US4579625A
Expired / Lapsed
US
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Method of producing a complementary semiconductor device with a dielectric isolation structure
Assignee: DFUJITSU Ltd
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Filing: 1984-09-19
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Granted: 1986-04-01
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Expires: 2004-09-19
Abstract
Abstract A method of producing a complementary semiconductor device having p-type islands and n-type islands in a dielectric isolation structure, including removing a projecting portion of a polycrystalline silicon layer, which is formed at the same time as the formation of an epitaxial silicon layer for one of two types of islands, so as to obtain an almost smooth exposed surface. The smooth surface contributes to the formation of a good masking pattern on the epitaxial silicon layer by a photoetching method, so that mesa portions for islands having exact dimensions are formed at predetermined positions.
Inventors
- 👤 Akira Tabata
- 👤 Motoshu Miyajima
- 👤 Yoshifumi Kikuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:35
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/01; H10D84/0112; H10D84/0119; H10D84/0121; H10D84/0123; H10D84/0126; H10D84/0165; H10D84/0188; H10D84/02; H10D84/03; H10D84/038; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/019; H10W10/10; Y; Y10; Y10S; Y10S438/00; Y10S438/928; Y10S438/969
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
154 words
A method of producing a complementary semiconductor device having at least one p-type island and at least one n-type island in a dielectric isolation structure, comprising the steps of: (a) forming a first mesa portion of a single crystalline semiconductor substrate having a first conductivity type; (b) covering said first mesa portion only with a first insulating layer; (c) epitaxially growing a semiconductor material to form a polycrystalline semiconductor layer on said first insulating layer and to form a single crystalline semiconductor layer of a second conductivity type, opposite said first conductivity type, on the exposed surface of said substrate; (d) forming a protective layer on said polycrystalline semiconductor layer and single crystalline semiconductor layer; (e) selectively removing said protective layer from a top portion of said first mesa portion; and (f) removing said exposed polycrystalline semiconductor layer of said first mesa portion by using the remainder of said protective layer as a mask.
Claim 2
Independent Claim
154 words
A method of producing a complementary semiconductor device having at least one p-type island and at least one n-type island in a dielectric isolation structure, comprising the steps of: (a) forming a first mesa portion of a single crystalline semiconductor substrate having a first conductivity type; (b) covering said first mesa portion only with a first insulating layer; (c) epitaxially growing a semiconductor material to form a polycrystalline semiconductor layer on said first insulating layer and to form a single crystalline semiconductor layer of a second conductivity type, opposite said first conductivity type, on the exposed surface of said substrate; (d) forming a protective layer on said polycrystalline semiconductor layer and single crystalline semiconductor layer; (e) selectively removing said protective layer from a top portion of said first mesa portion; and (f) removing said exposed polycrystalline semiconductor layer of said first mesa portion by using the remainder of said protective layer as a mask.
Claim 3
Dependent Claim
126 words
A method according to claim 1, further comprising the steps of: (g) selectively forming a first masking layer on said single crystalline semiconductor layer; (h) removing the remaining polycrystalline semiconductor layer; (i) forming a second mesa portion of said single crystalline layer by selectively etching said single crystalline layer by utilizing said first masking layer; (j) removing said first masking layer; (k) covering the exposed surfaces of said second mesa portion and said substrate, including said first mesa portion, with a second insulating layer; (l) forming a supporting layer on said second insulating layer; and (m) backlapping said substrate to island said first and second mesa portions and to expose portions of said second insulating layer, wherein steps (g) through (m) are performed after step (f).
Claim 4
Dependent Claim
23 words
A method according to claim 1, wherein said step (e) of selectively removing said protective layer is carried out by a lapping method.
Claim 5
Dependent Claim
22 words
A method according to claim 1, wherein in said forming step (c) of the first mesa portion, an anisotropic etchant is used.
Claim 6
Dependent Claim
57 words
A method according to claim 1, further comprising the steps of: (n) removing the remainder of said protective layer; and (o) forming a second masking layer on the first making layer on a top portion of said second mesa portion; wherein steps (n) and (o) occcur after said selectively forming step (g) of the first masking layer.
Claim 7
Dependent Claim
45 words
A method according to claim 5, further comprising the step of: (p) selectively etching said second masking layer to form a mask for the removal of said remaining polycrystalline semiconductor layer prior to said removal of the remainder of the protective layer in step (n).
