Novel Design of an Extremely Miniaturized Accelerometer Based on Quantum Tunneling Effect

Abstract

This paper presents the design of an extremely miniaturized accelerometer based on the tunneling effect. Because of its high sensitivity the tunneling effect allows the detection of smallest deflections. The aim of the novel design is a large geometric miniaturization at the lowest possible natural frequency with a nominal acceleration of +/−1 g corresponding to a deflection of +/−9.36 Å. The poly-silicon (PolySi) sensor structure with a size (L × W) of 98 µm × 85 µm is designed in a way that the main displacement operates just in one direction. To lead the sensor into operational conditions, control a constant distance between the tunneling electrodes and perform self-test actuations two electrodes are placed below the sensor structure. The tunneling tip is deposited by a focused ion beam (FIB) to provide the tunneling section with a third pad on the substrate. Within this paper the focus is on the functional implementation of the structure, the investigation of the electrostatic actuators and the deposition of the tunneling tip by the FIB.

Keywords

• accelerometer
• tunneling effect
• microsensors
• electrostatic
• focused ion beam