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US5376560A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for forming isolated semiconductor structures

Assignee: National Semiconductor Corp
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Filing: 1994-01-24
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Granted: 1994-12-27
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Expires: 2014-01-24
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Abstract

Abstract A number of dielectrically isolated single crystal islands are formed by implanting neon or other group Zero ions into a semiconductor substrate, preferably silicon, at a sufficiently high energy to created an amorphized region in the interior of the substrate, without excessively damaging the substrate surface through which the ions pass. The amorphized regions are highly resistive, and are suitable for isolation in some applications. Where better isolation is desired, a dielectric isolation structure is formed as follows. Trenches are formed down into the amorphized regions, and the substrate is heavily oxidized to convert the amorphized regions into buried oxide regions and the island sidewalls into oxide. The islands are made thicker by removing the oxide from the islands' top surfaces and sidewalls, and growing epitaxial silicon over the substrate. Second trenches are formed down to the buried oxide regions, and the substrate is again oxidized to convert the islands' sidewalls to oxide. The remaining open space of the second trenches is filled, and devices of any desired type are formed in the single crystal islands.

Inventors

  • 👤 Sheldon Aronowitz
  • 👤 Courtney L. Hart

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 12:57
CPC Classifications
H; H10; H10P; H10P36/00; H10P36/03; H10P36/07; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/012; H10W10/061; H10W10/10; H10W10/13; H10W10/181; H10P90/191; H10W10/014; H10W10/17; Y; Y10; Y10S; Y10S438/00; Y10S438/966

