High breakdown voltage of AlGaAs/GaAs/AlGaAs diode achieved by balanced charges considering residual carbon impurity in hole and electron channels

摘要

High breakdown voltage (BV) AlGaAs/GaAs/AlGaAs diodes with a pair of hole and electron channels were studied taking account of the residual carbon impurity. The residual acceptor that would affect the charge balance was evaluated by separate growth. Utilizing the residual concentration, the acceptor concentrations (N-A) were examined with a fixed donor concentration of 1.1 x 10(12) cm(-2). For N-A of 0.9 x 10(12) cm(-2), the diode with 113 mu m drift region length derived the highest BV of 1800 V. Temperature-dependent I-V measurements revealed the breakdown due to an avalanche multiplication. This implies a uniform electric field across the channels. Then, depletion of both channels was characterized by C-V measurements for obtaining capacitance shut-off voltages of the diodes. The lowest shut-off voltage was obtained for the 0.9 x 10(12) cm(-2) N-A diode. This would be due to the simultaneous depletion of hole and electron channels, i.e. the identical net concentration for acceptor and donor.