High speed, high gain InP-based heterostructure FETs with high breakdown voltage and low leakage

Most of the physical mechanisms determining breakdown, gate leakage, and output conductance of InAlAs/InGaAs HFET have been identified. This understanding leads to an impressive improvement with respect to breakdown and power performance of these high frequency devices. MBE as well as MOVPE grown structures have demonstrated that InGaAs FET-channels are suitable for corresponding applications and replacement by a higher bandgap material is not necessary up to P_DC ≈4.5 W/mm. Careful design of layer stacks in terms of buffer, spacer and barrier layers as well as of device layout, i.e. gate-drain distance and gate-recess process, makes available the superior transport properties of InGaAs for high speed, high gain, and yet high breakdown and power devices