Schottky device and process of making the same comprising a geometry gap
View Patent ↗A Schottky device and a semiconductor process of making the same are provided. The Schottky device comprises a substrate, a deep well, a Schottky contact, and an Ohmic contact. The substrate is doped with a first type of ions. The deep well is doped with a second type of ions, and formed in the substrate. The Schottky contact contacts a first electrode with the deep well. The Ohmic contact contacts a second electrode with a heavily doped region with the second type of ions in the deep well. Wherein the deep well has a geometry gap with a width formed under the Schottky contact, the first type of ions and the second type of ions are complementary, and the width of the gap adjusts the breakdown voltage.
1. A Schottky device with a breakdown voltage, comprising:
a substrate being doped with a first type of ions;
a deep well being doped with a second type of ions, and formed in the substrate;
a Schottky contact, at a top surface of the deep well, contacting a first electrode with the deep well;
two heavily doped regions being doped with the second type of ions in the deep well;
two Ohmic contacts contacting two second electrodes with the two heavily doped regions, respectively;
two first doped regions being doped with the first type of ions in the substrate, wherein each of the two first doped regions is separated from the deep well by a distance which is larger than 0 μm and equal to or smaller than 20 μm, and the distance between the deep well and each of the first doped regions adjusts the breakdown voltage; and
two second doped regions being doped with the first type of ions, and being only formed in the deep well and around the Schottky contact, wherein an ion concentration and a depth of the two second doped regions respectively adjust the breakdown voltage;
wherein the deep well has a geometry gap with a width, the geometry gap is formed at a bottom surface of the deep well and opposite the Schottky contact, and has a tapered shape having two side surfaces of a triangle in a cross-sectional view, the first type of ions and the second type of ions are complementary, and the width of the gap is configured to adjust the breakdown voltage.
2. The Schottky device as claimed in claim 1 , wherein a range of a depth of the deep well is from 2 to 10 μm.
3. The Schottky device as claimed in claim 1 , wherein a range of an ion concentration of the deep well is from 1E12 to 5E13 per square centimeter.
4. The Schottky device as claimed in claim 1 , wherein a range of an ion concentration of each of the two first doped regions is from 1E12 to 5E13 per square centimeter.
5. The Schottky device as claimed in claim 1 , wherein a range of a depth of each of the two first doped regions is from 1 to 5 μm.
6. The Schottky device as claimed in claim 1 , wherein the geometry gap is spaced in from one side of the deep well doped with the second type of ions leaving portions of the deep well doped with the second type of ions located outside the width of the geometry gap.
7. A semiconductor process for forming a Schottky device, comprising the steps of:
forming a deep well with a second type of ions in a substrate being doped with a first type of ions;
forming two first doped regions with the first type of ions;
forming an oxide layer;
forming two second doped regions only in the deep well with the first type of ions;
forming two heavily doped regions being doped with the second type of ions in the deep well; and
forming a first electrode on a Schottky contact at a top surface of the deep well and two second electrodes on two Ohmic contacts on the two heavily doped regions, respectively;
wherein each of the two first doped regions are separated from the deep well by a distance which is larger than 0 μm and equal to or smaller than 20 μm, the first type of ions and the second type of ions are complementary, the second doped regions are around the first electrode, and the deep well has a geometry gap with a width, the geometry gap is formed at a bottom surface of the deep well and opposite the Schottky contact, and has a tapered shape having two side surfaces of a triangle in a cross-sectional view, and the width of the gap is configured to adjust the breakdown voltage.
8. The semiconductor process of claim 7 , wherein the step of forming the deep well further comprises the step of:
thermal driving for 6 to 12 hours under 1000 to 1200 degrees of Celsius.
9. The semiconductor process of claim 7 , wherein the step of forming the two first doped regions further comprises the step of:
thermal driving for 6 to 12 hours under 1000 to 1200 degrees of Celsius.
10. The semiconductor process of claim 7 , wherein the deep well formed under the Schottky contact is formed to be spaced in from one side of the deep well doped with the second type of ions leaving portions of the deep well doped with the second type of ions located outside the width of the geometry gap.