Microwave Plasma Process for SiCN:H Thin Films Synthesis with Composition Varying from SiC:H to SiN:H in H₂/N₂/Ar/Hexamethyldisilazane Gas Mixture

Abstract

SiCxNy:H thin films are obtained with the microwave plasma assisted chemical vapour deposition (MPACVD) method in the gas mixture H2/Ar/Hexamethyldisilazane. When very few amounts of nitrogen are added to the gas mixture, the film composition changes drastically from SiCx:H like films to SiNx:H like films, according to X‐rays Photoelectron Spectroscopy and Fourier Transform Infra‐Red Spectroscopy (FTIR) analysis. The refractive index (n) and Tauc's optical gap (Eg) are modified over a wide range of values (1.75 ≤ n ≤ 2.15 and 3.5 eV ≤ Eg ≤ 5 eV) with nitrogen addition to the feed gas leading to thin films optical constants close to those of SiC or Si3N4. Therefore, for the films obtained without nitrogen, SiC nanoparticles with a size of about 20 nm embedded in an amorphous SiCN:H matrix are synthesized, leading to nanocomposite films.

Controlling of Chemical Bonding Structure, Wettability, Optical Characteristics of SiCN:H (SiC:H) Films Produced by PECVD Using Tetramethylsilane and Ammonia Mixture

“…The deposition temperature dependences of optical bandgap are presented in Figure 4c. Optical bandgap for SiC and Si3N4 are 3.3 and 5.4 eV, correspondingly [54]. These values are in agreement with the data obtained in this work.…”

Review—Silicon Nitride and Silicon Nitride-Rich Thin Film Technologies: Trends in Deposition Techniques and Related Applications

“…45 It is also worth noting that the mechanical, optical, and electronic characteristics of SiN x and SiC y can be tightly controlled and systematically customized as a function of carbon (C) and nitrogen (N) concentrations. 46,47 This feature makes the SiN x C y phase a prime candidate for applications which require micro-modulation of the SiN x C y system to enable adjustable properties, such as those requiring tunable optical bandgaps and refractive indicies. In particular, SiN x C y films were grown with a tunable bandgap in the range of 2.3eV to 5.0eV, depending on their C and N content.…”

“…It is more proper to designate amorphous hydrogenated silicon nitride as a-SiN x :H. Not only does the amount of hydrogen incorporation affect physical, optical, and dielectric properties (in accordance with the Lorentz-Lorenz relationship) 50 in what is commonly referred to as SiN x :H, the nature of the Si-H versus N-H bonding also plays a significant role in tailoring the resulting film characteristics. [46][47][48][49] Another influencing factor is the Pauling relative electronegativity of the Si, N, and H elements (namely, Si:1.90; N:3.04; H:2.20). Si-N and N-H bonds have relatively high dipole moments, while Si-H bonds have relatively low dipole moments.…”

Plasma CVD of B–C–N thin films using triethylboron in argon–nitrogen plasma

“…53,54 This is similar to the literature on plasma CVD of diamond, 55 carbon nanotubes, 56 carbon nitride 57 and silicon (oxy)carbonitride. 58,59 Thus, the formation of volatile CN compounds could be a carbon sink explaining the high B/C ratios observed in our films compared to films deposited in Ar-TEB plasma. 16 The presence of O in the films is believed to be due to exposure to air post deposition.…”