Clean lines in semiconductors
Figure 4. Continued improvements in nanofabrication processes have led to progressively more ideal structures. (a) An early (and rather rough) doubly clamped beam "carved" from a silicon wafer. (b) A compound torsional resonator made from silicon-on-insulator, and (c) a "clean" example made from gallium arsenide that is used to measure minute forces at high frequencies. (Picture credit: A N Cleland/Caltech, A N Cleland/Caltech, M J Murphy and D A Harrington/Caltech)