US5470799A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for pretreating semiconductor substrate by photochemically removing native oxide
Assignee: Mitsubishi Electric Corp
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Filing: 1989-04-24
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Granted: 1995-11-28
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Expires: 2009-04-24
Abstract
Abstract The present invention provides a method for removing a natural gas film or contaminant adhering on a surface of a silicon semiconductor substrate. The semiconductor substrate having the natural oxide film or contaminant adhered thereon is placed in a chamber. Then, a HCl gas is introduced into the chamber. The semiconductor substrate is heated at a temperature in the range of 200°˜700° C., while ultraviolet rays are irradiated into the chamber. According to the method, the reaction of the natural oxide with HCl gas is promoted by a synergistic effect of light and heat energy. Therefore, the natural oxide film or contaminant can be removed at a lower temperature with the help of the light energy.
Inventors
- 👤 Hiromi Itoh
- 👤 Masanobu Iwasaki
- 👤 Akira Tokui
- 👤 Katsuhiro Tsukamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:56
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/10; H10P70/12; Y; Y10; Y10S; Y10S438/00; Y10S438/906; Y10S438/974
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
129 words
A method for pretreating a silicon semiconductor substrate in order to remove a natural oxide film or contaminant adhering on a surface of the semiconductor substrate, said method comprising the steps of: placing said silicon semiconductor substrate in a chamber; introducing into said chamber a reaction gas capable of reacting with said natural oxide film or said contaminant, said reaction gas comprising HCl; heating said semiconductor substrate at a temperature in the range of 200°-700° C., and irradiating the reaction gas introduced into said chamber with light at said temperature in the range of 200°-700° C., while said semiconductor substrate is heated, said light having a wavelength which causes a photochemical reaction of the natural oxide film or contaminant adhering on said semiconductor substrate surface with said reaction gas.
Claim 2
Independent Claim
129 words
A method for pretreating a silicon semiconductor substrate in order to remove a natural oxide film or contaminant adhering on a surface of the semiconductor substrate, said method comprising the steps of: placing said silicon semiconductor substrate in a chamber; introducing into said chamber a reaction gas capable of reacting with said natural oxide film or said contaminant, said reaction gas comprising HCl; heating said semiconductor substrate at a temperature in the range of 200°-700° C., and irradiating the reaction gas introduced into said chamber with light at said temperature in the range of 200°-700° C., while said semiconductor substrate is heated, said light having a wavelength which causes a photochemical reaction of the natural oxide film or contaminant adhering on said semiconductor substrate surface with said reaction gas.
Claim 3
Dependent Claim
29 words
A method for pretreating a semiconductor substrate in accordance with claim 1, wherein a low pressure mercury lamp is used as a light source for irradiating said reaction gas.
Claim 4
Dependent Claim
34 words
A method for pretreating a semiconductor substrate in accordance with claim 1, wherein a pressure of an atmosphere of said reaction gas is selected in the range of from atmospheric pressure to 0.1 Torr.
Claim 5
Independent Claim
135 words
A method for pretreating a silicon semiconductor substrate in order to remove a natural oxide film or contaminant adhering on a surface of the semiconductor substrate, said method comprising the steps of: placing said silicon semiconductor substrate in a chamber; introducing into said chamber a reaction gas capable of reacting with said natural oxide film or contaminant, said reaction gas comprising HCl; heating the semiconductor substrate at a temperature in the range of 200°-700° C. by irradiating said semiconductor substrate with light; and irradiating the reaction gas introduced into said chamber with light at said temperature in the range of 200°-700° C., while said semiconductor substrate is heated, said light having a wavelength which causes a photochemical reaction of the natural oxide film or contaminant adhering on said semiconductor substrate surface with said reaction gas.
