| AVS 63rd International Symposium & Exhibition | |
| Thin Film | Tuesday Sessions |
| Session TF-TuM |
| Session: | Advanced CVD and ALD Processing, ALD Manufacturing and Spatial-ALD |
| Presenter: | Jaclyn Sprenger, University of Colorado, Boulder |
| Authors: | J.K. Sprenger, University of Colorado, Boulder A.S. Cavanagh, University of Colorado, Boulder H. Sun, University of Colorado, Boulder S.M. George, University of Colorado, Boulder |
| Correspondent: | Click to Email |
Electron enhancement can dramatically reduce the temperatures required for ALD. Electrons can desorb surface species, such as hydrogen, and create “dangling bonds”. These “dangling bonds” can facilitate reactant adsorption. Using sequential electron and reactant exposures, low temperature growth should be possible for the ALD of Si, SiNx, SiCx, C, and CNx films that can be grown with hydride precursors. In this work, silicon films were deposited at room temperature using sequential Si2H6 (disilane) and electron exposures.
Silicon film growth using an electron flood gun was monitored with an in situ spectroscopic ellipsometer in the high vacuum chamber. A silicon growth rate of 0.2 Å/cycle for sequential Si2H6 and electron exposures was observed at room temperature with electron energies of 50 eV. In situ Auger electron spectroscopy (AES) revealed strong silicon AES signals with ~15 at.% carbon and <4 at.% oxygen impurities. Ex situ x-ray photoelectron spectroscopy (XPS) analysis was consistent with the in situ AES measurements.
Silicon films were also grown using electrons from a DC glow discharge plasma in a spatial ALD chamber. Deposition was performed at room temperature on 150 mm Si wafers. Ex situ spectroscopic ellipsometry measurements obtained a linear growth rate of 0.24 Å/cycle for sequential Si2H6 and electron exposures. This growth rate is in excellent agreement with the growth rate measured in the high vacuum chamber. Uniform silicon film thicknesses were obtained with a variation of only 3.0% along the axis of the slit from the DC glow discharge plasma. XPS depth-profiling analysis revealed that the silicon films contained ~10 at.% carbon.