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US4935383A
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Preparation of dilute magnetic semiconductor films by metalorganic chemical vapor deposition
Assignee: California Institute of Technology
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Filing: 1988-09-23
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Granted: 1990-06-19
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Expires: 2008-09-23
Abstract
Abstract A method for preparation of a dilute magnetic semiconductor (DMS) film is provided, wherein a Group II metal source, a Group VI metal source and a transition metal magnetic ion source are pyrolyzed in the reactor of a metalorganic chemical vapor deposition (MOCVD) system by contact with a heated substrate. As an example, the preparation of films of Cd 1-x Mn x Te, wherein 0≦×≦0.7, on suitable substrates (e.g., GaAs) is described. As a source of manganese, tricarbonyl (methylcyclopentadienyl) maganese (TCPMn) is employed. To prevent TCPMn condensation during the introduction thereof int the reactor, the gas lines, valves and reactor tubes are heated. A thin-film solar cell of n-i-p structure, wherein the i-type layer comprises a DMS, is also described; the i-type layer is suitably prepared by MOCVD.
Inventors
- 👤 Akbar Nouhi
- 👤 Richard J. Stirn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:00
CPC Classifications
B; B82; B82Y; B82Y25/00; H; H01; H01F; H01F10/00; H01F10/32; H01F10/3213; H01F41/00; H01F41/14; H01F41/22; H10; H10F; H10F10/00; H10F10/10; H10F10/17; H10F10/174; H10F19/00; H10F19/40; H10F71/00; H10F71/125; H10F71/1257; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/547; Y10; Y10S; Y10S438/00; Y10S438/914; Y10S438/918
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
114 words
A method of preparing a dilute magnetic semiconductor film on a substrate in a deposition zone of a reactor of a metalorganic chemical vapor deposition system, said method comprising: heating the substrate in the deposition zone to an elevated temperature in the range of about 410° to about 450° C.; introducing into the reactor a gas mixture comprising a Group II metal source, a Group VI metal source a transition metal magnetic ion source, and a carrier gas; and forming said film by contacting the substrate with said gas mixture, thereby pyrolyzing the metal sources and forming a ternary alloy, whereby the magnetic ion source is incorporated into the lattice structure of said film.
Claim 2
Independent Claim
114 words
A method of preparing a dilute magnetic semiconductor film on a substrate in a deposition zone of a reactor of a metalorganic chemical vapor deposition system, said method comprising: heating the substrate in the deposition zone to an elevated temperature in the range of about 410° to about 450° C.; introducing into the reactor a gas mixture comprising a Group II metal source, a Group VI metal source a transition metal magnetic ion source, and a carrier gas; and forming said film by contacting the substrate with said gas mixture, thereby pyrolyzing the metal sources and forming a ternary alloy, whereby the magnetic ion source is incorporated into the lattice structure of said film.
Claim 3
Dependent Claim
22 words
A method according to claim 1, wherein said Group II metal is selected from the group consisting of Cd, Zn and Hg.
Claim 4
Dependent Claim
22 words
A method according to claim 1, wherein said Group VI metal is selected from the group consisting of Te, S and Se.
Claim 5
Dependent Claim
22 words
A method according to claim 1, wherein said transition metal magnetic ion is selected from the group consisting of Mn and Fe.
Claim 6
Dependent Claim
20 words
A metal according to claim 1, wherein said dilute magnetic semiconductor is Cd 1-x Mn x Te, in which 0<×≦0.7.
Claim 7
Dependent Claim
22 words
A method according to claim 5, wherein said Group II metal source is selected from the group consisting of dimethyl- and diethylcadmium.
Claim 8
Dependent Claim
23 words
A method according to claim 5, wherein said Group VI metal source is selected from the group consisting of dimethyl-, diethyl- and dibutyltellurium.
Claim 9
Dependent Claim
17 words
A method according to claim 5, wherein said transition metal magnetic ion source is tricarbonyl (methyl-cyclopentadienyl) manganese.
Claim 10
Dependent Claim
34 words
A method according to claim 8, wherein said tricarbonyl (methyl-cyclopentadienyl) manganese is provided from a source thereof via supply means maintained at a temperature sufficiently high to prevent condensation of said tricarbonyl (methylcyclopentadienyl) manganese.
Claim 11
Dependent Claim
14 words
A method according to claim 9, wherein said temperature is at least 100° C.
Claim 12
Dependent Claim
25 words
A method according to claim 9, wherein said source of tricarbonyl (methyl-cyclopentadienyl) manganese is heated to a temperature of about 100° to about 150° C.
Claim 13
Dependent Claim
14 words
A method according to claim 1, wherein said carrier gas is H 2 .
Claim 14
Dependent Claim
11 words
A method according to claim 1, wherein said substrate is GaAs.
Claim 15
Dependent Claim
23 words
A method according to claim 13, wherein said substrate is (100) GaAs misoriented up to about 13° in a (110) or (111) direction.
Claim 16
Dependent Claim
14 words
A method according to claim 1, wherein said substrate is a CdS thin film.
