Method for identifying latch-up structure

A method for identifying a latch-up structure, comprising:

• in a chip layout, finding a first positive-type (P-type) heavily doped region connected to a first input/output pad and located in a P-well;
• finding a first negative-type (N-type) heavily doped region located in a second N-well and a second N-type heavily doped region located in a first N-well, both of which being adjacent to the first P-type heavily doped region;
• finding a second P-type heavily doped region adjacent to the first N-type heavily doped region and located in a P-type substrate, wherein the P-well is located in a deep N-well, the deep N-well is located in the first N-well, and the first N-well and the second N-well are both located on the P-type substrate;
• and
• identifying an area formed by the first P-type heavily doped region, the first N-type heavily doped region, the second P-type heavily doped region, the second N-type heavily doped region, the P-well, the deep N-well, the first N-well, the second N-well and the P-type substrate as the latch-up structure;
• or,
• in the chip layout, finding a first N-type heavily doped region connected to the first input/output pad and located in the second N-well;
• finding a first P-type heavily doped region located in the P-well and a second P-type heavily doped region located in the P-type substrate, both of which being adjacent to the first N-type heavily doped region;
• finding a second N-type heavily doped region adjacent to the first P-type heavily doped region and located in the first N-well, wherein the P-well is located in a deep N-well, the deep N-well is located in the first N-well, and the first N-well and the second N-well are both located on the P-type substrate;
• and
• identifying an area formed by the first P-type heavily doped region, the first N-type heavily doped region, the second P-type heavily doped region, the second N-type heavily doped region, the P-well, the deep N-well, the first N-well, the second N-well and the P-type substrate as the latch-up structure.

A method for identifying a latch-up structure, comprising:

• in a chip layout, finding a first positive-type (P-type) heavily doped region connected to a first input/output pad and located in a P-well;
• finding a first negative-type (N-type) heavily doped region located in a second deep N-well and a second N-type heavily doped region located in a first N-well, both of which being adjacent to the first P-type heavily doped region;
• finding a second P-type heavily doped region adjacent to the first N-type heavily doped region and located in a P-type substrate, wherein the P-well is located in a first deep N-well, the first deep N-well is located in the first N-well, the second deep N-well is located in a second N-well, and the first N-well and the second N-well are both located on the P-type substrate;
• and
• identifying an area formed by the first P-type heavily doped region, the first N-type heavily doped region, the second P-type heavily doped region, the second N-type heavily doped region, the P-well, the first deep N-well, the second deep N-well, the first N-well, the second N-well and the P-type substrate being as the latch-up structure;
• or,
• in the chip layout, finding a first N-type heavily doped region connected to the first input/output pad and located in the second deep N-well;
• finding a first P-type heavily doped region located in the P-well and a second P-type heavily doped region located in the P-type substrate, both of which being adjacent to the first N-type heavily doped region;
• finding a second N-type heavily doped region adjacent to the first P-type heavily doped region and located in the first N-well, wherein the P-well is located in the first deep N-well, the first deep N-well is located in the first N-well, the second deep N-well is located in the second N-well, and the first N-well and the second N-well are both located on the P-type substrate;
• and
• identifying an area formed by the first P-type heavily doped region, the first N-type heavily doped region, the second P-type heavily doped region, the second N-type heavily doped region, the P-well, the first deep N-well, the second deep N-well, the first N-well, the second N-well and the P-type substrate as the latch-up structure.