Near-field etching on diamond mesa
Our paper was published in physica status solidi (a)
, Daisuke Takeuchi, Satoshi Koizumi, Kazuki Sato, Kohei Tsuzuki, Takayuki Iwasaki, Mutsuko Hatano, Toshiharu Makino, Masahiko Ogura, Hiromitsu Kato, Hideyo Okushi, and Satoshi Yamasaki, “Polarization-controlled dressed-photon–phonon etching of patterned diamond structures,” physica status solidi (a), Vol. 211, No. 10, October 2014, pp. 2339–2342, DOI: 10.1002/pssa.201431161
[Significance of this article]
Diamond has many excellent characteristics that make it an ideal material for high-performance power devices. For diamond-based devices such as diamond p-n junctions, the device must be constructed on a patterned substrate, but the final device should have smooth surfaces. Unfortunately, because of the hardness of diamond, ultra-flat surfaces are difficult to obtain. We developed a non-contact polishing method for realizing ultra-flat material surfaces: dressed-photon and phonon etching (DPP etching). In this study, we utilize DPP etching to produce ultra-flat surfaces on a three-dimensional diamond structure. By controlling the polarization of the incident light, we could obtain a smooth sidewall on the diamond mesa structure. We achieved the highest etching rates using an oblique incident angle of 45˚ with respect to the diamond substrate with polarization perpendicular to the corrugation on the mesa sidewall. We further confirmed the smoothness of the surface using selective deposition of n-layer diamond on the p-layer diamond mesa structure. Therefore, we believe DPP etching is an essential technique for realizing high-performance diamond devices.