A Novel Process for SiGe Core-Shell JAM Transistors Fabrication and Thermal Annealing Effect on Its Electrical Performance

In this study,we fabricate Si/SiGe core-shell Junctionless accumulation mode(JAM)FinFET devices through a rapid and novel process with four main steps,i.e.e-beam lithography definition,sputter deposition,alloy combination annealing,and chemical solution etching.The height of Si core is 30 nm and the thickness of Si/SiGe core-shell is about 2 nm.After finishing the fabrication of devices,we widely studied the electrical characteristics of poly Si/SiGe core-shell JAM FinFET transistors from a view of different Lg and Wch.A poly-Si/SiGe core-shell JAMFETs was successfully demonstrated and it also exhibits a superior subthreshold swing of 81mV/dec and high on/off ratio>10^5 when annealing for 1hr at 600℃.The thermal diffusion process condition for this study are 1hr at 600℃ and 6hr at 700℃ for comparison.The annealing condition at 700oC for 6 hours shows undesired electrical characteristics against the other.Results suggests that from over thermal budget causes a plenty of Ge to precipitate against to form SiGe thin film.Annealing JAMFETs at low temperature shows outstanding Subthreshold swing and better swing condition when compared to its counterpart i.e.at higher temperature.This new process can still fabricate a comparable performance to classical planar FinFET in driving current.