Development of a Micro Photoluminescence Measurement System for the Spectrum Inspection of Gallium Arsenide/Gallium Arsenide Phosphide (GaAs/GaAs1-X Px)

Abstract

This article mainly focuses on the spectrum measurement of the LED semi-conductor material Gallium Arsenide/Gallium Arsenide Phosphide (GaAs/GaAs1-x Px), using Photoluminescence (PL) method, by integrating the optical path design, the mechanism design, the motion control, the image processing, and the positioning technology to accomplish the development of automatic measurement system. The innovative method of micro-photoluminescence (µ-PL) is proposed in the optical path design. A microscope objective was adopted to focus the laser light to a tiny area and by enhancing the strength of laser light unit to increase the sensitivity of the luminescence. In the past, the examination of PL was used to do the image positioning and to collect the luminescence manually in two different platforms. The developed system integrates these two light path systems, PL and image positioning, as one machine. As a result, the image positioning and luminescence measurement can be done in one machine simultaneously, to save manpower and to avoid the manual positioning error.