Method of forming a Schottky diode and structure therefor
View Patent ↗In one embodiment, a Schottky diode is formed on a doped region having a thickness less than about eighteen microns.
1. A method of forming a Schottky diode comprising:
providing a semiconductor substrate having a first surface;
forming a first doped region extending into the semiconductor substrate from the first surface and having a resistivity no greater than about two ohm-cm;
forming a second doped region within the first doped region and extending less than first distance into the semiconductor substrate;
forming a Schottky barrier material contacting the first doped region;
forming a dielectric layer on the first surface and extending to overlie the second doped region and have a side substantially coplanar to an edge of the first doped region; and
forming a semi-insulating layer on the dielectric layer including forming a first semi-insulating layer on the dielectric layer and forming a second semi-insulating layer on the first semi-insulating layer.
2. The method of claim 1 wherein the Schottky diode has a reverse breakdown voltage less than about one hundred volts.
3. The method of claim 1 wherein forming the dielectric layer on the first surface includes forming the dielectric layer having a first portion of a first thickness on the first surface and extending to overlie a first portion of the second doped region and having a second portion of a second thickness overlying a second portion of the second doped region.
4. The method of claim 1 wherein forming the first doped region extending into the semiconductor substrate includes forming the first distance less than about eighteen microns.
5. The method of claim 1 wherein forming the first doped region extending into the semiconductor substrate includes forming the first doped region with a resistivity that is greater than a resistivity of the semiconductor substrate.
6. The method of claim 1 wherein forming the first and second semi-insulating layers includes forming the first semi-insulating layer having a first resistivity and the second semi-insulating layer having a second resistivity.
7. The method of claim 6 wherein forming the first and second semi-insulating layers includes forming the second resistivity greater than about 1E17 ohm-cm.
8. The method of claim 6 wherein forming the first and second semi-insulating layers includes forming the first resistivity lower than the second resistivity.
9. A method of forming a Schottky diode having a breakdown voltage less than about one hundred volts comprising:
providing a semiconductor substrate having a first surface;
forming a first doped region extending less than about eighteen microns into the semiconductor substrate from the first surface and having a resistivity no greater than about 0.2 ohm-cm;
forming a second doped region within the first doped region;
forming a Schottky barrier material contacting the first doped region;
forming a dielectric layer on the first surface and extending to overlie the second doped region and have an edge substantially coplanar to an edge of the first doped region; and
forming a semi-insulating layer on the dielectric layer including forming a first semi-insulating layer of a first resistivity disposed on the dielectric layer and forming a second semi-insulating layer of a second resistivity that is greater than the first resistivity wherein the second resistivity is no less than about 1E17 ohm-cm.
10. The method of claim 9 wherein forming the dielectric layer includes forming the dielectric layer having a first portion of a first thickness on the first surface and extending to overlie a first portion of the second doped region and having a second portion of a second thickness overlying a second portion of the second doped region.