EP0793263A2
Expired / Lapsed
EP
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Fabrication process of a semiconductor substrate
Assignee: Canon Inc
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Filing: 1997-02-27
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Granted: —
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Expires: 2017-02-27
Abstract
Abstract A process for producing a semiconductor substrate, in particular an SOI substrate, is provided which comprises a step of bonding a principal surface of a first substrate (11) to a principal surface of a second substrate (15), the first substrate (11) being an Si substrate in which at least one layer of non-porous thin film (13) is formed through a porous Si layer (12), a step of exposing the porous Si layer in a side surface of a bonding substrate comprised of the first substrate (11) and the second substrate (15), a step of dividing the porous Si layer by oxidizing the bonding substrate, and a step of removing porous Si (12) and oxidized porous Si layer (16) on the second substrate (15) separated by the division of the porous Si layer. The first substrate (11) may be reused.
Inventors
- 👤 Kiyofumi Sakaguchi
- 👤 Takao Yonehara
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 08:56
CPC Classifications
H; H10; H10D; H10D86/00; H10P; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1924; H10W; H10W10/00; H10W10/10; H10W10/181
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
122 words
A fabrication process of semiconductor substrate comprising: a step of bonding a principal surface of a first substrate to a principal surface of a second substrate, said first substrate being an Si substrate in which at least one layer of non-porous thin film is provided on a porous Si layer; a step of exposing said porous Si layer from the side surface of the bonded substrate comprised of said first substrate and said second substrate; a step of dividing said bonded substrate across said porous Si layer by oxidizing said bonded substrate; and a step of removing the porous Si and oxidized porous Si layer on said second substrate separated by the division of said bonded substrate across said porous Si layer.
Claim 2
Dependent Claim
119 words
A fabrication process of semiconductor substrate comprising: a step of bonding a principal surface of a first substrate to a principal surface of a second substrate, said first substrate being an Si substrate in which at least one layer of non-porous thin film is formed on a porous Si layer and in which said porous Si layer is exposed at a side surface thereof; a step of dividing said bonded substrate across said porous Si layer by oxidizing the bonded substrate comprised of said first substrate and said second substrate; and a step of removing the Si and oxidized porous Si layer on said second substrate separated by the division of said bonding substrate across said porous Si layer.
Claim 3
Dependent Claim
53 words
The fabrication process of semiconductor substrate according to Claim 1 or Claim 2, wherein after removing the porous Si and oxidized porous Si layer on the first substrate separated by said division of the porous Si layer, the first substrate is again used as a raw material for said first substrate before bonding.
Claim 4
Dependent Claim
53 words
The fabrication process of semiconductor substrate according to Claim 1 or Claim 2, wherein after removing the porous Si and oxidized porous Si layer on the first substrate separated by said division of the porous Si layer, the first substrate is again used as a raw material for said second substrate before bonding.
Claim 5
Dependent Claim
54 words
The fabrication process of semiconductor substrate according to either one of Claims 1 to 4, wherein at least one layer of non-porous thin film is provided on a porous Si layer on each of two principal surfaces of said first substrate and said second substrate is bonded to each of said two principal surfaces.
Claim 6
Dependent Claim
25 words
The fabrication process of semiconductor substrate according to either one of Claims 1 to 5, wherein said non-porous thin film is a single-crystal Si layer.
Claim 7
Dependent Claim
30 words
The fabrication process of semiconductor substrate according to either one of Claims 1 to 5, wherein said non-porous thin film comprises an oxidized Si layer and a single-crystal Si layer.
Claim 8
Dependent Claim
26 words
The fabrication process of semiconductor substrate according to either one of Claims 1 to 5, wherein said non-porous thin film is a single-crystal compound semiconductor layer.
Claim 9
Dependent Claim
27 words
The fabrication process of semiconductor substrate according to either one of Claims 1 to 4 and 6 to 8, wherein said second substrate is an Si substrate.
Claim 10
Dependent Claim
44 words
The fabrication process of semiconductor substrate according to either one of Claim 1 to 4 and 6 to 8, wherein said second substrate is an Si substrate in which an oxidized Si film is formed at least on a principal surface to be bonded.
Claim 11
Dependent Claim
28 words
The fabrication process of semiconductor substrate according to either one of Claims 1 to 4 and 6 to 8, wherein said second substrate is a light transparent substrate.
