Thermoreflectance mapping observation of Power MOSFET under UIS avalanche breakdown condition

In this study, we investigated the temperature variation of the top surface image of power MOSFET under UIS condition, measured by the optical probed thermo-reflectance image mapping (OPTIM) (using electro optical frequency mapping: EOFM). The measured data obtained by the thermoreflectance mapping was found to be sensitive to changes in temperature rather than the temperature distribution. These results suggest that the thermoreflectance mapping method has higher measuring ability of heat generation distribution, since it has higher time-resolution than that of thermography.