The atomic structure of the Si(111)-Pb buried interface grown on the Si(111)-(#sq root#3 x #sq root#3)-Pb reconstruction

The Si(111)-Pb interface is a prototypical metal-semiconductor interface and has been the subject of a number of experimental studies. The Schottky barrier height is known to depend on the initial reconstruction formed by the first monolayer of Pb atoms and we have previously shown that there are structural differences between the buried interfaces.

We present surface X-ray diffraction measurements of the interface grown from the incommensurate Si(111)-(root 3 x root 3)-R30 degrees-Pb reconstruction and show that, in contrast to the starting surface, the interface comprises the junction between unreconstructed, bulk-like Si(111) and disordered, bulk-like Pb(111). This interface is contrasted with the interface formed by growth on the Si(111)-(7 x 7)-Pb reconstruction at which the starting reconstruction is preserved.