Growth and properties of In0.52Al0.48As/In0.53Ga0.47As, GaAS: In and InGaAs/GaAs multilayers

We have investigated the properties of some In-containing materials and heterostructures grown by molecular beam epitaxy on GaAs and InP substrates. Photoluminescence spectra of InGaAs/InAlAs quantum wells have been related to growth kinetics and it is seen that growth interruption or the incorporation of a few periods of superlattices at the heterointerfaces smooths the growth front. Experiments have been performed to determine the properties of In0 52A1048Asgrown on InP. This lattice-matched alloy In0 52Al048As may be clustered under normal growth conditions at a substrate temperature 500°C. Addition of small amounts of In (0.2—1.2%)to GaAs reduces trap and defect densities in these materials, as seen from DLTS and low-temperature photoluminescence data. The improvement may be related to the higher surface migration rate of In compared to Ga and a subsequent reduction of point defects. Single-mode optical guides and direction couplers with losses as low as 1—3dB/cm have been fabricated with GaAs: In and In02Gao gAs/GaAs strained-layer superlattices. In5Ga1 _~As and In5Al1 ~As are important The different materials and heterostructures alloy semiconductors for electronic and opto-elec- were grown in a three-chamber RIBER 2300 epitronic heterostructure devices. Together with In taxy system. Extensive source and system baking Ga1 LAs—GaAsstrained-layer superlattice (SLS), were carried out [1] to grow high-purity materials. a large and important spectral energy range can be Undoped 120 A GaAs/A103Ga07As single quancovered. Molecular beam epitaxy (MBE) is a tum wells with 0.3 meV excitonic linewidths in the growth technique which is principally controlled 2 K photoluminescence spectra and lattice-matchby surface kinetics, and therefore, the electrical ed undoped In0 53Ga047As with fL3~K = 12,050 and optical properties of the grown films and cm2/V’ s and ~s77~ = 53,000 cm2/V. s assert the heterointerfaces can be non-ideal. The intent of purity of the growth ambient. In-doped GaAs and this paper is to highlight some electrical and opti- the InGaAs/GaAs SLS were grown on undoped cal properties in these alloys and heterostructures, or doped GaAs substrates at 560—580°C at a which can result from the growth kinetics. More growth rate of 1.2 ~u rn/h. InAlAs and InGaAs/in specificaly, results of photoluminescence measure- AlAs were usually grown in the temperature range ments on In 052Al048As/In 053Ga047As single 480—520°C on (001) Fe-doped semi-insulating or quantum wells lattice matched to InP substrates S-doped N + InP substrates at 0.5—1.3~tm/h. suggest clustered growth in the Al-containing alloy and interface roughness at the heterointerface under normal MBE growth conditions. Results from ~ Phototuminescence in In ~Ga0 7As/ high temperature Hall and carrier impact ioniza- In052Al0 ~As single quantum wells 0. .4 tion measurements are presented, which also indicate the presence of clustering in the InAlAs a!ioys. Finally, the growth of In~Ga1 - ~As (x ~ 0.01) Photoluminescence measurements were done at and In~Ga1 5As/GaAs SLS on GaAs substrates 10 K and higher temperatures and with variable and the properties of optical components made excitation intensity. The luminescence was excited with these materials are described,