High power high frequency metal-semiconductor field-effect transistor formed in silicon carbide
First Claim
1. A high power, high frequency, metal-semiconductor field-effect transistor comprising:
- a bulk single crystal silicon carbide substrate;
an n-type epitaxial layer of n-type conductivity silicon carbide upon said substrate,two separate well regions in said epitaxial layer that are respectively defined by higher n-type carrier concentrations than are present in the remainder of said epitaxial layer;
a p-type epitaxial layer of p-type conductivity silicon carbide between said substrate and said n-type epitaxial layer;
ohmic contacts upon said well regions in said n-type epitaxial layer for respectively defining one of said well regions as the source and the other of said well regions as the drain;
a Schottky metal contact upon a portion of said n-type epitaxial layer that is between said ohmic contacts and thereby between said source and said drain for forming an active channel in said n-type epitaxial layer between said source and said drain when a bias is applied to said Schottky metal contact; and
a conducting plane formed on said substrate opposite said p-type epitaxial layer.
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Accused Products
Abstract
A high power, high frequency, metal-semiconductor field-effect transistor comprises a bulk single crystal silicon carbide substrate, an optional first epitaxial layer of p-type conductivity silicon carbide formed upon the substrate, and a second epitaxial layer of n-type conductivity silicon carbide formed upon the first epitaxial layer. The second epitaxial layer has two separate well regions therein that are respectively defined by higher carrier concentrations of n-type dopant ions than are present in the remainder of the second epitaxial layer. Ohmic contacts are positioned upon the wells for respectively defining one of the well regions as the source and the other as the drain. A Schottky metal contact is positioned upon a portion of the second epitaxial layer that is between the ohmic contacts and thereby between the source and drain for forming an active channel in the second epitaxial layer when a bias is applied to the Schottky contact.
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Citations
67 Claims
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1. A high power, high frequency, metal-semiconductor field-effect transistor comprising:
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a bulk single crystal silicon carbide substrate; an n-type epitaxial layer of n-type conductivity silicon carbide upon said substrate, two separate well regions in said epitaxial layer that are respectively defined by higher n-type carrier concentrations than are present in the remainder of said epitaxial layer; a p-type epitaxial layer of p-type conductivity silicon carbide between said substrate and said n-type epitaxial layer; ohmic contacts upon said well regions in said n-type epitaxial layer for respectively defining one of said well regions as the source and the other of said well regions as the drain; a Schottky metal contact upon a portion of said n-type epitaxial layer that is between said ohmic contacts and thereby between said source and said drain for forming an active channel in said n-type epitaxial layer between said source and said drain when a bias is applied to said Schottky metal contact; and a conducting plane formed on said substrate opposite said p-type epitaxial layer. - View Dependent Claims (2, 3, 4, 5)
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6. A high power, high frequency, metal-semiconductor field-effect transistor comprising:
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a bulk single crystal silicon carbide substrate; a first epitaxial layer of p-type conductivity silicon carbide on said substrate; a second epitaxial layer of n-type conductivity silicon carbide upon said first epitaxial layer, wherein said epitaxial layers form a mesa having sidewalls extending downward from said second epitaxial layer into said first epitaxial layer which define the periphery of said transistor; two separate well regions in said second layer that are respectively defined by higher n-type carrier concentrations than are present in the remainder of said second epitaxial layer; ohmic contacts upon said well regions in said second epitaxial layer for respectively defining one of said well regions as the source and the other of said well regions as the drain; and a Schottky metal contact upon a portion of said second epitaxial layer that is between said ohmic contacts and thereby between said source and said drain for forming an active channel in said second epitaxial layer between said source and said drain when a bias is applied to said Schottky metal contact. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A high power, high frequency, metal-semiconductor field-effect transistor comprising:
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a bulk crystal silicon carbide substrate; an epitaxial layer of n-type silicon carbide formed on said substrate; a pair of mesas of n-type conductivity silicon carbide on said n-type epitaxial layer, said mesas having higher n-type carrier concentrations than said n-type epitaxial layer; ohmic contacts upon said mesas for respectively defining one of said mesas as the source and the other of said mesas as the drain; and a Schottky metal contact upon a portion of said epitaxial layer that is between said mesas and thereby between said source and said drain for forming an active channel in said n-type epitaxial layer between said source and said drain when a bias is applied to said Schottky metal contact. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36)
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37. A high power, high frequency, metal-semiconductor field-effect transistor comprising:
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a bulk crystal silicon carbide substrate; a first epitaxial layer of p-type conductivity silicon carbide on said substrate; a second epitaxial layer of n-type silicon carbide on said first epitaxial layer; a pair of mesas of n-type conductivity silicon carbide on said n-type second epitaxial layer, said mesas having higher n-type carrier concentrations than said n-type second epitaxial layer; ohmic contacts upon said mesas for respectively defining one of said mesas as the source and the other of said mesas as the drain; and a Schottky metal contact upon a portion of said second epitaxial layer that is between said mesas and thereby between said source and said drain for forming an active channel in said n-type epitaxial layer between said source and said drain when a bias is applied to said Schottky metal contact. - View Dependent Claims (38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59)
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60. A high power, high frequency, metal-semiconductor field-effect transistor comprising:
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bulk single crystal silicon carbide substrate; a first epitaxial layer of silicon carbide having a p-type conductivity formed upon said substrate; a second epitaxial layer of n-type conductivity silicon carbide formed upon said first epitaxial layer, said second epitaxial layer having a plurality of well regions therein that are respectively defined by higher n-type carrier concentrations than are present in the remainder of said second epitaxial layer; ohmic contacts upon said plurality of well regions in said second epitaxial layer for alternately electrically connecting said plurality of said well regions defining an alternating plurality of source regions and drain regions; a plurality of electrically connected Schottky metal contacts for forming a plurality of active channels in said second epitaxial layer between said plurality of source regions and said plurality of drain regions when a bias is applied to said Schottky metal contacts, each of said Schottky metal contacts being formed upon a portion of said second epitaxial layer that is between one of said source regions and one of said drain regions.
