Patent ID: 8169000

Claim:
A lateral transient voltage suppressor with ultra low capacitance, comprising a first conductivity type substrate; at least one diode cascade structure arranged in said first conductivity type substrate, wherein said diode cascade structure further comprises at least one second conductivity type lightly doped well arranged in said first conductivity type substrate, wherein a first heavily doped area and a second heavily doped area are arranged in said second conductivity type lightly doped well, and wherein said first heavily doped area and said second heavily doped area respectively belong to opposite conductivity types; and at least one first conductivity type lightly doped well arranged in said first conductivity type substrate and neighboring said second conductivity type lightly doped well, wherein a third heavily doped area and a fourth heavily doped area are arranged in said first conductivity type lightly doped well, wherein said third heavily doped area and said fourth heavily doped area respectively belong to opposite conductivity types, and wherein said second heavily doped area is connected with said third heavily doped area, and wherein said second heavily doped area and said third heavily doped area respectively belong to opposite conductivity types; a second conductivity type well arranged in said first conductivity type substrate and neighboring said diode cascade structure, wherein a fifth heavily doped area, a sixth heavily doped area and a seventh heavily doped area are arranged in said second conductivity type well, and wherein a conductivity type of said fifth heavily doped area is opposite to a conductivity type of said sixth and seventh heavily doped areas; and a plurality of deep isolation trenches arranged in said first conductivity type substrate, having a depth greater than depths of said second conductivity type lightly doped well, said second conductivity type well and said first conductivity type lightly doped well, and separating said second conductivity type lightly doped well, said second conductivity type well and said first conductivity type lightly doped well.