Energy dissipation in small-diameter Quartz Crystal Microbalance experimentally studied for ultra-high sensitive gravimetry

In this paper, the energy dissipation in small-diameter Quartz Crystal Microbalance (QCM) was experimentally studied for ultra-high sensitive gravimetric measurements. Newly developed deep reactive ion etching technology for smooth surface glass etching was used for the fabrication of small-diameter QCM. Minimum average surface roughness is 2.3 nm for an etching with SF/sub 6//Xe (=1/1) gases and 1.8 nm for SF/sub 6//Ar (=1/4) gases at a pressure of 0.2 Pa with a self-bias voltage of -390 V. The diameters of fabricated QCM were 0.2-1.0mm and their thickness was in the range of 6-82/spl mu/m. The Q-factor of the fabricated QCM increases exponentially from 2000 to 10000 as the thickness decreases due to the decrease of supporting loss. Interestingly, the increases of Q-factor deviate from simple exponential function and show a maximum peak of the Q-factor (30000).