N depth profiles in thin SiO2 grown or processed in N2O: The role of atomic oxygen

Abstract

Atomic oxygen, which can be liberated as an intermediate product in the decomposition of N2, is shown to be effective in removing N previously incorporated in SiO2 layers grown in N2O. This removal results in a N distribution that is sharply peaked at the Si–SiO2 interface for oxides grown in N2O by rapid thermal oxidation, but in a flat N distribution for N2O oxides grown in a furnace where the concentration of atomic oxygen is generally not substantial at the wafer position. This effect provides a means of tuning N profiles in a manner that may be useful for optimizing oxide quality.

High field stressing effects on the split N/sub 2/O grown thin gate dielectric by rapid thermal processing

“…The split N2O dielectric also probably has a nitrogen profile at the gate/oxide interface in addition to Si/SiO 2 interface. Carr et al [17] have recently reported the redistribution N (nitrogen) profile at the Si/SiO 2 interface of N 2 O grown oxide upon reoxidation in O 2 ambient. We feel accordingly, the N profile due to the first N2O oxidation in the split N2O cycle, was redistributed during RTO in O 2 and provided a N profile at the gate/oxide interface.…”

Thermal growth of silicon oxynitride films on Si: A reaction-diffusion approach

“…As atomic N is very reactive, it is responsible for the high N concentrations in the near-surface region. For longer times, however, atomic oxygen generated from NO dissociation at the surface, scavenges the incorporated nitrogen 13,16 and a pure oxide film is formed on top of a reaction region composed of oxynitrides and nonfully reacted Si, localized at the near-interface region. As this front moves deeper into the sample, atomic nitrogen formed at the surface no longer contributes to N incorporation due to its fast recombination in near-surface regions.…”

“…k 4 and k 8 govern the recombination of the atomic diffusive species producing O 2 or N 2 . Finally, k 5 models the removal of N by diffusive O, 13 a key ingredient to model the propagating nitrogen front that follows the oxynitride/Si interface. We also remark that fractional stoichiometric coefficients imply a mean-field approximation, since they describe the result of all possible reactions that transform the reactant species into the product ones.…”

Medium Energy Ion Scattering Studies of Silicon Oxidation and Oxynitridation

“…At least two different models for the mechanism of N removal have been put forward: Carr et. Al [53] proposed that atomic oxygen causes nitrogen removal, whereas Saks et. al [42] argued that NO is responsible.…”

“…It has recently been shown that nitrogen removal from a nitrided film occurs during silicon oxynitridation in N z O. [42,53] The high temperature gas phase chemistry of NzO is complex, [40] and both NO and (atomic)°are produced. At least two different models for the mechanism of N removal have been put forward: Carr et.…”