Truly three dimensional structures microfabricated by laser chemical processing

Abstract

A method for microfabrication of 3-D structures in free-space is presented. Laser-assisted chemical vapor deposition (LCVD) is used to grow a material at the point where the laser beam locally heats the substrate. This is done by moving a substrate perpendicularly relative to a laser beam by a micropositioning system, i.e. 3-D shapes can be created. The smallest structures that can be grown with this technique are about 1 mu m. Amorphous boron rods and crystalline boron springs have been manufactured as examples of micromechanical building units. The rods have a modulus of elasticity of 420-450 GPa, a fracture strain of 2.7-3.7%, and a fracture stress of 12-17 GPa. By development of the process more or less arbitrary details can be tailored for various applications.<>