Reactivity of the Si(100)-2$\times$1-Cl surface with respect to PH${}_3$, PCl${}_3$, and BCl${}_3$: Comparison with PH${}_3$ on Si(100)-2$\times$1-H

Abstract

Despite the interest in a chlorine monolayer on Si(100) as an alternative to hydrogen resist for atomic-precision doping, little is known about its interaction with dopant-containing molecules. We used the density functional theory to evaluate whether a chlorine monolayer on Si(100) is suitable as a resist for \ce{PH3}, \ce{PCl3}, and \ce{BCl3} molecules. We calculated reaction pathways for \ce{PH3}, \ce{PCl3}, and \ce{BCl3} adsorption on a bare and Cl-terminated Si(100)-2$\times$1 surface, as well as for \ce{PH3} adsorption on H-terminated Si(100)-2$\times$1, which is widely used in current technologies for atomically precise doping of Si(100) with phosphorus. It was found that the Si(100)-2$\times$1-Cl surface has a higher reactivity towards phosphine than Si(100)-2$\times$1-H, and, therefore, unpatterned areas are less protected from undesirable incorporation of \ce{PH3} fragments. On the contrary, the resistance of the Si(100)-2$\times$1-Cl surface against the chlorine-containing molecules turned out to be very high. Several factors influencing reactivity are discussed. The results reveal that phosphorus and boron trichlorides are well-suited for doping a patterned Cl-resist by donors and acceptors, respectively.

References in corpus (3)

• First-Principle Study of Phosphine Adsorption on Si(001)-2$\times$1-Cl
• Local removal of silicon layers on Si(100)-2x1 with chlorine-resist STM lithography
• Chlorine insertion and manipulation on the Si(100)-2x1-Cl surface in the regime of local supersaturation