Patent US5100822A successfully refreshed from Google Patents.
US5100822A
Expired / Lapsed
US
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Semiconductor integrated circuit device and method of production thereof
Assignee: Hitachi Ltd
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Filing: 1990-10-31
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Granted: 1992-03-31
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Expires: 2010-10-31
Abstract
Abstract Disclosed is a semiconductor device having grooves extending from the semiconductor substrate surface into the interior of the substrate, the grooves having an insulating layer, such as an oxide layer, on the surfaces thereof, with the insulating layer being covered with a conductive layer. The corners of the grooves are rounded-off, whereby the electrostatic destruction voltage of the insulating film is increased as compared with using grooves without having rounded-off corners. Also disclosed is a method of making such device, including steps of forming an initial insulating film on the surfaces of the grooves and removing such initial insulating film to expose surfaces of the grooves, the grooves thereby being provided with rounded-off corners, and then sequentially forming an insulating layer and then a conductive layer on the surfaces of the grooves. Structure including the groove, with rounded-off corners, in the semiconductor substrate, the insulating layer on surfaces of the groove and the conductive layer on the insulating layer can be used as a vertically-formed data storage capacitance element, connected in series with a switching element, of a memory cell of a DRAM.
Inventors
- 👤 Shinichiro Mitani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:02
CPC Classifications
H; H10; H10B; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/038; H10B12/033; H10B12/036; H10B12/05; H10B12/053; H10B12/30; H10B12/34; H10B12/37; H10B12/39; H10D; H10D1/00; H10D1/60; H10D1/62; H10D1/66; H10D1/665; H10P; H10P50/00; Y; Y10; Y10S; Y10S148/00; Y10S148/109
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
177 words
A method of producing a semiconductor device including the steps of forming a trench in a main surface of a semiconductor substrate by dry etching such that said trench extends from said main surface into the interior of said semiconductor substrate, said trench having a mouth at the main surface of the trench and a bottom in the interior, whereby said trench includes corners at the bottom and at the main surface; forming an initial insulating film, of an oxide, along the surface within said trench, including at said corners at the bottom and at the main surface, by thermal oxidation and selectively removing said initial insulating film by wet etching, so as to simultaneously round off said corners at the bottom and at the main surface, wherein the corners are rounded off to have a radius of at least three times the thickness of a further insulating film formed along the surface within the trench; forming the further insulating film along the surface within said trench; and forming a conductive layer over said further insulating film.
Claim 2
Independent Claim
177 words
A method of producing a semiconductor device including the steps of forming a trench in a main surface of a semiconductor substrate by dry etching such that said trench extends from said main surface into the interior of said semiconductor substrate, said trench having a mouth at the main surface of the trench and a bottom in the interior, whereby said trench includes corners at the bottom and at the main surface; forming an initial insulating film, of an oxide, along the surface within said trench, including at said corners at the bottom and at the main surface, by thermal oxidation and selectively removing said initial insulating film by wet etching, so as to simultaneously round off said corners at the bottom and at the main surface, wherein the corners are rounded off to have a radius of at least three times the thickness of a further insulating film formed along the surface within the trench; forming the further insulating film along the surface within said trench; and forming a conductive layer over said further insulating film.
Claim 3
Dependent Claim
21 words
A method of producing a semiconductor device as defined in claim 1, wherein said semiconductor substrate is a silicon single crystal.
Claim 4
Dependent Claim
31 words
A method of producing a semiconductor device as defined in claim 2, wherein the trench is formed by anisotropically etching the semiconductor substrate, whereby a trench having acute corners are formed.
Claim 5
Dependent Claim
28 words
A method of producing a semiconductor device as defined in claim 2, wherein said initial insulating film is formed to have a thickness of at least 0.03 μm.
Claim 6
Dependent Claim
25 words
A method of producing a semiconductor device as defined in claim 1, wherein said initial insulating film has a thickness of 0.03 to 0.20 μm.
Claim 7
Dependent Claim
27 words
A method of producing a semiconductor device as defined in claim 1, wherein the corners are rounded off to have a radius of at least 0.03 μm.
