| 摘要 |
PURPOSE:To decide propriety as a board for a radiation detector by using a photoluminescence intensity of a GaAs substrate. CONSTITUTION:A GaAs substrate is dipped in liquid He, optically excited by an Ar+ laser, and a photoluminescence (PL) intensity at an end of a band from the substrate is measured. The intensity sensitively reacts with a crystalline defect density due to a dislocation density of the substrate, a deviation of a stoichiometrical composition. Since most of optically excited carrier is recombined to emit a light if the defect density is low, the PL intensity and particularly the PL intensity of the end of the band is increased. The substrate can be simply evaluated, and excellent substrate obtained by selectively sorting is used to manufacture a GaAs radiation detector having high yield and high performance.
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