Local removal of silicon layers on Si(100)-2 x 1 with chlorine-resist STM lithography

We report the realization of STM-based lithography with silicon layers removal on the chlorinated Si(1 0 0)2 x 1 surface at 77 K. In contrast to other STM lithography studies, we were able to remove locally both chlorine and silicon atoms. Most of the etched pits have a lateral size of 10-20 angstrom and a depth of 1-5 angstrom. In the pits in which the STM image with atomic resolution is obtained, the bottom is mainly covered with chlorine. Some pits contain chlorine vacancies. Mechanisms of STM-induced removal of silicon and chlorine atoms on Si(1 0 0)-2 x 1-Cl are discussed and compared with the well-studied case of STM-induced hydrogen desorption on Si(1 0 0)-2 x 1-H. The results open up new possibilities of the three-dimensional local etching with STM lithography.