In situ arsenic doping during chemical vapor deposition (CVD) epitaxy of silicon is investigated. At low temperatures (around 700ЊC), a high arsenic concentration accumulates on the silicon surface. With a hydrogen bake (at 950ЊC) the surface concentration is significantly reduced and autodoping is inhibited. After the bake, the capping layer is grown at 700ЊC. At this temperature, the arsenic segregation, back to the surface, is suppressed. With this procedure, a relatively low baking temperature of 950ЊC is sufficient to reduce the autodoping level below 2 ϫ 10 16 cm Ϫ3 . Solid-state diffusion of the underlying arsenic profile is relatively slow at this temperature. This allows the fabrication of very sharp arsenic doping profiles. It is also shown that the arsenic surface concentration is proportional to the concentration that is incorporated into the epi layer. Furthermore it is shown that, in contrast to (kinetically limited) silicon growth, the arsenic transport is limited by gas-phase diffusion at 700ЊC, making the doping level dependent on pressure, temperature, and hydrogen flow.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.