Carbon ?-doping GaAs superlattices

Abstract

Carbon 6-doping GaAs superlattices incorporating 50 layers have been grown either by chemical beam epitaxy (CBE) using CBr4 as the source of the carbon or by metallorganic vapour phase epitaxy (MOVPE) using CCI4. Infrared (IR) localized vibrational mode (LVM) spectroscopy showed that carbon atoms were incorporated on the As sublattice and that hydrogen was incorporated as H-CAs pairs during growth by MOVPE. The hydrogen was removed by an anneal at 600°C for 15 min in N2, leading to an increase in the carrier concentration. High resolution X-ray diffractometry (HRXD) was used to measure the strain in the layers. Simulation of the 4 0 0 diffraction profiles using dynamical theory was used to determine the thickness ( ~ 1 nm) and peak concentrations (in excess of 2 × 102o cm-3) of the 5-doped layers. Device applications and 5-layers in AlAs are briefly considered.

Carbon delta-doped AlGaAs grown by metalorganic vapor phase epitaxy

“…12 Both intrinsic and extrinsic C doping of AlGaAs have been studied by several authors 4,7,8,11,12 who have shown that the C incorporation is more efficient for higher Al content in the alloy and lower growth temperatures (T g ). 6,11,14 In this communication results of a thorough investigation of C delta-doping of AlGaAs grown by MOVPE using CBr 4 as the C source are presented. 7 Another difficulty with the C doping is the passivation of the impurity by H atoms.…”

“…6,8,17,18 Points above the solid line correspond to a confinement over a region wider than 5 Å. The squares represent the samples grown for this work, while the other data points refer to results from the GaAs literature.…”