Modified LPE system used to diffuse Cd to obtain InSb infrared detectors

• Published in: Journal of crystal growth 2008-04, Vol.310 (7), p.1657-1663
• Main Authors: Guimarães, Sonia, de Lima, Joaquim Tavares, Petoilho, José Carlos, de Lucena, Emerson Ferreira, Hwang, Míriam Kasumi, Campos, Élson
• Format: Article
• Language: English
• Subjects: A1. Atomic force microscopy; A1. Optical microscopy; A1. X-ray diffraction; A3. Vapor phase epitaxy; Applied sciences; B1. Cd compounds; B1. InSb; B1. Te; B3. Homojunctions Semiconductor Infrared devices; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in interface structures; Electronics; Exact sciences and technology; Iii-v semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions; Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids); Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optoelectronic devices; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2007.11.176

We are presenting here p/n junctions obtained with a modified opened liquid-phase epitaxy (LPE) system, used to diffuse indium antimonide (InSb) doped with Cd over InSb doped with Te wafers, in order to make InSb infrared (IR) sensors. This technique has several advantages: the diffusion can be performed in bigger substrate areas improving the device production; this method decreases the device manipulation, decreasing human mistakes and increasing the process reproducibility. The opened LPE in this work produced sensors in the first case with vapor of the diffusion material, coming from a microholed carbon boat full of the diffusion material, over which is positioned the substrate at atmospheric pressure. In the second, the diffusion material is on the bottom of a quartz recipient, and the InSb/Te wafer works as its cover, and vacuum was used. The IR sensors produced with the first method measured 8.9×10 7 cm Hz 1/2/W as detectivity value and higher IR spectral response at 4.6 μm, and those produced with the second 2.8×10 9 cm Hz 1/2/W, at 4.4 μm. Besides the electrical–optical properties, the structural properties of diffused layers were investigated by X-ray diffraction (XRD), scanning electron and atomic force microscopy (SEM, AFM), energy-dispersive and secondary ion mass spectroscopy (EDS, SIMS).