Characterization of Dislocations in (112)B HgCdTe/CdTe/Si

Abstract

The electrical performance of HgCdTe/Si photodiodes is shown not to have a direct relationship with the dislocation density as revealed by defect etching. This has led to an equivalent circuit model to explain the relationship of the dislocation density and the electrical test data. A new (112)B HgCdTe/CdTe/Si and CdTe/Si etch pit density (EPD) etch has been demonstrated. The new etch has been used to look for distinctive features which may be responsible for the poor electrical performance of individual diode pixels. The new etch chemistry also reduces the surface roughness of the etched epilayer and makes EPD determination less problematic. The new (to HgCdTe) technique of electrostatic force microscopy has also been used to analyze the electrical properties of dislocations.

Evaluation of Surface Cleaning of Si(211) for Molecular-Beam Epitaxy Deposition of Infrared Detectors

“…In addition, there is now evidence that dislocation density alone cannot explain the bad pixels that are responsible for the poor electrical performance in the noise equivalent differential temperature (NEDT) tail distribution of LWIR FPAs grown on Si. 19 A hypothetical model has been put forward that suggests a combined process in which discrete contamination sources are available at the CdTe/Si interface for enhanced diffusion channels (killer pipes) to transport impurities to the depletion region. 20,21 Herein, we report an assessment of the reproducibility of the HF cleaning process and As passivation prior to nucleation of ZnTe on a Si(211) surface utilizing temperature desorption spectroscopy (TDS), x-ray photoelectron spectroscopy (XPS), scanning Auger microscopy (SAM), and ion scattering spectroscopy (ISS).…”

High-Performance MWIR/LWIR Dual-Band 640 × 480 HgCdTe/Si FPAs

“…Efforts are underway to understand the detailed physical mechanisms for these poorer-performing pixels. 10 Increasing the background flux by measuring at f/2.9 field-of-view improves the LWIR NETD characteristics significantly, as shown in Fig. 6, with LWIR NETD operability of 99.6% demonstrated (corresponding LWIR response operability was 99.9%).…”

Высокочувствительная Экспрессная Нелинейно-Оптическая Диагностика Кристаллического Состояния Гетероструктур Типа Сфалерита

“…Получение высокого качества этих структур для последующих практических применений в ИК детекторах [15] требует решения проблем, связанных с большим рассогласованием параметров решеток и неизовалентностью сопрягаемых материалов соединений КРТ и подложек из GaAs и Si [16]. Проведенные различными методами исследования выявили образование большого количества дефектов кристаллической структуры и выявили связь их образования с условиями роста [17][18][19][20][21]. Проведенные ранее исследования с помощью генерации второй гармоники зондирующего излучения позволили определить ориентацию и кристаллическое состояние слоев в ГЭС КРТ МЛЭ на подложках из (013)GaAs, показали высокую эффективность метода ВГ при экспериментальной отработке режимов создания высококачественных гетероструктур [9][10][11].…”