In0.52Al0.48As/In0.53Ga0.47As high electron mobility transistors (HEMTs) lattice-matched to InP substrates have achieved a great successful role on microwave devices and circuits. However, a significant kink effect is observed in I-V characteristics. This kink effect together with a high output conductance is associated with a higher impact ionization rate in the InGaAs channel, which deteriorates the device performance. Due to this disadvantage of low energy bandgap InGaAs channel, in this study, we added a small amount of Al into the InGaAs channel to enhance the bandgap, and expect a reduction of impact ionization process. In the mean while, the life-time testing associated device performance could also be improved.