Claims Analysis

Total Claims: 35
Claim 1
Independent Claim 143 words
A method of forming a dielectrically isolated single crystal semiconductor island in a semiconductor body, comprising the steps of: implanting ions of a group Zero element into the body through a surface of the body at an energy and a dose so that a first region inside the body is substantially amorphized while a second region of the body between the surface thereof and the first region is not substantially amorphized; forming a trench in the body from the surface to the first region, the trench being defined at least in part by a sidewall of the second region; and subjecting the body to an oxidizing environment to convert the first region to an oxide and the sidewall of the second region to an oxide; wherein the dose of said implanting step suppresses complete recrystallization of the first region during said subjecting step.
Claim 2
Independent Claim 143 words
A method of forming a dielectrically isolated single crystal semiconductor island in a semiconductor body, comprising the steps of: implanting ions of a group Zero element into the body through a surface of the body at an energy and a dose so that a first region inside the body is substantially amorphized while a second region of the body between the surface thereof and the first region is not substantially amorphized; forming a trench in the body from the surface to the first region, the trench being defined at least in part by a sidewall of the second region; and subjecting the body to an oxidizing environment to convert the first region to an oxide and the sidewall of the second region to an oxide; wherein the dose of said implanting step suppresses complete recrystallization of the first region during said subjecting step.
Claim 3
Dependent Claim 11 words
A method as in claim 1 wherein the body is silicon.
Claim 4
Dependent Claim 13 words
A method as in claim 1 wherein the group Zero element is neon.
Claim 5
Dependent Claim 32 words
A method as in claim 3, wherein the implanting step further comprises the step of implanting neon ions at a dose of at least about 1×10 16 Ne + /cm 2 .
Claim 6
Dependent Claim 32 words
A method as in claim 1, further comprising the step, subsequent to the group Zero ion implanting step, of annealing the body to heal any damage at the surface of the body.
Claim 7
Independent Claim 264 words
A method of forming a dielectrically isolated single crystal semiconductor island in a semiconductor body, comprising the steps of: implanting ions of a group Zero element into the body through a surface of the body at an energy and a dose so that a first region inside the body is substantially amorphized while a second region of the body including the surface and extending to the first region is not substantially amorphized; forming a first trench in the body from the surface to the first region, the trench being defined at least in part by a first sidewall of the second region; subjecting the body to an oxidizing environment to convert at least a portion of the first region to a continuous buried oxide layer, and the first sidewall and surface of the second region to oxide, wherein the dose of said implanting step suppresses complete recrystallization of the first region; removing oxide from the surface of the second region remaining after said first trench forming step and said oxidizing environment subjecting step to expose single crystal semiconductor material of the body; epitaxially depositing semiconductor material on the exposed single crystal semiconductor material of the body to form an epitaxial layer; forming a second trench in the epitaxial semiconductor layer from a surface thereof to the buried oxide layer, the second trench being defined at least in part by a sidewall of the epitaxial layer and a second sidewall of the second region; and forming a dielectric layer on the sidewall of the epitaxial layer and on the second sidewall of the second region.
Claim 8
Independent Claim 264 words
A method of forming a dielectrically isolated single crystal semiconductor island in a semiconductor body, comprising the steps of: implanting ions of a group Zero element into the body through a surface of the body at an energy and a dose so that a first region inside the body is substantially amorphized while a second region of the body including the surface and extending to the first region is not substantially amorphized; forming a first trench in the body from the surface to the first region, the trench being defined at least in part by a first sidewall of the second region; subjecting the body to an oxidizing environment to convert at least a portion of the first region to a continuous buried oxide layer, and the first sidewall and surface of the second region to oxide, wherein the dose of said implanting step suppresses complete recrystallization of the first region; removing oxide from the surface of the second region remaining after said first trench forming step and said oxidizing environment subjecting step to expose single crystal semiconductor material of the body; epitaxially depositing semiconductor material on the exposed single crystal semiconductor material of the body to form an epitaxial layer; forming a second trench in the epitaxial semiconductor layer from a surface thereof to the buried oxide layer, the second trench being defined at least in part by a sidewall of the epitaxial layer and a second sidewall of the second region; and forming a dielectric layer on the sidewall of the epitaxial layer and on the second sidewall of the second region.
Claim 9
Dependent Claim 11 words
A method as in claim 6 wherein the body is silicon.
Claim 10
Dependent Claim 13 words
A method as in claim 6 wherein the group Zero element is neon.
Claim 11
Dependent Claim 31 words
A method as in claim 8, wherein the implanting step further comprises the step of implanting neon ions at a dose of at least 1×10 16 Ne + /cm 2 .
Claim 12
Dependent Claim 32 words
A method as in claim 6, further comprising the step, subsequent to the group Zero ion implanting step, of annealing the body to heal any damages at the surface of the body.
Claim 13
Dependent Claim 14 words
A method as in claim 6, further comprising the step filling the second trench.
Claim 14
Dependent Claim 40 words
A method as in claim 6, wherein the first trench forming step is performed using a first mask, and wherein the second trench forming step is performed using a second mask, the second mask and the first mask being identical.
Claim 15
Dependent Claim 47 words
A method as in claim 6, wherein the first trench forming step is performed using a first mask, and wherein the second trench forming step is performed using a second mask, features of the second mask being slightly oversized relative to corresponding features of the first mask.
Claim 16
Independent Claim 237 words
