Ultradoping Boron on Si(100) via Solvothermal Chemistry*

Area of Science:

• Materials Science
• Solid State Physics
• Computational Chemistry

Background:

• Ultradoping silicon offers transformative electronic properties for next-generation devices.
• Current ultradoping methods require challenging ultra-high vacuum conditions, limiting commercialization.
• Solvothermal chemistry presents a scalable alternative, but dopant-silicon surface reactions are underdeveloped.

Purpose of the Study:

• To demonstrate ultradoping silicon with boron using a solvothermal process.
• To investigate the formation of direct dopant-silicon surface bonds via solvothermal reactions.
• To establish a foundation for scalable solvothermal ultradoping techniques.

Main Methods:

• Utilized a solvothermal chemistry approach for boron doping of silicon.
• Performed surface characterizations to analyze dopant-silicon interactions.
• Employed density functional theory (DFT) computations to elucidate reaction mechanisms and bonding.

Main Results:

• Achieved ultradoping concentrations of boron (approximately 1e14 cm⁻²) via the solvothermal method.
• Surface characterization revealed catalyst cross-reactivity, leading to complex surface products.
• DFT calculations confirmed the formation of direct boron-silicon surface bonds.

Conclusions:

• This work presents the first quantified demonstration of solvothermal ultradoping of silicon with boron.
• The findings validate the formation of direct B-Si bonds through solvothermal reactions, despite surface complexities.
• This proof-of-principle study supports the development of scalable solvothermal processes for ultradoping.