Activation energy values from the temperature dependence of silicon PN junction reverse current and its origin

Abstract

AbstractAccurate measurements of leakage reverse current (IR) for PN junctions from silicon device samples, available at this time as commercial devices have been performed. Above 125–150 °C junction temperature, the Arrhenius plots indicate activation energy values in a range of 0.65–1.22 eV depending on the junction type. For the cellular PN junction of power MOSFET transistors, the temperature dependence indicated a value of 1.05 eV, when most of the IR flows at the junction edge (bias voltage on the gate). For zero bias on the gate, 1.22 eV has been exhibited. For the PN junction from a bipolar transistor, a value of 1.16 eV has been found in the range of 125–200 °C and 0.91 eV in the range 200–275 °C. For silicon PN junction diodes, values of 0.89 and 0.65 eV have been found. Nevertheless values higher than 1 eV can be exhibited above 125–150 °C by other diode samples. Activation energies of 1.0–1.2 eV cannot be seen as confirmation that the junction diffusion (bulk) current component is the primary component of IR. Values greater than 1 eV are possible when most of the IR flows at the junction periphery. High values of the IR at 150–200 °C junction temperature, for silicon PN junctions from commercial devices could be caused by current flow at the semiconductor dielectric interface from the junction edge and not in the bulk. Understanding and better control of junction leakage IR could enable reliable operation of silicon devices above 150–200 °C, the maximum permissible junction temperature at this time.