Thin film silicon substrate formation using electrochemical anodic etching method

Abstract

The production of detached porous silicon (PS) layers for layer transfer (LT) has been investigated. Electrochemical anodisation (ECA) studies of monocrystalline silicon (mono-Si) wafers in a hydrofluoric acid/ethanol/deionised (DI) water solution showed that porosity can be controlled by controlling current density during ECA. Double layered PS layers consisting of low (26·5%) and high (86·3%) porosity layers were formed by ECA at 1·5 mA cm –2 and 100 mA cm –2 for etching times of 10 min and 10 sec respectively. These PS layers are considered viable for LT substrate technology.