Novel carbon-doped p-channel GaAs mesfet grown by mombe

A high performance GaAs p-MESFET using carbon as the p-dopant is demonstrated for the first time. The channel and contact layers were grown by metal organic molecular beam epitaxy (MOMBE). The cap contact layer was highly doped with carbon (5 × 10²⁰ cm⁻³) in order to minimize the parasitic resistance in the FET structure. The sheet resistivity and transfer resistance of the contacts were 220 ohm/□ and 0.2 ohm-mm respectively. These are comparable to values achieved on n-type GaAs. The room temperature extrinsic transconductance and K-factor values were 50 mS/mm and 165 mS/V·mm with 1 μm gate length and 3.5 μm source-to drain spacings. There are the highest room temperature values ever demonstrated for p-GaAs MESFET.