TY - GEN
T1 - A comprehensive study of growth techniques and characterization of epitaxial Ge1-xCx (111) layers grown directly on Si (111) for MOS applications
AU - Jamil, Mustafa
AU - Donnelly, Joseph P.
AU - Lee, Se Hoon
AU - Shahrjerdi, Davood
AU - Akyol, Tank
AU - Tutuc, Emanuel
AU - Banerjee, Sanjay K.
PY - 2008
Y1 - 2008
N2 - We report the growth and characterization of thin germanium-carbon layers grown directly on Si (111) by ultra high-vacuum chemical vapor deposition. The thickness of the films studied is 8-20 nm. The incorporation of small amount (less than 0.5%) of carbon facilitates 2D growth of high quality Ge crystals grown directly on Si (111) without the need of a buffer layer. The Ge 1-xCx layers were grown in ultra high vacuum chemical vapor deposition chamber, at a typical pressure of 50 mTorr and at a growth temperature of 440°C CH3GeH3 and GeH4 gases were used as the precursors for the epitaxial growth. The Ge 1-xCx films were characterized by atomic force microscopy (AFM), secondary ion mass spectroscopy, x-ray diffraction, crosssectional transmission electron microscopy and Raman spectroscopy. The AFM rms roughness of Ge1-xCx grown directly on Si (111) is only 0.34 nm, which is by far the lowest rms roughness of Ge films grown directly on Si (111). The dependence of growth rate and rms roughness of the films on temperature, C incorporation and deposition pressure was studied. In Ge, (111) surface orientation has the highest electron mobility; however, compressive strain in Ge degrades electron mobility. The technique of C incorporation leads to a low defect density Ge layer on Si (111), well above the critical thickness. Hence high quality crystalline layer of Ge directly on Si (111) can be achieved without compressive strain. The fabricated MOS capacitors exhibit well-behaved electrical characteristics. Thus demonstrate the feasibility of Ge 1-xCx layers on Si (111) for future high-carrier-mobility MOS devices that take advantage of high electron mobility in Ge (111).
AB - We report the growth and characterization of thin germanium-carbon layers grown directly on Si (111) by ultra high-vacuum chemical vapor deposition. The thickness of the films studied is 8-20 nm. The incorporation of small amount (less than 0.5%) of carbon facilitates 2D growth of high quality Ge crystals grown directly on Si (111) without the need of a buffer layer. The Ge 1-xCx layers were grown in ultra high vacuum chemical vapor deposition chamber, at a typical pressure of 50 mTorr and at a growth temperature of 440°C CH3GeH3 and GeH4 gases were used as the precursors for the epitaxial growth. The Ge 1-xCx films were characterized by atomic force microscopy (AFM), secondary ion mass spectroscopy, x-ray diffraction, crosssectional transmission electron microscopy and Raman spectroscopy. The AFM rms roughness of Ge1-xCx grown directly on Si (111) is only 0.34 nm, which is by far the lowest rms roughness of Ge films grown directly on Si (111). The dependence of growth rate and rms roughness of the films on temperature, C incorporation and deposition pressure was studied. In Ge, (111) surface orientation has the highest electron mobility; however, compressive strain in Ge degrades electron mobility. The technique of C incorporation leads to a low defect density Ge layer on Si (111), well above the critical thickness. Hence high quality crystalline layer of Ge directly on Si (111) can be achieved without compressive strain. The fabricated MOS capacitors exhibit well-behaved electrical characteristics. Thus demonstrate the feasibility of Ge 1-xCx layers on Si (111) for future high-carrier-mobility MOS devices that take advantage of high electron mobility in Ge (111).
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U2 - 10.1557/proc-1068-c07-03
DO - 10.1557/proc-1068-c07-03
M3 - Conference contribution
AN - SCOPUS:57649085404
SN - 9781605110387
T3 - Materials Research Society Symposium Proceedings
SP - 273
EP - 278
BT - Materials Research Society Symposium Proceedings - Advances in GaN, GaAs, SiC and Related Alloys on Silicon Substrates
PB - Materials Research Society
T2 - Advances in GaN, GaAs, SiC and Related Alloys on Silicon Substrates
Y2 - 24 March 2008 through 28 March 2008
ER -