Tetsuo Gejyo

Development of large scale ion beam milling machines

Abstract The higher-speed implementation and higher integration of electronic equipment gives increasingly higher importance to high-accuracy super-fine machining technology. A developed ion beam milling machine, which responds to this requirement, is a useful means to implement the higher performance of electronic equipment. The machine compactly comprises a large scale ion source that has been developed by the application of the essence of neutral beam injection equipment for heating plasma in nuclear fusion facilities, and a water cooled substrate holder that is capable of simultaneously treating up to 16 substrates and is rotated and revolved at any gradient angle with respect to the beam. The large scale ion source is used to generate uniform beams at low divergence angles. The result is that high accuracy and the highest throughput unheard of can be achieved with machining deviations at ± 3% or less.

Vapor Transport of Gallium in the Ga-PCl3-H2 System

A theoretical consideration based on thermodynamics has been developed and the result is compared with experimental results obtained for the transport of gallium. The transport rate of gallium is discussed as a function of the reaction temperature, the hydrogen flow rate and the mole ratio of Cl/H. A good agreement is found between the theory and experimental results. It is also shown that the experimental data of Luther and Roccasecca are predicted by the theory and that the theoretical results give an upper limit of the transport rate of the gallium.

Development of a high deposition rate machine by ion beam sputtering

Abstract Recently a deposition method by ion beam sputtering was developed which is interesting for making films with superconductive, optical or magnetic properties. The ion beam sputtering method has many advantages such as process controllability, low working pressure and no plasma contact. However, the deposition rates have not been so high as those of other methods such as magnetron sputtering. The authors have developed a large-capacity and high-efficiency ion source by applying the nuclear fusion ion source technology, and realized a high deposition rate ion beam sputter machine by using this ion source. This machine has a high-speed semiconductor switch for quick interruption and restart. It also maintains a constant deposition rate by controlling the ion beam current according to the rate monitor signal. A deposition rate of 340 nm/min is obtained for a copper film at a substrate 250 mm distant from a target, which is nearly the same level as with magnetron sputtering.