Patent ID: 8232601

Claim:
A transient voltage suppressor for directional ESD protection, comprising: a conductivity type substrate having highly doping concentration; a first type lightly doped region, having a first type heavily doped region arranged therein, wherein the first type lightly doped region and the conductivity type substrate respectively belong to opposite types, and wherein the first type heavily doped region and the first type lightly doped region belong to same types; a second type lightly doped region, having a second type heavily doped region and a third type heavily doped region arranged therein, wherein the second type lightly doped region and the conductivity type substrate respectively belong to opposite types, and wherein the second type heavily doped region and the third type heavily doped region respectively belong to opposite types, and the second type heavily doped region and the conductivity type substrate belong to same types, and wherein the second type heavily doped region is connected with the first type heavily doped region, and wherein a first transistor is formed by the second type heavily doped region, the second type lightly doped region and the conductivity type substrate; a third type lightly doped region, having a fourth type heavily doped region and a fifth type heavily doped region arranged therein, wherein the third type lightly doped region and the conductivity type substrate respectively belong to opposite types, and wherein the fourth type heavily doped region and the fifth type heavily doped region respectively belong to opposite types, and the fourth type heavily doped region and the conductivity type substrate belong to same types, and wherein the fourth type heavily doped region is connected with the third type heavily doped region; a fourth type lightly doped region, having a sixth type heavily doped region arranged therein, wherein the fourth type lightly doped region and the conductivity type substrate belong to same types; and wherein the fourth type lightly doped region and the sixth type heavily doped region respectively belong to opposite types, and wherein the sixth type heavily doped region is connected with the fifth type heavily doped region; a plurality of closed isolation trenches, arranged on the conductivity type substrate, wherein at least one of the plurality of closed isolation trenches is neighbored one of the type lightly doped regions; and a first pin, connected with the first type heavily doped region and the second type heavily doped region.