Claim 17
Dependent Claim
14 words
A method according to claim 1, wherein said substrate is InSb, silicon or sapphire.
Claim 18
Independent Claim
119 words
A method of preparing a dilute magnetic semiconductor single crystal film of Cd 1-x Mn x Te, where 0<×≦0.7, on a substrate in a deposition zone of a reactor of a metalorganic chemical vapor deposition system, the method comprising: heating the substrate in the deposition zone to an elevated temperature in the range of about 410°-450° C.; introducing into the reactor a gas mixture comprising a cadmium alkyl source, a tellurium alkyl source, a manganese alkyl magnetic ion source, and a carrier gas; and forming said film by contacting the substrate with the gas mixture, thereby pyrolyzing the metal sources and forming a ternary alloy, whereby the magnetic ion source is incorporated into the lattice structure of said film.
Claim 19
Independent Claim
119 words
A method of preparing a dilute magnetic semiconductor single crystal film of Cd 1-x Mn x Te, where 0<×≦0.7, on a substrate in a deposition zone of a reactor of a metalorganic chemical vapor deposition system, the method comprising: heating the substrate in the deposition zone to an elevated temperature in the range of about 410°-450° C.; introducing into the reactor a gas mixture comprising a cadmium alkyl source, a tellurium alkyl source, a manganese alkyl magnetic ion source, and a carrier gas; and forming said film by contacting the substrate with the gas mixture, thereby pyrolyzing the metal sources and forming a ternary alloy, whereby the magnetic ion source is incorporated into the lattice structure of said film.
Claim 20
Dependent Claim
32 words
A method a preparing a dilute magnetic semiconductor single crystal film according to claim 17 wherein the substrate is (100) GaAs misoriented up to about 13° in a (110) or (111) direction.
Claim 21
Dependent Claim
42 words
A method of preparing a dilute magnetic semiconductor single crystal film according to claim 17 wherein the alkyl manganese magnetic ion source is tricarbonyl (methyl-cyclopentadienyl) manganese, and wherein said source is heated to a temperature of about 100° to about 150° C.
Claim 22
Independent Claim
119 words
A method of preparing a dilute magnetic semiconductor film on a substrate in a deposition zone of a reactor of a metalorganic chemical vapor deposition system, wherein said dilute magnetic semiconductor is Cd 1-x Mn x Te, in which 0<×≦0.7., the method comprising: heating the substrate in the deposition zone to an elevated temperature; introducing into the reactor a gas mixture comprising a Group II metal source, a Group VI metal source, a transition metal magnetic ion source, and a carrier gas; and forming said film by contacting the substrate with said gas mixture, thereby pyrolyzing the metal sources and forming a ternary metal alloy, whereby the magnetic ion source is incorporated into the lattice structure of said film.
Claim 23
Independent Claim
119 words
A method of preparing a dilute magnetic semiconductor film on a substrate in a deposition zone of a reactor of a metalorganic chemical vapor deposition system, wherein said dilute magnetic semiconductor is Cd 1-x Mn x Te, in which 0<×≦0.7., the method comprising: heating the substrate in the deposition zone to an elevated temperature; introducing into the reactor a gas mixture comprising a Group II metal source, a Group VI metal source, a transition metal magnetic ion source, and a carrier gas; and forming said film by contacting the substrate with said gas mixture, thereby pyrolyzing the metal sources and forming a ternary metal alloy, whereby the magnetic ion source is incorporated into the lattice structure of said film.
Claim 24
Dependent Claim
21 words
A method according to claim 20, wherein said elevated temeprature is in the range of about 410° to about 450° C.
Claim 25
Dependent Claim
22 words
A method according to claim 20, wherein the Group II metal source is selected from the group consisting of dimethylcadmium and diethylcadmium.
Claim 26
Dependent Claim
23 words
A method according to claim 20, wherein the Group VI metal source is selected from the group consisting of dimethyl-, diethyl- and dibutyltellurium.
Claim 27
Dependent Claim
17 words
A method according to claim 20, wherein the transition metal magnetic ion source is tricarbonyl (methyl-cyclopentadienyl) manganese.
Claim 28
Dependent Claim
41 words
A method according to claim 24, wherein the tricarbonyl (methyl-cyclopentadienyl) manganese is provided through supply means for supplying a gas from a gas source, the supply means maintained at a temperature sufficiently high to prevent condensation of the tricarbonyl (methyl-cyclopentadienyl) manganese.
Claim 29
Dependent Claim
14 words
A method according to claim 25, wherein the temperature is at least 100° C.
Claim 30
Dependent Claim
25 words
A method according to claim 25, wherein the source of tricarbonyl (methyl-cyclopentadienyl) manganese is heated to a temperature of about 100° to about 150° C.
Claim 31
Dependent Claim
11 words
A method according to claim 20, wherein the substrate is GaAs.
Claim 32
Dependent Claim
23 words
A method according to claim 28, wherein the substrate is (100) GaAs misoriented up to about 13° in a (110) or (111) direction.
Claim 33
Dependent Claim
14 words
A method according to claim 28, wherein the substrate is a CdS thin film.
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