Plasma-Cleaned InSb (112)B for Large-Area Epitaxy of HgCdTe Sensors

Abstract

Plasma etching of (112)B InSb to prepare this semiconductor for the heteroepitaxy deposition of CdTe and initial studies of CdTe epilayers grown by molecular beam epitaxy (MBE) on InSb (112)B substrates cleaned with various plasma treatments are presented. X-ray diffraction rocking curve maps of the MBE CdTe epilayers on 3-inch InSb (112)B substrates have full-width at half-maxima (FWHM) values in the range of 20 arcsec to 30 arcsec. An etch pit density analysis of the 3-inch CdTe epilayers reveals a defect density of 1.0 · 10 7 cm -2 and 7.7 · 10 5 cm -2 at the center and edge of the wafer, respectively. Evaluation of a standard HgCdTe annealing process suggests that the removal of the InSb substrate is likely to be needed prior to any postgrowth annealing in Hg overpressure. Finally, we present a low-energy helium plasma exposure of wet-etched InSb (112)B substrates that provides a uniform epi-ready surface that is nearly stoichiometric, and free of oxide and residual contaminants.

The effects of RF power on the interfacial property between Al2O3 and Si3N4 and on the memory property in a MANOS structure

“…The free radicals and ions generated in the plasma flow into the process chamber during the deposition process. The influence of the plasma parameters on film formation ranges from simple substrate cleaning [16], resulting in enhanced adhesion [17], to morphological changes. Therefore, control of the amount of both free radical and ions in the plasma is very important for the determination of the material properties.…”

MBE Growth and Transfer of HgCdTe Epitaxial Films from InSb Substrates

“…Despite significant progress in midwavelength infrared (MWIR) array performance, the high threading dislocation density (>10 6 cm À2 ) for HgCdTe films on Si, arising from a large 19% lattice mismatch, is thought to limit the performance of long-wave infrared (LWIR) focalplane arrays. 1 As an alternative approach, we have begun to investigate molecular-beam epitaxy (MBE) growth of HgCdTe epitaxial films on InSb, following a recent report of CdTe epitaxial growth on InSb, 5 with the intent of ultimately developing a process for transfer of large-area, low-dislocation-density HgCdTe films from InSb substrates to other host substrates, such as Si, for array fabrication. InSb substrates offer several attractive features for HgCdTe heteroepitaxy, including close matches of lattice constant and thermal expansion coefficient to HgCdTe, potentially enabling growth of HgCdTe films with much lower dislocation densities than on Si substrates.…”

Effect of DC Bias on the Plasma Properties in Remote Plasma Atomic Layer Deposition and Its Application to HfO[sub 2] Thin Films

“…Additionally ions, which can be accelerated or decelerated using an electric field, are being extensively employed in the deposition of thin film. The influence of the plasma parameters on film formation ranges from simple substrate cleaning, 7 resulting in enhanced adhesion, 8 to morphological changes. Therefore, the control of the amount of free radical and ions in plasma are both very important in the chemical reaction for the determination of the material properties.…”