Semiconductor device having enhanced performance and method
View Patent ↗In one embodiment, a semiconductor device is formed in a body of semiconductor material. The semiconductor device includes a localized region of doping near a portion of a channel region where current exits during operation.
1. A semiconductor device, comprising:
a semiconductor material having a major surface, wherein the semiconductor material comprises a first conductivity type;
a control electrode formed in spaced relationship with the semiconductor material;
a body region of a second conductivity type formed in the major surface adjacent the control electrode, wherein a portion of the body region forms a channel region when the semiconductor device is in operation;
a source region of the first conductivity type formed in the body region; and
a localized region of doping of the first conductivity type formed in the semiconductor material in proximity to a drain edge of the channel region, wherein the localized region of doping is confined both vertically and horizontally adjacent the major surface, and wherein the localized region of doping has a dopant concentration at least five times greater than a dopant concentration of a portion of the semiconductor material, and wherein the portion of the semiconductor material is adjacent the major surface and adjacent to the localized region of doping.
2. The semiconductor device of claim 1 , wherein the localized region of doping extends a lateral distance from the body region in a range from about 0.1 microns and about 0.4 microns.
3. The semiconductor device of claim 1 , wherein the localized region of doping has a dopant concentration about five times to about fifty times greater than that of the semiconductor material.
4. The semiconductor device of claim 1 wherein a second surface of the substrate opposite the major surface forms a conduction electrode.
5. The semiconductor device of claim 1 , further comprising a pedestal structure formed overlying a portion of the major surface and having a side surface, wherein the control electrode includes a conductive material formed along the side surface, and wherein the localized region of doping has an edge defined by the side surface of the pedestal structure.
6. The semiconductor device of claim 1 further comprising a shield layer formed in proximity to the localized region of doping.
7. The semiconductor device of claim 6 wherein the shield layer comprises polycrystalline silicon.
8. The semiconductor device of claim 5 , wherein the pedestal structure includes:
a first dielectric layer formed over the major surface of the semiconductor material;
a second dielectric layer formed over the first dielectric layer; and
a conductive layer formed over the second dielectric layer, wherein the conductive layer is coupled to the control electrode.
9. The semiconductor device of claim 8 , wherein the conductive material includes polycrystalline silicon.
10. A semiconductor device, comprising:
a semiconductor substrate having a first layer of a first conductivity type and having a major surface;
a body region of a second conductivity type disposed in the first layer for forming a channel of the semiconductor device;
a source region of the first conductivity type formed in the body region;
a gate structure formed over the major surface adjacent the channel; and
a current spreading region formed in a first portion of the first layer and abutting a drain end of the channel, wherein the current spreading region comprises the first conductivity type, and wherein the current spreading region is localized and confined both vertically and horizontally adjacent the major surface, and wherein the current spreading region has a dopant concentration at least five times greater than that of the first layer, and wherein a second portion of the first layer is adjacent the major surface, and wherein the current spreading region is between the body region and the second portion of the first layer.
11. The semiconductor device of claim 10 , wherein the current spreading region extends laterally from the body region a distance in a range from about 0.1 microns to about 0.4 microns.
12. The semiconductor device of claim 10 further comprising a pedestal structure formed over the major surface, and wherein the gate structure includes a control electrode formed along a side surface of the pedestal structure.
13. The semiconductor device of claim 12 wherein the control electrode is extended over the pedestal structure to receive an external signal (V G ).
14. The semiconductor device of claim 12 wherein the pedestal structure includes a shield layer.
15. The semiconductor device of claim 10 , wherein the current spreading region has a peak doping concentration in range from about 5.0×10 16 atoms/cm 3 to about 1.0×10 17 atoms/cm 3 .
16. The semiconductor device of claim 10 , wherein the current spreading region has a dopant concentration about five times to about fifty times greater than that of the semiconductor layer.