Improvement of microwave ion source for higher B+ ion current

Okada, Morihiro; Sakudo, N.; Hayashi, Keiji; Ikenaga, Noriaki; Okuji, S.; Onogawa, T.; Maesaka, T.; Nishiyama, Yukio; Takahashi, Masato; Ito, Satoshi; Ito, Hiroyuki

doi:10.1063/1.1150270

Cited by 5 publications

(1 citation statement)

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“…Fig. 3, where the measured amplitudes of the (10) probe-current Fourier component under the laser irradiation ( io C( 4 pA, 6 W ) ) and under the dark condition ( i0 ( 4 .tA, 0 W ) ) along with the amplitude i0( 4 pA, 6 W ) of the apparent photoelectron current given by Eq. result, the estimated net rate Gr of neutral Cu atom production given by Eq.…”

Section: Resultsmentioning

confidence: 99%

How to sensitively measure the rate of neutral free radical production by photo-deionization of negative ion beams

et al. 2003

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Two measurement methods to determine the rate of neutral free radical production by the photo-deionization of negative ion beams ( PDINIB ) are introduced. These methods, namely, photoelectron-current measurement by low-frequency electro-modulation probe ( PMMP ) and measurement of decrease in the negative-ion beam current ( DNIC ) were employed to evaluate the production rate in a trial surface-processing apparatus developed in the author's laboratory utilizing a steady-flux refined beam of neutral free radicals produced by the PDINIB procedure. A 63Cu negative ion beam of kinetic energy E, varied up to 15 keY was irradiated with a 514.5 nm visible light beam from a 25 W CW Ar ion laser. The detection limit of the production rate by the PMMP setup was as high as 6x109 Is under the condition that E, = 15 keV, the negative ion beam current I = 4 j.tA, and the laser power P = 6 W. The DNIC method is simpler but less reliable than the PMMP method owing to larger uncertainty resulting from the fluctuation of the negative-ion beam current.

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Section: Resultsmentioning

confidence: 99%

How to sensitively measure the rate of neutral free radical production by photo-deionization of negative ion beams

et al. 2003

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Magnetic-field configuration fitted to the microwave ion-source plasma

Sakudo

Ito²,

Matsunaga³

et al. 2002

Review of Scientific Instruments

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Microwave ion sources for implantation have many advantages, such as the long life of source operation and the cleanliness of extracted beam, over the traditional dc-arc-discharge-type ion sources. We reported that optimizing the plasma-chamber structure made the microwave source exceed most of traditional dc-arc-discharge sources in extracted-ion currents of most species that are used for fabricating modern ultralarge scale integrations. After studying the source magnetic field in detail by computer simulation, the relationship between the magnetic-field profile and the plasma-chamber structure is found to be essential. Two-dimensional analysis is carried out since the plasma is generated between parallel plate electrodes. The optimum chamber structure with which the maximum current was obtained in the last beam-extraction experiments is shown to contain the major magnetic field that is focused by the iron pole pieces. Most of the magnetic-field lines that are crossing the region where ions are first generated do not disappear into the sidewalls of the chamber. Since the lifetimes of ions become longer, the plasma density increases.

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