Evaluation of deep etching techniques for silicon micromachined pressure sensor

Sensor fabrication often requires deep etching of silicon to form a thin diaphragm or cantilever beams. For pressure sensors, deep cavities are etched in the back of silicon wafers to make thin diaphragms. Although several tools and techniques are available for etching silicon, many of these tools and techniques fall short of fulfilling the need for process reliability and high throughput. This paper will discuss various etch methods and their intended purposes.