2018 Fiscal Year Research-status Report
Selective growth of ultra-long grain in metal thin film for microelectronic application
| Project/Area Number |
18K14139
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| Research Institution | Shimane University |
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Principal Investigator |
Pham Hoang.Anh 島根大学, 学術研究院理工学系, 助教 (60750213)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Keywords | Thin film / Aluminum film / Selective grain growth / Laser annealing |
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| Outline of Annual Research Achievements |
In the FY2018, we have investigated the laser annealing process of the aluminum thin films, which were deposited on quartz substrates by thermal evaporation and sputtering deposition methods. The single-grain stripes were grown successfully on the thermal evaporated Al films within the laser power range of 250-330 mW. The width of the stripes increased with laser power to a maximum of 9.5 um. All of the single-grain crystals exhibited a positive pitch rotation relative to the scan direction. The rotation axis was [001]c at laser power <303 mW and it changed to [101]c at laser power > 315 mW. A wide area containing ultra-long crystal grains were obtained by a 2D scan.
In case of sputtering deposited Al film, the single-grain crystal could not be obtained. The reason is being investigated.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
The single-grain crystal has been grown on the thermally deposited Al film and the crystal quality depends on the laser annealing parameters. However, it was difficult to control the surface morphology and the thickness of the thermally deposited Al films. We have tried to deposited Al films with various thickness by using sputtering method.At present, single-grain crystals could not be grown on these Al films by laser annealing. The reason was likely because of appreciably higher reflectivity of the sputter-deposited films than that of the thermally deposited films. We have tried to vary the deposition condition to modify the films surface morphology, which would help to reduce the reflectivity to some extents. The effect of reflectivity on the laser annealing process is being studied.
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| Strategy for Future Research Activity |
For laser annealing of metal thin films the most problem is the high reflectivity of the films. The reflectivity depends on the nature of the metal, the film surface condition and the laser wave length. We are trying to control the film surface to reduce its reflectivity and study the effect of reflectivity reduction on the laser annealing process. If the problem could not solved by surface modification solely, we are going to change the laser diode with a wave length corresponding to the minimum reflectivity (810 nm for Al films). Beside Al films, we are going to investigate the laser annealing process of other metal films like Cu or Au, which have different physical properties like melting temperature, thermal conductivity than that of the Al films.
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