Surface-Inhibiting Effect in Chemical Vapor Deposition of Boron–Carbon Thin Films from Trimethylboron

Here are deep insights to the understand of conformal boron-carbon films in very high aspect ratio structures by researchers from Linköping University, Sweden. If you don't have the journal access, please check the pre-print (LINK).

Surface-Inhibiting Effect in Chemical Vapor Deposition of Boron–Carbon Thin Films from Trimethylboron

Laurent Souqui, Hans Högberg, Henrik Pedersen
Chem. Mater. 201931155408-5412 LINK

We use the ability to control surface chemistry in chemical vapor deposition (CVD) to deposit boron–carbon films into pores with an aspect ratio of 60:1 without clogging the opening, and into lateral trenches with ratios of up to 2000:1. In contrast to many other surface-controlled CVD processes, operating at low temperatures (100–250 °C) and pressures (10–1000 Pa), we use trimethylboron at a higher temperature (700 °C) and pressure (5000 Pa), affording a surface-inhibited CVD process in hydrogen ambient. We show that the deposition rate is highly dependent on the partial pressure of hydrogen; decreasing proportionally to the logarithm of the partial pressure. The surface-controlled effect is not encountered in argon ambient. We propose that this is explained by a competitive adsorption of growth species and inhibiting dihydrogen or atomic hydrogen species following a Temkin isotherm.

.@CesiumTheDay covering Laurent and @hacp81's recent high aspect ratio B-C #CVDep work #BarryLab pic.twitter.com/9L84lQGOkr

— Scientist Tiger (@sean_t_barry) August 26, 2019