Effects of bombardment on optical properties during the deposition of silicon nitride by reactive ion-beam sputtering

Abstract

Thin silicon nitride (Si(1_x)N(x)) films were synthesized without substrate heating by means of reactive argon-ion sputtering of either silicon or a silicon nitride target in the 1000-1500-eV energy range at a nitrogen partial pressure of 1.3 × 10(-2) Pa and with simultaneous nitrogen ion-assisted bombardment in the 300-500-eV low energy range. The extinction coefficient and refractive index of the films were directly dependent on the N(+) ion-to-atom arrival ratio, assisted ion energy, film growth rate, and indicated a correlation with film stoichiometry and disorder. Si(3)N(4) films were obtained for N(+) ion/Si atom arrival ratios from 0.6 to 1.7 and for different Si:N atom arrival rates and had a refractive index as high as 2.04 (633 nm) and a low hydrogen content as indicated by IR spectra.

Tunable Optical Properties of SiNxThin Films by OES Monitoring in a Reactive RF Magnetron Plasma

“…In the high frequency region (2000–6000 cm −1 ), the large periodicity observed in all spectra is due to the film thickness . All samples exhibit a strong broad absorption band centered at about 860 cm −1 , which corresponds to the Si–N asymmetric stretching vibration mode . This assignment is supported by the presence of a smaller absorption band at ∼470 cm −1 which corresponds to the Si–N breathing mode .…”

“…[30] All samples exhibit a strong broad absorption band centered at about 860 cm À1 , which corresponds to the Si-N asymmetric stretching vibration mode. [16,31,32] This assignment is supported by the presence of a smaller absorption band at $470 cm À1 which corresponds to the Si-N breathing mode. [33,34] However, there is a tendency of shifting the Si-N vibration maximum toward higher frequencies as increasing F R up to 30%.…”

“…One of the common issues when using CVD for deposition of SiN x is the need to use heated substrates at relatively high temperatures (700–900 °C), being known that at lower temperatures the hydrogenated nitride films have degraded optical properties . One of the best alternative solutions to overcome this problem is the use of reactive magnetron sputtering instead, permitting to obtain SiN x films with negligible H and O content at low substrate temperatures (200–400 °C) …”

“…[15] One of the common issues when using CVD for deposition of SiN x is the need to use heated substrates at relatively high temperatures (700-900 8C), being known that at lower temperatures the hydrogenated nitride films have degraded optical properties. [16] One of the best alternative solutions to overcome this problem is the use of reactive magnetron sputtering instead, permitting to obtain SiN x films with negligible H and O content at low substrate temperatures (200-400 8C). [17] This work is focused on the description of the reactive process of sputtering Si in a reactive Ar/N 2 gas mixture with a magnetron configuration, being motivated by the need to control the deposition parameters in order to obtain tunable optical properties of SiN x by a reproducible deposition process.…”

Electrical properties of ion beam sputtered and ion assisted SiO2, SiOXNY, and SiNX films on silicon

“…11 A nominal base pressure of 1.0ϫ10 Ϫ4 Pa was attained prior to system operation and a liquid nitrogen trap, located in the vicinity of the substrate holder, maintained the H 2 O partial pressure below 2ϫ10 Ϫ5 Pa prior to sputtering. Full details of this deposition system have been described previously elsewhere.…”