Silicon nitride

About: Silicon nitride is a research topic. Over the lifetime, 32678 publications have been published within this topic receiving 413599 citations. The topic is also known as: N₄Si₃.

Selective plasma etching of silicon nitride in presence of silicon or silicon oxides using mixture of (CH3F or CH2F2) and CF4 and O2

Abstract: A chemical downstream etching (CDE) that is selective to silicon nitrides (SiN) over silicon oxides (SiO) uses at least one of a CH 3 F/CF 4 /O 2 recipe and a CH 2 F 2 /CF 4 /O 2 recipe. Inflow rates are mapped for the respective components of the input recipe to find settings that provide both high nitride etch rates and high selectivity towards the SiN material. A pins-up scheme is used for simultaneously stripping away backside nitride with topside nitride.

Residual stress in low pressure chemical vapor deposition SiNx films deposited from silane and ammonia

Abstract: Varied SiNx films have been deposited by low pressure chemical vapor deposition from silane SiH4 and ammonia NH3 and the influences of the deposition parameters (temperature, total pressure and NH3/SiH4 gaseous ratio) on the film deposition rate, refractive index (assessed at a 830 nm wavelength), stoichiometry and thermomechanical stress are investigated and correlated. Low stress (≈600 MPa) Si3N4 films are obtained for the highest deposition temperature and the lowest total pressure but the gaseous ratio is shown to be the dominant parameter. According to the SiNx stoichiometry, silicon-rich silicon nitride and nitrogen-doped silicon (called NIDOS) depositions are obtained and compressive to tensile stresses are reported. A maximum in compressive stress is put into evidence for N/Si ratio roughly equal to 0.7 and is related to the cumulated effects of silicon nitridation and crystallization, characterizing the transition between nitrogen-doped silicon and silicon-rich silicon nitride. Finally, by consid...

Effective surface passivation of crystalline silicon using ultrathin Al2O3 films and Al2O3/SiNx stacks

Abstract: We measure surface recombination velocities (SRVs) below 10 cm/s on p-type crystalline silicon wafers passivated by atomic–layer–deposited (ALD) aluminium oxide (Al2O3) films of thickness ≥10 nm. For films thinner than 10 nm the SRV increases with decreasing Al2O3 thickness. For ultrathin Al2O3 layers of 3.6 nm we still attain a SRV < 22 cm/s on 1.5 Ω cm p-Si and an exceptionally low SRV of 1.8 cm/s on high-resistivity (200 Ω cm) p-Si. Ultrathin Al2O3 films are particularly relevant for the implementation into solar cells, as the deposition rate of the ALD process is extremely low compared to the frequently used plasma-enhanced chemical vapour deposition of silicon nitride (SiNx). Our experiments on silicon wafers passivated with stacks composed of ultrathin Al2O3 and SiNx show that a substantially improved thermal stability during high-temperature firing at 830 °C is obtained for the Al2O3/SiNx stacks compared to the single-layer Al2O3 passivation. Al2O3/SiNx stacks are hence ideally suited for the implementation into industrial-type silicon solar cells where the metal contacts are made by screen-printing and high-temperature firing of metal pastes. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Improved electrical transport in Al-doped zinc oxide by thermal treatment

Abstract: A postdeposition thermal treatment has been applied to sputtered Al-doped zinc oxide films and shown to strongly decrease the resistivity of the films. While high temperature annealing usually leads to deterioration of electrical transport properties, a silicon capping layer successfully prevented the degradation of carrier concentration during the annealing step. The effect of annealing time and temperature has been studied in detail. A mobility increase from values of around 40 cm2/Vs up to 67 cm2/Vs, resulting in a resistivity of 1.4×10−4 Ω cm has been obtained for annealing at temperatures of 650 °C. The high mobility increase is most likely obtained by reduced grain boundary scattering. Changes in carrier concentration in the films caused by the thermal treatment are the result of two competing processes. For short annealing procedures we observed an increase in carrier concentration that we attribute to hydrogen diffusing into the zinc oxide film from a silicon nitride barrier layer between the zinc...