Research on AlN thin film microstructure processing technology based on ultra-thin cantilever beam structure

Abstract

Aiming at the problem of poor solution selection ratio when the AlN film and porous silicon sacrificial layer are released in the ultra-thin cantilever structure and at the problem of large surface roughness after AlN graphing, the wet corrosion process parameters were optimized, and the influence of different corrosive fluids and corrosion times on the surface roughness of AlN and the influence on the etching rate of AlN were studied, and different process parameters were selected for experiments. According to the experimental results, a suitable microstructure processing method was selected to effectively reduce the surface roughness of AlN and improve the integrity of the AlN film and the reliability and yield of the cantilever structure when the sacrificial layer is released. The microstructure fabrication of AlN films in ultra-thin cantilever structures enables the fabrication of ultra-micro-force sensors, accelerometers, acoustic sensors, and other devices.