Stable aluminium ohmic contact to surface modified porous silicon

Nanocrystalline Porous Silicon

“…Although Au and Cu showed some positive results Ni was proved to be ineffective for Ohmic contact. The stabilization of PS surface by noble metals for reliable metal contact has been recently reported by us (Kanungo et al 2009a). We used the noble metal (Pd, Pt, and Ru) ions to stabilize the surface of porous silicon.…”

“…However, the possible apprehension that Pd, Ru and Pt may create a continuous metal layer on the PS surface is ruled out by digital X-ray mapping and EDAX line scan analysis (Kanungo et al 2010a) that show distinctly a discontinuous dispersion of noble metals. Specific contact resistance of Al to Pd modified PS was measured by the transmission line model (TLM) method and the value obtained was of the order ~ 10 -1 ohm-cm 2 (Kanungo et al, 2009a). www.intechopen.com…”

“…were also used to modify the porous silicon surface to stabilize its photoluminescence properties (Andsager et al 1994;Steiner et al, 1994). Surface modification of PS using noble metals like Pd and Pt has also been studied recently (Kanungo et al 2009a). The details on PS are given in a comprehensive review published by Cullis et al (Cullis et al, 1997) and in the handbook on Porous Silicon properties edited by Canham (Canham, 1997a).…”

XPS study of palladium sensitized nano porous silicon thin film

“…We applied an etching current density of 10 mA/cm 2 for 40 min. The porosity and thickness of around 55% and 5 μm, respectively were measured gravimetrically (Kanungo et al 2006(Kanungo et al , 2009) using a precision semi-microbalance (290-9842/K, PAG OERLIKONAG CH-DIETKON, Switzerland).…”

“…Pd ++ formed by decomposition of PdCl 2 in an aqueous acidic solution is reduced to Pd metal islands by a chemical reduction process (Jeske et al 1995;Kanungo et al 2009) and two holes released. The h + oxidizes the PS surface to SiO 2 .…”