The wafers are loaded into a thermal oxidation furnace. The rate of oxidation in the nitrogen-ambient environment of the furnace is controlled by the furnace temperature (typically $1100 - 1150^\circ \textrm{C}$) and exposure time. Oxide thicknesses, $\theta_{\textrm{ox}}$, of 250, 500 and 1000 Å are prepared for the current investigation (Fig. 4.1a).
Figure 4.1. Oxide Patterning Process. a) Substrate is thermally oxidized, b) spin-coated with photoresist, c) masked while exposed to a 150 W UV lamp, d) developed to remove UV-exposed photoresist, e) etched to remove exposed oxide to produce an f.) oxide-patterned wafer after photoresist is removed with acetone. |
