Patent US6257925B1 successfully refreshed from Google Patents.
EP0143662A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Soi type semiconductor device
Assignee: Fujitsu Ltd
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Filing: 1984-11-29
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Granted: —
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Expires: 2004-11-29
Abstract
Abstract A method of fabricating a deep buried layer in an SOI device, for example for use in forming a bipolar transistor based on SOI technology, is provided. Also, the formation of a conduction path connecting to the deep buried layer is provided for. The side surface(s) of an epitaxial layer (18, 38) having a thickness of about ten microns, for example, which is grown on a single crystalline island (19, 39) - providing the deep buried layer - formed by recrystallizing a polycrystalline layer (13a) formed on an insulating layer (12, 12a), is tentatively exposed and a conduction path (21, 42) is formed at the side surface(s). Two ways of forming the tentative exposed side surface(s) and the conduction path (21, 42) are specifically described.
Inventors
- 👤 Kazuhiro C/O Fujitsu Limited Patent Dep. Kanbara
- 👤 Osamu C/O Fujitsu Limited Hataishi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 15:59
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10W; H10W20/00; H10W20/01; H10W20/021; H10D; H10D86/00; H10D86/01; H10D86/03; H10P14/00; H10P14/20; H10P14/27; H10P14/271; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/32; H10P14/3202; H10P14/3238; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; Y; Y10; Y10S; Y10S148/00; Y10S148/05
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
80 words
A method for fabricating an SOI (Semiconductor on Insulator) type semiconductor device, comprising: forming a single crystalline island on an insulating layer formed on a substrate, said single crystalline island having one conductivity type; forming an epitaxial layer on said single crystalline island; forming a tentative exposed side surface of said epitaxial layer; forming a conduction path at said exposed side surface, said conduction path extending from the upper surface of said epitaxial layer to said single crystalline island thereunder.
Claim 2
Independent Claim
80 words
A method for fabricating an SOI (Semiconductor on Insulator) type semiconductor device, comprising: forming a single crystalline island on an insulating layer formed on a substrate, said single crystalline island having one conductivity type; forming an epitaxial layer on said single crystalline island; forming a tentative exposed side surface of said epitaxial layer; forming a conduction path at said exposed side surface, said conduction path extending from the upper surface of said epitaxial layer to said single crystalline island thereunder.
Claim 3
Dependent Claim
14 words
A method as claimed in claim 1, wherein said substrate is a silicon substrate.
Claim 4
Dependent Claim
18 words
A method as claimed in claim 1 or 2, wherein said insulating layer is composed of silicon dioxide.
Claim 5
Dependent Claim
19 words
A method as claimed in claim 2, wherein said insulating layer is formed by oxidation of said silicon substrate.
Claim 6
Independent Claim
120 words
A method as claimed in any preceding claim, wherein said single crystalline island is formed by: forming a first polycrystalline layer on said insulating layer; selectively passivating said firstpolycrystalline layer except for the portion thereof corresponding to a region in which said single crystalline island is to be formed; coating the surface of said first polycrystalline layer, after said selective passivation, with a layer which is a source of dopant, for providing said first polycrystalline layer at the said portion with the said one conductivity type; heating for recrystallizing said first polycrystalline layer at the said portion and incidentally for diffusing said dopant into said first polycrystalline layer at the said portion; and removing said coating layer after said heating.
Claim 7
Dependent Claim
19 words
A method as claimed in claim 5, wherein said heating step is performed by irradiation with an energy beam.
Claim 8
Dependent Claim
15 words
A method as claimed in claim 6, wherein said energy beam is a laser beam.
Claim 9
Independent Claim
35 words
A method as claimed in any one of claims 5 to 7, wherein said first polycrystalline layer is formed from a material which can result in the same substance as said insulating layer when passivated.
Claim 10
Independent Claim
21 words
A method as claimed in any one of claims 5 to 8, wherein said first polycrystalline layer is a polysilicon layer.
Claim 11
Independent Claim
20 words
A method as claimed in an one of claims 5 to 9, wherein said selective passivation is performed by oxidation.
Claim 12
Dependent Claim
23 words
ll. A method as claimed in any one of claims 5 to 10, wherein said coating layer is formed from antimonysilicate glass (Sb-SG).
