Jun Kawai

(11-20) Face Channel MOSFET with Low On-Resistance

We have investigated the techniques to improve the channel mobility of SiC MOSFETs and found that the hydrogen termination of dangling bonds at a MOS interface is very effective in improving the channel mobility, particularly that of the interface fabricated on a (11-20) face wafer. A high channel mobility of MOSFET on the (11-20) face was achieved to 244cm2/Vs by new process which can terminate dangling bonds by hydrogen. The vertical MOSFET, which is prepared using this process, has a low on-resistance of 5.7 mΩcm2 and a breakdown voltage of 1100 V. The channel resistance is estimated at 0.58 mΩcm2.

Prominent interface structure and bonding material of power module for high temperature operation

Sintered Ag is well known for die-attach materials, suitable for Ag metalized interfaces with a self-healing function of generated cracks. A remaining risk of sintered Ag bonding may be possible degradation of interfacial strength at high temperatures. Molding process is thus important for supporting the die-attach in the encapsulated power module once certain adhesion strength is assured between a lead-flame and mold resin. We propose a prominent interface structure using novel bonding materials for electronic power modules targeting high-temperature operation.