US6020247A
Expired / Lapsed
US
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Method for thin film deposition on single-crystal semiconductor substrates
Assignee: Texas Instruments Inc
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Filing: 1997-07-31
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Granted: 2000-02-01
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Expires: 2017-07-31
Abstract
Abstract A method of preparing a surface for and forming a thin film on a single-crystal silicon substrate is disclosed. One embodiment of his method comprises forming an oxidized silicon layer (which may be a native oxide) on at least one region of the substrate, and thermally annealing the substrate in a vacuum while supplying a silicon-containing flux to the oxide surface, thus removing the oxidized silicon layer. Preferably, the thin film is formed immediately after removal of the oxidized silicon layer. The silicon-containing flux is preferably insufficient to deposit a silicon-containing layer on top of the oxidized silicon layer, and yet sufficient to substantially inhibit an SiO-forming reaction between the silicon substrate and the oxidized silicon layer. The method of the invention allows for growth or deposition of films which have exceptionally smooth interfaces (less than 0.1 nm rms roughness) with the underlying silicon substrate at temperatures less than 800 DEG C., and is ideally suited for deposition of ultrathin films having thicknesses less than about 5 nm.
Inventors
- 👤 Glen D. Wilk
- 👤 Yi Wei
- 👤 Robert M. Wallace
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:29
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/10; H10P14/00; H10P14/20; H10P14/24; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/60; H10P14/63; H10P14/6302; H10P14/6322; H10P14/6326; H10P14/6328; H10P14/6329; H10P14/6334; H10P14/65; H10P14/6502; H10P14/6504; H10P14/6512; H10P14/66; H10P14/668; H10P14/6681; H10P14/6682; H10P70/12; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309; H10P14/69; H10P14/692; H10P14/6921; H10P14/69215; Y; Y10; Y10S; Y10S438/00; Y10S438/974
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
151 words
A method of forming a non-epitaxial thin film on a single-crystal silicon substrate, said method comprising the steps of: forming a first oxidized silicon layer on a first region of said substrate by allowing a native oxide layer to form; forming a second oxidized silicon layer on at least one second region of said substrate; placing said substrate in a vacuum; providing a silicon-containing flux to said substrate, said flux being insufficient to deposit a silicon-containing layer on said first oxidized silicon layer but sufficient to substantially inhibit an SiO-forming reaction between said silicon substrate and said first oxidized silicon layer; continuing said flux until said first oxidized silicon layer is removed from said first region of said substrate, wherein said second oxidized silicon layer is not completely removed during said removal of said first oxidized silicon layer; and forming said non-epitaxial thin film on said first region of said substrate.
Claim 2
Independent Claim
151 words
A method of forming a non-epitaxial thin film on a single-crystal silicon substrate, said method comprising the steps of: forming a first oxidized silicon layer on a first region of said substrate by allowing a native oxide layer to form; forming a second oxidized silicon layer on at least one second region of said substrate; placing said substrate in a vacuum; providing a silicon-containing flux to said substrate, said flux being insufficient to deposit a silicon-containing layer on said first oxidized silicon layer but sufficient to substantially inhibit an SiO-forming reaction between said silicon substrate and said first oxidized silicon layer; continuing said flux until said first oxidized silicon layer is removed from said first region of said substrate, wherein said second oxidized silicon layer is not completely removed during said removal of said first oxidized silicon layer; and forming said non-epitaxial thin film on said first region of said substrate.
Claim 3
Dependent Claim
16 words
The method of claim 1, wherein said single-crystal substrate is oriented substantially in the (100) plane.
Claim 4
Dependent Claim
14 words
The method of claim 1, wherein said second layer is a field oxide layer.
Claim 5
Dependent Claim
30 words
The method of claim 1, wherein said vacuum is maintained in a range of about 10 -10 torr to about 10 -8 torr during said providing a silicon-containing flux step.
Claim 6
Dependent Claim
20 words
The method of claim 1, wherein said silicon-containing flux is provided to said substrate by a physical vapor deposition method.
Claim 7
Dependent Claim
21 words
The method of claim 5, wherein said physical vapor deposition method is selected from the group consisting of sputtering and evaporation.
Claim 8
Dependent Claim
20 words
The method of claim 1, wherein said silicon-containing flux is provided to said substrate by a chemical vapor deposition method.