Claim 8
Dependent Claim
42 words
A method of producing a semiconductor device as defined in claim 1, wherein said further insulating film comprises a first layer, of silicon oxide, formed adjacent the surface within the trench, and a second layer, of silicon nitride, adjacent the first layer.
Claim 9
Dependent Claim
21 words
A method of producing a semiconductor device as defined in claim 1, wherein said conductive layer is a polycrystalline silicon layer.
Claim 10
Dependent Claim
25 words
A method of producing a semiconductor device as defined in claim 1, wherein said dry etching to form the trench is an anisotropic dry etching.
Claim 11
Dependent Claim
34 words
A method of producing a semiconductor device as defined in claim 1, wherein the further insulating film and conductive layer formed thereover provide a data storage capacitance element of a dynamic random access memory.
Claim 12
Dependent Claim
71 words
A method of producing a semiconductor device as defined in claim 1, wherein the step of forming the trench includes the sub-steps of forming an oxidation-resistance layer on the main surface of the semiconductor substrate; removing a portion of said oxidation-resistant layer at the location where the trench is to be formed, leaving a remaining portion of the oxidation-resistant layer; and performing said dry etching so as to form said trench.
Claim 13
Dependent Claim
55 words
A method of producing a semiconductor device as defined in claim 11, wherein said remaining portion of said oxidation-resistant layer is retained on said main surface of said semiconductor substrate during said forming an initial insulating film, whereby oxidation of the main surface of the semiconductor substrate when forming the initial insulating film is avoided.
Claim 14
Dependent Claim
52 words
A method of producing a semiconductor device as defined in claim 12, wherein said removing a portion of the oxidation-resistant layer and said dry etching so as to form said trench are performed using the same mask, whereby said remaining portion of the oxidation-resistant layer is formed in self-alignment with said trench.
Claim 15
Dependent Claim
57 words
A method of producing a semiconductor device as defined in claim 1, wherein said forming an initial insulating film along the surface within the trench is performed with an oxidation-resistant layer on said main surface of said semiconductor substrate, whereby oxidation of the main surface of the semiconductor substrate when forming the initial insulating film is avoided.
Claim 16
Independent Claim
231 words
A method of producing a semiconductor device including the steps of forming a trench in a main surface of a semiconductor substrate by dry etching such that said trench extends from said main surface into the interior of said semiconductor substrate, said trench having a mouth at the main surface of the substrate and a bottom in the interior, whereby said trench has corners at said bottom and at said main surface, said forming the trench including forming a mask on the substrate surface, said mask having an opening at the location of the trench, and forming the trench utilizing said mask; forming an initial insulating film, of an oxide, along the surface within the trench, including at said corners at said bottom and at said main surface, by thermal oxidation, using said mask, and selectively removing said initial insulating film along the surface within the trench by wet etching, so as to simultaneously round off said corners at the bottom and at the main surface, wherein said corners are rounded off to have a radius of at least three times the thickness of an insulating film formed over the main surface of the semiconductor substrate and along the surface within the trench; forming the insulating film over said main surface of said semiconductor substrate and along the surface within said trench; and forming a conductive layer over said insulating film.
Claim 17
Independent Claim
231 words
A method of producing a semiconductor device including the steps of forming a trench in a main surface of a semiconductor substrate by dry etching such that said trench extends from said main surface into the interior of said semiconductor substrate, said trench having a mouth at the main surface of the substrate and a bottom in the interior, whereby said trench has corners at said bottom and at said main surface, said forming the trench including forming a mask on the substrate surface, said mask having an opening at the location of the trench, and forming the trench utilizing said mask; forming an initial insulating film, of an oxide, along the surface within the trench, including at said corners at said bottom and at said main surface, by thermal oxidation, using said mask, and selectively removing said initial insulating film along the surface within the trench by wet etching, so as to simultaneously round off said corners at the bottom and at the main surface, wherein said corners are rounded off to have a radius of at least three times the thickness of an insulating film formed over the main surface of the semiconductor substrate and along the surface within the trench; forming the insulating film over said main surface of said semiconductor substrate and along the surface within said trench; and forming a conductive layer over said insulating film.
Claim 18
Dependent Claim
52 words
A method of producing a semiconductor device as defined in claim 15, wherein said trench is formed by etching and said initial insulating film is formed by thermal oxidation, and further wherein said mask is formed of materials resistant to the etching used in said etching and resistant to said thermal oxidation.
