Process for producing doped gallium arsenide substrate wafers having low optical absorption coefficient

摘要

A process is disclosed for producing a doped gallium arsenide single crystal by melting a gallium arsenide starting material and subsequently solidifying the gallium arsenide melt, wherein the gallium arsenide melt contains an excess of gallium relative to the stoichiometric composition, and wherein it is provided for a boron concentration of at least 5×1017 cm−3 in the melt or in the obtained crystal. The thus obtained crystal is characterized by a unique combination of low dislocation density, high conductivity and yet excellent, very low optic absorption, particularly in the range of the near infrared.

主权项

1. A gallium arsenide single crystal, comprising a charge carrier concentration of at least 1×1016 cm−3 and at most 1×1018 cm−3, wherein an optical absorption coefficient of the gallium arsenide single crystal is at most 2.5 cm−1 at a wavelength of 1000 nm, at most 1.8 cm−1 at a wavelength of 1100 nm and at most 1.0 cm−1 at a wavelength of 1200 nm, wherein the area density of etch pitches on cross-sections perpendicular to the crystal axis does not exceed 1500 cm−2, and wherein an EL 2-concentration is below 1016 cm−3.