CORE ELECTRON-EXCITATION EFFECTS ON ALUMINUM CHEMICAL-VAPOR-DEPOSITION

We show that the effects of synchrotron radiation (SR) on Al chemical vapor deposition (CVD) is clearly different depending on whether core or valence electrons are excited. When high-energy photons are used to excite the core electrons, aluminum growth on a Si surface is effecti vely suppressed, and thus negative projection patterning is clearly ac hieved. On the other hand, when low-energy photons, which can only exc ite valence electrons, are utilized, growth initiation occurs on the S iO2 surface. Chemical shift analysis is performed using Auger electron spectroscopy. The results reveal that aluminum carbide is formed on t he high-energy photon-irradiated Si surface, while metallic aluminum i s formed on the low-energy photon-irradiated SiO2 surface. The clear d ifference in CVD characteristics when core/valence electrons are excit ed is discussed based on the changes in surface chemistry caused by su rface photochemical reaction.