Features of designing of polysilicon sensors of thermal streams

Designing of polysilicon thermal sensors using photolithography and photomasks was analysed. Dielectric isolation which divides a sensitive element of a thermal sensor and a substrate. A polycrystalline material is composed of small crystallites joined together by grain boundaries. The angle between the orientations of the adjoining crystallites is often large. In a real polycrystalline material, the crystallites have a distribution of sizes and irregular shapes. It was assumed that polysilicon is composed of identical crystallites having equal size of a grain and there is only one type impurity atom which are totally ionised. On the basis of this assumption, the thermal sensor was developed.