Specific contact resistance of the porous silicon and silver metal Ohmic contact structure

Abstract

We report the experimental result of the specific contact resistance (ρc) of porous silicon and silver metal Ohmic contact structure formed on the n+ region (doped with phosphorous atoms) to boron-doped p-type single crystalline silicon. The contact structure consists of sintered Ag metal grid contact on a porous silicon surface, which was formed on the n+ region by an electrochemical etching process. The electrical properties of the Ohmic contact thus formed are estimated by measuring the specific contact resistance at the interface of the porous silicon/silver Ohmic contact structure as a function of surface doping concentration. The measured value of ρc as a function of the surface doping shows that ρc is a strong function of surface doping, and decreases with increasing doping. The measured data provide reliable values of ρc for the silver metal/porous silicon/p-type c-Si structure, which enable us to study the electrical properties of the porous silicon/silver Ohmic contact.