Formation of Insulated-Gate Bipolar Transistor Highly Activated Anodes via Nickel Silicidation With Dopant Segregation

Abstract

We propose a low-temperature nickel silicidation with a dopant segregation approach to form shallow anode profiles in thin wafer insulated-gate bipolar transistors (IGBTs). The process provides an anode with a boron peak concentration of 3 × 10 19 /cm 3 after annealing at 400°C. The silicidation results in a NiSi phase with a strong interface roughness, independent of the polishing process after grinding. The devices exhibit characteristics comparable with the state-of-the-art IGBTs in terms of voltage drop (V CE,ON ), which indicates that a higher anode activation was achieved at low temperature in comparison with the reference samples, since the anode is <27% of its initial thickness. Devices that underwent chemical mechanical planarization exhibit higher V CE,ON than those without, possibly due the increase of surface roughness.