Mitsuhiro Nishio

Reactive Ion Etching of Zinc Oxide Using Methane and Hydrogen

The reactive ion etching characteristics of ZnO have been investigated as functions of CH4/H2 gas composition, total gas pressure, and radio frequency (rf) plasma power. It was found that the etching rate of ZnO strongly depends on gas composition and gas pressure, suggesting that the etching of ZnO largely involves a process in which a volatile metalorganic zinc compound is formed. The etching rate of ZnO increased linearly with rf plasma power owing to its high bond-breaking efficiency, dc bias, and the degree of sputter desorption of etch products.

Design of Beamline BL9 at Saga Light Source

Saga Light Source (SAGA‐LS), which has been constructed at Tosu city in Saga prefecture, is a compact synchrotron light source with storage electron energy of 1.4 GeV. A new beamline for the development of advanced materials and processing has been designed, and is now under construction at BL9 of SAGA‐LS. This beamline is one of the three bending magnet beamlines (BL9, BL12, and BL15) constructed by Saga Prefectural Government. In this paper, we describe the design and the expected optical performance of the beamline BL9 at SAGA‐LS.

Recovery from Dry Etching Damage in ZnTe by Thermal Annealing

Thermal annealing has been applied to the recovery from dry-etch-induced damage on ZnTe surfaces. We have demonstrated that the optical property of dry-etched ZnTe can be fully recovered by thermal annealing at temperatures above 300°C for 10 min, indicating that thermal annealing can eliminate the damage on ZnTe induced during reactive ion etching.

Synchrotron Radiation‐Excited Etching of ZnTe

Synchrotron radiation‐excited etching of compound semiconductor, ZnTe, was investigated using the SF6 and Ar gases. In the case of SF6 gas, the ZnTe was not etched but thin film of a fluorine containing material, e.g. ZnF2, was deposited on the surface of ZnTe. On the other hand, ZnTe was etched by using Ar gas under the negative sample bias to the sample. The etched pattern obtained by placing a Ni mesh showed that only the irradiated area was etched. The etching rate was estimated to be around 4.5×10−2 A/mA⋅min.

Selective dry etching of zinc telluride using aluminum mask

Selective reactive ion etching of zinc telluride using aluminum mask has been investigated. The etching rate for Al mask was determined to be 0.7 nm/min, which is much smaller than that of ZnTe under the same etching condition using CH4 and H2 gases. The mask selectivity of Al was determined to be approximately 88 for ZnTe, indicating that the thin layer of Al film can be a good mask for fabricating ZnTe microelectronic devices.