Vincent Jarry

Laser micro-cutting of wide band gap materials

This paper investigates laser micro cutting of wide band gap materials for semiconductor industry purposes. Laser is an alternative to blade sawing for hard materials such as sapphire (α-Al2O3) and silicon carbide (SiC) which are useful for new functions. An ultraviolet (355 nm) diodepumped solid-state (DPSS) nanosecond laser is used in this investigation. The properties of the materials are analyzed by the means of ellipsometry and X-ray diffraction in order to understand laser/matter interaction physics. The effect of pulse energy and feed rate (scanning speed) is studied on the depth of the cutting street of α-Al2O3 and SiC. The depth of the grooves increases with laser energy (10 to 147.5 μJ/pulse with typical frequencies of 40 to 160 kHz) It decreases with the feed rate (10 to 150 mm/s) until saturation except for certain conditions for α-Al2O3. Indeed, results show periodic patterns produced by phase explosion that can influence on the achieved depth. The shape, size and periodicity of the recast ma...