Zener diode haviing a polysilicon layer for improved reverse surge capability and decreased leakage current
View Patent ↗A semiconductor device such as a Zener diode includes a first semiconductor material of a first conductivity type and a second semiconductor material of a second conductivity type in contact with the first semiconductor material to form a junction therebetween. A first oxide layer is disposed over a portion of the second semiconductor material such that a remaining portion of the second semiconductor material is exposed. A polysilicon layer is disposed on the exposed portion of the second semiconductor material and a portion of the first oxide layer. A first conductive layer is disposed on the polysilicon layer. A second conductive layer is disposed on a surface of the first semiconductor material opposing a surface of the first semiconductor material in contact with the second semiconductor material.
1. A semiconductor device, comprising:
a first semiconductor material of a first conductivity type;
a second semiconductor material of a second conductivity type in contact with the first semiconductor material to form a junction therebetween;
a first oxide layer disposed over a portion of the second semiconductor material such that a remaining portion of the second semiconductor material is exposed;
a polysilicon layer disposed on and in contact with the exposed portion of the second semiconductor material and a portion of the first oxide layer;
a first conductive layer disposed on the polysilicon layer; and
a second conductive layer disposed on a surface of the first semiconductor material opposing a surface of the first semiconductor material in contact with the second semiconductor material.
2. The semiconductor device of claim 1 further comprising a second oxide layer disposed on the first oxide layer and a portion of the polysilicon layer.
3. The semiconductor device of claim 2 wherein the second oxide layer includes a low temperature oxide (LTO).
4. The semiconductor device of claim 1 further comprising a semiconductor substrate, the first semiconductor material being a first semiconductor layer disposed on or in the substrate.
5. The semiconductor device of claim 1 further comprising a semiconductor substrate that includes the first semiconductor material.
6. The semiconductor device of claim 1 wherein the polysilicon layer has a thickness between 1 and 4 microns.
7. The semiconductor device of claim 1 wherein the polysilicon layer has a thickness between 1 and 2 microns.