Claim 12
Dependent Claim
52 words
The fabrication process of semiconductor substrate according to Claim 5, wherein said second substrates respectively bonded to the two principal surfaces of said first substrate are those selected from Si substrate, Si substrate with an oxidized Si film formed at least on a principal surface to be bonded, and light transparent substrate.
Claim 13
Dependent Claim
43 words
The fabrication process of semiconductor substrate according to Claim 12, wherein the second substrate bonded to one principal surface of said first substrate and the second substrate bonded to the other principal surface thereof are made of respective materials different from each other.
Claim 14
Dependent Claim
44 words
The fabrication process of semiconductor substrate according to either one of Claims 1 to 5, wherein a flattening process in a direction spreaded with the principal surface of the second substrate is carried out after removing said porous Si and oxidized porous Si layer.
Claim 15
Dependent Claim
22 words
The fabrication process of semiconductor substrate according to Claim 14, wherein said surface flattening process is annealing in an ambient containing hydrogen.
Claim 16
Dependent Claim
85 words
The fabrication process of semiconductor substrate according to either one of Claims 1 to 7 and 9 to 15, wherein removal of said porous Si and oxidized porous Si layer is selectively carried out by soak in either one of hydrofluoric acid, a mixture solution in which at least one of alcohol and hydrogen peroxide solution is added to hydrofluoric acid, buffered hydrofluoric acid, and a mixture solution in which at least one of alcohol and hydrogen peroxide solution is added to buffered hydrofluoric acid.
Claim 17
Dependent Claim
51 words
The fabrication process of semiconductor substrate according to either one of Claims 8 to 15, wherein removal of said porous Si and oxidized porous Si layer is carried out by selective chemical etching of porous Si with an etchant having a faster etch rate of porous Si against a compound semiconductor.
Claim 18
Dependent Claim
41 words
The fabrication process of semiconductor substrate according to either one of Claims 1 to 15, wherein removal of said porous Si and oxidized porous Si layer is carried out by polishing the layer, using said non-porous thin film as a stopper.
Claim 19
Dependent Claim
37 words
The fabrication process of semiconductor substrate according to either one of Claims 1 to 18, wherein bonding of said first substrate to said second substrate is performed by bringing the substrates into close contact with each other.
Claim 20
Dependent Claim
40 words
The fabrication process of semiconductor substrate according to either one of Claims 1 to 19, wherein bonding of said first substrate to said second substrate is carried out by a method selected from anodic bonding, pressing, annealing, and combinations thereof.
Claim 21
Dependent Claim
52 words
The fabrication process of semiconductor substrate according to either one of Claims 1 to 20, wherein formation of the non-porous thin film on the porous Si layer is carried out by performing anodization of an Si substrate to form porous Si and thereafter forming a non-porous thin film on said porous Si.
Claim 22
Dependent Claim
68 words
The fabrication process of semiconductor substrate according to either one of Claims 1 to 7, 9 to 16, and 18 to 20, wherein formation of the non-porous thin film on the porous Si layer is carried out by implanting ions of at least one element of rare gases, hydrogen, and nitrogen into an Si substrate to form a porous layer in a certain depth from a surface thereof.
Claim 23
Dependent Claim
90 words
The fabrication process of semiconductor substrate according to either one of Claims 1 to 20, wherein formation of the non-porous thin film on the porous Si layer is carried out by anodizing an Si substrate to form a porous Si layer, thereafter forming a non-porous thin film on said porous Si layer, and then implanting ions of at least one element of rare gases, hydrogen, and nitrogen through the non-porous thin film into said porous Si layer so as to have a projected range thereof in said porous Si layer.
Claim 24
Dependent Claim
23 words
The fabrication process of semiconductor substrate according to Claim 21 or Claim 23, wherein said anodization is carried out in an HF solution.
Claim 25
Dependent Claim
51 words
The fabrication process of semiconductor substrate according to either one of Claims 1 to 24, wherein prior to the oxidation of said bonding substrate, a layer of a material having a smaller coefficient of thermal expansion than Si is formed on at least one of outer surfaces of said bonding substrate.
Claim 26
Independent Claim
44 words
A method of producing a semiconductor device comprising steps of: producing a semiconductor substrate, including a layer of non-porous thin film, by the process according to any preceding claim; and producing a component or components of said semiconductor device in said non-porous thin film.
References Cited (Backward Citations)
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