LPE and VPE silicon thin film on porous sacrificial layer

Thin film single crystal silicon on foreign substrate is an attractive way to realize cheap and efficient photovoltaic devices. In this paper, we focus on the realisation of porous silicon sacrificial layer and subsequent epitaxial growth obtained with VPE and LPE. Porous silicon is elaborated by electrochemical anodisation of monocrystalline silicon. The sample is annealed under H/sub 2/ flow in the growth temperature range (1050-1100/spl deg/C). During this step, the restructuration of the low porosity layer allows epitaxial growth from the surface whereas the pores enlargement of the buried layer facilitates the subsequent detachment. We discuss and compare electrical properties (mobility and diffusion length) of epitaxial layer obtained with both techniques.