Latchup characterization of high energy ion implanted new CMOS twin wells that comprised the BILLI (buried implanted layer for lateral isolation) and BL/CL (buried layer/connecting layer) structures

We have investigated the latchup characteristics of various CMOS well structures possible with high energy ion implantation processes, including conventional retrograde well, BILLI well and BL/CL structure. We also compare those characteristics with conventional diffused wells in bulk and retrograde wells with STI isolation technology. We show DC latchup characterization results that allow us to evaluate each technology and suggest guidelines for the optimization of latchup hardness.