Gas source molecular beam epitaxy of InP-based heterostructures for OEIC applications

We report in this paper on high quality InGaAs/InAlAs/InP heterostructure and its application to optoelectronic integrated circuit (OEIC) structures grown by gas source molecular beam epitaxy. Electron mobilities of the modulation doped heterostructure are as high as 1.1×104 cm2/V s at room temperature and 6.4×104 cm2/V s at liquid nitrogen temperature. An OEIC structure consisting of high electron mobility transistors (HEMT) and a metal semiconductor metal photo-detector (MSM-PD) was then achieved within a single growth run. An etch stop layer was inserted between the MSM and HEMT structure in order to ease the device process by employing the excellent etch selectivity between InP and InAlAs. The MSM photo-detector, with an active area of 80×80 μm2, has the responsivity of 0.62 A/W. The DC transconductance of an InGaAs/InAlAs HEMT with 1 μm gate length is 305 mS/mm with threshold voltage of −1.4 V. High frequency measurements show that the −3 dB bandwidth of the OEIC receiver is 1.0 GHz indicating that it can operate at a transmitting rate of 1.3 Gb/s.