Ultraviolet (UV)/ozone cleaning is a promising way of decontaminating silicon wafers for industrial very large scale integrated processing. We have investigated the cleaning process in high-vacuum conditions utilizing a pulsed supersonic valve and an excimer lamp. With this setup, we are able to supply atomic oxygen onto Si surfaces with and without the simultaneous UV light exposure. We have discovered that thermal desorption spectroscopy analysis of the surface adsorbed species shows marked differences in the wafers processed under different conditions in high vacuum. We have confirmed that UV irradiation is a very essential factor in the UV/ozone cleaning process. In addition, we have carried out time-resolved studies of species coming off the wafer surfaces during UV/ozone cleaning, and found that the main by-products are CO, CO2, and H2O. The hydrocarbon removal reaction is not oxygen-supply limited.
|Number of pages
|Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures
|Published - 1997
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Electrical and Electronic Engineering