Theoretical Simulations of Silicon-On-Nothing (SON) Structures

C. Grau Turuelo[1], B. Bergmann[1], C. Breitkopf[1], F. Hoffmann[2], L. Brencher[2]
[1]Technische Universit├Ąt Dresden, Dresden, Saxony, Germany
[2]Infineon Technologies GmbH, Dresden, Dresden, Saxony, Germany

A novel technique for semiconductor manufacturing is introduced: Silicon-On-Nothing. This process consists of an initial cylindrical trench which has a shape evolution under certain conditions: high temperature (1100 ┬░C), low pressure (10 Torr) and a non-oxidizing atmosphere such as hydrogen. These conditions enable a, mainly, surface diffusion phenomenon whose final result is an empty space (usually spherical) below a silicon layer which has several applications (micro sensors, transistors, optical devices, etc.) and, moreover, it incurs in fewer costs than traditional etching processes. The use of custom PDEs and Moving Mesh interfaces let us make simulations of the morphological evolution of the silicon structure.