US4451503A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photo deposition of metals with far UV radiation
Assignee: International Business Machines Corp
•
Filing: 1982-06-30
•
Granted: 1984-05-29
•
Expires: 2002-06-30
Abstract
Abstract A method for depositing a refractory metal onto a substrate wherein a carbonyl compound vapor of the metal in the vicinity of or on the substrate is photodecomposed by ultraviolet radiation of wavelengths less than 200 nm. This causes the release of atoms of the metal, which then condense onto the substrate. In an example, a tungsten layer is photodeposited by this method onto a GaAs semiconductor layer to form a Schottky barrier diode.
Inventors
- 👤 Samuel E. Blum
- 👤 Karen H. Brown
- 👤 Rangaswamy Srinivasan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:07
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/012; H10D64/0124; C; C23; C23C; C23C16/00; C23C16/06; C23C16/16; C23C16/44; C23C16/48; C23C16/483
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
75 words
A method for photodeposition of a refractory metal onto a substrate, comprising the steps of: producing a carbonyl compound vapor of said metal in the vicinity of said substrate, directing ultraviolet light of wavelengths less than 200 nm onto said vapor to photodecompose said vapor to release atoms of said metal in the vicinity of or on said substrate, and condensing said metal atoms onto said substrate to form a continuous refractory metal layer thereon.
Claim 2
Independent Claim
75 words
A method for photodeposition of a refractory metal onto a substrate, comprising the steps of: producing a carbonyl compound vapor of said metal in the vicinity of said substrate, directing ultraviolet light of wavelengths less than 200 nm onto said vapor to photodecompose said vapor to release atoms of said metal in the vicinity of or on said substrate, and condensing said metal atoms onto said substrate to form a continuous refractory metal layer thereon.
Claim 3
Dependent Claim
13 words
The method of claim 1, where said photodeposition occurs at substantially room temperatures.
Claim 4
Dependent Claim
20 words
The method of claim 1, where said refractory metals are chosen from the group consisting of Mo, W, and Cr.
Claim 5
Dependent Claim
20 words
The method of claim 1, where said substrate is selected from the group consisting of semiconductors, polymers, insulators, and metals.
Claim 6
Dependent Claim
16 words
The method of claim 1, where said refractory metal is W, and said substrate is GaAs.
Claim 7
Dependent Claim
22 words
The method of claim 1, where said ultraviolet light is produced by an ArF excimer laser at a wavelength of 193 nm.
Claim 8
Dependent Claim
23 words
The method of claim 1, where said ultraviolet light is produced by a low pressure Hg lamp at a wavelength of 185 nm.
Claim 9
Dependent Claim
19 words
The method of claim 1, where said ultraviolet radiation is applied as a continuous wave or as a pulse.
Claim 10
Dependent Claim
22 words
The method of claim 1, where said carbonyl compound vapor is mixed with a buffer gas in the vicinity of said substrate.
Claim 11
Dependent Claim
16 words
The method of claim 1, where said ultraviolet light is focussed and scanned across said substrate.
Claim 12
Dependent Claim
18 words
The method of claim 1, where said ultraviolet light is directed through a mask before striking said substrate.
Claim 13
Independent Claim
111 words
A method for forming a GaAs Mesfet, comprising the steps of: introducing an impurity into a body of GaAs to form a doped layer therein, photodepositing a layer of tungsten onto said doped layer to form a gate electrode by photodecomposing a carbonyl compound vapor of tungsten with ultraviolet light of wavelengths less than 200 nm in the vicinity of or on said doped layer to free tungsten atoms which then condense onto said doped layer in a first region thereof defined by said ultraviolet radiation, forming additional more highly doped regions in said doped layer surrounding said first region, and forming source and drain contacts to said additionally doped regions.
Claim 14
Independent Claim
111 words
A method for forming a GaAs Mesfet, comprising the steps of: introducing an impurity into a body of GaAs to form a doped layer therein, photodepositing a layer of tungsten onto said doped layer to form a gate electrode by photodecomposing a carbonyl compound vapor of tungsten with ultraviolet light of wavelengths less than 200 nm in the vicinity of or on said doped layer to free tungsten atoms which then condense onto said doped layer in a first region thereof defined by said ultraviolet radiation, forming additional more highly doped regions in said doped layer surrounding said first region, and forming source and drain contacts to said additionally doped regions.
Claim 15
Dependent Claim
14 words
The method of claim 12, where said carbonyl compound is a hexacarbonyl of tungsten.
Claim 16
Independent Claim
115 words
A method for depositing a refractory metal onto selected areas of a substrate, comprising the steps of: locating said substrates in a reaction chamber, producing carbonyl compound vapors of said refractory metal in said reaction chamber in the vicinity of said substrates, directing ultraviolet light of wavelengths less then 200 nm into said reaction chamber and through a mask to photodecompose said vapor to release atoms of said refractory metal in the vicinity of or on said substrate, said atoms being released in locations defined by said ultraviolet light, condensing said refractory metal atoms onto said substrate in said selected locations determined by said ultraviolet light to form a continuous layer of said refractory metal.
Claim 17
Independent Claim
115 words
A method for depositing a refractory metal onto selected areas of a substrate, comprising the steps of: locating said substrates in a reaction chamber, producing carbonyl compound vapors of said refractory metal in said reaction chamber in the vicinity of said substrates, directing ultraviolet light of wavelengths less then 200 nm into said reaction chamber and through a mask to photodecompose said vapor to release atoms of said refractory metal in the vicinity of or on said substrate, said atoms being released in locations defined by said ultraviolet light, condensing said refractory metal atoms onto said substrate in said selected locations determined by said ultraviolet light to form a continuous layer of said refractory metal.
Claim 18
Dependent Claim
20 words
The method of claim 14, where said refractory metals are selected from the group consisting of Mo, W, and Cr.
Claim 19
Dependent Claim
11 words
The method of claim 15, where said ultraviolet light is focussed.
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) | 1987-05-29 | 1987-11-28 | 1988-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-29 | 1991-11-28 | 1992-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-29 | 1995-11-28 | 1996-05-29 | $7700.00 | Window Closed / Lapsed |