GALLIUM NITRIDE SINGLE CRYSTAL SUBSTRATE AND METHOD OF PROUCING SAME
First Claim
1. A gallium nitride single crystal substrate being doped with oxygen as an n-type dopant and containing no foreign element as a component of the substrate.
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Abstract
An n-type GaN substrate having a safe n-type dopant instead of Si which is introduced by perilous silane gas. The safe n-dopant is oxygen. An oxygen doped n-type GaN free-standing crystal is made by forming a mask on a GaAs substrate, making apertures on the mask for revealing the undercoat GaAs, growing GaN films through the apertures of the mask epitaxially on the GaAs substrate from a material gas including oxygen, further growing the GaN film also upon the mask for covering the mask, eliminating the GaAs substrate and the mask, and isolating a freestanding GaN single crystal. The GaN is an n-type crystal having carriers in proportion to the oxygen concentration.
95 Citations
11 Claims
- 1. A gallium nitride single crystal substrate being doped with oxygen as an n-type dopant and containing no foreign element as a component of the substrate.
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5. A method of producing a gallium nitride single crystal substrate comprising the steps of:
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preparing a GaAs(111) substrate, coating the GaAs substrate with a mask, etching the mask for making windows;
growing a GaN buffer layer on the masked GaAs substrate by a first via-GaCl method which converts a Ga material once to GaCl and makes the GaCl react with NH3 for producing GaN;
growing a GaN epitaxial layer by a second via-GaCl method which converts a Ga material once to GaCl, makes the GaCl react with NH3 for producing GaN from materials of HCl, NH3 and H2 at least one of which contains oxygen (O2) or water (H2O);
eliminating the GaAs substrate and the mask; and
obtaining a freestanding n-type GaN single crystal substrate having oxygen as an n-dopant. - View Dependent Claims (6, 7, 8, 9, 10, 11)
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Specification