Improvement of the minority carrier mobility in low-quality multicrystalline silicon using a porous silicon-based gettering under an O2 atmosphere

Abstract

Abstract In this work we study the effect of O2/porous silicon-based gettering on the electrical characteristics of lowquality multicrystalline silicon substrate. The gettering process is achieved by forming porous silicon (PS) layers on both sides of the wafers. The PS layers were formed by the stain-etching technique. The realized PS/Si/PS structure undergoes a heat treatment in an infrared furnace under an O2 controlled atmosphere. PS damage is introduced like a simple sequence for efficient extrinsic gettering schemes. After the removal of the PS layer, gettering effect was evaluated by measuring minority carrier lifetime which was performed using a WTC-120 photoconductance lifetime tester and dark I–V characteristics. As a result, an improvement of the minority carrier lifetime and dark I-V catacteristecs was observed The gettering at 950 °C exhibits a more obvious effect on the increase in the short-circuit current density (), open-circuit voltage ().