
- 👤 Tatsuya Seino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:44
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10W10/0142; H10W10/10; H10W10/17
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
199 words
A method of fabricating a semiconductor device which comprises the steps of: forming a first oxide layer on a top surface of a silicon substrate; forming a first polysilicon layer on a top surface of said first oxide layer; forming a second oxide layer on a top surface of said first polysilicon layer; forming a silicon nitride layer on a top surface of the second oxide layer; removing a selected portion of the silicon nitride layer and said second oxide layer so as to form an aperture, said aperture reaching said first polysilicon layer; forming one of a silicon layer and a second polysilicon layer on an exposed portion of the first polysilicon layer so as to close the aperture; selectively oxidizing said one of a silicon layer and a second polysilicon layer and a portion of the first polysilicon layer defined beneath said one of a silicon layer and a second polysilicon layer to form an oxide layer as a field insulating means while said silicon nitride layer serves as a mask; and removing the silicon nitride layer and the first polysilicon silicon layer while leaving the oxide layer as said field insulating means on the silicon substrate.
Claim 2
Independent Claim
199 words
A method of fabricating a semiconductor device which comprises the steps of: forming a first oxide layer on a top surface of a silicon substrate; forming a first polysilicon layer on a top surface of said first oxide layer; forming a second oxide layer on a top surface of said first polysilicon layer; forming a silicon nitride layer on a top surface of the second oxide layer; removing a selected portion of the silicon nitride layer and said second oxide layer so as to form an aperture, said aperture reaching said first polysilicon layer; forming one of a silicon layer and a second polysilicon layer on an exposed portion of the first polysilicon layer so as to close the aperture; selectively oxidizing said one of a silicon layer and a second polysilicon layer and a portion of the first polysilicon layer defined beneath said one of a silicon layer and a second polysilicon layer to form an oxide layer as a field insulating means while said silicon nitride layer serves as a mask; and removing the silicon nitride layer and the first polysilicon silicon layer while leaving the oxide layer as said field insulating means on the silicon substrate.
Claim 3
Independent Claim
225 words
A method of fabricating a semiconductor device which comprises the steps of: forming a first oxide layer on a top surface of a silicon substrate; forming a first polysilicon layer on a top surface of said first oxide layer; forming a second oxide layer on a top surface of said first polysilicon layer; forming a silicon nitride layer on a top surface of the second oxide layer; removing a selected portion of the silicon nitride layer and the second oxide layer so as to form an aperture, said aperture reaching said first polysilicon layer; forming one of a silicon layer and a second polysilicon layer on an exposed portion of the first polysilicon layer so as to close the aperture; selectively oxidizing said one of a silicon layer and a second polysilicon layer and a portion of the first polysilicon layer defined beneath said one of a silicon layer and a second polysilicon layer to form a third oxide layer as a field insulating means while said silicon nitride layer serves as a mask; removing the silicon nitride layer; subjecting a portion of the first polysilicon layer which is left unoxidized to oxygen so as to form a fourth oxide layer; and removing the first, second and fourth oxide layers while leaving the third oxide layer as a field insulating means on the silicon substrate.
Claim 4
Independent Claim
225 words
A method of fabricating a semiconductor device which comprises the steps of: forming a first oxide layer on a top surface of a silicon substrate; forming a first polysilicon layer on a top surface of said first oxide layer; forming a second oxide layer on a top surface of said first polysilicon layer; forming a silicon nitride layer on a top surface of the second oxide layer; removing a selected portion of the silicon nitride layer and the second oxide layer so as to form an aperture, said aperture reaching said first polysilicon layer; forming one of a silicon layer and a second polysilicon layer on an exposed portion of the first polysilicon layer so as to close the aperture; selectively oxidizing said one of a silicon layer and a second polysilicon layer and a portion of the first polysilicon layer defined beneath said one of a silicon layer and a second polysilicon layer to form a third oxide layer as a field insulating means while said silicon nitride layer serves as a mask; removing the silicon nitride layer; subjecting a portion of the first polysilicon layer which is left unoxidized to oxygen so as to form a fourth oxide layer; and removing the first, second and fourth oxide layers while leaving the third oxide layer as a field insulating means on the silicon substrate.
