An investigation of hybrid laser–waterjet ablation of silicon substrates

A novel hybrid laser–waterjet ablation technology is developed to minimize the thermal damages, which occur during material melting and vaporization associated with the traditional laser machining processes. With this technology, the target material is heated and softened by a laser and the softened material is expelled by a waterjet. The waterjet also takes a cooling action. Using a single-crystalline silicon as the specimen material, the process parameters relevant to the hybrid process were investigated along with the interactions between the laser and waterjet. Further, the cut geometries and the surface characteristics after machining have been experimentally studied. It has been found that almost no heat-affected zone (HAZ) with a higher material removal rate can be achieved when using this hybrid laser–waterjet technology, as compared to the conventional laser dry micromachining process.