InP-Based Heterojunction FET with Composite Channel Consisting of In0.53Ga0.47As / In0.4Ga0.6As Layers for High Drain Voltage Operation

A novel InP-based heterojunction FET (HJFET) with composite channel consisting of In_0.53Ga_0.47As and In_0.4Ga_0.6As layers is designed and characterized for high drain voltage operation. By this structure, gate leakage current (Ig ) resulting from impact ionization is reduced to half of that of an InP-HJFET with uniform In_0.53Ga_0.47As channel, with maintaining large transconductance (~800mS/mm). The Ig reduction decreases minimum noise figure NF dependence on drain voltage (Vd) and improves NF(@12 GHz) by 0.1 dB at Vd=2 V where NF of an InP-based HJFET with uniform In_0.53Ga_0.47As channel increases due to large Ig.