Method of making electrical elements on the sidewalls of micromechanical structures

Abstract

A method of forming electrical elements on the sidewalls of deformable micromechanical structures such as flexible, high aspect ratio beams. The micromechanical structure is made of a semiconductor material such as silicon. The method includes angled ion implantation at an angle nonnormal to the substrate surface. The angle ensures that ions are implanted into appropriately oriented sidewalls. Multiple ion implantations can be performed to form electrical elements into different sidewalls. Masking techniques can be used to restrict the locations where ions are implanted. Alternatively, several different types of ion diffusion can be used to expose the sidewall in selected regions. The present invention can form conductive pathways which are continuous between perpendicular surfaces. This enables electrical elements on vertical surfaces to communicate with electronics on horizontal surfaces, for example. The dopant ion concentration and ion species can be controlled to form many different electrical elements. Resist masking techniques can be used to mask sidewall areas not desired to have electrical elements. The present invention can form piezoresistors, conductive paths, resistors, diodes, and capacitor electrodes, for example, on desired areas of a micromechanical structure sidewall.

Dependencies are inferred from the claim text.