Simulation of the oxidation pathway on Si(100) using high‐resolution EELS

Abstract

We compute high-resolution electron energy loss spectra (HREELS) of possible structural motifs that form during the dynamic oxidation process on Si(100), including the important metastable precursor silanone and an adjacent-dimer bridge (ADB) structure that may seed oxide formation. Spectroscopic fingerprints of single site, silanone, and ''seed'' structures are identified and related to changes in the surface bandstructure of the clean surface. Incorporation of oxygen into the silicon lattice through adsorption and dissociation of water is also examined. Results are compared to available HREELS spectra and surface optical data, which are closely related. Our simulations confirm that HREELS offers complementary evidence to surface optical spectroscopy, and show that its high sensitivity allows it to distinguish between energetically and structurally similar oxidation models.

Quantum ESPRESSO: One Further Step toward the Exascale

“…Along the line shape, single spectral transitions computed with the Sternheimer method , are shown, showing consistency between the two approaches. Noticeably, the spectral line shape is in fair agreement with the overall EELS spectrum obtained in more accurate and extensive studies. ,, …”

“…In Figure we show the phonon dispersions of the 100 surface of silicon with c(4 × 2) reconstruction (reported among the most stable ones by a number of previous studies , ), simulated using a base centered orthorhombic primitive cell ( a = 2 b ). , The first Brillouin Zone of the slab has been sampled with a 8 × 8 × 1 uniform Monkhorst–Pack mesh (21 total symmetry inequivalent k -points), whereas two different depths have been considered in the third direction, one with 16 layers of silicon atoms (referred to as Si(100)-16L hereafter, with 64 atoms per cell) and one with 32 layers (Si(100)-32L, 128 atoms per cell).…”

“…Noticeably, the spectral line shape is in fair agreement with the overall EELS spectrum obtained in more accurate and extensive studies. 48,49,54 A turboEELS calculation with Lanczos scheme involves two main computationally intensive parts, namely, a non-SCF step, to compute wave functions and band energies at (k + q)points, and a following Lanczos chains step. Images are not available here, and the calculation can be distributed by using pools and R&G parallelism only.…”

“…Noticeably, the spectral line shape is in fair agreement with the overall EELS spectrum obtained in more accurate and extensive studies. 48 , 49 , 54 …”

Preparation, characterization, and protein-resistance of films derived from a series of α-oligo(ethylene glycol)-ω-alkenes on H–Si(111) surfaces

“…71 Moreover, the resultant oxide defects accelerate the oxidation of adjacent silicon. 102 Therefore, decreasing oxygen level in the system is crucial to achieve a high packing density and low oxide defects. On the other hand, longer OEG chains generally increase protein resistance, but are expected to decrease packing density and stability of the lms.…”