EP0767486A2
Expired / Lapsed
EP
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Semiconductor substrate and producing method thereof
Assignee: Canon Inc
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Filing: 1996-10-07
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Granted: —
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Expires: 2016-10-07
Abstract
Abstract A method is provided for producing, with high reproducibility, an SOI substrate which is flat and high in quality, and simultaneously for achieving resources saving and reduction in cost through recycling of a substrate member. For accomplishing this, a porous-forming step is performed forming a porous Si layer on at least a surface of an Si substrate and a large porosity layer forming step is performed for forming a large porosity layer in the porous Si layer. This large porosity layer forming step is performed by implanting ions into the porous Si layer with a given projection range or by changing current density of anodization in said porous-forming step. At this time, a non-porous single-crystal Si layer is epitaxial-grown on the porous Si layer. Thereafter, the surface of the porous Si layer and a support substrate are bonded together, and then separation is performed at the porous Si layer with the large porosity. Subsequently, selective etching is performed to remove the porous Si layer.
Inventors
- 👤 Nobuhiko Sato
- 👤 Takao Yonehara
- 👤 Kiyofumi Sakaguchi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 23:08
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P90/00; H10P90/12; H10P90/16; H10F; H10F71/00; H10F71/139; H10P36/00; H10P36/03; H10P36/07; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1914; H10P90/1916; H10P90/1924; H10P95/00; H10P95/40; H10P95/402; H10P95/405; H10W; H10W10/00; H10W10/10; H10W10/181; Y; Y02; Y02E; Y02E10/00; Y02E10/50
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
52 words
A semiconductor substrate producing method comprising: a porous-forming step for forming a porous Si layer on at least a surface of an Si substrate; and a large porosity layer forming step for forming large porosity layer at a constant depth from a surface of said porous Si in said porous Si layer.
Claim 2
Dependent Claim
34 words
The semiconductor substrate producing method according to claim 1, wherein said large porosity layer forming step has an ion implanting step for implanting ions into said porous Si layer with a given projection range.
Claim 3
Dependent Claim
33 words
The semiconductor substrate producing method according to claim 2, further comprising a non-porous layer forming step for forming a non-porous layer on a surface of said porous layer before said ion implanting step.
Claim 4
Dependent Claim
23 words
The semiconductor substrate producing method according to claim 2, wherein said ions comprises at least one kind of noble gas, hydrogen and nitrogen.
Claim 5
Dependent Claim
40 words
The semiconductor substrate producing method according to claim 3, further comprising a bonding step for bonding said non-porous layer and a support substrate together; and a separating step for separating said Si substrate into two at said large porosity layer.
Claim 6
Dependent Claim
20 words
The semiconductor substrate producing method according to claim 5, wherein said separating step is performed by heat-treating said Si substrate.
Claim 7
Dependent Claim
28 words
The semiconductor substrate producing method according to claim 5, wherein said separating step is performed by pressurizing said Si substrate in a direction perpendicular to a surface thereof.
Claim 8
Dependent Claim
28 words
The semiconductor substrate producing method according to claim 5, wherein said separating step is performed by drawing said Si substrate in a direction perpendicular to a surface thereof.
Claim 9
Dependent Claim
24 words
The semiconductor substrate producing method according to claim 5, wherein said separating step is performed by applying a shearing force to said Si substrate.
Claim 10
Dependent Claim
18 words
The semiconductor substrate producing method according to claim 3, wherein said non-porous layer is made of single-crystal Si.
Claim 11
Dependent Claim
29 words
The semiconductor substrate producing method according to claim 3, wherein said non-porous layer is made of single-crystal Si having an oxidized Si layer on a surface to be bonded.
Claim 12
Dependent Claim
20 words
The semiconductor substrate producing method according to claim 3, wherein said non-porous layer is made of a single-crystal compound semiconductor.
Claim 13
Dependent Claim
17 words
The semiconductor substrate producing method according to claim 5, wherein said support substrate is an Si substrate.
