Methods of fabricating voltage breakdown resistant monocrystalline silicon carbide semiconductor devices
AssigneeNorth Carolina State University
InventorsBantval J. Baliga, Dev Alok
Life of this patent
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Abstract
Voltage breakdown resistant monocrystalline silicon carbide semiconductor devices are obtained by forming an amorphous silicon carbide termination region in a monocrystalline silicon carbide substrate, at a face thereof, adjacent and surrounding a silicon carbide device. The amorphous termination region is preferably formed by implanting electrically inactive ions, such as argon, into the substrate face at sufficient energy and dose to amorphize the substrate face. The device contact or contacts act as an implantation mask to provide a self-aligned termination region for the device. The terminated devices may exhibit voltage breakdown resistance which approaches the ideal value for silicon carbide.
Claims21
A method of forming a breakdown resistant silicon carbide semiconductor device, comprising the steps of:
- forming a silicon carbide semiconductor device in a monocrystalline silicon carbide substrate, extending to a face thereof;
- and
- amorphizing said monocrystalline silicon carbide substrate, at said face, adjacent and surrounding said silicon carbide semiconductor device.
A method of forming a breakdown resistant silicon carbide Schottky barrier rectifier, comprising the steps of:
- forming a Schottky contact on a face of a monocrystalline silicon carbide substrate, such that said Schottky contact and said silicon carbide substrate form a Schottky barrier therebetween;
- and
- implanting argon ions into said face of said monocrystalline silicon carbide substrate, at an energy of about 30 keV and at a dose of at least 10.sup.15 /cm.sup.2, to thereby form an amorphous silicon carbide region surrounding said Schottky contact.
A method of forming a breakdown resistant silicon carbide rectifier, comprising the steps of:
- forming a monocrystalline silicon carbide region of second conductivity type in a monocrystalline silicon carbide substrate of first conductivity type, said monocrystalline silicon carbide region extending to a face of said monocrystalline silicon carbide substrate;
- forming an ohmic contact on said monocrystalline silicon carbide region, at said face;
- and
- implanting argon ions into said face of said monocrystalline silicon carbide substrate, at an energy of about 30 keV and at a dose of at least 10.sup.15 /cm.sup.2, to thereby form an amorphous silicon carbide region surrounding said ohmic contact.
A method of forming a breakdown resistant contact for a silicon carbide semiconductor device, comprising the steps of:
- forming a contact region on a face of a monocrystalline silicon carbide substrate, said contact region being sufficiently thick to block implanted ions from entering said silicon carbide substrate therethrough;
- and
- implanting electrically inactive ions into said face at a dose and at an energy which is sufficient to amorphize said face surrounding said contact region, to thereby form an amorphous silicon carbide region at said face, adjacent and surrounding said contact region.
A method of forming a breakdown resistant silicon carbide Schottky barrier rectifier, comprising the steps of:
- forming a Schottky contact on a face of a monocrystalline silicon carbide substrate, so that the Schottky contact and the silicon carbide substrate form a Schottky rectifier therebetween;
- and
- implanting ions, which are electrically inactive in silicon carbide, into the face at a dose and energy level sufficient to form an amorphous silicon carbide region which at least substantially surrounds the Schottky contact.
A method of forming a breakdown resistant silicon carbide P-N rectifying junction, comprising the steps of:
- forming a monocrystalline silicon carbide region of second conductivity type in a silicon carbide substrate of first conductivity type, at a face thereof, to thereby define a P-N junction;
- forming an ohmic contact on the monocrystalline silicon carbide region of second conductivity type, at the face;
- implanting ions, which are electrically inactive in silicon carbide, into the face at a dose and energy level sufficient to form an amorphous silicon carbide region which at least substantially surrounds the ohmic contact.
Dependencies are inferred from the claim text.