Fabrication of trench isolation and trench power MOSFETs in a smart power IC Technology with a single trench unit process

We report on using a single trench unit process for the trench isolation and for the trench power MOSFET of a common-drain smart power IC technology. The trench power MOSFET has a maximum specific on-resistance, (R_onldrA), below 50 mOmega-mm² and a typical breakdown voltage, V_br, of 95 V. The trench isolation provides well isolation up to 90 V. Using a single trench unit process for both devices results in low process costs. In addition both power and logic areas of a chip benefit from the trench process.