Table 2: PHEMT heterostructure for FET operating in 10–40 GHz range.

GaAs:Si  cm−3 40 nm i- (>0.23) 25 nm i-GaAs   ~0.6 nm δ-Si  cm−2   i-GaAs   ~0.6 nm i- 4 nm i-GaAs   1 nm i- (<0.2) 11 nm i-GaAs   30 nm i- 50 nm i-GaAs  cm−3 0.5–0.8 m CP AlAs/GaAs   (1 nm/2 nm) 5 GaAs:Sb   100 nm   Fianite substrate 400 m