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US 7,605,412 B2Granted
Distributed high voltage JFET
AssigneeTexas Instruments Incorporated
InventorsPhilip L. Hower, David A. Walch, John Lin, Steven L. Merchant
Life of this patent
Estimating the term…
Abstract
A Junction Field Effect Transistor (JFET) can be fabricated with a well region that include a channel region having an average dopant concentration substantially less the average doping concentration of the remaining portions of the well region. The lower average doping concentration of channel region compared to the remaining portions of the well region reduces the pinch-off voltage of the JFET.
Claims10
A Junction Field Effect Transistor (JFET) comprising:
- a semiconductor layer of a first conductivity type;
- a well region of a second conductivity type formed in a substrate, the well region including a channel region having the same conductivity type as the well region and having an average dopant concentration less than the average dopant concentration of remaining portions of the well region;
- and wherein the channel region comprises a plurality of alternating implant and diffusion regions of the second conductivity type, the implant regions being separated from one another by the diffusion regions, and the implant regions having a higher average dopant concentration than the diffusion regions;
- a source region and a drain region of the second conductivity type arranged in spaced apart relationship in the well region;
- and
- a gate region of the first conductivity type interposed between the source region and the drain region, and extending through the channel region of the well region and positioned on the implant and diffusion regions.
3 more elements
A method of fabricating a Junction Field Effect Transistor (JFET), the method comprising:
- providing a semiconductor layer of a first conductivity type;
- forming a well region of a second conductivity type in a substrate, the well region including a channel region having the same conductivity type as the well region and having average dopant concentration less than the average dopant concentration of remaining portions of the well region;
- heating the well region to form a plurality of implant regions and diffusion regions of the second conductivity type, the implant regions being separated from one another by the diffusion regions, and the implant regions having a higher average dopant concentration than the diffusion regions;
- forming a source region and a drain region of the second conductivity type in spaced apart relationship in the well region;
- and
- forming a gate region of the first conductivity type in the channel region of the well region, the gate region being interposed between the source region and the drain region.
3 more elements
Dependencies are inferred from the claim text.