EP0540277A2
Expired / Lapsed
EP
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Method for planarized isolation for CMOS devices
Assignee: STMicroelectronics lnc USA
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Filing: 1992-10-26
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Granted: —
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Expires: 2012-10-26
Abstract
Abstract A method for forming field oxide regions includes the formation of cavities in a semiconductor substrate. A layer of thermal oxide is then grown on the substrate. A layer of planarizing material is deposited over the device, filling the cavities. The planarizing layer is etched back to expose a portion of the cavities. A conformal layer of undoped oxide or a layer of polycrystalline silicon that is converted to oxide is deposited over the device, followed by a second layer of planarizing material, The planarizing material and conformal layer are then etched back to expose the active areas in the substrate.
Inventors
- 👤 Girish Anant Dixit
- 👤 Fusen E. Chen
- 👤 Robert O. Miller
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 18:43
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10W10/041; H10W10/10; H10W10/17; H10W10/40; Y; Y10; Y10S; Y10S148/00; Y10S148/05
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
103 words
A method for formation of an isolation region, comprising the steps of: creating cavities in a semiconductor substrate where oxide will be formed; forming a layer of oxide over the substrate; depositing a first planarizing layer over the device and extending into said cavities; removing a portion of said first planarizing layer and oxide layer to expose a portion of the substrate between the cavities and a portion of the cavities; depositing a second planarizing layer over the device and extending into said cavities; and removing a portion of said second planarizing layer to expose a portion of the substrate between the cavities.
Claim 2
Dependent Claim
43 words
The method of Claim 1, wherein said step of creating cavities in the semiconductor substrate comprises: depositing and patterning a masking layer on the substrate to define openings; removing a portion of the substrate exposed within the openings; and removing the masking layer.
Claim 3
Independent Claim
132 words
A method for formation of an isolation region, comprising the steps of: depositing and patterning a masking layer on a semiconductor substrate to define openings therein; removing a portion of the substrate exposed in the openings to define cavities in the substrate; removing the masking layer; forming a layer of oxide over the substrate; depositing a first planarizing layer over the device and extending into said cavities; etching back the first planarizing layer and oxide layer to expose a portion of the substrate between the cavities and a portion of the cavities; depositing a conformal layer over the device and extending into said cavities; depositing a second planarizing layer over the device; and etching back said second planarizing layer and conformal layer to expose a portion of the substrate between the cavities.
Claim 4
Dependent Claim
15 words
The method of Claim 2 or 3 wherein the masking layer includes a photoresist mask.
Claim 5
Dependent Claim
22 words
The method of Claim 2 or 3 wherein said step of removing a portion of the substrate comprises anisotropically etching said substrate.
Claim 6
Dependent Claim
21 words
The method of Claim 1 or 3, wherein said step of forming a layer of oxide comprises thermally growing said oxide.
Claim 7
Dependent Claim
19 words
The method of Claim 1 or 3, wherein said first planarizing layer includes a material other than thermal oxide.
Claim 8
Dependent Claim
16 words
The method of Claim 7, wherein said first planarizing layer comprises reflowable or spin on glass.
Claim 9
Dependent Claim
26 words
The method of Claim 3, wherein said first planarizing layer is a multilayer comprising a first conformal layer and a second layer which can be planarized.
Claim 10
Dependent Claim
18 words
The method of Claim 3, wherein said conformal layer comprises undoped oxide or polycrystalline silicon converted to oxide.
Claim 11
Dependent Claim
19 words
The method of Claim 1 or 3 wherein said second planarizing layer incudes a material other than thermal oxide.
Claim 12
Dependent Claim
31 words
The method of Claim 11, when dependent on Claim 1, wherein said second planarizing layer is a multilayer comprising a first conformal layer and a second layer which can be planarized.
Claim 13
Dependent Claim
21 words
The method of Claim 9 or 12 wherein said first conformal layer comprises undoped oxide or polycrystalline silicon converted to oxide.
Claim 14
Dependent Claim
18 words
The method of Claim 9 or Claim 12, wherein said second layer comprises reflowable or spin on glass.
Claim 15
Dependent Claim
21 words
The method of Claim 11, when dependent on Claim 3, wherein said second planarizing layer comprises reflowable or spin on glass.
Claim 16
Dependent Claim
26 words
The method of Claim 1 or 3 wherein said step of removing a portion of the first and second planarizing layers comprises anisotropically etching said layers.
Claim 17
Dependent Claim
23 words
The method of Claim 1 or 3, wherein a channel stop region is formed beneath the cavities before the oxide layer is grown.
Claim 18
Dependent Claim
23 words
The method of Claim 17, wherein said step of forming a channel stop region comprises implanting dopants into said region of the substrate.
Claim 19
Dependent Claim
57 words
A structure for an integrated circuit, comprising: a semiconductor substrate; and an isolation region with an upper surface that is substantially planar with the substrate and contains a layer of thermal oxide, a first material other than thermal oxide, and a second material other than thermal oxide which lies at the upper surface of the isolation region.
Claim 20
Dependent Claim
19 words
The structure of Claim 19 wherein the thermal oxide is substantially perpendicular to the upper surface of the substrate.
Claim 21
Dependent Claim
80 words
The structure of Claim 19, wherein the isolation region has a configuration formed by: creating cavities in a semiconductor substrate; forming a layer of oxide over the substrate; depositing a first material over the device; etching back the oxide and material to expose a portion of the substrate between the cavities and a portion of the cavities; depositing a second material over the device; and etching back the second material to expose a portion of the substrate between the cavities.
References Cited (Backward Citations)
No citation records indexed.
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