Wafer preparation1 is conducted in onsite clean room facilities. UV-ozone cleaning is used. 3-inch Si(100) and Si(111) wafers are initially cleaned by brief submersion in a dilute hydroflouric solution (10:1). The acid is removed in a deionized water cascade to $15.0 \textrm{M}\Omega \cdot \textrm{cm}$ then exposed to ultraviolet light for 30 s. This process is repeated again with only 5 s UV exposure.

• 1. Wafer cleaning and thermal oxidation were conducted by N. Lakshminarayana.