The √7 x √3-In surface reconstruction consisting of triple layer on the Si (111) surface

The formation process of the 'rect' structure of the Si(111)-root 7 x root 3-In surface (referred to as root 7v x root 3-rect) is studied in detail by varying the post-heating temperature after indium deposition on the Si(111) substrate. We find that at a low post-heating temperature of about 400 degrees C, two-dimensional indium islands of tens of nm in size are formed, consisting of triple layer with a root 7 x root 3-In reconstruction different from the root 7 x root 3-rect reconstruction (referred to as root 7 x root 3-TL). Although the atomic arrangements in the topmost indium layers of the root 7 x root 3-TL and the root 7 x root 3-rect reconstructions are considered to be nearly the same, their dI(t)/dV(s)(V-s) curves look different from each other. Surface defects in the disordered domain around the root 7 x root 3-TL islands originate from the partially remaining 7 x 7 reconstruction at the interface between the Si substrate and the indium layers. Additional indium atoms evaporated on the root 7 x root 3-rect surface with the root 7 x root 3-TL islands form flat wide single indium layers incorporating the root 7 x root 3-TL islands. However, the layers do not adopt the root 7 x root 3-TL reconstruction, but the incommensurate similar to 5.4x similar to 5.4 reconstruction.