In order to effectively develop the atomic layer deposition (ALD) reactor and process, having huge potentials and applications in the advanced technology fields, a practical design method of the gas conditions for the...In order to effectively develop the atomic layer deposition (ALD) reactor and process, having huge potentials and applications in the advanced technology fields, a practical design method of the gas conditions for the ALD was studied using computational fluid dynamics (CFD). The design method consisting of the following four steps was studied. 1) At a low gas pressure producing no gas recirculation, the maximum difference in the gas phase temperature from the sample stage temperature, ΔT, was obtained at various chamber wall temperatures. 2) The ΔT value was studied at various gas pressures producing the gas recirculation. 3) For determining the applicable process conditions, contour diagrams of the temperature uniformity were obtained utilizing the temperature uniformity equations consisting of various process parameters. 4) The relationships of the maximum gas residence time with the gas flow rate and the gas pressure were obtained. The process in this study is expected to be practical for designing the thermal and gas flow conditions for achieving a fast ALD.展开更多
This study investigated the performance of magnetic fields in reducing gas back-mixing in bubbling fluidized beds with Geldart-B magnetizable particles.The Peclet number(Pe)and axial dispersion coefficient(Da,g)were d...This study investigated the performance of magnetic fields in reducing gas back-mixing in bubbling fluidized beds with Geldart-B magnetizable particles.The Peclet number(Pe)and axial dispersion coefficient(Da,g)were determined using the one-dimensional dispersion model.A weak magnetic field reduced gas back-mixing to a certain extent,while a moderate field resulted in minimal decrease.The performance of a strong magnetic field varied significantly depending on the operation mode.Under the magnetization-FIRST operation mode,gas back-mixing was significantly reduced.The corresponding Pe and Da,g were calculated as∼76 and∼3.6×10^(−4) m^(2)/s,indicating that the gas flow approached the ideal plug-flow manner.However,when the magnetization-LAST operation mode was used,the strong magnetic field failed to mitigate gas back-mixing.Therefore,the performance of magnetic fields in reducing gas back-mixing depended not only on their intensity but also on their application sequence to the gas flow field.展开更多
文摘In order to effectively develop the atomic layer deposition (ALD) reactor and process, having huge potentials and applications in the advanced technology fields, a practical design method of the gas conditions for the ALD was studied using computational fluid dynamics (CFD). The design method consisting of the following four steps was studied. 1) At a low gas pressure producing no gas recirculation, the maximum difference in the gas phase temperature from the sample stage temperature, ΔT, was obtained at various chamber wall temperatures. 2) The ΔT value was studied at various gas pressures producing the gas recirculation. 3) For determining the applicable process conditions, contour diagrams of the temperature uniformity were obtained utilizing the temperature uniformity equations consisting of various process parameters. 4) The relationships of the maximum gas residence time with the gas flow rate and the gas pressure were obtained. The process in this study is expected to be practical for designing the thermal and gas flow conditions for achieving a fast ALD.
基金supported by Shandong Provincial Natural Science Foundation (grant No.ZR2023MB038)Youth Innovation Team Program of Shandong Higher Education Institution (grant No.2022KJ156).
文摘This study investigated the performance of magnetic fields in reducing gas back-mixing in bubbling fluidized beds with Geldart-B magnetizable particles.The Peclet number(Pe)and axial dispersion coefficient(Da,g)were determined using the one-dimensional dispersion model.A weak magnetic field reduced gas back-mixing to a certain extent,while a moderate field resulted in minimal decrease.The performance of a strong magnetic field varied significantly depending on the operation mode.Under the magnetization-FIRST operation mode,gas back-mixing was significantly reduced.The corresponding Pe and Da,g were calculated as∼76 and∼3.6×10^(−4) m^(2)/s,indicating that the gas flow approached the ideal plug-flow manner.However,when the magnetization-LAST operation mode was used,the strong magnetic field failed to mitigate gas back-mixing.Therefore,the performance of magnetic fields in reducing gas back-mixing depended not only on their intensity but also on their application sequence to the gas flow field.
