Back to results
US 5,627,385 AGranted
Lateral silicon carbide transistor
AssigneeMotorola, Inc.
InventorsMohit Bhatnagar, Charles E. Weitzel
Life of this patent
Estimating the term…
Abstract
A lateral silicon carbide transistor (10) utilizes a modulated channel region (18) to form an accumulation region that facilitates a low on-resistance. A doped region of the channel layer forms a channel insert (14) that also lowers the on-resistance of the transistor (10). Field plates (23,24) are utilized to facilitate providing a high breakdown voltage. A high resistance layer (29)between the field plates (23,24) also assists in increasing the breakdown voltage and decreasing on-resistance of the transistor (10).
Claims15
A silicon carbide transistor comprising:
- a silicon carbide substrate;
- a sub-channel layer of a first conductivity type on the substrate;
- a channel layer having a second conductivity type and a first doping concentration wherein the channel layer is on the sub-channel layer;
- a channel insert on the channel layer, the channel insert having the second conductivity type and a second doping concentration that is higher than the first doping concentration;
- a source region of the second conductivity type on the channel layer and spaced a first distance from the channel insert;
- a modulated channel region extending laterally from the source region to the channel insert;
- a gate electrode overlying the modulated channel region;
- and
- a drain region of the second conductivity type in connection with the channel insert.
6 more elements
A lateral silicon carbide transistor comprising:
- a silicon carbide substrate;
- an epitaxial sub-channel layer having a first doping concentration and a first conductivity type wherein the epitaxial sub-channel layer is on the substrate;
- an epitaxial channel layer of a second conductivity type and a second doping concentration that is greater than the first doping concentration wherein the epitaxial channel layer is on the sub-channel layer;
- a channel insert that is a doped area within the channel layer, the channel insert having the second conductivity type and a third doping concentration that is greater than the second doping concentration;
- a source region of the second conductivity type within the channel layer and spaced a first distance from the channel insert;
- a modulated channel region that is a portion of the channel layer between the channel insert and the source region;
- a drain region of the second conductivity type within the channel insert;
- a field dielectric on a surface of the channel layer, the field dielectric having an edge that is substantially .aligned with an edge of the channel insert;
- and
- a high resistivity layer on the field dielectric, the high resistivity layer overlying a portion of the channel insert.
7 more elements
Dependencies are inferred from the claim text.