MINIATURE 3-AXIS MICROPOSITIONER FOR SCANNING PROXIMAL PROBE AND OTHER APPLICATIONS

A small, 2X2X1.1 cm (height), three-axis micropositioner has been deve loped. It combines sub-nm positioning capability with a large range of travel of more than 1 mm in each direction. Its applications range fr om scanning proximal probe instruments to sample stages for electron o r light microscopes. Two shear piezos are provided in each direction t o facilitate motion. They are located at opposite sides of a moving fr ame which is guided by V grooves on sapphire balls (or rods). A critic al point in designing this kind of positioners is how to generate the ''attachment'' force that holds the parts of the positioner together. Gravity cannot be used as the stage needs to work in all orientations. Springs, connecting the two parts moving relative to each other, gene rate a force in the direction of the desired motion that is changing w ith position, making the stage motion nonlinear. Magnets are not appro priate when low-energy electrons are involved in the vicinity. This pr oblem is solved by especially designed leaf springs coupled to V groov es and balls (or rods). This design allows the attachment force to rem ain constant and orthogonal to the direction of motion when the stage moves, thus making the motion very linear and independent of the orien tation of the positioner. The positioner is exceptionally compact and can be operated in ultrahigh vacuum. These properties make the positio ner attractive for atomic scale resolution scanning proximal probe mic roscopes and a wide range of other applications. (C) 1995 American Vac uum Society.