Different deposition behavior of copper on silicon and porous silicon surfaces during immersion plating

Abstract

AbstractThe deposition behavior of Cu during immersion plating was investigated on Si and porous Si (PS) surfaces. The deposition of Cu could be observed on the PS surface, but not on the native Si surface. In the electrochemical characterization of the two surfaces in HF solution, a plateau of anodic current was observed at the PS structure, but not at the Si surface. The potential region of the plateau was more negative than the potential at which Si dissolution or PS formation takes place. The electrochemical measurements of the PS samples in HF solution revealed that oxidation of hydrogen remaining in the PS layer can not participate in the appearance of the anodic plateau. The different deposition behavior on the Si and PS surfaces enables selective deposition of Cu on a PS pattern drawn on n ‐type Si by laser scanning. A new patterning method of Cu on n ‐type Si by utilizing this behavior was successfully achieved. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)