Micro-object Pick and Place Operation under SEM based on Micro-physics

Abstract

Recently, techniques of arranging micrometer-sized objects under a scanning electron microscope (SEM) are required to construct micro-devices such as quantum optics devices. Since micro-objects tend to adhere to other objects mainly by electrostatic force, it is possible to pick them easily with a needle-tip instead of grasping by a gripper. However, it is difficult to place them on a substrate precisely, and furthermore even picking them is not achieved with enough reliability. To solve this problem, in this study, basic strategy for pick and place operation is indicated based on the actual measurement of adhesion under SEM first. Secondly dynamics for pick and place operation of a microsphere by a needle-shaped tool is analyzed. Thirdly a new method of practical pick and place is proposed on the basis of the basic strategy and the dynamics. Experimental system for executing the proposed operation is constructed based on the numeric-control of the position measurement of the target object. On this system, a lot of numeric-controlled experiments with 2µm polystyrene spheres reveal that under the optimal conditions, pick operation has never failed once out of over 20 trials and place operation has 140nm precision in position. From these results, this paper concludes that the proposed method can realize practical pick operation and place operation under SEM based on micro-physics.