Piezoresistive sensors for scanning probe microscopy

In this article we summarize the efforts devoted to the realization of our ideas of the development of piezoresistive sensor family used in scanning p robe microscopy. All the sensors described here are fabricated based on adv anced silicon micromachining and standard CMOS processing. The fabrication scenario presented in this article allows for the production of different s ensors with the same tip deflection piezoresistive detection scheme. In thi s way we designed and fabricated, as a basic sensor, piezoresistive cantile ver for atomic force microscopy, which enables surface topography measureme nts with a resolution of 0.1 nm. Next, by introducing a conductive tip isol ated from the beam we obtained a microprobe for scanning capacitance micros copy and scanning tunneling microscopy. With this microprobe we measured ca pacitance between the microtip and the surface in the range of 10(-22) F. F urthermore, a modification of the piezoresistors placement, based on the fi nite element method (FEM) simulation permits fabrication of the multipurpos e sensor for lateral force microscopy, which enables measurements of fricti on forces with a resolution of 1 nN. Finally, using the same basic device i dea and only slightly modified process sequence we manufactured femtocalori meter for the detection of heat energy in the range of 50 pJ. (C) 2000 Publ ished by Elsevier Science B.V. All rights reserved.