Innovative designs enable 300-V TMBS® with ultra-low on-state voltage and fast switching speed

A 300-V TMBS^® (Trench MOS Barrier Schottky) rectifier with novel active-cell and termination design is first proposed and demonstrated. The device features a combination of p-transparent anode and Schottky contact, considerably reducing on-state voltage and ensuring a high degree of performance uniformity. A floating p-layer is used in termination region under a trench area to significantly enhance the blocking capability to 95% of the ideal breakdown voltage. In addition, the new termination design is area-efficient, being only 30 to 40 μm in width, which is less than 33% of the conventional guard-ring terminations. Experimental results have shown that the new 300-V TMBS structure with the novel active cell and termination design exhibits ultra-low on-state voltage of less than 0.9 V at 250 A/cm², a fast turn-off time lower than 55 ns and a high breakdown voltage over 380 V. It is noteworthy that these new components in active and termination regions can be formed without any additional masks, and hence at no extra cost.