Fast thermal annealing for manufacturing of silicon diodes and photodiodes

The influence of rapid thermal annealing (RTA) in hydrogen atmosphere on ohmic properties of double-layer composition Ti/Au as contact on р + -Si was investigated. Based on experimental results it was confirmed that RTA at 340 °С for 20 s in hydrogen atmosphere allows to obtain an ohmic contact with the minimum of resistivity. This is due to titanium silicides formation on the Si/Ti interface. It also known silicides formation on Si-interface with other transition metals such as Ni, Pd and Cr, which determines the application of RTA for obtaining ohmic contacts based on them. The applicability of RTA for manufacture technology of silicon diodes to reduce the serial resistance, which leads to increased yield rate of diodes, was confirmed by applying on a limited diode p + – n as an example. Also, the influence of RTA in hydrogen atmosphere on a dark current was investigated by applying on a silicon multi-element p – i – n photosensitive element (PE) as an example. Based on experimental results it was confirmed that RTA at 450 °С for 5 s improved dark current of the photosensitive areas and the guard ring and as a result increased yield rate of photodiodes. This is due to decreasing of the density of surface states and stabilization of charge properties of the SiO 2 / p -Si interface through saturation of dangling Si-bonds with hydrogen. This confirmed the applicability of RTA in hydrogen atmosphere for manufacture technology of photodiodes on high-resistance p -Si to reduce its dark current.