Development of a multi-flash lamp in pulse photo conductivity method

In the manufacturing field of semiconductor devices, improvement of yield and increase of throughput is very important issue. Therefore, in the evaluation of semiconductor devices, a method using a light source is frequently used for in-line measurement. In our laboratory, we propose Pulsed Photo Conductivity Method (PPCM) as a device evaluation method for non-destructive and non-contact measurement. To inspect the whole wafer in one minute using PPCM evaluation equipment, high repetition frequency lamp is required .In general, laser is used as light source in device evaluation using light. Laser has a high repetition frequency, but the cost is very high compared with other light sources. Therefore, in this study, we developed a multi-flash system to be used for PPCM evaluation equipment. This system is a high repetition frequency and cheaper. In this study, the maximum repetition frequency of an L11035 Hamamatsu xenon flash lamp used is 530Hz which is not high. Therefore, we developed a light source with high repetition frequency by using several xenon flash lamps in this system.