Reactive ion etch-induced effects on 0.2 μm T-gate In_0.52Al_0.48As/In_0.53Ga_0.47As/InP high electron mobility transistors

The effect of CH₄/H₂ reactive ion etching on In_0.52Al_0.48As surfaces and In052Al048As/ In_0.53Ga_0.47AsAnP heterostructure have been studied using Schottky diode, x-ray photoelectron spectroscopy, and room temperature transport experiments. The application of CH₄/H₂ as a dry etch gas for the gate recess step in the fabrication of 0.2 μm T-gate In_0.52Al_0.48As/In_0.53Ga_0.47As/InP high electron mobility transistor has been explored. We show that while the room temperature mobility and the dc and high frequency performance of the dry etched devices are at least comparable to the wet etched ones, their microwave noise behaviours are extremely sensitive to dry etch-induced defects.