Oxynitride Deposition Kinetics in a SiH4 ‐  CO 2 ‐  NH 3 ‐  H 2 System

Abstract

Silicon oxynitride films false(SilOmNpfalse) have been deposited from SiH4‐CO2‐NH3‐H2 chemical system in a vertical, cold‐wall, multiple wafer, barrel‐type reactor. The kinetics of SiH4‐CO2 and SiH4‐NH3 reactions, both in H2 , have also been studied in the same reactor. All three reactions are first order with respect to SiH4 under conditions of “isolation technique.” Within the selected experimental range, the SiO2 deposition rate is independent of CO2 concentration, the Si3N4 deposition rate is independent of NH3 concentration, and the SilOmNp deposition rate is nearly independent of both CO2 and NH3 concentrations. The deposition rate of SiO2 , Si3N4 , and SilOmNp are not dependent on the H2 flow rate in the experimental range of 60–130 liters/min; thus all three reactions are chemical‐surface rate limited within the experimental range. The activation energies are 23.5, 24, and 29 kcal/g‐mole for SilOmNp , SiO2 , and Si3N4 , respectively. An anomalous effect of deposition temperature on silicon oxynitride refractive index (composition) was discovered and has been explained by the use of adsorption theory.

Physicochemical Properties of Chemical Vapor‐Deposited Silicon Oxynitride from a SiH4 ‐ CO 2 ‐ NH 3 ‐ H 2 System

“…The dependence of refractive index of SilOml~p films on NH3:CO2 ratio and the relationship of infrared absorption maxima with the refractive index have been previously established (9). Throughout this paper we have reported the physicochemical prop-er~ies in terms of the composition of SilOmNp films rather than their refractive indexes.…”

“…The details of the reactor used (10), the sample preparation, thickness measurement procedures, and typical deposition conditions have been described elsewhere (9). During this study, 1000-1500A films were used for the determination of most properties, except for stress measurements for which film thicknesses ranged between ~600-8000/k.…”

“…Silicon oxynitride (SilOmNp) films have been chemical vapor deposited from various chemical systems (1)(2)(3)(4)(5)(6), and the resulting properties have been reported (1)(2)(3)(4)(5)(6)(7)(8). It was shown earlier by Gaind et al (9) that the SiH4-CO2-NHs-H2 chemical system results in better process control, especially in forming Si3N4-rich oxynitride films; e.g., SilOmNp films with refractive index ~1.73 can be formed with NH3:CO2 ratio of ~6 at 900~C, whereas for other chemical systems, the NH3:oxidant ratio must be at least 50, usually ~5000 depending upon the oxidant (1)(2)(3)(4)(5).…”

Spectroscopic Investigation of the Synthesis of Thin Silicon Nitride Films on Silicon Single-Crystal Wafers via Ammonia-Assisted Pyrolysis of Organosilicon Polymers

“…Important applications of monolithic Si 3 N 4 involve the formation of films or coatings such as (i) membranes for X-ray masks used in synchrotron radiation lithography, , (ii) thin dielectric layers in metal−nitride−oxide−semiconductor (MNOS) and nonvolatile memory devices, (iii) inversion layers in solar cells, and (iv) the gate dielectric in bulk and thin film transistors (TFTs) .…”

Lippmann waveguide spectrometer with enhanced throughput and bandwidth for space and commercial applications

“…Thin films of silicon oxynitride (SiO m N p ) can be grown on silica using a variety of plasma deposition techniques [38][39][40][41][42]. One advantage of silicon oxynitride is that by changing the nitrogen/oxygen ratio in these films, their refractive index can be continuously tuned between the value of ∼ 1.45 for silicon dioxide (SiO 2 ) and ∼ 2.025 for silicon nitride (Si 3 N 4 ).…”