Claim 5
Independent Claim
229 words
A method of fabricating a semiconductor device which comprises the steps of: forming a first oxide layer on a top surface of a silicon substrate; forming a first polysilicon layer on a top surface of said first oxide layer; forming a second oxide layer on a top surface of said first polysilicon layer; forming a silicon nitride layer on a top surface of said second oxide layer; removing a selected portion of the silicon nitride layer and the second oxide layer so as to form an aperture, said aperture reaching said first polysilicon layer; implanting an impurity ion into a portion of the silicon substrate below the aperture so as to prevent inversion; forming one of a silicon layer and a second polysilicon layer on an exposed portion of the first polysilicon layer so as to close the aperture; selectively oxidizing said one of a silicon layer and a second polysilicon layer and a portion of the first polysilicon layer defined beneath said one of a silicon layer and a second polysilicon layer to form an oxide layer as a field insulating means while said silicon nitride layer serves as a mask, and activating the impurity ion to form a layer for preventing inversion; and removing the silicon nitride layer and the first silicon layer while leaving the oxide layer as said field insulating means on the silicon substrate.
Claim 6
Independent Claim
229 words
A method of fabricating a semiconductor device which comprises the steps of: forming a first oxide layer on a top surface of a silicon substrate; forming a first polysilicon layer on a top surface of said first oxide layer; forming a second oxide layer on a top surface of said first polysilicon layer; forming a silicon nitride layer on a top surface of said second oxide layer; removing a selected portion of the silicon nitride layer and the second oxide layer so as to form an aperture, said aperture reaching said first polysilicon layer; implanting an impurity ion into a portion of the silicon substrate below the aperture so as to prevent inversion; forming one of a silicon layer and a second polysilicon layer on an exposed portion of the first polysilicon layer so as to close the aperture; selectively oxidizing said one of a silicon layer and a second polysilicon layer and a portion of the first polysilicon layer defined beneath said one of a silicon layer and a second polysilicon layer to form an oxide layer as a field insulating means while said silicon nitride layer serves as a mask, and activating the impurity ion to form a layer for preventing inversion; and removing the silicon nitride layer and the first silicon layer while leaving the oxide layer as said field insulating means on the silicon substrate.
Claim 7
Independent Claim
256 words
A method of fabricating a semiconductor device which comprises the steps of: forming a first oxide layer on a top surface of a silicon substrate; forming a first polysilicon layer on a top surface of said first oxide layer; forming a second oxide layer on a top surface of said first polysilicon layer; forming a silicon nitride layer on a top surface of said second oxide layer; removing a selected portion of the silicon nitride layer and said second oxide layer so as to form an aperture, said aperture reaching said first polysilicon layer; implanting an impurity ion into a portion of the silicon substrate below the aperture so as to prevent inversion; forming one of a silicon layer and a second polysilicon layer on an exposed portion of the first polysilicon layer so as to close the aperture; selectively oxidizing said one of a silicon layer and a second polysilicon layer and a portion of the first polysilicon layer defined beneath said one of a silicon layer and a second polysilicon layer to form a third oxide layer as a field insulating means while said silicon nitride layer serves as a mask, and activating the impurity ion to form a layer for preventing inversion; removing the silicon nitride layer; subjecting a portion of the first polysilicon layer which is left unoxidized to oxygen so as to form a fourth oxide layer; and removing the first, second and fourth oxide layer while leaving the third oxide layer as said field insulating means on the silicon substrate.
Claim 8
Independent Claim
256 words
A method of fabricating a semiconductor device which comprises the steps of: forming a first oxide layer on a top surface of a silicon substrate; forming a first polysilicon layer on a top surface of said first oxide layer; forming a second oxide layer on a top surface of said first polysilicon layer; forming a silicon nitride layer on a top surface of said second oxide layer; removing a selected portion of the silicon nitride layer and said second oxide layer so as to form an aperture, said aperture reaching said first polysilicon layer; implanting an impurity ion into a portion of the silicon substrate below the aperture so as to prevent inversion; forming one of a silicon layer and a second polysilicon layer on an exposed portion of the first polysilicon layer so as to close the aperture; selectively oxidizing said one of a silicon layer and a second polysilicon layer and a portion of the first polysilicon layer defined beneath said one of a silicon layer and a second polysilicon layer to form a third oxide layer as a field insulating means while said silicon nitride layer serves as a mask, and activating the impurity ion to form a layer for preventing inversion; removing the silicon nitride layer; subjecting a portion of the first polysilicon layer which is left unoxidized to oxygen so as to form a fourth oxide layer; and removing the first, second and fourth oxide layer while leaving the third oxide layer as said field insulating means on the silicon substrate.
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