2 research outputs found
Scalable Patterning of One-Dimensional Dangling Bond Rows on Hydrogenated Si(001)
Silicon dangling bonds exposed on the monohydride silicon (001) (Si(001):H) surface are highly reactive, thus enabling site-selective absorption of atoms and single molecules into custom patterns designed through the controlled removal of hydrogen atoms. Current implementations of high-resolution hydrogen lithography on the Si(001):H surface rely on sequential removal of hydrogen atoms using the tip of a scanning probe microscope. Here, we present a scalable thermal process that yields very long rows of single dimer wide silicon dangling bonds suitable for self-assembly of atoms and molecules into one-dimensional structures of unprecedented length on Si(001):H. The row consists of the standard buckled Si dimer and an unexpected flat dimer configuration
Controlling the Atomic Layer Deposition of Titanium Dioxide on Silicon: Dependence on Surface Termination
Patterned fabrication
depends on selective deposition that can
be best achieved with atomic layer deposition (ALD). For the growth
of TiO<sub>2</sub> by ALD using TiCl<sub>4</sub> and H<sub>2</sub>O, X-ray photoelectron spectroscopy reveals a marked difference in
growth on oxidized and hydrogen-terminated silicon surfaces, characterized
by typical and predictable deposition rates observed on SiO<sub>2</sub> surfaces that can be 185 times greater than the deposition rates
on hydrogen-terminated Si(100) and Si(111) surfaces. Large-scale patterning
is demonstrated using wet chemistry, and nanometer-scale patterned
TiO<sub>2</sub> growth is achieved through scanning tunneling microscopy
(STM) tip-based lithography and ALD. The initial adsorption mechanisms
of TiCl<sub>4</sub> on clean, hydrogen-terminated, and OH-terminated
Si(100)-(2 × 1) surfaces are investigated in detail through density
functional theory calculations. Varying the reactive groups on the
substrate is found to strongly affect the probability of precursor
nucleation on the surface during the ALD process. Theoretical studies
provide quantitative understanding of the experimental differences
obtained for the SiO<sub>2</sub>, hydrogen-terminated, and clean Si(100)
and Si(111) surfaces