IC with recombination layer and guard ring separating VDMOS and CMOS or the like.

摘要

In an integrated circuit device having a highly doped bottom substrate layer of a first conductivity type, a lightly doped top layer of the first conductivity type formed on the substrate layer, a vertical MOSFET formed in the lightly doped top layer and a second circuit component, such as a CMOS, formed in the lightly doped top layer, there are further provided a guard ring and a recombination layer for preventing latchup of the second component by preventing minority carriers from moving from the vertical MOSFET to the second component. The guard ring is formed in the lightly doped top layer between the vertical MOSFET and the second component, and made of a second conductivity type single crystal semiconductor, or a first conductivity type polycrystalline silicon or an insulating material such as SiO2. The recombination layer is formed between the bottom substrate layer and the lightly doped top layer so as to separate at least the second component from the bottom substrate layer, and made of the first conductivity type polycrystalline silicon.