Two-Mask Silicides Fully Self-Aligned for Trench Gate Power IGBTs With Superjunction Structure

We present a new trench gate power IGBT with superjunction structures in its drift region, which exhibits a strongly improved relationship between blocking voltage and on-resistance. An accurate control of the impurity concentration of the n drift region in the trench sidewall is important in achieving the performance of the proposed IGBT, and angle ion implantation is considered to be the most suitable method for its fine controllability; therefore, we optimized the trench sidewall doping by adjusting the implanted ion dosage and incident angles. In addition, source and gate contacts are realized by self-aligned silicides technology; therefore, the devices are made fully self-aligned with two masks - one for trench and another for source and body doping selection. The output I-V characteristics and threshold voltage are measured after the devices were fabricated.