Thermal desorption spectroscopy (TDS) is applied to analyze the oxidation reactions of hydrogen-terminated Si(100) surfaces in both the heating and cooling processes after hydrogen desorption. The oxidation reaction of oxygen and water with a silicon surface after hydrogen desorption shows hysteresis in the heating and cooling processes. In the cooling process, oxidation finishes when the silicon surface is adequately oxidized to about a 10 thickness. Oxidation continues to occur at lower temperatures when the total volume of oxygen and water is too small to saturate the bare silicon surface. The reaction of water with silicon releases hydrogen at more than 500. Hydrogen does not adsorb on the silicon oxide surface. A trace amount of oxygen, less than 110-6 Torr, roughens the surface.

We have found out the effects of surfactant addition to developer on the developing characteristics: very uniform developing, scum-free developing, contact hole formation at lower exposure energy and substrate surfaces protection. Although these are excellent effects required for ULSI manufacturing, we have also discovered the problem that surfactant added to developer remains after the developing process. We has successfully established two effective methods for removing residual surfactant: the addition of 0.15 wt% hydrogen peroxide to surface-active developer, and 1-minute ozone-added ultrapure water rinsing at room temperature. We can therefore make best use of the developing characteristics of surface-active developer without any degradations.