Gas source molecular beam epitaxy of InP-based microstructures: material growth, characterization and device applications

InP epitaxial layers and InGaAs/InAlAs/InP modulation doped heterostructures were grown by gas source molecular beam epitaxy, in which arsenic and phosphorus beams were obtained by thermal cracking of AsH3 and PH3. High purity InP layers have been obtained by optimizing growth parameters. To identify the species of impurity and defect in high quality InP layers, low temperature photoluminescence (PL) and photothermal ionization spectroscopy measurements were carried out. The residual donors were determined to be silicon and sulfur. To obtain a deep insight to the electronic subband structure of the two-dimensional electron gas (2DEG) system, Shubnikov-de Haas, quantum Hall effect measurements and field-dependent cyclotron resonance measurements were conducted. The electron density on each subband in 2DEG was determined to be 2.84×1012 and 3.4×1011 cm−2, respectively. The effective masses of the two subbands are (0.061±0.001)m0 for the zero subband and (0.049±0.001)m0 for the first subband. An optoelectronic integrated circuit (OEIC) structure consisting of high electron mobility transistor (HEMT) and metal semiconductor metal photo detector (MSM-PD) was achieved by gas source molecular beam epitaxy with one growth run. The responsibility of MSM-PD is 0.5A/W. DC transconductance of an InGaAs/InAlAs HEMT with 1.5-μm gate length is 305 mS mm−1; the maximum saturation current is 350 mA mm−1 and the pinch-off voltage is −1.4 V. The gain of the HEMT amplifier is 14 dB. The integrated photoreceiver could successfully operate at a data rate of 622 Mbit s−1.