Substrate isolation design
A substrate isolation design includes a P substrate, a P well positioned on the P substrate, at least a device positioned in the P well, and at least a P substrate guard ring surrounding the device. A P+ guard ring, an N well guard ring, or a deep N well guard ring can be selectively interposed between the P substrate guard ring and the device to facilitate blocking substrate coupling effect.
1. A substrate isolation design, comprising:
a P substrate;
a P well positioned on the substrate;
at least a device positioned in the P well;
at least a P substrate guard ring surrounding the device; and
an N well guard ring positioned between the device and the P substrate guard ring,
wherein the P substrate guard ring is positioned beneath a shallow isolation trench formed within the P well.
2. The substrate isolation design of claim 1 , further comprising at least a P+ guard ring surrounding the device.
3. The substrate isolation design of claim 2 , wherein the P+ guard ring is between the device and the P substrate guard ring.
4. The substrate isolation design of claim 3 , wherein the N well guard ring is positioned between the P+ guard ring and the P substrate guard ring.
5. The substrate isolation design of claim 4 , further comprising at least a deep N well guard ring positioned beneath the P well to contact to the N well guard ring.
6. The substrate isolation design of claim 1 , wherein the N well guard ring surrounds the device.
7. The substrate isolation design of claim 6 , wherein the N well guard ring is between the device and the P substrate guard ring.
8. The substrate isolation design of claim 7 , further comprising at least a deep N well guard ring positioned beneath the P well to contact to the N well guard ring.
9. A substrate isolation design, comprising:
a substrate;
at least a device positioned on the substrate;
a first guard ring surrounding the device;
a second guard ring surrounding the first guard ring; and
a third guard ring surrounding the second guard ring, the third guard ring being a substrate guard ring, wherein the second guard ring comprises an N well guard ring and the substrate guard ring is positioned beneath a shallow isolation trench.
10. The substrate isolation design of claim 9 , wherein the first guard ring comprises a P+ guard ring.
11. The substrate isolation design of claim 9 , wherein the third guard ring comprises a P substrate guard ring.
12. The substrate isolation design of claim 9 , further comprising at least a deep N well guard ring connecting to the N well guard ring.
13. A substrate isolation design, comprising:
a P substrate;
at least a device positioned in the substrate;
at least a P substrate guard ring surrounding the device; and
an N well guard ring positioned between the device and the P substrate guard ring,
wherein the P substrate guard ring is positioned beneath a shallow isolation trench.
14. The substrate isolation design of claim 13 , further comprising at least a P+ guard ring positioned between the device and the P substrate guard ring.
15. The substrate isolation design of claim 14 , wherein the N well guard ring is between the P+ guard ring and the P substrate guard ring.
16. The substrate isolation design of claim 15 , further comprising at least a deep N well guard ring contacting to the N well guard ring.
17. The substrate isolation design of claim 13 , further comprising at least a deep N well guard ring contacting to the N well guard ring.