Silicon nitride films (p-SiN) with different high stresses were formed by changing the monosilane-to-ammonia source gas ratio, RF power, and deposition temperature in a conventional plasma-enhanced chemical vapor deposition (PECVD). PECVD was used to deposit p-SiN films with high-stresses because it can flexibly change the stress of the film to be formed from tensile to compressive direction. The formed films were analyzed by Fourier transform-infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), nanoindentation, and positron-beam annihilation to obtain data on local bonding structure, mechanical properties and the behavior of vacancies in the p-SiN films. In this study, to clarify the local bonding structure of high stress SiN films, we investigated p-SiN films with and without ultraviolet (UV) curing that is effective in tensile stress. It has been confirmed that total hydrogen (Si{H þ N{H) concentration decreases with increasing film stress of p-SiN films. It has been found that UV curing promotes Si-N-Si crosslinking due to dehydrogenization, leading to the formation of a stoichiometric silicon nitride, Si 3 N 4 , network structure, and the vacancies in the p-SiN films shrink during UV curing. Finally, we proposed a structural model for the local bonding arrangement in p-SiN films with UV curing.
We have investigated the characteristics of silicon oxide films deposited by plasma-enhanced atomic layer deposition (PEALD) and plasma-enhanced chemical vapor deposition (PECVD) as offset spacer films of high-k/metal gate stacks. From the results of bonding structure analysis, the silicon oxide film deposited by PEALD has been found to be composed of a Si–O bond network of the stoichiometric silicon oxide film. On the other hand, the silicon oxide film deposited by PECVD is considered to contain suboxide bond structures. From the results of physical and mechanical evaluations, the silicon oxide film deposited by PEALD exhibits a lower wet etch rate, a higher film density, a lower dielectric constant, a smaller amount of water in the film, and a higher elastic modulus than that deposited by PECVD. PEALD showed excellent thickness controllability. From these results, the silicon oxide film deposited by PEALD has higher quality and is more suitable for use as an offset spacer than that deposited by PECVD. X-ray photoelectron spectroscopy showed that the surface oxidation of a titanium nitride film, which is used as a metal gate electrode, during PEALD can be suppressed by using a lower PEALD temperature. Finally, we have demonstrated that the drain current of a high-k/metal gate transistor with a silicon oxide offset spacer deposited by PEALD is markedly increased, compared with that with a high-temperature-deposited silicon oxide offset spacer.
Please note that terms and conditions apply.The quantum nonthermal effect of a nonstationary Kerr-Newman black hole and the average range of the effective particles
A series of new single-step methods and their corresponding algorithms with automatic step size adjustment for model equations of fiber Raman amplifiers are proposed and compared in this paper. On the basis of the Newton-Raphson method, multiple shooting algorithms for the two-point boundary value problems involved in solving Raman amplifier propagation equations are constructed. A verified example shows that, compared with the traditional Runge-Kutta methods, the proposed methods can increase the accuracy by more than two orders of magnitude under the same conditions. The simulations for Raman amplifier propagation equations demonstrate that our methods can increase the computing speed by more than 5 times, extend the step size significantly, and improve the stability in comparison with the Dormand-Prince method. The numerical results show that the combination of the multiple shooting algorithms and the proposed methods has the capacity to rapidly and effectively solve the model equations of multipump Raman amplifiers under various conditions such as co-, counter-and bi-directionally pumped schemes, as well as dual-order pumped schemes.
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