Tvs structures for high surge and low capacitance

A method for manufacturing a transient voltage suppressing (TVS) device comprising:

• growing a lower epitaxial layer having a first conductivity type on a semiconductor substrate of the first conductivity type and applying an implant mask to implant a buried dopant layer of the first conductivity type then growing a top epitaxial layer of the first conductivity type on top of the lower epitaxial layer followed by blank implanting a top compensation layer of a second conductivity type near a top surface of the top epitaxial layer and opening a plurality of contact trenches in the upper epitaxial layer then implanting a trench-bottom dopant region of a second conductivity type below each of the contact trenches in the top epitaxial layer;
• carrying out a deposition process to form a conductive trench-filling layer to fill in the contact trenches followed by the etching back the conductive trench-filling layer to the top compensation layer followed by applying a mask to implant dopant regions near the top surface of the top compensation layer followed by carrying out a diffusion process to diffuse trench-bottom dopant region to surround the contact trenches and to merge with the buried dopant layer;
• and
• applying a trench mask to open a plurality of isolation trenches followed by filling the isolation trenches with an insulation material.