Claim 9
Dependent Claim
25 words
The method of claim 7, wherein said silicon-containing flux is selected from the group consisting of silane, disilane, chlorosilane, dichlorosilane, trichlorosilane, tetrachlorosilane, and combinations thereof.
Claim 10
Dependent Claim
22 words
The method of claim 1, wherein said depositing said non-epitaxial film step is performed without first returning said substrate to atmospheric pressure.
Claim 11
Independent Claim
140 words
A method of forming a non-epitaxial thin film on a single-crystal silicon substrate, said method comprising the steps of: forming an oxidized silicon layer on a first region of said substrate; placing said substrate in a vacuum and heating said substrate to a first temperature range of about 640° C. to about 780° C.; providing a silicon-containing flux to said substrate, said flux being insufficient to deposit a silicon-containing layer on said oxidized silicon layer but sufficient to substantially inhibit an SiO-forming reaction between said silicon substrate and said oxidized silicon layer; while continuing said flux, maintaining said substrate in a second temperature range of about 640° C. to about 1050° C. until said first oxidized silicon layer is removed from said first region of said substrate; and forming said non-epitaxial thin film on said first region of said substrate.
Claim 12
Independent Claim
140 words
A method of forming a non-epitaxial thin film on a single-crystal silicon substrate, said method comprising the steps of: forming an oxidized silicon layer on a first region of said substrate; placing said substrate in a vacuum and heating said substrate to a first temperature range of about 640° C. to about 780° C.; providing a silicon-containing flux to said substrate, said flux being insufficient to deposit a silicon-containing layer on said oxidized silicon layer but sufficient to substantially inhibit an SiO-forming reaction between said silicon substrate and said oxidized silicon layer; while continuing said flux, maintaining said substrate in a second temperature range of about 640° C. to about 1050° C. until said first oxidized silicon layer is removed from said first region of said substrate; and forming said non-epitaxial thin film on said first region of said substrate.
Claim 13
Dependent Claim
15 words
The method of claim 10, wherein said non-epitaxial thin film is a dielectric thin film.
Claim 14
Dependent Claim
34 words
The method of claim 11, wherein said dielectric thin film is selected from the group consisting of silicon dioxide, silicon nitride, tantalum pentoxide, titanium dioxide, barium titanate, strontium titanate, bismuth titanate, and combinations thereof.
Claim 15
Dependent Claim
15 words
The method of claim 10, wherein said non-epitaxial thin film is a conductive thin film.
Claim 16
Independent Claim
149 words
A method of forming a gate dielectric thin film on a single-crystal silicon substrate oriented substantially in the (100) plane and having a first oxidized silicon layer formed on a first region of a first surface thereof and a field oxide layer formed on a second region of said first surface, said method comprising the steps of: placing said substrate in a vacuum chamber and evacuating said chamber to less than about 10 -6 torr; heating said substrate to a first temperature range of about 680° C. to about 780° C.; providing a silicon-containing flux to said first surface at an equivalent rate greater than 0.01 nm/s; while continuing said flux, maintaining said substrate in a second temperature range of about 680° C. to about 1050° C. until said first oxidized silicon layer is removed from said first surface; and depositing said gate dielectric thin film on said substrate.
Claim 17
Independent Claim
149 words
A method of forming a gate dielectric thin film on a single-crystal silicon substrate oriented substantially in the (100) plane and having a first oxidized silicon layer formed on a first region of a first surface thereof and a field oxide layer formed on a second region of said first surface, said method comprising the steps of: placing said substrate in a vacuum chamber and evacuating said chamber to less than about 10 -6 torr; heating said substrate to a first temperature range of about 680° C. to about 780° C.; providing a silicon-containing flux to said first surface at an equivalent rate greater than 0.01 nm/s; while continuing said flux, maintaining said substrate in a second temperature range of about 680° C. to about 1050° C. until said first oxidized silicon layer is removed from said first surface; and depositing said gate dielectric thin film on said substrate.
Claim 18
Dependent Claim
16 words
The method of claim 14, wherein said gate dielectric film is a silicon dioxide thin film.
Claim 19
Dependent Claim
40 words
The method of claim 15, wherein said providing a silicon-containing flux step deposits a layer of silicon on said field oxide layer, and wherein said depositing a gate dielectric thin film step at least partially oxidizes said layer of silicon.
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