Summary
Research Interests
Our research is centered on the investigation of growth mechanisms of semiconductor materials during processes such as plasma-enhanced chemical vapor deposition (PECVD). To mimic these plasmas under more carefully controlled conditions, we use a hyperthermal beam of the reactive species of interest and single crystal semiconductor wafers. Specifically, we generate a variable energy beam of mass-selected, reactive atomic or molecular ions, with energies in the 1-100 eV range, and use this as the source of growth species. The interaction of these species with clean, well characterized semiconductor surfaces is then examined in an ultrahigh vacuum environment (pictured below). Mass spectrometry is used to examine the identity of desorbing and scattered species and to provide kinetic information about reactions occurring on the surface. Low-energy electron diffraction and Auger electron spectroscopy are used to examine the crystallinity and composition of the resulting surfaces. Results from such experiments allow for a more complete understanding of the mechanisms involved in reactive ion-surface interactions, an area of great importance during these PECVD processes.
Systems of particular interest for our group involve heteroepitaxial growth of lattice-mismatched materials, such as Ge/Si or SiC/Si. These systems are becoming increasingly technologically important; however, the growth mechanisms of the materials are not yet completely understood. Results from our experiments will provide data about many of the fundamental heterogeneous reactions involved in the growth of these materials.
Education
- NRC-NIST Postdoctoral Fellow (1993-1995) and Postdoctoral (1995-1997), JILA, University of Colorado (Stephen R. Leone)
- Ph.D. (1993), University of Minnesota (Doreen G. Leopold)
- B.S. (1988), State University of New York, College at Purchase
Publications
- Lee, M.V.; Richards, J.L.; Linford, M.R.; Casey, S.M. Gas phase chemomechanical modification of silicon. J. Vac. Sci. Technol., B: Microelectron. Nanometer Struct.—Process., Meas., Phenom. 2006, 24, 750-755.
- Tam-Chang, S.-W.; Seo, W.; Rove, K.O.; Casey, S.M. Molecularly designed chromonic liquid crystals for the fabrication of broad spectrum polarizing materials. Chem. Mater. 2004, 16, 1832-1834. [Communication]
- Zhang, L.; Carman, A.J.; Casey, S.M. Adsorption and thermal decomposition chemistry of 1-propanol and other primary alcohols on the Si(100) surface. J. Phys. Chem. B 2003, 107, 8424-8432.
- Carson, T.D.; Seo, W.; Tam-Chang, S.-W.; Casey, S.M. Novel polarized photoluminescent films derived from sequential self-organization, induced-orientation, and order transfer processes. Chem. Mater. 2003, 15, 2292-2294. [Communication]
- Carman, A.J.; Zhang, L.; Liswood, J.L.; Casey, S.M. Methylamine adsorption on and desorption from Si(100). J. Phys. Chem. B 2003, 107, 5491-5502.
- Tam-Chang, S.-W.; Seo, W.; Iverson, I.K.; Casey, S.M. Ionic quaterrylenebis(dicarboximide): A novel mesogen and long-wavelength polarizing material. Angew. Chem., Int. Ed. 2003, 42, 897-900. [Communication]
- Iverson, I.K.; Casey, S.M.; Seo, W.; Tam-Chang, S.-W.; Pindzola, B.A. Controlling molecular orientation in solid films via self-organization in the liquid-crystalline phase. Langmuir 2002, 18, 3510-3516.
- Ervin, K.M.; Ramond, T.M.; Davico, G.E.; Schwartz, R.L.; Casey, S.M.; Lineberger, W.C. Naphthyl radical: Negative ion photoelectron spectroscopy, Franck-Condon simulation, and thermochemistry. J. Phys. Chem. A 2001, 105, 10822-10831.
- Mulcahy, C.P.A.; Carman, A.J.; Casey, S.M. The adsorption and thermal decomposition of dimethylamine on Si(100). Surf. Sci. 2000, 459, 1-13.