Patent US4474829A successfully refreshed from Google Patents.
US4474829A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-temperature charge-free process for forming native oxide layers
Assignee: Raytheon Co
•
Filing: 1983-07-28
•
Granted: 1984-10-02
•
Expires: 2003-07-28
Abstract
Abstract The specification discloses a low-temperature, charge-free process for forming a layer of a native oxide on the surface of a substrate of a chosen semiconductor material. The substrate is exposed to neutral, charge-free oxygen atoms that are the primary oxidizing species and are formed in a manner which eliminates the generation of charged particles or high energy radiation. These oxygen atoms then react with the surface of the substrate to form the native oxide thereof. The use of neutral oxygen atoms avoids damage to the substrate due to exposure to charged particles or high energy radiation, both in the manner in which the oxidizing species is formed and in the manner in which the native oxide layer is grown. In a preferred embodiment, the neutral oxygen atoms are formed by exposing a chosen oxygen-containing precursor to radiation of a selected wavelength to cause the direct dissociation of the precursor to generate oxygen solely in atomic form.
Inventors
- 👤 John W. Peters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:52
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309; H10P14/6312; H10P14/69; H10P14/692; H10P14/65; H10P14/6502; H10P14/6504; H10P14/6921; H10P14/69215
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
137 words
A low-temperature, charge-free process for forming a layer of a native oxide of a chosen material on the surface of a substrate of said chosen material, comprising the steps of: (a) providing said substrate of said chosen material; and (b) exposing said surface of said substrate at a temperature within the range of about 30 to 300° C. and a pressure below atmospheric pressure to an atmosphere comprising neutral, charge-free oxygen atoms as the primary oxidizing species and formed in a manner which eliminates the generation of charged particles or high energy radiation, to bring about a reaction between said oxygen atoms and said surface of said substrate to form said native oxide while simultaneously minimizing damage to said substrate caused by said charged particles or said high energy radiation and minimizing thermal damage to said substrate.
Claim 2
Dependent Claim
137 words
A low-temperature, charge-free process for forming a layer of a native oxide of a chosen material on the surface of a substrate of said chosen material, comprising the steps of: (a) providing said substrate of said chosen material; and (b) exposing said surface of said substrate at a temperature within the range of about 30 to 300° C. and a pressure below atmospheric pressure to an atmosphere comprising neutral, charge-free oxygen atoms as the primary oxidizing species and formed in a manner which eliminates the generation of charged particles or high energy radiation, to bring about a reaction between said oxygen atoms and said surface of said substrate to form said native oxide while simultaneously minimizing damage to said substrate caused by said charged particles or said high energy radiation and minimizing thermal damage to said substrate.
Claim 3
Dependent Claim
24 words
The process set forth in claim 1 wherein said oxygen atoms are generated by a photochemical reaction which produces oxygen solely in atomic form.
Claim 4
Dependent Claim
156 words
A low-temperature process for forming a layer of a native oxide of a chosen material on the surface of a substrate of said chosen material by a photochemical reaction, comprising the steps of: (a) providing said substrate of said chosen material; and (b) exposing said surface of said substrate at a temperature within the range of about 30 to 300° C. to photochemically generated neutral oxygen atoms as the primary oxidizing species, said oxygen atoms being formed by exposing a chosen oxygen-containing precursor at a pressure below atmospheric pressure to radiation of a selected wavelength to cause the direct dissociation of said precursor to form said oxygen atoms, whereby said oxygen atoms react with said surface of said substrate to form said native oxide and said neutral oxygen atoms are formed and said native oxide is formed in a manner which avoids damage to said substrate causes by exposure to charged particles or high energy radiation.
Claim 5
Dependent Claim
156 words
A low-temperature process for forming a layer of a native oxide of a chosen material on the surface of a substrate of said chosen material by a photochemical reaction, comprising the steps of: (a) providing said substrate of said chosen material; and (b) exposing said surface of said substrate at a temperature within the range of about 30 to 300° C. to photochemically generated neutral oxygen atoms as the primary oxidizing species, said oxygen atoms being formed by exposing a chosen oxygen-containing precursor at a pressure below atmospheric pressure to radiation of a selected wavelength to cause the direct dissociation of said precursor to form said oxygen atoms, whereby said oxygen atoms react with said surface of said substrate to form said native oxide and said neutral oxygen atoms are formed and said native oxide is formed in a manner which avoids damage to said substrate causes by exposure to charged particles or high energy radiation.
Claim 6
Dependent Claim
41 words
The process set forth in claim 3 wherein said oxygen-containing precursor is selected from the group consisting of: nitrous oxide (N 2 O); nitrogen dioxide (NO 2 ); and molecular oxygen (O 2 ) under selected pressure and flow rate conditions.
Claim 7
Dependent Claim
54 words
The process set forth in claim 3 wherein said chosen material is selected from the group consisting of mercury cadmium telluride (HgCdTe), gallium aluminum arsenide (GaAlAs), indium gallium arsenide (InGaAs), indium gallium phosphide (InGaP), indium phosphide (InP), indium antimonide (InSb), gallium arsenide (GaAs), gallium antimonide (GaSb), gallium phosphide (GaP), silicon (Si), and germanium (Ge).
