EP0164646A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Buried field shield for an integrated circuit
Assignee: International Business Machines Corp
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Filing: 1985-05-29
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Granted: —
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Expires: 2005-05-29
Abstract
Abstract A method for fabrication of a buried field shield (64) in a semiconductor substrate. A seed substrate is prepared by depositing an epitaxial layer (54) onto a seed wafer (80) and then depositing a heavily doped layer (56) and a thin dielectric (58). The thin dielectric is patterned for contact holes and then a conductive field shield (64) is deposited and patterned. A thick quartz layer (66) is deposited over the field shield and dielectric. A mechanical substrate (68) is anodically bonded to the quartz (66) of the seed substrate and the original seed wafer (80) is etched back to expose the epitaxial layer (54) for further fabrication of integrated electronic devices therein.
Inventors
- 👤 Paul E. Cade
- 👤 Badih El-Kareh
- 👤 Ick W. Kim
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 23:42
CPC Classifications
H; H10; H10D; H10D86/00; H10D86/01; H10P; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1914; H10W; H10W10/00; H10W10/10; H10W10/181; H10W15/00; H10W15/01; H10W20/00; H10W20/01; H10W20/021; H10W42/00; H10W72/00; H10W72/30; H10W72/071; H10W72/073; H10W72/07331; H10W72/07337; Y; Y10; Y10S; Y10S148/00; Y10S148/025; Y10S148/05; Y10S148/135
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
123 words
A method of fabricating a semiconductor structure, comprising the steps of: depasiting an epitaxial semiconductor layer (54) on a first semiconductor substrate (36; 80); and forming and patterning a dielectric layer (58) overlying said epitaxial layer; characterized by the further steps of: forming a field shield layer (64) of a conductive material on predetermined portions of said dielectric layer and on predetermined portions of said epitaxial layer; covering said field shield layer and all exposed portions of said dielectric layer and said epitaxial layer with a bonding material (66); bonding a second substrate (68) to the side of said first substrate covered with said bonding material (66), thereby forming a bonded structure; and removing said first substrate (36; 80) from said bonded structure.
Claim 2
Independent Claim
123 words
A method of fabricating a semiconductor structure, comprising the steps of: depasiting an epitaxial semiconductor layer (54) on a first semiconductor substrate (36; 80); and forming and patterning a dielectric layer (58) overlying said epitaxial layer; characterized by the further steps of: forming a field shield layer (64) of a conductive material on predetermined portions of said dielectric layer and on predetermined portions of said epitaxial layer; covering said field shield layer and all exposed portions of said dielectric layer and said epitaxial layer with a bonding material (66); bonding a second substrate (68) to the side of said first substrate covered with said bonding material (66), thereby forming a bonded structure; and removing said first substrate (36; 80) from said bonded structure.
Claim 3
Dependent Claim
54 words
A method of fabricating a semiconductor structure as recited in Claim 1, further comprising the step of: forming on said first substrate (36) before the depositing of said epitaxial layer (54) an etch stopping layer (46-52); and wherein said removing step is an etching step that does not substantially etch said etch stopping layer.
Claim 4
Dependent Claim
39 words
A method of fabricating a semiconductor structure as recited in Claim 2, wherein; said step of forming an etch stopping layer (46-52) includes patterning said layer to define aligning areas; and said etching step is an anisotropic etching step.
Claim 5
Dependent Claim
37 words
A method of fabricating a semiconductor structure, as recited in Claim 1, wherein said removing step is an etching step that etches away said first semiconductor substrate (80) but does not substantially etch said epitaxial layer (54).
Claim 6
Dependent Claim
68 words
A method of fabricating a semiconductor structure as recited in Claim 4, wherein the conductivity type of said epitaxial layer (54) is n-type and the doping concentration of said epitaxial layer is equal to or less than 10 /cm ; and the conductivity type of said first substrate (80) is p-type and the doping concentration of said first substrate is substantially greater than 10 18 /cm 3 .
Claim 7
Dependent Claim
22 words
A method of fabricating a semiconductor structure as recited in Claim 5, wherein said etching step uses an etchant of hydrofluoric-nitric-acetic acid.
Claim 8
Independent Claim
87 words
A method of fabricating a semiconductor structure as recited in a previous Claim, further comprising the step of: forming on said epitaxial layer (54), before the forming and patterning of said dielectric layer (58), an emitter layer (56) of a semiconductor of the same conductivity type as said epitaxial layer (54) and having a doping concentration substantially larger than the doping concentration of said epitaxial layer; wherein said patterning of said dielectric layer (58) includes an etching step that does not substantially etch said emitter layer (56).
Claim 9
Independent Claim
31 words
A method of forming a semiconductor, as recited in one or more of Claims 4-7, further comprising scribing alignment marks with a laser on said first substrate before said bonding step.
Claim 10
Dependent Claim
98 words
A buried field shield semiconductor structure comprising: a mechanical substrate (68) of silicon; a first dielectric layer (66) overlying and bonded to said mechanical substrate; characterized by: a field shield of a conductive material (64; 104) overlying a first portion of said first dielectric layer; a second dielectric layer (58) overlying the portion of said first dielectric layer (66) other than said first portion and overlying a second portion of said field shield; and a layer of epitaxial silicon (54, 56) overlying said second dielectric layer and the portion of said field shield other than said second portion.
Claim 11
Dependent Claim
98 words
A buried field shield semiconductor structure comprising: a mechanical substrate (68) of silicon; a first dielectric layer (66) overlying and bonded to said mechanical substrate; characterized by: a field shield of a conductive material (64; 104) overlying a first portion of said first dielectric layer; a second dielectric layer (58) overlying the portion of said first dielectric layer (66) other than said first portion and overlying a second portion of said field shield; and a layer of epitaxial silicon (54, 56) overlying said second dielectric layer and the portion of said field shield other than said second portion.
References Cited (Backward Citations)
No citation records indexed.
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