InP-based HEMTs: status and potential

InP based HEMT technology has evolved from research in a few labs into the mainstream of high speed microwave and millimeter wave circuits. InP HEMTs produce lower noise figures, higher gain, and higher cut-off frequencies in comparison to the best GaAs based FETs. Recent improvement in the performance of the GaInAs-channel HEMT may be attributed to: (i) obtaining superior transport properties in higher In mole-fraction channels; (ii) reducing parasitic resistance by self-aligning the ohmic contacts to the gate; and (iii) reducing the gate-length while maintaining a high aspect ratio. These efforts combined have led to a successful fabrication of ultrafast 0.1 μm gate-length HEMTs in the late 80´s to present state-of-the-art 0.05 μm gate-lengths in the early 90´s. Consequently, they are now the most promising candidate for low noise amplifiers, millimeter wave power amplification, broadband distributed amplifiers, and high frequency oscillator circuits. A review of the low noise performance is presented along with recent diversification in the InP based HEMT technology to microwave and millimeter wave power amplification