Claim 14
Dependent Claim
28 words
The semiconductor substrate producing method according to claim 5, wherein said support substrate is an Si substrate having an oxidized Si layer on a surface to be bonded.
Claim 15
Dependent Claim
18 words
The semiconductor substrate producing method according to claim 5, wherein said support substrate is a light transmittable substrate.
Claim 16
Dependent Claim
25 words
The semiconductor substrate producing method according to claim 5, wherein said bonding step is performed by anode bonding, pressurization, heat treatment or a combination thereof.
Claim 17
Dependent Claim
39 words
The semiconductor substrate producing method according to claim 5, further comprising a porous Si removing step, after said separating step, for removing the porous Si layer exposed on a surface of said support substrate and exposing said non-porous layer.
Claim 18
Dependent Claim
70 words
The semiconductor substrate producing method according to claim 17, wherein said porous Si removing step is performed by an electroless wet etching using at least one of hydrofluoric acid, a mixed liquid obtained by adding at least one of alcohol and hydrogen peroxide water to hydrofluoric acid, buffered hydrofluoric acid, and a mixed liquid obtained by adding at least one of alcohol and hydrogen peroxide water to buffered hydrofluoric acid.
Claim 19
Dependent Claim
28 words
The semiconductor substrate producing method according to claim 17, further comprising a flattening step for flattening a surface of said non-porous layer after said porous Si removing step.
Claim 20
Dependent Claim
23 words
The semiconductor substrate producing method according to claim 19, wherein said flattening step is performed by heat treatment in the atmosphere including hydrogen.
Claim 21
Dependent Claim
45 words
The semiconductor substrate producing method according to claim 5, wherein said porous-forming step forms porous Si layers on both sides of said Si substrate, and said bonding step bonds two support substrates to said porous Si layers formed on both sides of said Si substrate.
Claim 22
Dependent Claim
70 words
The semiconductor substrate producing method according to claim 5, further comprising a second non-porous layer forming step, after said separating step, for forming non-porous layer again on the surface of said porous Si layer, and a second ion implanting step, after said second non-porous layer forming step, for implanting ions into said porous Si layer with a given projection range and forming large porosity layer in said porous Si layer.
Claim 23
Dependent Claim
17 words
The semiconductor substrate producing method according to claim 1, wherein said porous-forming step is performed by anodization.
Claim 24
Dependent Claim
27 words
The semiconductor substrate producing method according to claim 23, wherein said anodization is performed in an HF solution or a mixture of an HF solution and alcohol.
Claim 25
Dependent Claim
29 words
The semiconductor substrate producing method according to claim 1, wherein said large porosity layer forming step is performed by changing a current density of anodization in said porous-forming step.
Claim 26
Dependent Claim
50 words
A semiconductor substrate comprising: a porous Si layer formed at a surface layer of an Si substrate; and a large porosity layer formed in said porous Si layer wherein said large porosity layer exists in a region located at a constant depth from a surface of said porous Si layer.
Claim 27
Dependent Claim
47 words
The semiconductor substrate according to claim 26, wherein non-porous Si layer exists on surface of said porous Si layer, and electrodes are formed on surface of said non-porous Si layer and on surface of said Si substrate, in order that said semiconductor substrate becomes an EL element.
Claim 28
Dependent Claim
30 words
Method of producing an electroluminescent element comprising: producing a semiconductor substrate by the method of claim 3; and forming electrodes on respective surfaces of said non-porous silicon layer and substrate.
Claim 29
Dependent Claim
60 words
Method of producing an integrated circuit device or other electronic device which method comprises: producing a semiconductor substrate by the method of claim 3; transferring the non-porous silicon layer onto the insulating surface of another substrate; processing said non porous layer to produce an integrated circuit or one or more electronic device elements; and completing fabrication of the electronic device.
References Cited (Backward Citations)
No citation records indexed.
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