1994 Fiscal Year Final Research Report Summary
Ultra-thin film Growth of the oxide ion conducting material on the porous substrate by thermal CVD
| Project/Area Number |
05555215
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
反応・分離工学
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
IMAISHI Nobuyuki KYUSHU UNIVERSITY,Institute of Advanced Material Study, Professor, 機能物質科学研究所, 教授 (60034394)
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| Co-Investigator(Kenkyū-buntansha) |
AKIYAMA Yasunobu KYUSHU UNIVERSITY,Institute of Advanced Material Study, Research Associate, 機能物質科学研究所, 助手 (10231846)
SATO Tsuneyuki KYUSHU UNIVERSITY,Institute of Advanced Material Study, Associate Professor, 機能物質科学研究所, 助教授 (80170760)
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| Project Period (FY) |
1993 – 1994
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| Keywords | CVD / Monte Carlo Method / Fuel Cell / YSZ / Step Coverage / Solid Electrolyte |
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| Research Abstract |
The followings are main accomplishment of this research, problems unsolved and research policies from now on.
1.We investigated from the view point of chemical reaction engineering how to model CVD film growth processes for ZrO_2, Y_2O_3 and YSZ (ZrO_2 stabilized by Y_2O_3) during a low pressure metal organic CVD (LPMOCVD) using DPM complex as source material, and determined the reaction rate constants as a function of the temperature by means of a semi-micro and a macro simulation.
2.We developed a three dimensional simple Monte Carlo simulation code to reproduce the film shape grown on and in a contact hole of arbitrary form. This code provides a quantitative discussion about the film growth on porous substrates.
3.Applying this code to different LPCVD systems (LiO_2, Nb_2O_3 and ZnO) , we also determined the value of each reactive sticking coefficient and activation energy from the simulated step coverage on a contact hole. The values of these sticking coefficients for the metal oxide are large at high temperature, and decrease dramatically with decreasing temperature.
4.Based on the above findings, we proposed a novel method to occlude a hole on a porous substrate with thin film by a modified thermal CVD.
・During the first stage, film growth is processed at higher temperature to reduce the hole opening by making large transversal bulges of grown film near the opening with less deposition depth in the hole. During the next stage, the operating temperature is reduced to occlude the opening quickly.
This method was confirmed to be effective by the deposition experiments.
5.At the present, we undertake the optimization of this process.
We intend to perfrom the choke tests to the sample fabricated by the above method using a permeability measurement apparatus, and in addition, measure the actual oxide ion conductance of the fabricated YSZ film.
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Research Products
(10 results)
