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

We use the ability to control the surface chemistry in chemical vapor deposition (CVD) to deposit boron-carbon films into pores with aspects ratios of 60:1 without clogging the opening and into lateral trenches with ratios 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 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.