Microgrooving of Germanium Wafers Using Laser and Hybrid Laser-Waterjet Technologies

Abstract

Lasers have the potential for the micromachining of germanium (Ge). However, the thermal damages associated with the laser machining process need to be properly controlled. To minimize the thermal damages, a hybrid laser-waterjet ablation technology has recently been developed for micromachining. This paper presents an experimental study to assess the machining performances in microgrooving of Ge by using a nanosecond laser and the hybrid laser-waterjet technology. The effects of laser pulse energy, pulse overlap and focal plane position on the groove geometry and heat affected zone (HAZ) size are analyzed and discussed. It is shown that the hybrid laser-waterjet technology can give rise to narrow and deep microgrooves with minimum HAZ.