SOI substrate and process for preparing the same, and semiconductor device and process for preparing the same
First Claim
1. An SOI substrate comprising an insulating base, and a crystalline silicon layer epitaxially grown on the insulating base, wherein the insulating base is a single crystal oxide substrate, a multi-layered substrate comprising a silicon substrate and a crystalline oxide layer, or a crystalline fluoride layer deposited on the silicon substrate, andwherein the defect density of the crystalline silicon layer determined by a defect density measuring method using an iodine-containing etching solution is not more than 4×
- 108/cm2 in an entire depth direction, and the surface roughness of the crystalline silicon layer is not more than 4 nm but not less than 0.05 nm.
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Accused Products
Abstract
When producing an SOS substrate by growing a silicon layer on a sapphire substrate, or when producing an SOI substrate by depositing an oxide layer or a fluoride layer, as an intermediate layer, on a silicon substrate, and growing a silicon layer on the deposited layer, (A) after growth of the silicon layer, heat treatment is performed in an oxidizing atmosphere to oxidize a part of a surface side of the silicon layer, and the resulting silicon oxide layer is removed by etching with hydrofluoric acid. (B) With this silicon layer as a seed layer, a silicon layer is regrown homoepitaxially thereon.
42 Citations
77 Claims
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1. An SOI substrate comprising an insulating base, and a crystalline silicon layer epitaxially grown on the insulating base, wherein the insulating base is a single crystal oxide substrate, a multi-layered substrate comprising a silicon substrate and a crystalline oxide layer, or a crystalline fluoride layer deposited on the silicon substrate, and
wherein the defect density of the crystalline silicon layer determined by a defect density measuring method using an iodine-containing etching solution is not more than 4× - 108/cm2 in an entire depth direction, and the surface roughness of the crystalline silicon layer is not more than 4 nm but not less than 0.05 nm.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 71)
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11. A method for producing an SOI substrate having a silicon layer with a low defect density formed on an insulating base, comprising the steps of:
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(a) forming a first silicon layer on the insulating base;
(b) heat treating the first silicon layer in an oxidizing atmosphere containing a gas mixture of oxygen and hydrogen or containing steam to oxidize a part of the first silicon layer;
(c) removing a silicon oxide film formed in the preceding step (b) by etching;
and (d) epitaxially growing a second silicon layer on the remaining first silicon layer. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 62, 63, 64)
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50. A method for producing an SOI substrate having a silicon layer with a low defect density formed on an insulating base, comprising the steps of:
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(a) forming a first silicon layer on the insulating base;
(b) implanting silicon ions into the first silicon layer, to make a deep portion of the first silicon layer amorphous, performing annealing for recrystallization, and then heat treating the first silicon layer in a hydrogen atmosphere; and
(c) epitaxially growing a second silicon layer on the first silicon layer heat treated in a hydrogen atmosphere. - View Dependent Claims (51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61)
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65. A semiconductor device having an SOI substrate used as a substrate,
wherein the SOI substrate comprising an insulating base, and a crystalline silicon layer epitaxially grown on the insulating base, wherein the insulating base is a single crystalline oxide substrate, a multi-layered substrate comprising a silicon substrate and a crystalline oxide layer, or a crystalline fluoride layer deposited on the silicon substrate, and wherein the defect density of the crystalline silicon layer determined by a defect density measuring method using an iodine-containing etching solution is not more than 4× - 108/cm2 in an entire depth direction, and the surface roughness of the crystalline silicon layer is not more than 4 nm but not less than 0.05 nm.
- View Dependent Claims (66, 67, 68, 69, 70)
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72. A method for producing a semiconductor device on an SOI substrate comprising an insulating base, and a silicon layer formed on the insulating base, comprising the steps of:
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(a) forming a first silicon layer on the insulating base;
(b) heat treating the first silicon layer in an oxidizing atmosphere comprising a mixture of oxygen and hydrogen or steam to oxidize a part of the first silicon layer;
(c) removing a silicon oxide film formed in the preceding step (b) by etching;
(d) epitaxially growing a second silicon layer on the remaining first silicon layer; and
(e) heat treating a silicon layer, formed in the preceding step (d), in an oxidizing atmosphere to oxidize a part of the surface of the silicon layer, and then removing a silicon oxide film, which has been formed, by etching to adjust the silicon layer to a desired thickness. - View Dependent Claims (73, 74, 75)
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76. A method for producing a semiconductor device on an SOI substrate comprising an insulating base, and a silicon layer formed on the insulating base, comprising the steps of:
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(a) forming a first silicon layer on the insulating base;
(b) implanting silicon ions immediately after the step of forming the first silicon layer, to make a deep portion of the first silicon layer amorphous, annealing to recrystallize at least a portion thereof, and then heat treating the first silicon layer in a hydrogen atmosphere;
(c) epitaxially growing a second silicon layer on the first silicon layer heat treated in a hydrogen atmosphere; and
(d) heat treating a silicon layer, formed in the step (c), in an oxidizing atmosphere to oxidize a part of the silicon layer, and then removing the silicon oxide film, which has been formed, by etching to adjust the silicon layer to a desired thickness. - View Dependent Claims (77)
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Specification