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.
The properties of nickel in silicon
This paper describes the properties of active nickel centers in silicon. In particular, the role of nickel in both increasing and reducing minority carrier lifetime in silicon integrated circuits is described, and an assessment made of its use in this application.
Failure analysis for poor solderability of Au surface of PCB
Nonwetting is one of the common problems and is always rejected in electronic assemblies. ENIG pads of a PCBA exhibited nonwetting after lead-free reflow soldering. With the aid of stereomicroscope, SEM&EDS and XRF, a series of analysis was performed. And after visual inspection, surface and cross section analysis, thickness measurement and solderability test, it can be inferred that oxidation of plating surface was the main reason for nonwetting, and corrosion in Ni plating caused an adverse impact on solderalibity.