STABILITY OF SI(111)ROOT-3X-ROOT-3R30-DEGREES-B SURFACE IN AIR

The Si(111)root 3 x root 3R30 degrees-B surface was prepared by irradi ation of HBO2 in a molecular beam epitaxy (MBE) system, and its stabil ity in air was studied using reflection high-energy electron diffracti on (RHEED) and contact angle measurements. The boron (B)-passivated Si (111) surface was found to be much more stable against oxidation than a clean Si(111)7 x 7 surface. The measurements of contact angle betwee n the surface and a water droplet revealed that the B-passivated Si(11 1) surface was hydrophilic (similar to 5 degrees), and that the contac t angle increased with oxidation of the surface and saturated at 27 de grees. It was also found that the contact angle of the Si(111) native oxide increases from similar to 0 to similar to 27 degrees in about 10 00 minutes in room air or nitrogen ambient.