Claim 8
Dependent Claim
22 words
A method according to claim 2, wherein, in said forming step (i) of the second mesa portion, an anisotropic etchant is used.
Claim 9
Dependent Claim
14 words
A method according to claim 1, wherein said single crystalline semiconductor substrate is silicon.
Claim 10
Dependent Claim
12 words
A method according to claim 1, wherein said semiconductor material is silicon.
Claim 11
Dependent Claim
13 words
A method according to claim 2, wherein said supporting layer is polycrystalline silicon.
Claim 12
Independent Claim
305 words
A method of producing a complementary semiconductor device having at least one p-type island and at least one n-type island in a dielectric isolation structure, comprising the steps of: (a) forming a first mesa portion of a single crystalline semiconductor substrate having a first conductivity type; (b) covering said first mesa portion only with a first insulating layer; and (c) epitaxially growing a semiconductor material to form a polycrystalline semiconductor layer on said first insulating layer and to form a single crystalline semiconductor layer of a second conducitivity type, opposite said first conductivity type, on the exposed surface of said substrate; (d) forming a protective layer on said pooycrystalline semiconductor layer and single crystalline semiconductor layer; (e) selectively removing said protective layer from a top portion of said first mesa portion; (f) removing said exposed polycrystalline semiconductor layer of said first mesa portion by using the remainder of said protective layer as a mask; (g) removing the remainder of said protective layer; (h) forming a first masking layer on the entire exposed surface; (i) selectively forming a second masking layer on said first masking layer above said single cyrstalline semiconductor layer; (j) selectively removing the first and second masking layers from a top portion of the first mesa portion; (k) removing the remaining polycrystalline semiconductor layer; (l) forming a second mesa portion of said single crystalline layer by selectively etching said single crystalline layer by utilizing said first and second masking layers; (m) removing said first and second masking layers; (n) covering the exposed surfaces of said second mesa portion and said substrate, including said first mesa portion, with a second insulating layer; (o) forming a supporting layer on said second insulating layer; and (p) backlapping said substrate to expose portions of said second insulating layer and to isolate said first and second mesa portions.
Claim 13
Independent Claim
305 words
A method of producing a complementary semiconductor device having at least one p-type island and at least one n-type island in a dielectric isolation structure, comprising the steps of: (a) forming a first mesa portion of a single crystalline semiconductor substrate having a first conductivity type; (b) covering said first mesa portion only with a first insulating layer; and (c) epitaxially growing a semiconductor material to form a polycrystalline semiconductor layer on said first insulating layer and to form a single crystalline semiconductor layer of a second conducitivity type, opposite said first conductivity type, on the exposed surface of said substrate; (d) forming a protective layer on said pooycrystalline semiconductor layer and single crystalline semiconductor layer; (e) selectively removing said protective layer from a top portion of said first mesa portion; (f) removing said exposed polycrystalline semiconductor layer of said first mesa portion by using the remainder of said protective layer as a mask; (g) removing the remainder of said protective layer; (h) forming a first masking layer on the entire exposed surface; (i) selectively forming a second masking layer on said first masking layer above said single cyrstalline semiconductor layer; (j) selectively removing the first and second masking layers from a top portion of the first mesa portion; (k) removing the remaining polycrystalline semiconductor layer; (l) forming a second mesa portion of said single crystalline layer by selectively etching said single crystalline layer by utilizing said first and second masking layers; (m) removing said first and second masking layers; (n) covering the exposed surfaces of said second mesa portion and said substrate, including said first mesa portion, with a second insulating layer; (o) forming a supporting layer on said second insulating layer; and (p) backlapping said substrate to expose portions of said second insulating layer and to isolate said first and second mesa portions.
Claim 14
Dependent Claim
23 words
The method according to claim 11, wherein said step (e) of selectively removing said protective layer is carried out by a lapping method.
Claim 15
Dependent Claim
22 words
The method according to claim 12, wherein, in said forming step (c) of the first mesa portion, an anisotropic etchant is used.
Claim 16
Dependent Claim
22 words
The method according to claim 13, wherein, in said forming step (1) of the second mesa portion, an anisotropic etchant is used.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-03-31 | 1989-09-30 | 1990-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-31 | 1993-09-30 | 1994-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-31 | 1997-09-30 | 1998-04-01 | $7700.00 | Window Closed / Lapsed |