A CONSTANT TEMPERATURE BATH FOR DAMAGE REMOVAL ETCH PROCESS IN PLASMA TEXTURING OF MC-SI WAFERS

摘要

A Constant Temperature Bath, for damage removal etch process in plasma texturing of mc-Si wafers, comprising a coil of ¼" diameter Teflon tube inserted into a PVC tank having internal diameter of 27 cm containing acid mixture consisting of 2%Hydrofluoric Acid(HF), 48%Nitric Acid(HNO3) and 50%water, extracting heat effectively from the acid mixture during an exothermic reaction with silicon and maintaining the acid mixture temperature at 11 °C ± 1°C throughout its volume by flowing chilled water through the tube at a flow rate of 2 1pm (liters per minutes) to ensure uniform etching in 80-100 sec etching time across a wafer and from wafer to wafer in a batch.