Claim 19
Dependent Claim
38 words
A method of producing a semiconductor device as defined in claim 16, wherein said mask includes two layers, a first layer of material resistant to said etching and a second layer of material resistant to said thermal oxidation.
Claim 20
Dependent Claim
30 words
A method of producing a semiconductor device as defined in claim 17, wherein said first layer is made of phosphosilicate glass and said second layer is made of silicon nitride.
Claim 21
Dependent Claim
21 words
A method of producing a semiconductor device as defined in claim 15, wherein said insulating film has a substantially uniform thickness.
Claim 22
Dependent Claim
33 words
A method of producing a semiconductor device as defined in claim 15, wherein the insulating film and conductive layer formed thereover provide a data storage capacitance element of a dynamic random access memory.
Claim 23
Dependent Claim
25 words
A method of producing a semiconductor device as defined in claim 15, wherein said dry etching to form the trench is an anisotropic dry etching.
Claim 24
Independent Claim
225 words
A method of producing a semiconductor device having a plurality of memory cells, each memory cell comprising a data storage capacitances element and a switching MISFET connected in series, said data storage capacitance element including a trench, including the steps of: forming said trench extending from a main surface of a semiconductor substrate, into the interior thereof, by anisotropically etching said semiconductor substrate, said trench having a mouth at the main surface of the substrate and a bottom in the interior, whereby said trench has corners at said bottom and at the main surface of the semiconductor substrate; forming an initial insulating film, of an oxide, along the surface within the trench, including at said corners at said bottom and at the main surface, by thermal oxidation; removing said initial insulating film from said surface within the trench so as to simultaneously round off the corners at said bottom and at the main surface of the semiconductor substrate, wherein said corners are rounded off to have a radius of at least three times the thickness of a further insulating film formed over the main surface of the semiconductor substrate and along the surface within the trench; forming the further insulating film along the surface of said semiconductor substrate, including along the surface within the trench; and forming a conductive layer over said further insulating film.
Claim 25
Independent Claim
225 words
A method of producing a semiconductor device having a plurality of memory cells, each memory cell comprising a data storage capacitances element and a switching MISFET connected in series, said data storage capacitance element including a trench, including the steps of: forming said trench extending from a main surface of a semiconductor substrate, into the interior thereof, by anisotropically etching said semiconductor substrate, said trench having a mouth at the main surface of the substrate and a bottom in the interior, whereby said trench has corners at said bottom and at the main surface of the semiconductor substrate; forming an initial insulating film, of an oxide, along the surface within the trench, including at said corners at said bottom and at the main surface, by thermal oxidation; removing said initial insulating film from said surface within the trench so as to simultaneously round off the corners at said bottom and at the main surface of the semiconductor substrate, wherein said corners are rounded off to have a radius of at least three times the thickness of a further insulating film formed over the main surface of the semiconductor substrate and along the surface within the trench; forming the further insulating film along the surface of said semiconductor substrate, including along the surface within the trench; and forming a conductive layer over said further insulating film.
Claim 26
Dependent Claim
22 words
A method of producing a semiconductor device as defined in claim 22, wherein said further insulating film has a substantially uniform thickness.
Claim 27
Dependent Claim
25 words
A method of producing a semiconductor device as defined in claim 22, wherein said initial insulating film has a thickness of 0.03 to 0.2 μm.
Claim 28
Dependent Claim
21 words
A method of producing a semiconductor device as defined in claim 22, wherein said conductive layer is a polycrystalline silicon layer.
Claim 29
Dependent Claim
25 words
A method of producing a semiconductor device as defined in claim 22, wherein the anisotropic etching to form said trench is an anisotropic dry etching.
Claim 30
Dependent Claim
30 words
A method of producing a semiconductor device as defined in claim 22, wherein said data storage capacitance element is a data storage capacitance element of a dynamic random access memory.
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) | 1995-03-31 | 1995-09-30 | 1996-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-31 | 1999-09-30 | 2000-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-31 | 2003-09-30 | 2004-03-31 | $7700.00 | Window Closed / Lapsed |