Missing dimer defects investigated by adsorption of nitric oxide (NO) on silicon (100) 2 × 1

Abstract

This paper describes a study concerning the interaction of nitric oxide (NO) with the clean Si(100)2 x 1 surface in ultra-high vacuum at room temperature. Differential reflectometry (DR) in the photon energy range of 2.4-4.4 eV. Auger electron spectroscopy (AES) and low energy electron diffraction (LEED) have been used to investigate the chemisorption of NO on Si(100)2 x 1. With this combination of techniques it is possible to make an analysis of the geometric and electronic structure and chemical composition of the surface layer. The aim of the present study was to explain the experimental results of the adsorption of NO on the clean Si(100)2 x 1 at 300 K. Analysing the electronic and geometric structure of a simplified stepped 2 x 1 reconstructed Si(100) surface and of the NO molecule in combination with the use of Woodward-Hoffmann rules (WHR) we were able to model a surface defect specific adsorption mechanism. Surface defects such as missing dimer defects seem to play an important role in the adsorption mechanism of NO on the silicon surface. The experimental results are consistent w:,th this developed model. We also suggest a relation between the missing dimer defects and the number of steps on the silicon surface.

Decomposition of N2O on the Si(100)2×1 and Si(111)7×7 surfaces: Determination of the density of broken bonds

“…Recent STM studies have confirmed the basic dimer model. It is also well established that the real Si(100)2 x 1 surface may have a defect density ranging from 5 to 25% [13,19,21], most of which is due to missing dimers [19]. In ref.…”

The adsorption of nitric oxide on a silicon (100) 2 × 1 surface studied with Auger electron spectroscopy

“…[1][2][3][5][6][7][8][9]. The adsorption behaviour of these molecules on Si(100) is investigated with considerably less intensity [2, 4,10]. To our knowledge only two AES investigations of NO adsorbed on the Si(100) surface were published before: He and Smith [2] (T > 1200 K), and Boszo and Avouris [4] (T--90 K).…”

“…In ref. [10] it has been argued that NO is predominantly molecularly adsorbed at missing dimer defects.…”

“…From the Si L2.3VV Auger spectra site specific chemical information can be obtained [11,12]. The gas-solid reactions were studied in ultrahigh vacuum (UHV) at a sample temperature of 330 and 550 K. The experimental setup, surface cleaning, and gas handling are described in detail elsewhere [9,10]. The pressure during the exposures is 2.5 × 10 -6 Torr in all our experiments.…”

The adsorption behaviour of O2 on the clean Si(110) surface in the early stage

“…It has been shown here for the first time that the initial sticking probability of molecular oxygen on this surface is almost 1. A careful investigation of the low exposure region should always be an integral part of gas adsorption studies on clean silicon surfaces: preliminary results of the room temperature adsorption of O2 on Si(lll)7 x 7, studied by the contact potential difference method [12] and NO on Si(100)2 • 1, monitored by AES-LEED and DR [13] both show a distinct adsorption behaviour between 0 and 0.2 L 02 (NO) exposure.…”