Adsorbed states of cyclopentene, cyclohexene, and 1,4-cyclohexadiene on Si(1 0 0)(2 1): towards the fabrication of novel organic ®lms/Si hybrid structures

In order to fabricate atomically controlled organic materials on Si surfaces, the electronic states of unsaturated cyclic hydrocarbons chemisorbed on Si(1 0 0)(2 1) surfaces were investigated by synchrotron radiation ultraviolet photoelectron spectroscopy (UPS) as a fundamental study. For cyclopentene and cyclohexene, the C=C bond interacts with the Si dimer, resulting in the formation of di-s Si±C bonds. In the case of 1,4-cyclohexadiene, on the other hand, one of two C=C bonds reacts with the Si dimer and another C=C bond remains unreacted with the Si surface. This intact C=C bond may introduce the possibility of subsequent functionalization of the organic ®lm, and for the fabrication of atomically controlled and highly functional organic ®lm/Si devices. # 2001 Elsevier Science B.V. All rights reserved.