EP0595233A2
Expired / Lapsed
EP
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Method for constructing semiconductor-on-insulator
Assignee: Texas Instruments Inc
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Filing: 1993-10-25
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Granted: —
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Expires: 2013-10-25
Abstract
Abstract A method for constructing a semiconductor-on-insulator is provided. A sacrificial layer (12) of a predetermined thickness is first formed on a semiconductor wafer (10) surface. The wafer (10) is then subjected to an ion implantation process to place the ions (16) at predetermined depths below the semiconductor wafer surface. During the implantation process, the sacrificial layer (12) is gradually sputtered away and thereby compensating the gradual outgrowth of the silicon surface due to the volume of the implanted ions (16). A post-implant anneal is performed to allow the ions (16) to react with the semiconductor to form a buried insulating layer (24). <IMAGE>
Inventors
- 👤 Keith A. Joyner
- 👤 Mohamed K. El-Ghor
- 👤 Harold H. Hosack
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 16:16
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/208; H10P30/209; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1908; H10W; H10W10/00; H10W10/10; H10W10/181
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
62 words
A method for constructing a semiconductor-on-insulator, comprising the steps of: forming a sacrificial layer having a predetermined thickness on a surface of a semiconductor wafer; implanting ions of a predetermined dosage into said semiconductor wafer at predetermined depths below said semiconductor wafer surface, said sacrificial layer being gradually sputtered away by said ions; and annealing said semiconductor wafer at a predetermined temperature.
Claim 2
Dependent Claim
26 words
The method, as set forth in claim 1, further comprising the step of forming a protective layer on said semiconductor wafer surface before said annealing step.
Claim 3
Dependent Claim
24 words
The method, as set forth in claim 2, wherein said protective layer forming step includes depositing an oxide layer on said semiconductor wafer surface.
Claim 4
Dependent Claim
25 words
The method, as set forth in claim 1, wherein said sacrificial layer forming step includes growing a silicon oxide layer on said semiconductor wafer surface.
Claim 5
Dependent Claim
28 words
The method, as set forth in claim 1, wherein said sacrificial layer forming step includes growing an oxide film approximately 1200-1500 A thick on said semiconductor wafer surface.
Claim 6
Dependent Claim
39 words
The method, as set forth in claim 1, wherein said sacrificial layer forming step includes forming a film having a thickness and material properties so that a substantial portion of said film is sputtered away during said implantation step.
Claim 7
Dependent Claim
20 words
The method, as set forth in claim 1, wherein said sacrificial layer forming step includes growing a silicon nitride layer.
Claim 8
Dependent Claim
42 words
The method, as set forth in claim 1, wherein said ion implanting step includes implanting oxygen ions having a dosage of approximately 1.8x10¹⁸ cm⁻² into said sacrificial layer, and implanting said oxygen ions at approximately 1600-5600 A below said semiconductor wafer surface.
Claim 9
Dependent Claim
18 words
The method, as set forth in claim 8, wherein said ion implanting step further includes implanting nitrogen ions.
Claim 10
Dependent Claim
28 words
The method, as set forth in claim 1, further comprising the step of heating said semiconductor wafer to a surface temperature of about 600°C during said implanting step.
Claim 11
Dependent Claim
26 words
The method, as set forth in claim 1, wherein said annealing step includes heating said semiconductor wafers to at least 1100°C in a neutral ambient gas.
Claim 12
Dependent Claim
73 words
Semiconductor-on-insulator in a semiconductor wafer, comprising: a buried oxide layer being at a predetermined depth below a surface of said semiconductor wafer constructed by forming a sacrificial layer having a predetermined thickness on said semiconductor wafer surface, implanting oxygen ions into said semiconductor wafer, said sacrificial layer being gradually sputtered away by said oxygen ions, and annealing said semiconductor wafer at high temperature; and said buried oxide layer being substantially free of inclusions.
Claim 13
Dependent Claim
116 words
Silicon-on-insulator in a silicon wafer, comprising: a surface silicon layer of approximately 1600 A thickness forming a top surface of said wafer; an oxide layer at least 3500 A thick and buried below said top surface of said wafer constructed by forming a sacrificial oxide layer of at least 1400 A thick on said wafer surface, implanting a high dose of oxygen ions into said wafer, said sacrificial oxide layer being gradually sputtered away by said oxygen ions, and annealing said semiconductor wafer at high temperature; a substrate silicon layer below said oxide layer; and said buried oxide layer being substantially free of inclusions near an interface between said buried oxide layer and substrate silicon layer.
Claim 14
Independent Claim
79 words
A method for constructing semiconductor-on-insulator, comprising the steps of: forming a sacrificial layer having a predetermined thickness on a surface of a semiconductor wafer; implanting ions of a predetermined dosage into said semiconductor wafer at predetermined depths below said semiconductor wafer surface, the depth of implantation remaining substantially constant due to a gradual decrease in thickness in said sacrificial layer caused by sputtering by said ions; and annealing said semiconductor wafer at high temperature in a neutral ambient atmosphere.
References Cited (Backward Citations)
No citation records indexed.
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