A particular study of MOCVD growth parameters of InP-based materials is demonstrated and evaluated their impact on InAlAs/InGaAs HEMT structures. The growth temperature was 650°C in order to minimize trap effects in InAlAs while at the same time achieving minimum background concentration and reduced gate leakage. At higher temperature, InAlAs showed better photoluminescence (PL) and X-ray characteristics. The impact of growth temperature on the electrical properties of bulk InAlAs layers is, however, more complex. This permitted improved uniformity, reduced source consumption and less equipment maintenance. The studies were finally validated by the state of the art characteristics of 1 μm gate length InAlAs/InGaAs HEMT's which showed ft=60GHz and fmax=120GHz.
