@article{celik_ozturk_1999, title={Low thermal budget surface preparation for selective epitaxy a study on process robustness}, volume={146}, ISSN={["0013-4651"]}, DOI={10.1149/1.1391804}, abstractNote={The robustness of a low thermal budget surface preparation method for selective silicon epitaxial growth has been investigated. After the HF dip, the stability of hydrogen passivation on Si(100) in deionized water and air has been studied. No significant increase was observed in oxygen and carbon coverage for deionized water rinse times varying from 10 to 1000 s. On wafers exposed to air for up to 10,000 s, carbon coverage on Si(100) stayed at the same level, whereas the oxygen coverage increased steadily. An in situ clean at 800°C for 10 s reduced the interfacial oxygen below the secondary ion mass spectroscopy detection levels on wafers that had been contaminated by exposure to air for up to 1000 s. In situ cleaning was studied in ambients with different partial pressures of intentionally introduced oxygen and nitrogen backgrounds. Oxygen was removed from Si(100) during the in situ clean for nitrogen partial pressures up to I X 10 -6 Torr. When the oxygen partial pressure is sufficiently high (I X 10 -6 Torr), oxide removal was not complete after in situ cleaning. There was no observable increase in the surface roughness for samples annealed in oxygen partial pressure up to I × 10 -5 Torr. Hydrogen passivation was removed from the substrates and the surfaces were exposed to vacuum at room temperature for different times. After 10,000 s, the oxygen coverage was less than 2% of a monolayer. The carbon contamination on the surface was instantaneous and no additional carbon accumulation on the surface was observed up to 10,000 s. There was no apparent increase in the defect density for these wait times.}, number={4}, journal={JOURNAL OF THE ELECTROCHEMICAL SOCIETY}, author={Celik, SM and Ozturk, MC}, year={1999}, month={Apr}, pages={1557–1564} }
 @article{celik_ozturk_1998, title={Low thermal budget in situ surface cleaning for selective silicon epitaxy}, volume={145}, ISSN={["0013-4651"]}, DOI={10.1149/1.1838849}, abstractNote={In this paper, we present a process which provides low thermal budget removal of carbon, oxygen, and chlorine from the silicon surface by annealing the substrate in a vacuum ambient with water and oxygen partial pressures less than 10 9 Torr. Following the in situ clean, silicon was deposited epitaxially, and carbon, oxygen, and chlorine levels at the epitaxy/substrate interface were quantified using secondary ion mass spectroscopy. It was demonstrated that these contaminants were removed from the silicon surface with a 10 s anneal at temperatures as low as 750°C. Both SiO 2 patterned and bare silicon wafers were employed, and the patterns on the surface did not show any effect on the in situ clean efficiency. The impact of chlorine as a contaminant was also studied, and no effect on the in situ cleaning efficiency was observed. Surface roughness was quantified by atomic force microscopy, which revealed that surface roughness on Si did not increase after in situ cleaning in vacuum. A defect analysis was performed using optical and scanning electron microscopy. A correlation was obtained between the defect density and the carbon levels at the epitaxy/substrate interface. However, electrical device characterization did not show any correlation between different in situ clean temperatures and the n-channel metal-oxidation-silicon field effect transistor leakage current or transconductance.}, number={10}, journal={JOURNAL OF THE ELECTROCHEMICAL SOCIETY}, author={Celik, SM and Ozturk, MC}, year={1998}, month={Oct}, pages={3602–3609} }
 @inproceedings{srivastava_sun_bellur_bartholomew_o'neil_celik_osburn_masnari_ozturk_westhoff_et al._1997, title={A 0.18 ?m CMOS technology for elevated source/drain MOSFETs using selective silicon epitaxy}, booktitle={ULSI science and technology/1997: Proceedings of the Sixth International Symposium on UltraLarge Scale Integration Science and Technology (Proceedings (Electrochemical Society); v. 97-3)}, publisher={Pennington, NJ: Electrochemical Society}, author={Srivastava, A. and Sun, J. and Bellur, K. and Bartholomew, R. F. and O'Neil, P. and Celik, S. M. and Osburn, C. M. and Masnari, N. A. and Ozturk, M. C. and Westhoff, R. and et al.}, year={1997}, pages={571–585} }