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61. A high power, high frequency, metal-semiconductor field-effect transistor comprising:
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a bulk single crystal silicon carbide substrate; a first epitaxial layer silicon carbide having a p-type conductivity formed upon said substrate; a second epitaxial layer of n-type conductivity silicon carbide formed upon said first epitaxial layer, a plurality of mesas on said second epitaxial layer, said mesas having higher n-type carrier concentrations than are present in said second epitaxial layer; ohmic contacts upon said plurality of mesas for alternately electrically connecting said plurality of said mesas defining an alternating plurality of source mesas and drains mesas; a plurality of electrically connected Schottky metal contacts formed upon said second epitaxial layer for forming a plurality of active channels in said second epitaxial layer between said plurality of source mesas and said plurality of drain mesas when a bias is applied to said Schottky metal contacts, each of said plurality of Schottky metal contacts positioned between one of said source mesas and one of said drain mesas.
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62. A high power, high frequency, metal-semiconductor field-effect transistor comprising:
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a bulk single crystal semi-insulating silicon carbide substrate; an epitaxial layer of n-type conductivity silicon carbide upon said substrate, two separate well regions in said epitaxial layer that are respectively defined by higher n-type carrier concentrations than are present in the remainder of said epitaxial layer; ohmic contacts upon said well regions in said epitaxial layer for respectively defining one of said well regions as the source and the other of said well regions as the drain; and a Schottky metal contact upon a portion of said epitaxial layer that is between said ohmic contacts and thereby between said source and said drain for forming an active channel in said epitaxial layer between said source and said drain when a bias is applied to said Schottky metal contact. - View Dependent Claims (63)
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64. A high power, high frequency, metal-semiconductor field-effect transistor comprising:
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a bulk single crystal silicon carbide substrate; an epitaxial layer of n-type conductivity silicon carbide upon said substrate, two separate well regions in said epitaxial layer that are respectively defined by higher n-type carrier concentrations than are present in the remainder of said epitaxial layer; ohmic contacts upon said well regions in said epitaxial layer for respectively defining one of said well regions as the source and the other of said well regions as the drain; a Schottky metal contact upon a portion of said epitaxial layer that is between said ohmic contacts and thereby between said source and said drain for forming an active channel in said epitaxial layer between said source and said drain when a bias is applied to said Schottky metal contact; and a conducting plane formed on said substrate opposite said epitaxial layer. - View Dependent Claims (65)
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66. A high power, high frequency, metal-semiconductor field-effect transistor comprising:
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a bulk single crystal silicon carbide substrate; an epitaxial layer of n-type conductivity silicon carbide upon said substrate, wherein said substrate and said epitaxial layer form a mesa having sidewalls extending downward from said epitaxial layer into said substrate which define the periphery of said transistor; two separate well regions in said epitaxial layer that are respectively defined by higher n-type carrier concentrations than are present in the remainder of said epitaxial layer; ohmic contacts upon said well regions in said epitaxial layer for respectively defining one of said well regions as the source and the other of said well regions as the drain; a Schottky metal contact upon a portion of said epitaxial layer that is between said ohmic contacts and thereby between said source and said drain for forming an active channel in said epitaxial layer between said source and said drain when a bias is applied to said Schottky metal contact; and a conducting plane formed on said substrate opposite said epitaxial layer. - View Dependent Claims (67)
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Specification