Lateral PiN diodes and schottky diodes

1. A structure, comprising a diode with breakdown voltage determined by a dimension between p- and n-terminals formed in an i-region above a substrate, wherein at least the p-terminals are isolated from each other by isolation material in shallow openings between the p-terminals and from the substrate by lateral undercut isolation regions of a same material as the isolation material between the p-terminals, wherein the substrate is composed of silicon and the i-region directly contacts the substrate.

2. The structure of claim 1 , wherein the i-region is one of i-Si, i-SiGe, i-SiGeC, and i-SiC such that the p- and n-terminals are one of Si, SiGe and SiGeC material.

3. The structure of claim 1 , wherein the p-terminals and the n-terminals are isolated from the substrate by lateral undercut isolation regions.

4. The structure of claim 1 , wherein a first of the p- and n-terminals are spaced apart at a first distance to provide a lateral PiN diode with a high voltage breakdown region and a second of the p- and n-terminals are spaced apart at a second distance to provide a lateral PiN diode with a low voltage breakdown region.

5. A structure, comprising:

a substrate;

an i-region comprising one of i-Si, i-SiGe, i-SiGeC, and i-SiC, formed above the substrate;

a first lateral PiN diode comprising a first p-terminal formed in the i-region at a first distance from a first n-terminal formed in the i-region; and

a second lateral PiN diode comprising a second p-terminal formed in the i-region at a second distance from a second n-terminal formed in the i-region, wherein:

the first distance is greater than the second distance;

the first distance forms a high breakdown voltage region for the first lateral PiN diode;

the second distance forms a low breakdown voltage region for the second lateral PiN diode, wherein the first and second p-terminals are isolated from the substrate by lateral undercut isolation regions and the p-terminals are isolated from each other by isolation material in shallow openings between the p-terminals, the isolation material and material of the lateral undercut isolation regions are same material, wherein the isolation material directly contacts vertical sidewalls of the first and second p-terminals, and the material of the lateral undercut isolation regions directly contacts bottom surfaces of the first and second p-terminals;

the substrate is composed of silicon; and

the i-region directly contacts the substrate.

6. The structure of claim 5 , wherein the first and second p- and n-terminals are isolated from the substrate by lateral undercut isolation regions.

7. The structure of claim 5 , wherein the lateral undercut isolation regions and the isolation material comprise isolation material of Boron Phosphate Silicate Glass (BPSG).

8. The structure of claim 5 , wherein the lateral undercut isolation regions comprise isolation material of oxide.

9. The structure of claim 5 , wherein the lateral undercut isolation regions extend only partly under the p- and n-terminals.

10. The structure of claim 5 , wherein the lateral undercut isolation regions extend only partly under the first and second p-terminals.

11. The structure of claim 5 , further comprising a third p-terminal located laterally between the first p-terminal and the second p-terminal, wherein the first, second, and third p-terminals are located laterally between the first and second n-terminals.

12. The structure of claim 11 , wherein the isolation material directly contacts vertical sidewalls of the third p-terminal and the material of the lateral undercut isolation region directly contacts a bottom surface of the third p-terminal.

13. The structure of claim 1 , wherein:

the isolation material in the shallow openings between the p-terminals directly contacts vertical sidewalls of the p-terminals; and

the material in the lateral undercut isolation regions directly contacts bottom surfaces of the p-terminals.

14. The structure of claim 13 , wherein the p-terminals comprise a first p-terminal and a second p-terminal located laterally between a first n-terminal and a second n-terminal, and further comprising a third p-terminal located laterally between the first p-terminal and the second p-terminal.