| AVS 63rd International Symposium & Exhibition | |
| Surface Science | Friday Sessions |
| Session SS+HC-FrM |
| Session: | Deposition and Analysis of Complex Interfaces |
| Presenter: | Abijith Krishnan, Arizona State University/BASIS HS Scottsdale/SiO2 Innovates LLC |
| Authors: | A.S. Krishnan, Arizona State University/BASIS HS Scottsdale/SiO2 Innovates LLC N.X. Herbots, Arizona State University/SiO2 Innovates LLC Y.W. Pershad, Arizona State University/BASIS HS Scottsdale/SiO2 Innovates LLC S.D. Whaley, SiO2 Innovates LLC/Arizona State University R.J. Culbertson, Arizona State University R.B. Bennett-Kennett, Arizona State University |
| Correspondent: | Click to Email |
Metal Oxide Semiconductor Field Emission Transistors (MOSFETs) have been key to micro- and nano-electronics for the past six decades, but electrically active defects resulting from dangling bonds (unbounded electrons) or mobile ions create parasitic charges, known as surface charges (Qss for dangling bonds and Qo for mobile ions), that limit performance. Passivation via oxygen and hydrogen species can reduce surface defects. However, surface state charge analysis via capacitance-voltage (C-V) curves is used to evaluate the extent of passivation but does not accurately reflect the number of structural defects. On the other hand, surface characterization by Tapping Mode Atomic Force Microscopy (TMAFM) can be used for topographic observation and surface roughness measurements but has not been used to measure surface defect density. The new theoretical model proposed the Surface Energy Defect Density (SEDD) Model [1] aims to relate surface defect density to surface energy, a macroscopic quantity measured via high statistics Three Liquid Contact Angle Analysis (3LCAA) metrology [2,3]. Three Liquid Contact Angle Analysis (3LCAA) conducted in a class 100 clean-room using the Sessile Drop method and the Van Oss theory enables for accurate and reproducible contacts angles analysis within 1°, and a reproducible relative error lower than 2-3% for the total surface energy. These results have led to the conception a new theoretical model, the Surface Energy -Defect Density Model (SEDD) which relates the macroscopic surface energy density to the microscopic defect density. To test this model with experimental defect densities, this work uses PIXNANOVERT, a new algorithm to extract defect densities from high resolution large area (1 x10 µm2) TMAFM topographs taken on Si(100) passivated by the Herbots-Atluri process [5-7]. Analysis using surface effect density extracted. PIXNANOVERT shows that the SEDD Model predicts, within 5 the measured surface defect densities of oxidized Si surfaces with known surface energies. With this model, MOSFET manufacturers can determine the defect density in the oxide interface of their transistors by measuring the surface energy of the oxide. Testing transistor effectiveness for computers and other electronic devices would thus become more accurate than relying on C-V curves to quantify surface charge density. The SEDD Model would also allow us to determine the surface chemistry (e.g. hydrophobicity) of many other crystalline or amorphous materials, such as polymers and glasses, by measuring the surface energy.
[1] AS Krishnan, Senior Thesis (2016)
[2] Pat. pend., Herbots et al. (2011,2012,2016)
[3] SD Whaley, PhD, ASU (2013)