Claim 8
Dependent Claim
41 words
The process set forth in claim 3 wherein: (a) said chosen material is indium phosphide (InP); (b) said oxygen-containing precursor is molecular oxygen under selected pressure and flow rate conditions; and (c) said selected wavelength of said radiation is 1849 Å.
Claim 9
Dependent Claim
110 words
A low-temperature process for forming a layer of a native oxide of a chosen material on the surface of a substrate of said chosen material while simultaneously minimizing damage to said substrate by charged species or high energy radiation, comprising the steps of: (a) photochemically generating neutral oxygen atoms at a pressure below atmospheric pressure; and (b) exposing said substrate at a temperature of about 30 to 300° C. to said neutral oxygen atoms as the primary oxidizing species to cause a chemical reaction between said neutral oxygen atoms and said surface of said substrate to form said native oxide in a manner which avoids said damage to said substrate.
Claim 10
Dependent Claim
110 words
A low-temperature process for forming a layer of a native oxide of a chosen material on the surface of a substrate of said chosen material while simultaneously minimizing damage to said substrate by charged species or high energy radiation, comprising the steps of: (a) photochemically generating neutral oxygen atoms at a pressure below atmospheric pressure; and (b) exposing said substrate at a temperature of about 30 to 300° C. to said neutral oxygen atoms as the primary oxidizing species to cause a chemical reaction between said neutral oxygen atoms and said surface of said substrate to form said native oxide in a manner which avoids said damage to said substrate.
Claim 11
Dependent Claim
50 words
The process defined in claim 7 wherein the photochemical generation of said neutral oxygen atoms comprises the direct impingement of a selected oxygen-containing precursor with radiation of a selected wavelength sufficient to cause the direct dissociation of said precursor to generate said neutral oxygen atoms as the sole oxidizing species.
Claim 12
Dependent Claim
31 words
The process set forth in claim 7 wherein the photochemical generation of said neutral oxygen atoms comprises the mercury-photosensitized dissociation of a selected oxygen-containing precursor to form said neutral oxygen atoms.
Claim 13
Dependent Claim
72 words
A low-temperature process for forming a native oxide on a selected semiconductor material which comprises exposing said material at a temperature of about 30° to 300° C. to a selected oxygen-containing precursor which is irradiated at a pressure below atmospheric pressure with radiation of a predetermined wavelength and sufficient to release oxygen atoms from said precursor, whereby said oxygen atoms in turn react with said material to form said native oxide thereon.
Claim 14
Dependent Claim
72 words
A low-temperature process for forming a native oxide on a selected semiconductor material which comprises exposing said material at a temperature of about 30° to 300° C. to a selected oxygen-containing precursor which is irradiated at a pressure below atmospheric pressure with radiation of a predetermined wavelength and sufficient to release oxygen atoms from said precursor, whereby said oxygen atoms in turn react with said material to form said native oxide thereon.
Claim 15
Dependent Claim
22 words
The process set forth in claim 10 wherein said radiation causes the direction dissociation of said precursor to release said oxygen atoms.
Claim 16
Dependent Claim
31 words
The process set forth in claim 10 wherein said irradiation is performed in the presence of a selected photosensitizer to produce the dissociation of said precursor to release said oxygen atoms.
Claim 17
Dependent Claim
71 words
A low-temperature process for forming a native oxide on a substrate of a chosen semiconductor material which comprises: (a) providing a selected oxygen-containing precursor; (b) irradiating said precursor at a pressure below atmospheric pressure with radiation of a predetermined wavelength and sufficient to dissociate oxygen atoms therefrom; and then (c) reacting said oxygen atoms with said substrate at a temperature of about 30° to 300° C. to form said native oxide.
Claim 18
Dependent Claim
71 words
A low-temperature process for forming a native oxide on a substrate of a chosen semiconductor material which comprises: (a) providing a selected oxygen-containing precursor; (b) irradiating said precursor at a pressure below atmospheric pressure with radiation of a predetermined wavelength and sufficient to dissociate oxygen atoms therefrom; and then (c) reacting said oxygen atoms with said substrate at a temperature of about 30° to 300° C. to form said native oxide.
Claim 19
Dependent Claim
40 words
The process set forth in claim 13 wherein said precursor is selected from the group consisting of: nitrous oxide (N 2 O); nitrogen dioxide (NO 2 ); and molecular oxygen (O 2 ) under selected pressure and flow rate conditions.
Claim 20
Dependent Claim
20 words
The process set forth in claim 13 wherein said irradiating is performed in the presence of a mercury photosensitizing agent.
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) | 1987-10-02 | 1988-04-02 | 1988-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-02 | 1992-04-02 | 1992-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-02 | 1996-04-02 | 1996-10-02 | $7700.00 | Window Closed / Lapsed |