This letter presents CMOS-MEMS fixed-fixed beam resonators with wide active frequency tuning range capability attributed to the axial stress modulation using embedded heaters. Two resonators, consisting of multiple metal, dielectric layers, and poly1 layers, were designed; the first resonator at 303.4 kHz, while the second at 2053 kHz, achieve the frequency tuning ranges of 35.7%-42.6%, respectively. Electrostatic transduction is achieved by embedded metal beams, and used to drive the device into resonance. The heaters, made of poly1, are embedded directly into the resonators during the CMOS process to achieve low power consumption and optimum heating efficiency. A power consumption of 900 µW/beam is achieved for the first design of 152 µm length beam, while providing a frequency tuning of 35.7%.

Microbolometers and photon detectors are two main technologies to address the needs in Infrared Sensing applications. While the microbolometers in both complementary metal-oxide semiconductor (CMOS) and Micro-Electro-Mechanical Systems (MEMS) technology offer many advantages over photon detectors, they still suffer from nonlinearity and relatively low temperature sensitivity. This paper not only offers a reliable solution to solve the nonlinearity problem but also demonstrate a noticeable potential to build ultra-sensitive CMOS–MEMS temperature sensor for infrared (IR) sensing applications. The possibility of a 31× improvement in the total absolute frequency shift with respect to ambient temperature change is verified via both COMSOL (multiphysics solver) and theory. Nonlinearity problem is resolved by an operating temperature sensor around the beam bending point. The effect of both pull-in force and dimensional change is analyzed in depth, and a drastic increase in performance is achieved when the applied pull-in force between adjacent beams is kept as small as possible. The optimum structure is derived with a length of 57 µm and a thickness of 1 µm while avoiding critical temperature and, consequently, device failure. Moreover, a good match between theory and COMSOL is demonstrated, and this can be used as a guidance to build state-of-the-art designs.

An efficient silicon-based light source presents an unreached goal in the field of photonics, due to Silicon's indirect electronic band structure preventing direct carrier recombination and subsequent photon emission. Here we utilize inelastically tunneling electrons to demonstrate an electrically-driven light emitting silicon-based tunnel junction operating at room temperature. We show that such a junction is a source for plasmons driven by the electrical tunnel current. We find that the emission spectrum is not given by the quantum condition where the emission frequency would be proportional to the applied voltage, but the spectrum is determined by the spectral overlap between the energy-dependent tunnel current and the modal dispersion of the plasmon. Experimentally we find the highest light outcoupling efficiency corresponding to the skin-depth of the metallic contact of this metalinsulator-semiconductor junction. Distinct from LEDs, the temporal response of this tunnel source is not governed by nanosecond carrier lifetimes known to semiconductors, but rather by the tunnel event itself and Heisenberg's uncertainty principle.

No abstract