A method for forming dielectrically isolated single crystal semiconductor islands in a semiconductor substrate, comprising the steps of: implanting ions of a group Zero element into the substrate at an energy and a dose so that an amorphized region is formed within the substrate; forming a first trench mask over the substrate, windows thereof being disposed over the amorphized region; etching the substrate through the first trench mask at least into proximity with the amorphized region to form single crystal substrate regions separated from one another by trenches and from an underlying region of the substrate by respective sections of the amorphized region. oxidizing the amorphized region sections to form dielectric segments underlying the single crystal substrate regions, wherein the dose of the implanted group Zero ion suppresses completed recrystallization of the amorphized region; exposing respective upper surfaces of the single crystal substrate regions; growing a layer of epitaxial semiconductor material on the upper surfaces of the single crystal substrate regions; forming a second trench mask over the epitaxial semiconductor material layer, the epitaxial semiconductor material layer being exposed through the second trench mask in a pattern substantially similar to the pattern of the first trench mask; and etching the epitaxial semiconductor material through the second trench mask at least into proximity with the dielectric segments to form single crystal islands separated from one another by trenches and from the underlying substrate region by the dielectric segments.
Claim 17
Independent Claim 237 words
A method for forming dielectrically isolated single crystal semiconductor islands in a semiconductor substrate, comprising the steps of: implanting ions of a group Zero element into the substrate at an energy and a dose so that an amorphized region is formed within the substrate; forming a first trench mask over the substrate, windows thereof being disposed over the amorphized region; etching the substrate through the first trench mask at least into proximity with the amorphized region to form single crystal substrate regions separated from one another by trenches and from an underlying region of the substrate by respective sections of the amorphized region. oxidizing the amorphized region sections to form dielectric segments underlying the single crystal substrate regions, wherein the dose of the implanted group Zero ion suppresses completed recrystallization of the amorphized region; exposing respective upper surfaces of the single crystal substrate regions; growing a layer of epitaxial semiconductor material on the upper surfaces of the single crystal substrate regions; forming a second trench mask over the epitaxial semiconductor material layer, the epitaxial semiconductor material layer being exposed through the second trench mask in a pattern substantially similar to the pattern of the first trench mask; and etching the epitaxial semiconductor material through the second trench mask at least into proximity with the dielectric segments to form single crystal islands separated from one another by trenches and from the underlying substrate region by the dielectric segments.
Claim 18
Dependent Claim 21 words
A method as in claim 14 further comprising the step of filling space between the single crystal island with dielectric material.
Claim 19
Dependent Claim 37 words
A method as in claim 14, further comprising the step of oxidizing sidewalls of the single crystal islands, the oxidized sidewalls of the single crystal islands merging with the dielectric segments to form a dielectric isolation structure.
Claim 20
Dependent Claim 25 words
A method as in claim 16 wherein the dielectric isolation structure includes gaps between the single crystal islands, comprising the step of filling the gaps.
Claim 21
Dependent Claim 28 words
A method as in claim 17, wherein the gap is filled with a material having a coefficient of thermal expansion similar to that of the single crystal islands.
Claim 22
Dependent Claim 43 words
A method as in claim 14, wherein the group Zero ion implanting step comprises the step of implanting neon ions at a dose of at least about 1×10 16 Ne + /cm 2 and at an energy of at least about two Mev.
Claim 23
Dependent Claim 13 words
A method as in claim 14 wherein the group Zero element is neon.
Claim 24
Dependent Claim 14 words
A method as in claim 14 wherein the single crystal semiconductor islands are silicon.
Claim 25
Dependent Claim 12 words
A method as in claim 14 wherein the semiconductor substrate is silicon.
Claim 26
Dependent Claim 13 words
A method as in claim 14 wherein the epitaxial semiconductor material is silicon.
Claim 27
Independent Claim 99 words
A method of forming a resistively isolated single crystal semiconductor island in a semiconductor body, comprising the steps of: implanting ions of a group Zero into the body through a surface of the body at an energy and a dose so that a first region inside the body is substantially amorphized while a second region of the body between the surface thereof and the first region is not substantially amorphized; and forming a trench in the body from the surface to the first region, the trench being defined at least in part by a sidewall of the second region.
Claim 28
Independent Claim 99 words
A method of forming a resistively isolated single crystal semiconductor island in a semiconductor body, comprising the steps of: implanting ions of a group Zero into the body through a surface of the body at an energy and a dose so that a first region inside the body is substantially amorphized while a second region of the body between the surface thereof and the first region is not substantially amorphized; and forming a trench in the body from the surface to the first region, the trench being defined at least in part by a sidewall of the second region.
Claim 29
Dependent Claim 11 words
A method as in claim 24, wherein the body is germanium.
Claim 30
Dependent Claim 32 words
A method as in claim 24, further comprising the step, subsequent to the group Zero ion implanting step, of annealing the body to heal any damage at the surface of the body.
Claim 31
Dependent Claim 11 words
A method as in claim 24 wherein the body is silicon.
Claim 32
Dependent Claim 13 words
A method as in claim 24 wherein the group Zero element is neon.
Claim 33
Dependent Claim 13 words
A method as in claim 24 wherein the group Zero element is Helium.
Claim 34
Dependent Claim 13 words
A method as in claim 24 wherein the group Zero element is Argon.
Claim 35
Dependent Claim 13 words
A method as in claim 24 wherein the group Zero element is Krypton.

References Cited (Backward Citations)

US3622382A Cited
US3663308A Cited
JPS5568651A Cited
JPS5575238A Cited
JPS56110247A Cited
JPS5763841A Cited
JPS64744A Cited
DD259715A1 Cited
US4810667A Cited
US5049521A Cited
US5043292A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-12-26 1998-06-27 1998-12-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-12-26 2002-06-27 2002-12-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-12-26 2006-06-27 2006-12-27 $7700.00 Window Closed / Lapsed

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