NANOSCALE NATURE AND LOW THERMAL-CONDUCTIVITY OF POROUS SILICON LAYERS

Recently discovered phenomenon of low thermal conductivity of porous s ilicon (PS) layers is discussed in detail. A proposed theoretical mode l explains the considerable decrease of the thermal conductivity of na noscale PS in comparison with meso-PS and bulk silicon. The thermal co nductance dependence of Si/porous Si structures on the formation condi tions of PS layers has been studied. By varying the values of anodisat ion current density and anodisation time it is possible to optimize th e thermal conductance values of the Si/porous Si structures, In this w ay, an efficient thermal isolation can be obtained by forming thick PS layers. (C) 1998 Elsevier Science B.V.