Integrated Schottky diode and transistor
First Claim
1. A process for forming a semiconductor device having an integral Schottky diode, comprising:
- providing a semiconductor substrate of a first type and first impurity concentration and having a principal surface;
providing a first doped region of a second type opposite the first type and of a second impurity concentration and which forms a first junction with the substrate extending to the surface;
providing a second doped region of the first type and a third impurity concentration in the first region and which forms a second junction with the first region extending to the surface;
then in either order, (a) providing a third doped region of the second type and a fourth impurity concentration located at the intersection of the first junction and the surface and a fourth doped region of the second type and a fifth impurity concentration laterally within the second region at the surface, and (b) providing a fifth doped region of the first type and a sixth impurity concentration located at the intersection of the second junction and the surface;
exposing first, second and third portions of the surface, respectively, on the third, fourth and fifth doped regions and a fourth portion of the surface laterally within the second region adjacent to the second portion of the surface; and
providing a Schottky contact to the fourth portion of the surface and ohmic contact to the second portion of the surface.
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Accused Products
Abstract
An improved means and method is described for forming a Schottky diode integrated with transistors and other devices which is particularly useful where both control circuits and a large power device are on the same chip.
Nested N-, P-, N- and P+ regions are formed on an N+ semiconductor substrate. A portion of the overlying dielectric is removed adjacent one of the P+ regions over the N- region and a Schottky contact formed to the N- region and an ohmic contact to the adjacent P+ region. N+ and P+ regions are desirably provided where the junctions between the N-/P- regions and the P-/N- regions intersect the surface to provide contact to the N- and P- regions respectively.
A P region extends through the upper N- region and has U-shaped arms which partially overlie an annular shaped P+ region and is located between the active region of the PNP transistor and the collector contact to serve as a Kelvin probe. The arrangement is particularly valuable where a vertical PNP device without a buried collector region is required.
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Citations
16 Claims
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1. A process for forming a semiconductor device having an integral Schottky diode, comprising:
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providing a semiconductor substrate of a first type and first impurity concentration and having a principal surface; providing a first doped region of a second type opposite the first type and of a second impurity concentration and which forms a first junction with the substrate extending to the surface; providing a second doped region of the first type and a third impurity concentration in the first region and which forms a second junction with the first region extending to the surface; then in either order, (a) providing a third doped region of the second type and a fourth impurity concentration located at the intersection of the first junction and the surface and a fourth doped region of the second type and a fifth impurity concentration laterally within the second region at the surface, and (b) providing a fifth doped region of the first type and a sixth impurity concentration located at the intersection of the second junction and the surface; exposing first, second and third portions of the surface, respectively, on the third, fourth and fifth doped regions and a fourth portion of the surface laterally within the second region adjacent to the second portion of the surface; and providing a Schottky contact to the fourth portion of the surface and ohmic contact to the second portion of the surface. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A process for forming a transistor having an integral Schottky diode, comprising:
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providing a semiconductor substrate having a major surface, wherein the substrate has a first region of a first type and impurity concentration extending to the surface; providing in the first region a second region of a second type opposite the first type and having a second impurity concentration and forming a first junction extending to the surface; then in either order, (i) providing a third region of the first type, having a third impurity concentration, located laterally within the second region and forming a second junction extending to the surface, and (ii) providing a fourth region of the second type, having a fourth impurity concentration, having a first part located laterally within the third region at the surface, wherein the first part of the fourth region extends from the surface through the third region into the second region; and forming a Schottky contact to a first portion of the surface of the third region adjacent the first part of the fourth region wherein the contact is shorted to the first part of the fourth region. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification