MOSFET with integrated schottky diode
View Patent ↗Aspects of the present disclosure describe a Schottky structure with two trenches formed in a semiconductor material. The trenches are spaced apart from each other by a mesa. Each trench may have first and second conductive portions lining the first and second sidewalls. The first and second portions of conductive material are electrically isolated from each other in each trench. The Schottky contact may be formed at any location between the outermost conductive portions. The Schottky structure may be formed in the active area or the termination area of a device die. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
1. A Schottky structure comprising:
two trenches formed into a semiconductor material and spaced apart from each other by a mesa, wherein each trench is lined with a dielectric material, and wherein a first portion of conductive material is disposed along a first sidewall of each trench and a second portion of conductive material is disposed along a second sidewall of each trench, and wherein the first and second portions of conductive material are electrically isolated from each other, wherein the first portion of conductive material in the first trench is maintained at a gate potential; and
one or more Schottky contacts formed between the outermost walls of the two trenches, wherein the one or more Schottky contacts extend in a direction parallel to the two trenches.
2. The Schottky structure of claim 1 , wherein the two trenches are formed in an active region of a MOSFET device.
3. The Schottky structure of claim 2 , wherein the first portion of conductive material in the first trench is maintained at a gate potential, the second portion of conductive material in the first trench is maintained at a source potential, the first portion of conductive material in the second trench is maintained at the source potential, and the second portion of conductive material in the second trench is maintained at the gate potential.
4. The Schottky structure of claim 1 , wherein the two trenches are formed in a termination region of a MOSFET device.
5. The Schottky structure of claim 4 , wherein the first portion of conductive material in the first trench is maintained at a gate potential, the second portion of conductive material in the first trench is maintained at a source potential, the first portion of conductive material in the second trench is maintained at the source potential, and the second portion of conductive material in the second trench is maintained at drain potential.
6. The Schottky structure of claim 1 , wherein a width of the mesa between the two trenches is equal to a width of a mesa between device trenches formed in the semiconductor material.
7. The Schottky structure of claim 1 , wherein a width of the mesa between the two trenches is smaller than a device mesa separating device trenches.
8. The Schottky structure of claim 7 , wherein the width of the mesa between the two trenches is between one fourth and three fourths of the width of the device mesa.
9. The Schottky structure of claim 1 , wherein the Schottky contact is formed in the mesa between the two trenches.
10. The Schottky structure of claim 9 , wherein the Schottky contact further contacts the conductive portions in each trench proximate to the mesa.
11. The Schottky structure of claim 1 , wherein one of the one or more Schottky contacts is formed in one of the trenches between the first conductive portion and the second conductive portion.
12. A Schottky structure comprising:
two trenches formed into a semiconductor material and spaced apart from each other by a mesa, wherein each trench is lined with a dielectric material, and wherein a first portion of conductive material is disposed along a first sidewall of each trench and a second portion of conductive material is disposed along a second sidewall of each trench, and wherein the first and second portions of conductive material are electrically isolated from each other; and
two or more Schottky contacts formed between the outermost walls of the two trenches, wherein the two or more Schottky contacts extend in a direction parallel to the two trenches, wherein two of the two or more Schottky contacts are formed in the two trenches respectively between the first conductive portions and the second conductive portions, wherein at least one of the two or more Schottky contacts is deactivated by selectively doping the semiconductor material with dopants configured to prevent a Schottky diode from forming.
13. The Schottky structure of claim 1 , wherein a first Schottky contact is formed in the mesa between the two trenches and a second Schottky contact is formed in at least one of the trenches between the first conductive portion and the second conductive portion.
14. The Schottky structure of claim 13 , wherein the second Schottky contact is configured as a closed cell structure.
15. The Schottky structure of claim 1 , wherein the Schottky structure is integrated into a bipolar transistor, insulated gate bipolar transistor (IGBT), junction field effect transistor (JFET), a diode, a resistor or a capacitor.