Ultradoping Boron on Si(100) via Solvothermal Chemistry**

Ultradoping introduces unprecedented dopant levels into Si, which transforms its electronic behavior and enables its use as a next-generation electronic material. Commercialization of ultradoping is currently limited by gas-phase ultra-high vacuum requirements. Solvothermal chemistry is amenable to scale-up. However, an integral part of ultradoping is a direct chemical bond between dopants and Si, and solvothermal dopant-Si surface reactions are not well-developed. This work provides the first quantified demonstration of achieving ultradoping concentrations of boron (similar to 1e14 cm(2)) by using a solvothermal process. Surface characterizations indicate the catalyst cross-reacted, which led to multiple surface products and caused ambiguity in experimental confirmation of direct surface attachment. Density functional theory computations elucidate that the reaction results in direct B-Si surface bonds. This proof-of-principle work lays groundwork for emerging solvothermal ultradoping processes.

Automated summary

This study demonstrates the achievement of ultradoping concentrations of boron using a solvothermal process, but faces challenges such as catalyst cross-reactions and ambiguity in experimental confirmation of direct surface attachment.