A study into the formation and characterisation of electroless nickel silicide for laser doped solar cells

In this paper we will study the formation and characteristics of nickel silicide compounds and the subsequent specific contact resistivity (Ω.cm²) during the formation of an ohmic contact in solar cells. Using Transmission Line Method (TLM) we will analyse the electrical characteristics of the formed nickel silicides at different sintering temperatures and durations. In each sintering condition tested, the relationship between the total resistance and the distance between the contact pads on the fabricated test structures is measured and graphed. From these graphs the contact resistance (Ω) and specific contact resistivity (Ω.cm²) of the metallisation stack is calculated and tabulated. We conclude the paper by showing the optimum sintering condition of 350°C for three minutes for laser doped solar cells which yields negligible contact resistance.