Smart flexible microrobots for scanning electron microscope (SEM) applications

In the scanning electron microscope (SEM), specially designed microrobots c an act as a flexible assembly facility for hybrid microsystems, as probing devices for in-situ tests on IC structures or just as a helpful teleoperate d tool for the SEM operator when examining samples. Several flexible micror obots of this kind have been developed and tested. Driven by piezoactuators , these few cubic centimeters small mobile robots can perform manipulations with a precision of up to 10 nm and transport the gripped objects at speed s of up to 30 mm/s. In accuracy, flexibility and price they are superior to conventional precision robots. A new SEM-suited microrobot prototype is de scribed in this paper. The SEM's vacuum chamber has been equipped with vari ous elements like flanges and CCD cameras to enable the robot to operate. I n order to use the SEM image for the automatic real-time control of the rob ots, the SEM's electron beam is actively controlled by a PC. The latter sub mits the images to the robots'control computer system. For obtaining three- dimensional information in real time, especially for the closed-loop contro l of a robot endeffector, e.g., microgripper, a triangulation method with t he luminescent spot of the SEM's electron beam is being investigated.