At AXT, we are committed to quality in every step of our manufacturing sequence. To ensure our products' quality, we use state-of-the-art, highly automated equipment and perform extensive quality control in every processing step. For instance, we employ a computerized Van der Pauw system to measure resistivity, conduction type, carrier concentration, and the Hall mobility. In addition, we use infrared transmission to monitor lattice defects, impurities and internal stress. We also apply sophisticated characterization techniques to track product quality, such as photoluminescence and X-Ray diffraction, to monitor the impurity distribution and crystal orientation, respectively. In addition, we are in the process of installing a Total Reflection X-Ray Fluorescence (TXRF) system for monitoring and controlling surface trace metals on our substrates.

As a result, our substrates generally have such characteristics as low dislocation density, low internal stress, plus uniform and consistent mechanical and electrical properties from wafer to wafer and boule to boule. Furthermore, our quality management system has been certified to conform to ISO 9001, currently the highest international standard.