Silicon Oxynitride Films from the NO-NH[sub 3]-SiH[sub 4] Reaction

Abstract

Silicon oxynitride films from the NO‐NH3‐SiH4 reaction in nitrogen at 850°C are clear, adherent, amorphous dielectrics whose composition may be varied over the entire range between SiO2 and Si3N4 by controlling the NH3/NO ratio employed. The refractive index is a convenient and accurate measure of the composition. Over much of the nitrogen‐rich range, the Si content is about 2% ower than stoichiometric, and the hypothesis is made that one nitrogen in three is bonded to only two other skeletal atoms instead of three, and that some of these nitrogens bear bonded hydrogen. The N‒H groups are believed to play a role similar to that of O‒H in silicas. Compositions near Si2ON2 are highly resistant to ionizing radiation under bias, and are excellent Na+ barriers at 300°C and 106 V/cm. However, they are not better barriers to Na+ thermal diffusion at 600°C than SiO2 . With appropriate pre‐ and post‐deposition chemical treatments, oxynitride films give low Si surface charge and small nonionicshifts in flatband voltage with bias‐temperature aging. Other properties investigated for various compositions include etch rate, i.r. spectrum, film stress,and cathodoluminescence spectra. Films from the NO‐SiH4 and NO‐NH3‐SiH4 processes are compared.

Nitride Ceramics

“…If nitrogen existed as precipitated Si 3 N 4 the position of the Si-O-Si peak would not be expected to change. Rand and Roberts (1973) also observed a similar shift of the Si-O-Si stretching vibration to lower wavelengths in nitrided silicon thin films. XPS studies by Brow and Pantano also revealed that nitrogen is usually present in more than one form, and they proposed that non-bridging nitrogen ions may also be present, similar to the following:…”

Characterization of silicon oxynitride thin films by infrared reflection absorption spectroscopy

“…Films obtained from low pressure chemical vapor deposition ͑LPCVD͒ have homogenous composition throughout the layer but the LPCVD process requires a high substrate temperature ͑800°C͒. 4,5 Microelectronic industries are actually looking for a lower temperature deposition process. The passivation must not modify the dopants profile and not induce new crystalline defects.…”

Critical evaluation of the state of the art of the analysis of light elements in thin films demonstrated using the examples of SiOXNY and AlOXNY films (IUPAC Technical Report)

“…The assignment of vibrations to wave numbers in several publications is summarized in Table 1 together with the references. Regardless of the interpretation of the structural background of the main IR absorption band of SiO X N Y films, many authors tried to find correlations between the peak position and the composition of the oxynitride films [10,14,23,[53][54][55], which by most authors is supposed to be rectilinear, between the peak position and the deposition parameters [27,56,57], or between the peak position and the physical properties [6,25,52,58,59]. In most publications, such a correlation is indicated, but not verified due to the low sample number or the lack in cross-checking.…”

“…With this background, NRA was the main tool used in this publication, because of the high sensitivity and selectivity that could be achieved by this method. The total amounts of 2 H (D), 14 N, 15 N, 16 O, and 18 O were determined using the cross-section "plateaus" of the following reactions: 2 H( 3 He,p) 4 15 N, were also mentioned. The total amount of 1 H was S. DREER AND P. WILHARTITZ detected by the resonance given above or by ERDA.…”