in order to reduction of the on-state loss and the switching loss leading to the improvement of the energy saving performance of the product,the 7th generation charge storage type igbt (CSTBT tm)and MOS (Metal Oxide Semiconductor) chip structure has been optimized using thinner wafers . the 7th generation diode chip has been made with thinner wafer and has applied the RFC(Relaxed field of Cathode)structure using backside diffusion layer formation technology.