ABSTRACT
Micro-electromechanical systems (MEMS) and the scale-reduced nano-electromechanical systems (NEMS) are promising for fabricating new categories of semiconductor devices that will provide mechanical functionality on existing optical and electrical semiconductor devices [1]. Many attempts to build semiconductor MEMS/NEMS structures have been made, using mainly Si [1-4], and also GaAs [5-7], SiC [8], and very recently AIN [9]. They utilize the extremely high detection sensitivity of those structures on several kinds of physical quantities, such as force and displacement [1,2,6], electric charges [3], magnetic moment [7], and acceleration [4]. When the characteristic frequency of the mechanical structures, such as beams and cantilevers, becomes high enough to make the quantized energy associated with the mechanical motion of freedom larger than the average thermal energy of the ambience, novel quantum mechanical functions are imported to NEMS devices [10]. The typical length scale necessary for realizing these “quantum NEMS” is 100 x 20 x 20 nm, where the energy quantum is roughly 10 μεν~100 mK or more, which is possibly detectable in a dilution refrigerator.
