Piezoresistive Platinum Diselenide Pressure Sensors with Reliable High Sensitivity and Their Integration into Complementary Metal-Oxide-Semiconductor Circuits.

Membrane-based sensors are an important market for microelectromechanical systems (MEMS). Two-dimensional (2D) materials, with their low mass, are excellent candidates for suspended membranes to provide high sensitivity, small footprint sensors. The present work demonstrates pressure sensors employing large-scale-synthesized 2D platinum diselenide (PtSe) films as piezoresistive membranes supported only by a thin polymer layer. We investigate three different synthesis methods with contrasting growth parameters and establish a reliable high yield fabrication process for suspended PtSe/PMMA membranes across sealed cavities. The pressure sensors reproducibly display sensitivities above 6 × 10 kPa. We show that the sensitivity clearly depends on the membrane diameter and the piezoresistive gauge factor of the PtSe film. Reducing the total device size by decreasing the number of membranes within a device leads to a significant increase in the area-normalized sensitivity. This allows the manufacturing of pressure sensors with high sensitivity but a much smaller device footprint than the current state-of-the-art MEMS technology. We further integrate PtSe pressure sensors with CMOS technology, improving the technological readiness of PtSe-based MEMS and NEMS devices.