Method for applying selectively a layer to a structured substrate by the usage of a temperature gradient in the substrate

Abstract

A semiconductor wafer () is structured such that fine structures (), such as membranes, bridges or tongues, with a thickness d<<D are formed, wherein D designates the thickness of the semiconductor wafer (). Then particles of a desired material are applied. A temporal or spatial temperature gradient is generated in the semiconductor wafer (), e.g. by progressive heating. In such a heating process the fine structures heat up more quickly and become hotter than the remaining wafer because they have a smaller heat capacity per area and cannot carry off heat as quickly. In this manner, the fine structures can be heated to a temperature that allows a sintering of the particles. For coating the semiconductor wafer () is brought into a reactor (). A precursor compound of a metal is provided and fed to the reactor (), where a reaction takes place during which the metal is transformed to a final compound and is deposited in the form of particles on the semiconductor wafer ().