Claim 6
Independent Claim
135 words
A method for pretreating a silicon semiconductor substrate in order to remove a natural oxide film or contaminant adhering on a surface of the semiconductor substrate, said method comprising the steps of: placing said silicon semiconductor substrate in a chamber; introducing into said chamber a reaction gas capable of reacting with said natural oxide film or contaminant, said reaction gas comprising HCl; heating the semiconductor substrate at a temperature in the range of 200°-700° C. by irradiating said semiconductor substrate with light; and irradiating the reaction gas introduced into said chamber with light at said temperature in the range of 200°-700° C., while said semiconductor substrate is heated, said light having a wavelength which causes a photochemical reaction of the natural oxide film or contaminant adhering on said semiconductor substrate surface with said reaction gas.
Claim 7
Dependent Claim
30 words
A method for pretreating a semiconductor substrate in accordance with claim 4, wherein an infrared ray lamp is used as a light source irradiating light for heating said semiconductor substrate.
Claim 8
Dependent Claim
31 words
A method for pretreating a semiconductor substrate in accordance with claim 4, wherein a low pressure mercury lamp is used as a light source irradiating light which causes said photochemical reaction.
Claim 9
Dependent Claim
34 words
A method for pretreating a semiconductor substrate in accordance with claim 4, wherein a pressure of an atmosphere of said reaction gas is selected in the range of from atmospheric pressure to 0.1 Torr.
Claim 10
Independent Claim
88 words
A method for pretreating a silicon semiconductor substrate in order to remove a natural oxide film or contaminant adhering on a surface of the silicon semiconductor substrate, said method comprising the steps of: placing said silicon semiconductor substrate in a chamber; introducing HCl gas into the chamber; heating said silicon semiconductor substrate at a temperature in the range of 200°-700° C., and irradiating said HCl gas with an excimer laser which is introduced into said chamber along a path parallel with the surface of said silicon semiconductor substrate.
Claim 11
Independent Claim
88 words
A method for pretreating a silicon semiconductor substrate in order to remove a natural oxide film or contaminant adhering on a surface of the silicon semiconductor substrate, said method comprising the steps of: placing said silicon semiconductor substrate in a chamber; introducing HCl gas into the chamber; heating said silicon semiconductor substrate at a temperature in the range of 200°-700° C., and irradiating said HCl gas with an excimer laser which is introduced into said chamber along a path parallel with the surface of said silicon semiconductor substrate.
Claim 12
Independent Claim
113 words
A method for pretreating silicon semiconductor substrates in order to remove a natural oxide film or contaminant adhering on the surface of the silicon semiconductor substrates, said method comprising the steps of: placing into a chamber a rotating susceptor capable of holding a plurality of the silicon semiconductor substrates; mounting the plurality of the silicon semiconductor substrates on the rotating susceptor such that the back side of each silicon semiconductor substrate contacts the surface of the rotating susceptor; introducing HCl gas into the chamber; rotating the rotating susceptor with the plurality of the silicon semiconductor substrates; and irradiating each silicon semiconductor substrate with infrared rays and irradiating the HCl gas with ultraviolet rays.
Claim 13
Independent Claim
113 words
A method for pretreating silicon semiconductor substrates in order to remove a natural oxide film or contaminant adhering on the surface of the silicon semiconductor substrates, said method comprising the steps of: placing into a chamber a rotating susceptor capable of holding a plurality of the silicon semiconductor substrates; mounting the plurality of the silicon semiconductor substrates on the rotating susceptor such that the back side of each silicon semiconductor substrate contacts the surface of the rotating susceptor; introducing HCl gas into the chamber; rotating the rotating susceptor with the plurality of the silicon semiconductor substrates; and irradiating each silicon semiconductor substrate with infrared rays and irradiating the HCl gas with ultraviolet rays.
Claim 14
Dependent Claim
30 words
A method for pretreating silicon semiconductor substrates in accordance with claim 9, wherein the silicon semiconductor substrates are heated at a temperature in the range of 200° to 700° C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-11-27 | 1999-05-29 | 1999-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-11-27 | 2003-05-29 | 2003-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-11-27 | 2007-05-29 | 2007-11-28 | $7700.00 | Window Closed / Lapsed |