Takeru Suto

Highly oriented diamond (111) films synthesized by pulse bias-enhanced nucleation and epitaxial grain selection on a 3C-SiC/Si (111) substrate

We report the synthesis of highly oriented diamond (HOD) (111) films on 3C-SiC/Si (111) substrates. Bias-enhanced nucleation (BEN) is a key process for the heteroepitaxial growth of HOD films. Conventional long nucleation periods have been found to lead to a polycrystalline diamond film on the 3C-SiC (111) surface. Here, we propose a method that combines brief BEN (<30 s), called pulse BEN, and epitaxial grain selection by oxidative etching. Smaller diamond nuclei with a higher spatial density on the substrate were formed by pulse BEN with a pulse duration of <30 s. We found that precisely controlling the pulse duration is important for obtaining a nucleation density that is sufficiently high to obtain the HOD films. By adding oxygen gas to the subsequent growth process, non-epitaxial nuclei were removed and epitaxial diamond grains selectively remained. There was no notable difference in the relative growth rate of [111] to [100] with and without oxygen, and the orientation improvement was observed on bo...

Heteroepitaxial Growth of Diamond on 3C-SiC/Si Substrates by Antenna-Edge Microwave Plasma CVD

1 Department of Physical Electronics, Tokyo Institute of Technology. Ookayama, Meguro, Tokyo 152-8552, Japan Phone : +81-03-3726-3999 Email : suto.t.ac@m.titech.ac.jp 2 JST-CREST. Chiyoda, Tokyo 102-0076, Japan JST-ALCA. Chiyoda, Tokyo 102-0076, Japan Department of Electrical Engineering, University of South Florida. Tampa, Florida 33620 Abstract Large-area diamond films are in demand as semiconductor materials for future devices and sensors. Diamond seed crystals were nucleated on both (100) and (111) 3C-SiC/Si substrates for the growth of heteroepitaxial diamond films by a unique antenna-edge microwave plasma chemical vapor deposition system. In this work, we found that lower voltage improved the diamond nuclei orientation resulting in highly epitaxial diamond nucleation on Si substrates via (100) and (111)3CSiC buffer layers.