External infrared reflection absorption spectroscopy of methanol on an epitaxially grown Si(100)2 × 1 surface

Reaction of methanol with porous silicon

“…Figure 6, all decrease uniformly to zero with only slight changes in frequency over the temperature range 500 K to 700 K. This argues that the OCH 3 surface species on porous silicon is stable only up to -500 K. This is consistent with data derived from EELS and IRAS studies on Si(! 00) in which the OCH 3 surface species began to decompose at 500 K [21]. The initial v (Si-H) mode (2091 cm '1) decreases in intensity starting at -550 K, F;gure 5(B), in accordance with other studies P36] of hydrogen on porous silicon.…”

“…The primary focus has been to determine whether H 2 0 adsorbs by a dissociative or a nondissociative pathway and to determine the thermal decomposition properties of the resulting Si-H and Si-OH surface species . The interaction of organic molecules, such as ethanol and methanol with Si(100), is less well studied [20][21][22]. Work by Crowell and co-workers [22] on ethanol decomposition on Si(100) appears to be one of the first few detailed studies to be completed for Si (100).…”

Theoretical modelling of surface phonons

“…The calculated symmetric and asymmetric stretch CH 3 modes for both models are in agreement with Raman measurements [29]. Similarly, the theoretical estimates of the Si-H (stretch), CH (deformation), CH (rocking) and C-O (stretch) for both models are in agreement with the analysis of infra-red spectroscopic measurements [31].…”

“…Investigations using angle-resolved electron energy loss spectroscopy in reflection mode suggest [30] suggest that the methoxy group (-OCH 3 ) bonds to silicon dangling bond via the oxygen atom. Investigations using Fourier transform reflection-absorption infrared spectroscopy have led to the conclusion [31] that the adsorption of methanol occurs as a dissociative process, with the formation of Si-OCH 3 and Si-H bonds. Further evidence for the dissociative adsorption of methanol is provided from investigations using synchrotron radiation-excited photoemission and photon-stimulated desorption spectroscopies [32], and from Auger electron spectroscopy (AES), low-energy electron diffraction (LEED) and thermal desorption spectroscopy (TDS) [33].…”

In Situ Detection of Surface SiHn in Synchrotron-Radiation-Induced Chemical Vapor Deposition of a-Si on an SiO2 Substrate

“…Despite these characteristics, the application of IRAS to semiconductor process monitoring is severely limited, because when the adsorbate is on a semiconductor or an insulator surface, its sensitivity is low and the band shape is significantly distorted depending on the incident angle, the wavelength, and the anomalous dispersion of the adsorbate. To overcome these disadvantages, several authors have proposed the use of a buried-metal-layer (BML) substrate (Bermudez & Prokes, 1991;Ehrley, Butz & Mantl, 1991), which has a metal layer buried under a thin film of semiconductor or insulator material (buffer layer) that is thinner than the wavelength of the infrared radiation. Such a substrate exhibits the characteristics of the buffer layer for surface chemical reactions, while it behaves as a metal for the infrared radiation.…”