Maskless selective area molecular beam epitaxy of semiconductors and metals using atomic step networks on silicon

Step-patterned substrates of vicinal Si(111) were used for the selective growth of a variety of materials, both semiconductor (GaAs and Ge) and metal (Au and Ag) Step patterning was performed by etching substrates photolithographically, and annealing them. Subsequent growth by molecular beam epitaxy was observed by in situ ultra-high vacuum scanning: electron microscopy. Materials grew preferentially on the prepared step bands either by a desorption mechanism or by a diffusion mechanism, depending on the temperature. The growth of silver was different, although the initial monolayer was also selective. This growth technique can be applied to a small region or an entire wafer. Growth areas fan be several microns wide, or, in principle, can be of nanometer scale (C) 1999 Elsevier Science B.V. All rights reserved.