Abstract by Victoria Carver
Chemistry and Biochemistry
The Measurement of silanol (SiOH) Groups on Chemically Treated Fused Silica Surfaces by ALD.
Silanol groups (SiOH) and surface hydroxyl (OH) groups heavily determine the absorption behavior of compounds on silica surfaces (SiO2). We believe the combination of chemical and thermal treatment and ALD technique will help us to get a better insight about these surfaces. In this work, we are going to study the density of hydroxyl (OH) groups on fused silica surfaces using atomic layer deposition (ALD). We hydroxylated pieces of fused silica with hydrofluoric acid (HF) followed by heat treatments at 200, 500, 700 and 900°C. The samples underwent different cycles of ALD process to produce thin films of Al2O3. Analysis of these surfaces by X-ray photoelectron spectroscopy (XPS) showed as expected, as we go to higher temperatures the amount of Aluminum loading decreases. As a result heat-treated samples at 900°C were strongly depleted of surface silanols. This illustrates the significance of surface chemistry in the production of conformal thin films which is very important in semiconductor industries.