Oxidation of Si(100) in nitric oxide at low pressures: An x-ray photoelectron spectroscopy study

Abstract

Ultrathin (8–23 Å) silicon oxynitrides have been studied in the temperature range of 560–1000 °C in 4 Torr of NO using a sequential growth and analysis approach. X-ray photoelectron spectroscopy indicates that with increasing growth temperature and time, a bonding structure with predominantly Si–O rather than Si–N formation is favored. Simultaneously, the average volume fraction of N (N/N+O) in the dielectric decreases, as a consequence of which the N1s binding energy increases by 0.2–0.8 eV from its initial value of 397.8 eV at a thickness of 8 Å. A correlation of the electrical characteristics of NO grown oxynitrides with nitrogen content and location has been made. A film growth mechanism that takes into account the removal of previously incorporated N by NO is also proposed.

Nitrogen Incorporation atSi(001)−SiO2Interfaces: Relation between N1sCore-Level Shi

“…X-ray photoemission spectroscopy (XPS) on N 1s core levels has widely been applied to silicon nitrided oxides [2,[5][6][7][8][9][10]. This technique is sensitive to the concentration of N atoms and can provide distribution profiles when resolved as a function of take-off angle or used in conjunction with chemical etching.…”

Optimization of bimodal nitrogen concentration profiles in silicon oxynitrides

“…23. Further, an oxidation process following an initial oxynitridation step in either N 2 O [9][10][11][12]16 or NO [13][14][15] has never been reported to result in a bimodal N concentration profile in the literature, too. It is interesting to note that Figs.…”

“…Since N 2 O and NO do not result in hydrogen incorporation into the dielectric film, they are preferred to NH 3 for the fabrication of oxynitrides. 3 Growth in N 2 O 9-12,16 and NO [13][14][15] has been generally seen to incorporate N near the oxynitride/Si interface, whereas reoxidation in O 2 , 12,16,18 after oxynitridation, has been found to shift the interface deeper into the substrate, thus taking the N concentration profile relatively away from the interface. A bimodal profile of N in silicon oxynitride films might, therefore, be obtained via the following steps: [17][18][19][20] This study aims at identifying the growth sequence͑s͒ and processing conditions necessary to obtain a bimodal N concentration profile in silicon oxynitrides.…”

Core-Level Shifts in Si(001)-SiO2 Systems: The Value of First-Principle Investigations

“…In this section, we charater-ize these N atoms by establishing a correspondence between their bonding environment and the N Is shifts measured in photoemission experiments. The experimental N Is spectra show a broad principal peak (FWHM="" 1.5 eV), approximately at the same energy as in bulk Si 3 N 4 , which appears to shift to larger binding energies for samples of increasing oxide thickness [24,26,27]. A deeper analysis of the shape of this peak, has led to the recognition of two components [28,29].…”