Switch-OFF Avalanche-Breakdown-Induced Electrical Degradations of RF-LDMOS Transistor for SMPAs Applications

The electrical parameters degradations of a radio frequency lateral-diffused metal-oxide-semiconductor transistor under switch-OFF avalanche breakdown stress have been first experimentally investigated. A modified three-port dc-IV method is proposed to demonstrate the degradation mechanisms. It shows that the interface states generation under the edge of the polygate at the n-drift region brings the increase in ON-resistance due to the decrease in carrier mobility, while the hot-holes injection and trapping there leads to the increase in gate-drain capacitance due to the widening restriction of the depletion layer in the n-drift region. Furthermore, the output power and the power gain are also decreased under the avalanche shocks. However, other electrical parameters, such as threshold voltage, gate-source capacitance, and drain-source capacitance, can be kept unchanged.