Study on THz InP DHBT Device

InP DHBT has excellent high frequency characteristic, good heat dissipation, breakdown and noise performance. It is one of the devices with the most performance advantages in realizing ultra-high-frequency (UHF) low noise and power amplifier circuit design. In this paper, the main factors affecting the electrical performance parameters of high frequency InP DHBT devices are briefly introduced and analyzed. And combined with the factors, the device was optimized in the aspects of material structure and layout design. The device with emitter line width of 0. 7 μm was developed by using three-mesa wet etching process, self-alignment process, self-termination process and air bridge process. Metal film resistor and MIM capacitor were also integrated in the process. And the device consistency on the chip was good. By reducing the mesa area of the base region, the electrical performance of the 0. 7 μm×6 μm InP DHBT was finally achieved: the maximum DC gain β was 30, the breakdown voltage can reach 3. 2 V at 10 μA, the current gain cut-off frequency was measured of 358 GHz and the maximum oscillation frequency was measured of 407 GHz, which can meet the design requirements of digital analog hybrid integrated circuits, such as 220 GHz amplifier, voltage controlled oscillator (VCO) under 100 GHz.