Silicon nitride antireflective coating

Antireflection coatings are used over the silicon surface which, without the coating, reflects ca 35% of incident sunlight. A typical coating consists of a single layer of a transparent dielectric material with a refractive index of ca 2, which is between the index of siUcon and ait or cover material. Materials such as titanium dioxide, tantalum pentoxide, Ta20, or siUcon nitride, Si N, ca 0.08-p.m thick are common. The coating and a physically textured... 

Silicon Nitride. Silicon nitride produced by high-temperature (>700 °C) CVD is a dense, stable, adherent dielectric that is useful as a passivation or protective coating, interlevel metal dielectric layer, and antireflection coating in solar cells and photodetectors. However, these applications often demand low deposition temperatures (<400 °C) so that low-melting-point substrates or films (e.g., Al or polymers) can be coated. Therefore, considerable effort has been expended to form high-quality silicon nitride films by PECVD. 

Inorganic antireflection coatings are typically deposited by sputtering, and as opposed to organic antireflection coatings, may in some cases be left in the finished device. Typical inorganic antireflection coatings include silicon oxynitride, amorphous silicon, tantalum silicide, titanium nitride, etc. 

To demonstrate the existence of the SPR effect, which was shown to redshift with an increase in NP size, surface-enhanced Raman scattering (SERS) measurements using rhodamine-6G were performed. The study emphasized the efficiency of the resulting antireflection coating, which was fabricated for solar cell applications and was made of black silicon, a silicon nitride passivated layer together with a coating of Ag NPs. 

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