Integrated lateral high-voltage diode and thyristor
View Patent ↗The present invention relates to integration of lateral high-voltage devices, such as a lateral high-voltage diode (LHVD) or a lateral high-voltage thyristor, with other circuitry on a semiconductor wafer, which may be fabricated using low-voltage foundry technology, such as a low-voltage complementary metal oxide semiconductor (LV-CMOS) process. The other circuitry may include low-voltage devices, such as switching transistors used in logic circuits, computer circuitry, or the like, or other high-voltage devices, such as a microelectromechanical system (MEMS) switch. The reverse breakdown voltage capability of the LHVD may be increased by using an intrinsic material between the anode and the cathode. Similarly, in a lateral high-voltage thyristor, such as a lateral high-voltage Silicon-controlled rectifier (LHV-SCR), the withstand voltage capability of the LHV-SCR may be increased by using an intrinsic material between the anode and the cathode.
1. A semiconductor wafer comprising:
a first insulator layer;
a first semiconductor device layer formed over the first insulator layer comprising;
a first section, which provides a combined PNP base-NPN collector;
a second section, which provides a combined NPN base-PNP collector; and
first intrinsic material between the first section and the second section, such that the first intrinsic material has a resistivity greater than about one ohm·centimeter and the first section, the second section, and the intrinsic material form a lateral high-voltage thyristor (LHVT).
2. The semiconductor wafer of claim 1 wherein a breakdown voltage between the first section and the second section is greater than about 20 volts.
3. The semiconductor wafer of claim 1 wherein a breakdown voltage between the first section and the second section is greater than about 50 volts.
4. The semiconductor wafer of claim 1 further comprising a Silicon-on-Insulator (SOI) wafer having a substrate.
5. The semiconductor wafer of claim 4 wherein an SOI insulator layer is formed over the substrate, an SOI device layer is formed over the SOI insulator layer, the SOI insulator layer provides the first insulator layer, and the SOI device layer provides the first semiconductor device layer.
6. The semiconductor wafer of claim 4 wherein an SOI insulator layer is formed over the substrate, an SOI device layer is formed over the SOI insulator layer, an epitaxial layer is formed over the SOI device layer, and the epitaxial layer provides the first semiconductor device layer.
7. The semiconductor wafer of claim 1 wherein:
the combined PNP base-NPN collector comprises doped N-type semiconductor material; and
the combined NPN base-PNP collector comprises doped P-type semiconductor material.
8. The semiconductor wafer of claim 7 wherein:
a carrier concentration of the doped N-type semiconductor material is approximately less than about 10 18 cm −3 ; and
a carrier concentration of the doped P-type semiconductor material is approximately less than about 10 18 cm −3 .
9. The semiconductor wafer of claim 1 wherein the LHVT is laterally isolated from at least one other device in the first semiconductor device layer using deep trench isolation.
10. The semiconductor wafer of claim 1 wherein the LHVT is used in a level-shifting circuit.
11. The semiconductor wafer of claim 1 wherein the LHVT is a lateral high-voltage Silicon-controlled rectifier (LHV-SCR).
12. The semiconductor wafer of claim 1 wherein the LHVT is a lateral high-voltage triac.
13. The semiconductor wafer of claim 1 wherein the LHVT is latching.
14. The semiconductor wafer of claim 1 wherein the LHVT is non-latching.
15. The semiconductor wafer of claim 1 wherein the LHVT is used in a level-shifting circuit.
16. A method comprising:
providing a semiconductor wafer having a first insulator layer;
forming a first semiconductor device layer over the first insulator layer;
forming a combined PNP base-NPN collector in the first semiconductor device layer;
forming a combined NPN base-PNP collector in the first semiconductor device layer;
providing intrinsic material between the combined PNP base-NPN collector and the combined NPN base-PNP collector, such that the intrinsic material has a resistivity greater than about one ohm·centimeter; and
forming a lateral high-voltage thyristor (LHVT) using the combined PNP base-NPN collector, the combined NPN base-PNP collector, and the intrinsic material.
17. The method of claim 16 wherein the forming the first semiconductor device layer, the forming the combined PNP base-NPN collector, the forming the combined NPN base-PNP collector, the providing the intrinsic material, and the forming the LHVT are based on a low-voltage foundry technology.