Selective deposition of H atoms on silicon was achieved by using a UHV-STM with a Pd tip. The deposition of hydrogen atoms occurs on the Si(100) 2×1 surface at a negative sample bias in a pressure of 1×10 −10 Torr. The H atom adsorbed sites appear dark in a constant current mode in an STM image. H atoms are supplied from the Pd tip, while, at a positive bias, adsorbed H atoms get desorbed. The surface was selectively oxidized by exposing it to oxygen (1.0 × 10 −5 Torr, 60 s, at room temperature). Nanoscale Al patterns were made by selective Al CVD on the H-termtnated Si surface using DMAH (dirnethylaluminium hydride) as a gas source.