Chemical beam epitaxy of Ga 0.47In 0.53As/InP quantum wells and heterostructure devices

Chemical beam epitaxy (CBE) is the newest development in epitaxial growth technology. It combines many important advantages of molecular beam epitaxy (MBE) and organometallic chemical vapor deposition (OMCVD). This paper briefly reviews some of the recent progress in the preparation of Ga _0.47In _0.53As/InP heterostructures and devices by CBE in our laboratories. Extreme composition uniformity has been obtained for Ga _0.47In _0.53As epilayers which exhibited excitonic transitions with linewidths (full-width at half-maxima) as narrow as 1.2 meV at 2K. Such linewidth represents the narrowest ever obtained for GaInAs grown by any technique. Similarly, Ga _0.47In _0.53As/InP single quantum wells with thickness as thin as 6 Å have 2 K photoluminescence linewidths substantially narrower than all previous reported values. These linewidths indicate the "effective" interface roughness to be 0.12 lattice constant. Double-heterostructure p-i-n photodetectors exhibited high quantum efficiency of 70% (without anti-reflection coating) and <1 nA dark current at -10 V. Ga _0.47In _0.53As/InP double-heterostructure and multiquantum well lasers emitting at 1.47-1.72 μm have threshold current densities of 1.3 and 1.5 kA/cm ². Such values are the best reported so far. An improvement in the threshold-temperature dependence in multiquantum well lasers was also demonstrated unambiguously for the first time. Two-dimensional electron gas mobilities at the Ga _0.47In _0.53As/InP hetero-interfaces were as high as 130 × 10 ³ cm ²/V·s at 4.2 K. Such mobilities are higher than those obtained by other growth techniques. Quantum Hall effect and shubnikov-De Haas measurements also demonstrated the extremely high quality of the Ga _0.47In _0.53As/InP hetero-interfaces. Our results undisputedly established CBE as a superior technique for producing extremely high quality Ga _0.47In _0.53As/InP heterostructures and quantum wells and advanced the epitaxial growth technology beyond both MBE and OMCVD.