4H-SiC pn Diode Grown by LPE Method for High Power Applications

摘要

The current-voltage (I-V) characteristics of large area (5 mm~2) 4H-SiC pn diodes fabricated by liquid phase epitaxy (LPE) were studied up to 2 kA/cm~2 in the temperature range from 20 to 300℃. At 200 A/cm and room temperature, the forward voltage drop (V_F) was measured to be 3.7 V. The specific on-state resistance (R_(on)) was found to be (2.3-3.4) mΩ·cm~2. The V_F showed a negative temperature coefficient in the investigated region. The long-term stability testing of the pn diodes during 100 hr at forward current density of 200 A/cm~2 was performed. The V_F increased by 0.2 V with time. Deep traps were investigated before and after long-term testing. A deep trap with thermal activation energy of E_C-1.43+-0.03 eV was detected after diode operation during 20 hr at 200 A/cm~2. It is speculated that this deep trap determines the degradation of electrical characteristics.