Semiconductor devices with graded dopant regions
AssigneeGreenthread, LLC
InventorG. R. Mohan Rao
Life of this patent
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Abstract
Most semiconductor devices manufactured today, have uniform dopant concentration, either in the lateral or vertical device active (and isolation) regions. By grading the dopant concentration, the performance in various semiconductor devices can be significantly improved. Performance improvements can be obtained in application specific areas like increase in frequency of operation for digital logic, various power MOSFET and IGBT ICs, improvement in refresh time for DRAMs, decrease in programming time for nonvolatile memory, better visual quality including pixel resolution and color sensitivity for imaging ICs, better sensitivity for varactors in tunable filters, higher drive capabilities for JFETs, and a host of other applications.
Claims36
A semiconductor device, comprising:
- a substrate of a first doping type at a first doping level having first and second surfaces;
- a first active region disposed adjacent the first surface of the substrate with a second doping type opposite in conductivity to the first doping type and within which transistors can be formed;
- a second active region separate from the first active region disposed adjacent to the first active region and within which transistors can be formed;
- transistors formed in at least one of the first active region or second active region;
- at least a portion of at least one of the first and second active regions having at least one graded dopant concentration to aid carrier movement from the first surface to the second surface of the substrate;
- and
- at least one well region adjacent to the first or second active region containing at least one graded dopant region, the graded dopant region to aid carrier movement from the first surface to the second surface of the substrate.
A semiconductor device, comprising:
- a substrate of a first doping type at a first doping level having first and second surfaces;
- a first active region disposed adjacent the first surface of the substrate with a second doping type opposite in conductivity to the first doping type and within which transistors can be formed in the surface thereof;
- a second active region separate from the first active region disposed adjacent to the first active region and within which transistors can be formed in the surface thereof;
- transistors formed in at least one of the first active region or second active region;
- at least a portion of at least one of the first and second active regions having at least one graded dopant concentration to aid carrier movement from the surface to the substrate;
- and
- at least one well region adjacent to the first or second active region containing at least one graded dopant region, the graded dopant region to aid carrier movement from the first surface to the second surface of the substrate.
Dependencies are inferred from the claim text.