US4016017A
Expired / Lapsed
US
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Integrated circuit isolation structure and method for producing the isolation structure
Assignee: International Business Machines Corp
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Filing: 1975-11-28
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Granted: 1977-04-05
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Expires: 1995-11-28
Abstract
Abstract A semiconductor device, such as a transistor, integrated circuit or the like, having a pattern of oxidized and densified porous silicon regions extending onto one of its major surfaces for isolating regions of the semiconductor is manufacturable by a relatively simple process. The process involves forming porous silicon regions in the surface of the semiconductor body such as a silicon wafer, in the areas where dielectric isolation between semiconductor devices is desired. The porous silicon regions are then oxidized at a temperature sufficient to completely oxidize the porous silicon. The oxidiation is such that the oxidized porous silicon extends above the surface of the semiconductor wafer. The oxidized porous silicon regions are then subjected to a temperature higher than the oxidizing temperature utilized in the previous step to cause the densification of the oxidized porous silicon regions. The result of this densification step is the collapse of the porous oxide to a dense structure which is substantially planar with the surface of the semiconductor wafer. This densified silicon dioxide structure has an etch rate which is substantially the same as thermally grown silicon dioxide.
Inventors
- 👤 Joseph Adam Aboaf
- 👤 Robert Wallace Broadie
- 👤 William Aaron Pliskin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:32
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/66; H10P14/665; H10P14/63; H10P14/6302; H10P14/6322; H10P14/65; H10P14/6516; H10P14/6529; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/191; H10P95/00; H10W; H10W10/00; H10W10/10; H10W10/181; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309; Y; Y10; Y10S; Y10S148/00; Y10S148/003; Y10S148/085; Y10S148/117; Y10S148/118
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
87 words
A method of producing a semiconductor device comprising: forming porous silicon regions in a semiconductor body; oxidizing said porous silicon regions at a temperature sufficient to completely oxidize said porous silicon regions and so that the oxidized porous silicon extends above the surface of the said body; and subjecting the said oxidized porous silicon regions to a temperature higher than said oxidizing temperature to cause the densification of said oxidized porous silicon regions which result in their being substantially planar with the surface of the semiconductor body.
Claim 2
Independent Claim
87 words
A method of producing a semiconductor device comprising: forming porous silicon regions in a semiconductor body; oxidizing said porous silicon regions at a temperature sufficient to completely oxidize said porous silicon regions and so that the oxidized porous silicon extends above the surface of the said body; and subjecting the said oxidized porous silicon regions to a temperature higher than said oxidizing temperature to cause the densification of said oxidized porous silicon regions which result in their being substantially planar with the surface of the semiconductor body.
Claim 3
Dependent Claim
15 words
The method of claim 1 wherein the said oxidizing temperature is above about 970° C.
Claim 4
Dependent Claim
11 words
The method of claim 1 wherein the said semiconductor is silicon.
Claim 5
Dependent Claim
17 words
The method of claim 1 wherein said temperature to cause densification is greater than about 1150° C.
Claim 6
Dependent Claim
15 words
The method of claim 4 wherein the said densification is accomplished in an inert atmosphere.
Claim 7
Dependent Claim
21 words
The method of claim 1 wherein said porous regions were made porous by anodic treatment in a solution of hydrofluoric acid.
Claim 8
Dependent Claim
31 words
The method of claim 1 wherein the said porous silicon regions and subjected to said oxidizing temperature long enough to grow a thermal oxide layer under the oxidized porous silicon regions.
Claim 9
Dependent Claim
27 words
The method of claim 7 wherein a junction is formed in a semiconductor region adjacent to one of said regions which junction abuts said thermal oxide layer.
Claim 10
Dependent Claim
18 words
The method of claim 1 wherein said porous silicon regions have a porosity of less than about 60%.
Claim 11
Independent Claim
126 words
A method of producing integrated circuit devices comprising: forming a pattern of porous silicon regions where dielectric isolation between semiconductor devices is desired in a silicon wafer; oxidizing said porous silicon regions at a temperature sufficient to completely oxidize said porous silicon regions and so that the oxidized porous silicon extends above the surface of the said wafer; subjecting the said oxidized porous silicon regions to a temperature higher than said oxidizing temperature to cause the densification of said oxidized porous silicon regions which result in their being substantially planar with the surface of the said silicon wafer; forming said semiconductor devices in portions of said wafer between said densified oxidized porous regions and electrically connecting said semiconductor devices into the desired said integrated circuit devices.
Claim 12
Independent Claim
126 words
A method of producing integrated circuit devices comprising: forming a pattern of porous silicon regions where dielectric isolation between semiconductor devices is desired in a silicon wafer; oxidizing said porous silicon regions at a temperature sufficient to completely oxidize said porous silicon regions and so that the oxidized porous silicon extends above the surface of the said wafer; subjecting the said oxidized porous silicon regions to a temperature higher than said oxidizing temperature to cause the densification of said oxidized porous silicon regions which result in their being substantially planar with the surface of the said silicon wafer; forming said semiconductor devices in portions of said wafer between said densified oxidized porous regions and electrically connecting said semiconductor devices into the desired said integrated circuit devices.
Claim 13
Dependent Claim
38 words
The method of claim 10 wherein the porosity of said porous silicon regions is less than about 60%, said oxidizing temperature is above about 970° C., and said temperature to cause densification is greater than about 1150° C.
Claim 14
Dependent Claim
31 words
The method of claim 10 wherein the said porous silicon regions are subjected to said oxidizing temperature long enough to grow a thermal oxide layer under the oxidized porous silicon regions.
Claim 15
Dependent Claim
26 words
The method of claim 12 wherein certain junctions formed as part of said semiconductor devices abut said thermal oxide layer under the oxidized porous silicon regions.
References Cited (Backward Citations)
US3640806A
Cited
US3919060A
Cited
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