MEMS Housing with Optical Window and Mechanical Stop

The patent applies preliminary action by performing the encapsulation of MEMS/MOEMS on the wafer level before the separation process. The housing is formed around the microstructures while they are still on the carrier wafer, creating a protective enclosure prior to exposure to contamination and mechanical stress during sawing. This allows subsequent separation to produce pre-encapsulated chips without compromising the protected components.

The patent employs a thin-film housing structure formed by depositing protective layers (such as silicon nitride, silicon oxide, or metal layers) directly over the MEMS/MOEMS on the wafer. This thin-film encapsulation provides hermetic sealing against contamination while maintaining a simple, integrated structure that does not significantly increase device complexity. The housing is formed as a continuous protective barrier rather than a complex mechanical assembly.

The patent extracts the encapsulation function from a complex deep-recess structure and implements it through a simpler approach: forming a continuous housing layer over the entire wafer surface that extends beyond the edges of the MEMS/MOEMS structures. This eliminates the need for precise deep recess etching while providing equivalent or superior protection, as the housing is formed by straightforward deposition processes rather than complex subtractive machining.

The patent integrates multiple functions into the housing structure itself. The housing serves simultaneously as a protective enclosure against contamination, a mechanical support structure, and an optical window for interferometric measurements. By making the housing material transparent to the measurement wavelength and positioning it to allow optical access to the MEMS/MOEMS, the same structure provides both protection and optical functionality without requiring separate components.