Effect of material variations on performance of double-recessed gate powerpseudomorphic high electron mobility transistors in monolithic microwave and millimeter wave integrated circuit applications

We report the effect of start epi-material variability on the performance o f double-recessed power pseudomorphic high electron mobility transistors. V ariation in channel-recess depth, which is related to variation in the star t material, is critically linked to rf performance of monolithic microwave and millimeter wave integrated circuit high power amplifiers. For high yiel d, it is important to control the channel recess, which in turn has implica tions on acceptable variation in epi-material. Design tweaks can relax chan nel-recess tolerance limits, but it is still important to account for mater ial variation. (C) 1999 American Vacuum Society. [S0734-211X(99)01206-8].