| AVS 65th International Symposium & Exhibition | |
| Nanometer-scale Science and Technology Division | Thursday Sessions |
| Session NS-ThP |
| Session: | Nanometer-scale Science and Technology Division Poster Session |
| Presenter: | Daisuke Ohori, Tohoku University, Japan |
| Authors: | D. Ohori, Tohoku University, Japan S. Samukawa, Tohoku University, Japan |
| Correspondent: | Click to Email |
Si NP structures have a great potential for thermoelectric and cooling device applications. However, current fabrication techniques are too complicated. Furthermore, it is difficult to modulate the properties of the NP by those methods. In this work, we proposed an excellent method to fabricate the NP structure. The water-repellent characteristic of the fabricated Si nanopillar (NP) structure was investigated, and we try clearing the contact angle of density dependence for Si-NPs structure.
12 nm in diameter Si-NPs structure with various density ranging from 1.6 x1011/cm2 (low-density) to 7.1 x1011 /cm2 (high-density) were fabricated. These samples were fabricated with a unique technique of a bio-template mask and a neutral beam etching. The bio-template mask is a protein shell with an iron oxide core, called ferritin. The density of the Si-NPs can be easily adjusted by modulating the distance between ferritins. The ferritin arrangement was carefully adjusted by controlling the length of the decorated poly( ethylene - glycol ) (PEG); a spin-coating was carried out for this arrangement process . Thereafter, an etching process was done by a neutral beam etching (NBE) technique . The NBE process could realize the damage - less etching on the surface/interface utilizing a bottom electrode that neutralize s ion in pulsed-plasma. The NBE process could realize the damage-less etching on the surface/interface utilizing a bottom electrode that neutralizes ion in pulsed-plasma. NBE can also minimize a UV irradiation to the sample which is beneficial to reduce the occuring lattice defects.
We measured the contact angle for all samples under the conditions that were the as-etch and removed SiO2 layer. For the as-etched condition, the contact angle of the low-density and high-density samples were 4.6 and 9.1 deg, respectively. Meanwhile, the contact angle of Si wafer with a SiO2 layer was 48.1 deg. After the removal of the SiO2 layer, the contact angle of the low-density, high-density samples, and Si wafer became 112, 104, 89.8 deg, respectively. T his indicates that the removal of the SiO2 layer also helps to improve the contact angle, especially the Si-NPs samples.