Claim 13
Independent Claim
27 words
A method as claimed in any one of claims 5 to 11, wherein the epitaxial layer is formed from the same material as said first polycrystalline layer.
Claim 14
Independent Claim
16 words
A method as claimed in any preceding claim wherein said epitaxial layer is composed of silicon.
Claim 15
Independent Claim
52 words
A method as claimed in any preceding claim, wherein said tentative exposed side surface of said epitaxial layer is formed by: forming a mask layer on the surface of said epitaxial layer; and removing a second polycrystalline layer which has been formed around said epitaxial layer during formation of said epitaxial layer.
Claim 16
Dependent Claim
62 words
A metod as claimed in claim 14, wherein the formation of said conduction path at said exposed side surface of said epitaxial layer is performed by introducing impurity of the said one conductivity type into said exposed side surface of said epitaxial layer (for example using a mask layer to prevent such introduction into an exposed upper surface of said epitaxial layer).
Claim 17
Dependent Claim
56 words
A method as claimed in claim 14 or 15, wherein the formation of said conduction path is followed by: forming a third polycrystalline layer on the surface of said substrate bearing said epitaxial layer; passivating said third polycrystalline layer; and exposing the upper surface of said epitaxial layer after said passivation of said third polycrystalline layer.
Claim 18
Dependent Claim
25 words
A method as claimed in claim 16, wherein said third polycrystalline layer is formed from the same material as that forming said single crystalline island.
Claim 19
Dependent Claim
18 words
A method as claimed in claim 16 or 17, wherein said third polycrystalline layer is a polysilicon layer.
Claim 20
Dependent Claim
22 words
A method as claimed in claim 16, 17 or 18, wherein said passivation of said third polysilicon layer is performed by oxidation.
Claim 21
Dependent Claim
37 words
A method as claimed in claim 16, 17, 18, or 19, wherein said exposing of the upper surface of said epitaxial layer after said passivation of said third polycrystalline layer is performed by using a mechanical polishing.
Claim 22
Dependent Claim
56 words
A method as claimed in claim 16, 17, 18, 19 or 20 wherein said exposing of the upper surface of said epitaxial layer after said passivation of said third polycrystalline layer is performed so that the surface of said epitaxial layer is leveled to the surface of the passivated third polycrystalline layer around said epitaxial layer.
Claim 23
Independent Claim
123 words
A method as claimed in any one of claims 1 to 13, wherein the said tentative exposed side surface of said epitaxial layer is formed by: forming a first mask layer on the surface of said epitaxial layer by a first resist layer; passivating a second polycrystalline layer which has been formed around said epitaxial layer during said process for forming said epitaxial layer; removing said first mask layer; selectively forming a second mask layer on the surface of said epitaxial layer so that a peripheral area of said surface of said epitaxial layer is exposed; and forming a groove in said epitaxial layer, below said peripheral area, said groove having depth equal to or greater than the thickness of said epitaxial layer.
Claim 24
Dependent Claim
70 words
A method as claimed in claim 22, wherein the formation of said conduction path at said tentative exposed side surface of said epitaxial layer is performed by forming a further polycrystalline layer on the surface of said substrate bearing said epitaxial layer so that said groove formed in said epitaxial layer is filled with said further polycrystalline layer, said further polycrystalline layer including impurity of the said one conductivity type.
Claim 25
Dependent Claim
25 words
A method as claimed in claim 23, wherein said further polycrystalline layer is formed from the same material as that forming said single crystalline island.
Claim 26
Dependent Claim
18 words
A method as claimed in claim 23 or 24, wherein said further polycrystalline layer is a polysilicon layer.
Claim 27
Dependent Claim
29 words
A method as claimed in claim 22, 23, 24 or 25, wherein the formation of said conduction path is followed by exposing the upper surface of said epitaxial layer.
Claim 28
Dependent Claim
25 words
A method as claimed in claim 26, wherein the exposing of the upper surface of said epitaxial layer is performed by using a mechanical polishing.
Claim 29
Dependent Claim
47 words
A method as claimed in claim 26 or 27, wherein the exposing of the upper surface of said epitaxial layer is performed so that the upper surface of the said expitaxial layer is levelled to the surface of the passivated second polycrystalline layer around said epitaxial layer.
Claim 30
Dependent Claim
16 words
An SOI device formed with the use of a method as claimed in any preceding claim.
References Cited (Backward Citations)
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