Paper SS+EM-WeA10
Lowering the Density of Electronic Defects on Organic-Functionalized Si(100) Surfaces

Wednesday, October 30, 2013, 5:00 pm, Room 201 A

The integration of self-assembled monolayers (SAM) with semiconductor surfaces helps to provide the functionality necessary for various application possibilities, ranging from molecular electronics, hybrid optoelectronics to chemical sensing. So far, Si(111) surfaces have been the most explored systems mainly due to the fact that atomically flat hydrogen terminated Si(111) surfaces can be easily prepared for further chemical functionalization. Recently a method to produce quasi atomically flat H-Si(001) surfaces has been developed¹ and the surface structure carefully studied with FTIR analysis, STM imaging and kinetic Monte Carlo simulations.

In this work, we compare the density of interface electronic states after organic functionalization (hydrosilylation) on both atomically rough and atomically flat Si(100) surfaces. Although differences in surface morphology are not detectable with FTIR or XPS, conductance voltage measurements² are able to detect a clear difference in interface state densities D_it (i.e., defect densities). Specifically, atomically flat Si(100) surfaces functionalized with C₁₁H₂₃ monolayers have D_it values three times lower than those of rough functionalized surfaces, leading to D_it values very close to our previous results on atomically-flat Si(111) surfaces functionalized with the same molecule.² These findings open the way for integrating common functionalization methods using the technologically important Si(100) surfaces to meet the needs of critical applications.

¹M. A. Hines, M. F. Faggin, A. Gupta, B. S. Aldinger, and K. Bao, J. Phys. Chem. C 116 (35), 18920 (2012).

²W. Peng, O. Seitz, R. A. Chapman, E. M. Vogel, and Y. J. Chabal, Appl. Phys. Lett. 101 (5) (2012).