Authors: Y. Ichida, Y. Morimoto, R. Sato and M. Murakami
Affilation: Utsunomiya University, Japan
Pages: 534 - 537
Keywords: nanomachining, scratching, atomic force microscope, single crystal silicon, process characteristics
In recent years, the surface modification with an atomic force microscope (AFM) has attracted special interest as one of the surface processing techniques in a nanometer scale [1-3]. Particularly, this technique will play an increasingly important role in the field of the ultrafine fabrication for manufacturing nanometer scale devices [4,5]. However, the material removal mechanism in this surface modification is very complicated, so that the processing characteristics by this process are not yet elucidated sufficiently. In this study, we investigate and discuss the possibility and the characteristic of the nanometer-scale mechanical processing by a scratching method with the AFM. For the purpose, a series of nanometer-scale scratching on polished Si (100) surfaces has been carried out by using an AFM with a three sided pyramidal diamond tip combined with two force/displacement transducers which could detect and control the normal and lateral forces with the accuracy of 0.1 mN. We consider the effects of processing force and probe tip shape for processing characteristics. As a result of the scratching, it is clarified that the transition point from elastic deformation to plastic deformation exists between 10~20mN. Also, the groove depth increases rapidly with an increase of the normal force when the normal force reaches to a certain value, although the groove depth increases gradually with an increase of the normal force after transition to plastic deformation. It is shown that the force at the transition point that the active removal action begins is influenced by the processing direction, in other words, probe tip shape. Furthermore, it is shown that the ratio of force components becomes high in the low force range before the active removal action and the trend is particularly obvious in the elastic deformation region. This is the result that the effects of van der Waals force, coulomb force and surface tension of adsorption layer become relatively larger to normal force. We are convinced that the results obtained in this study are useful as the manufacturing of a micromachine, MEMS etc.