Oxidized Macro Porous Silicon layer as an effective material for thermal insulation in thermal effect microsystems.

In this work the process for the realization of Oxidised Macro Porous Silicon (OMPS) layer as a material for thermal isolation has been studied. Macro Porous silicon layers are created by anodisation of P-type (10–20 Ω-cm) silicon with HF and DMF (Dimethylformamide), which are then followed by thermal oxidation in order to find a compromise between higher thermal isolation and good mechanical stability. The morphology of the samples are studied by FESEM. A simple model for determining the thermal conductivity (TC) of the OMPS layer has also been formulated which shows that the TC of OMPS layer are two to three order less than crystalline silicon. Heat distribution of a microheater over the OMPS layer has been simulated by using finite element analysis with ANSYS software which shows the higher degree of thermal isolation and better mechanical strength with OMPS layer compared to conventional methods.