Characterization of adsorption-desorption processes on semiconductor surfaces using nanocantilever mass sensors

Abstract

Characterization of adsorption-desorption (AD) processes of gas particles on semiconductors is necessary in order to investigate the influence of these processes on the micro/nano-devices performance. By applying a numerical computational method we determined the pressure dependence of the equilibrium coverage of the semiconductor surface by chemisorbed gas particles. We concluded that the pressure dependence of the total coverage of the surface by adparticles, and also of coverages by both the neutral and ionized adparticles, can be obtained by measuring the adsorbed mass. We propose the use of nanocantilever sensors for such extremely sensitive mass measurements. The obtained adsorption induced cantilever's resonant frequency shifts are higher than the detection threshold set by the termomechanical noise. This confirms the applicability of the used nanocantilever sensor for experimental characterization of AD processes at semiconductor surfaces.