Process for producing an electrostatically deformable thin silicon membranes utilizing a two-stage diffusion step to form an etchant resistant layer

摘要

The invention relates to thin silicon membranes formed in layers of silicon such as are normally utilized as substrates in the manufacture of integrated electronic circuits. The thin membranes constructed in accordance with the invention are capable of deformation by electrostatic forces and are applicable to a wide range of uses including the manufacture of solid state pressure sensors, resonant, and antenna structures, as well as electro-optical display elements. A processing technique is disclosed which is particularly adapted to forming membranes in silicon substrates in a manner which is compatible with the construction thereon of other integrated circuit components. The process involves a short and concentrated deposition diffusion of boron into one of the surfaces of the substrate, followed by rapid and substantially oxygen and water vapor free transfer of the substrate to a drive furnace which is oxygen and water vapor free in which diffusion to a preselected depth takes place over a controlled period of time.