Fabrication and Characterization of 0.2μm InAlAs/InGaAs Metamorphic HEMT’s with Inverse Step- Graded InAlAs Buffer on GaAs Substrate

Metamorphic InAlAs/InGaAs HEMT are successfully demonstrated, exhibiting several advantages over conventional P-HEMT on GaAs and LM-HEMT on InP substrate. The strainrelaxed metamorphic structure is grown by MBE on the GaAs substrate with the inverse-step graded InAlAs metamorphic buffer. The device with 40% indium content shows the better characteristics than the device with 53% indium content. The fabricated metamorphic HEMT with 0.2μm T-gate and 40% indium content shows the excellent DC and microwave characteristics of Vth=-0.65V, g m,max=620mS/mm, fT=120GHz and fmax=210GHz. Index Terms – GaAs, HEMT, InGaAs, metamorphic, M-HEMT, Power