Composite MEMS Resonator for Low Temperature Frequency Drift

The patent changes the physical parameters of the beam by introducing controlled internal stresses through specific manufacturing processes (e.g., selective etching, differential thermal processing). This allows the beam to have pre-stressed regions that compensate for thermal expansion without requiring external fixation points at both ends, thereby achieving thermal compensation while reducing structural complexity

The patent employs composite structures where the beam is formed from multiple materials or layers with different thermal expansion coefficients. By carefully selecting and combining materials (e.g., silicon nitride, silicon oxide, polysilicon), the composite beam inherently compensates for thermal effects through the differential expansion of its constituents, eliminating the need for complex fixation mechanisms

The patent creates a composite movable element by combining silicon with other materials having different thermal expansion properties. The silicon provides manufacturing compatibility and mechanical strength, while the combined structure's effective thermal expansion coefficient is tuned to compensate for temperature-induced frequency drift, achieving both ease of manufacture and low temperature drift

The patent applies different material properties to different regions of the movable element. By creating zones with varying material composition and stress states within the silicon structure, local regions compensate for each other's thermal expansion characteristics, maintaining overall dimensional stability and frequency consistency across temperature variations while preserving silicon's manufacturing advantages