F. Ho et Y. Yamamoto, ANALYSIS AND OPTIMIZATION OF FORCE SENSITIVITY IN ATOMIC-FORCE MICROSCOPY USING OPTICAL AND ELECTRICAL DETECTION, Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena, 16(1), 1998, pp. 43-50
Atomic force microscopy is a versatile tool for ultrasensitive measure
ment. We explore the fundamental and practical limits to force sensiti
vity that are imposed by optical and electrical deflection sensing tec
hniques, and present a method for designing cantilevers to optimize fo
rce sensitivity. We calculate the optimized force sensitivity to be 1.
2x10(-18) N/root Hz at a temperature of 4 K, using a gallium arsenide
piezoresistive cantilever with dimensions w=0.1 mu m, t = 0.1 mu m, an
d L = 81 mu m, and mechanical quality factor Q = 10(4). The optimized
force sensitivities obtained using silicon piezoresistive and optical
detection are not far behind. (C) 1998 American Vacuum Society.