A novel atomic doping technology for ultra-shallow junction of SOI-MOSFETs

A novel technology to fabricate an ultra shallow source and drain extension (SDE) junctions for the future SOI-MOSFETs was investigated. In this technology, a dopant in an adsorbed layer on SOI surface diffuses into the substrate by the rapid thermal annealing (RTA) or laser annealing (LA). Arsenic adsorbed layer is formed using UHV CVD apparatus during thermal decomposition of AsH3 on Si (001) at 550 °C with a base pressure of ∼1×10−10 Torr. RTA and LA have been identified as preferred annealing process for shallow junction formation because it provides low thermal budget control for junctions and high level of dopant activation and defect annealing. This method made it possible to control the junction depth with low sheet resistance for the sub 0.1 μm SOI-MOSFET.