“…Single-side polished Si͑111͒ chips ͑11 ϫ 2 mm 2 , 0.3 mm thick͒, with a resistivity of 0.005 ⍀ cm ͑Virginia Semiconductors͒, were cleaned by first outgassing at 400°C overnight, followed by flash annealing at 1200°C several times ͑by direct-current heating͒, until no C contaminants were detectable by XPS and large-area terraces with the 7 ϫ 7 reconstruction were observed by SPM. 1,8,10,17 Given that the corresponding binding energy of the O 1s spectrum for the 960 s deposition is found to be consistent with that of carboxylate ͑COO − ͒ ͑see below͒, this glycine film exists predominantly in the zwitterionic form, as expected for glycine in the bulk state. During evaporation, the temperature of the effusion cell was kept at 140°C, leading to a partial pressure of 5.0ϫ 10 −9 Torr for the 30 amu mass fragment ͑corresponding to the base ion NH 2 CH 2 + of glycine͒, as registered by a quadrupole mass spectrometer.…”