Analysis and Optimization of a Thyristor Structure Using Backside Schottky Contacts Suited for the High Temperature

In high current, high voltage, high temperature power applications, commercially available conventional silicon thyristors are not suited because they present high leakage current. In this context, this paper presents a high-symmetrical (voltage) thyristor structure that presents a lower leakage current and higher breakover voltage as compared with the conventional thyristor at. It is shown through 2-D physical simulations that the replacement of the P-emitter of a standard symmetrical thyristor by a judicious association of P diffusions and Schottky contacts at the anode side contributes to the reduction of the leakage current in the forward blocking state at high temperature. A fine tune of the anode side configuration will improve the forward OFF-state behavior with only a negligible ON-state voltage drop degradation. Moreover, the comparison with the conventional anode short thyristor shows that the insertion of Schottky contacts leads to the same improvements in terms of OFF-state forward breakover voltage and leakage current and also presents a high reverse blocking voltage.