Recent Development and Application of the XSTM

Abstract

The development of the cross-section scanning tunneling microscope (XSTM) and its application to the study of the cross-section of boron(B)-implanted Si wafers are reported. To obtain a cross-section of wafer samples, we examined the cleavage on the {111} plane in two ways. As a result the cleavage, by pushing the side of the sample wafer, was found to be preferable in obtaining a flat {111} cross-section from both (111) and (001) wafers. Our devices in the mounting angle and the guiding line for the cleavage are also described in detail, Using this XSTM, we observed the {111} cleaved cross-sectional surface of the B-implanted Si(111) wafer, The local surface structure was found to change on the cleaved cross-section from the 7 × 7 to the [Formula: see text] reconstruction through the disordered phase, The change was found to be consistent with the depth profile of the implanted B in the Si water. The arrangement of B and Si atoms in the disordered phase was determined by the site and the sample bias dependence of protrusions in STM images.