Low thermal-budget silicon sealed-cavity microencapsulation process

This work demonstrates the application of pulsed-laser processing for sealing release holes in silicon membranes. Holes in the membrane are sealed without deposition, similar to the silicon surface migration sealing process. In contrast to the 1100°C furnace anneal required for the migration process, the pulsed-laser process localizes the heat to the top few microns of the substrate, with the bulk kept at near to room temperature. In addition, there is no need for special surface treatment, or for a controlled environment. Furthermore, the treatment can be applied to selected regions of the substrate.