Horizontal Slider Research Articles

Horizontal slider LPE of (Hg,Cd)Te

We report the epitaxial growth of single and double layers of Hg1−xCdxTe on 2×3 cm single-crystal CdTe substrates, using liquid phase epitaxy (LPE) from tellurium solution in an atmospheric pressure horizontal slider apparatus. The layers are found to be extremely uniform in composition (x) across individual layer areas and in layer-to-layer reproducibility (standard deviation 0.002). We report our observations of the morphological, compositional and crystalline quality of the layers, and measurements of the electrical parameters of the layers.

Simulation of slider-induced convection in horizontal LPE slider system

The control of thickness uniformity and compositional homogeneity is extremely important in the growth of high quality heterostructure lasers. Slider-induced convection within the growth solution in the horizontal LPE system can affect both of these factors and has been largely neglected in the modeling of layer growth. A plexiglas boat with water and dyes was used to simulate the fluid motions in the melts of the LPE horizontal slider system. The simulation shows that there are substantial fluid motions induced by the movement (push) of the slider. The duration of the convective cell thus generated can be comparable to the growth time of thin layers. Therefore, a substantial portion of the growth time for thin layers is under non-steady-state conditions. Furthermore, convection dominates in the initial period of epitaxial growth. The dependence of the convective cell on melt geometry is discussed. A video tape was made showing the solution dynamics of several boat designs used in the growth of (GaAl)As heterostructure lasers.

Liquid phase epitaxy of Hg 1− xCd xCd xTe

We describe the epitaxy of n- and p-Hg 1− x Cd x Te on CdTe substrates up to 2 cm × 3 cm in area, using an atmospheric pressure horizontal slider system with a tellurium-rich growth liquid. Well controlled growth of Hg 1− x Cd x Te with x values of 0.2, 0.3, and 0.4 is described. Measurements of the semiconductor characteristics of the grown layers are presented.

Liquidus isotherms, solidus lines and LPE growth in the Te-rich corner of the Hg-Cd-Te system

Liquidus isotherms for the Hg1−xCdxTe primary phase field in the Te-rich corner of the Hg-Cd-Te ternary system have been determined for temperatures from 425 to 600‡C by a modified direct observational technique. These isotherms were used to help establish conditions for the open-tube liquid phase epitaxial growth of Hg1−xCdxTe layers on CdTe1−ySey substrates. Layers with x ranging from 0.1 to 0.8 have been grown from Te-rich HgCdTe solutions under flowing H2 by means of a horizontal slider technique that prevents loss of Hg from the solutions by evaporation. Growth temperatures and times of 450–550‡C and 0.25–10 min, respectively, have been used. The growth solution equilibration time is typically 1 h at 550‡C. Source wafers, supercooled solutions, and (111)-oriented substrates were employed in growing the highest quality layers, which were between 3 and 15 Μm thick. Electron microprobe analysis was used to determine x for the epitaxial layers, and the resulting data, along with the liquidus isotherms, were used to obtain solidus lines. In addition to EMP data, optical transmission results are given.

Liquid phase epitaxial growth of Gal-xInxSb on GaSb by stepwise grading

The Gal-xInxSb alloy system is a potentially important material for the fabrication of middle wavelength infrared detectors and emitters. In order to develop the use of this material we have investigated the liquid phase epitaxial growth of Ga1−xInxSb on GaSb via stepwise grading in the range of 400–600°C using a horizontal slider boat in a transparent furnace. Single crystal layers of Ga1−xInxSb have been obtained for the composition range 0<x<.30. As-grown undoped layers are p-type and have been characterized by lattice constant, surface morphology, bandgap, carrier concentration and carrier lifetime.