Gate leakage lowering and kink current suppression for antimonide-based field-effect transistors

Conventional InAs/AlSb HEMTs suffer from chemical instability in materials and high kink current. To avoid these drawbacks, this work proposes a novel layer structure of an InAsSb/AlSb HEMT and a novel two-step passivation process. Performance improvements are reduced dc output conductance by approximately 4.6 times at VDS = 0.5 V and ID = 100 mA/mm, and gate leakage to 1 × 10−3 mA/mm from 4 at VGS = −1.2 V and VDS = 0.8 V compared with those of two InAs/AlSb HEMTs, one with the conventional one-step and the other with the proposed two-step passivation process. Both dc and rf performances show strong evidences of impact ionization suppression.