Sputtering yield measurements with size-selected gas cluster ion beams

2009 ◽  
Vol 1181 ◽  
Author(s):  
Kazuya Ichiki ◽  
Satoshi Ninomiya ◽  
Toshio Seki ◽  
Takaaki Aoki ◽  
Jiro Matsuo

AbstractAr cluster ions in the size range 1000�16000 atoms/cluster were irradiated onto Si substrates at incident energies of 10 and 20 keV and the sputtering yields were measured. Incident cluster ions were size-selected by using the time-of-flight (TOF) method. The sputtering yield was calculated from the sputtered Si volume and irradiation dose. It was found that the sputtering yields decreased with increasing incident cluster size under the same incident energy conditions. The integrated sputtering yields calculated from the sputtering yields measured for each size of Ar cluster ions, as well as the cluster size distributions, were in good agreement with experimental results obtained with nonselected Ar cluster ion beams.

1993 ◽  
Vol 316 ◽  
Author(s):  
G. H. Takaoka ◽  
G. Sugahara ◽  
R. E. Hummel ◽  
J. A. Northby ◽  
M. Sosnowski ◽  
...  

ABSTRACTThe effects of energetic Ar cluster ion impacts on Si(111) surfaces have been studied for cluster energies up to l5keV. The mean cluster size was about 1000 atoms, and the smaller sizes could be systematically excluded. Si samples irradiated at different cluster ion energies were analyzed by RBS, ellipsometry, and differential reflectometry. Implantation of Ar in samples irradiated with cluster ions was found by RBS to be detectable, but very small in comparison with samples irradiated with monomer ions of the same energy. The thickness of the damage layer as measured by both ellipsometry and differential reflectometry was also much smaller in the cluster ion irradiated samples.


2003 ◽  
Vol 792 ◽  
Author(s):  
Masahiro Nagano ◽  
Shingo Houzumi ◽  
Noriaki Toyoda ◽  
Susumu Yamada ◽  
Shirabe Akita ◽  
...  

ABSTRACTGas cluster ion beam (GCIB) techniques have recently been proposed as new processing methods. We have been investigating the characteristics of GCIB techniques through sputtering GaAs and GaP by Ar gas cluster ion beams as a function of cluster size and acceleration energy. The Ar cluster size was selected by a magnetic spectrometer, and was obtained from the mass spectra measured by a time of flight mass spectrometer. The average sputtering yields of GaAs and GaP were 0–47 and 0–66 atoms/ion for 5–30 k V, respectively. The sputtering yields of GaAs and GaP were higher than those of an Ar monomer ion.


2004 ◽  
Vol 843 ◽  
Author(s):  
Toshio Seki ◽  
Jiro Matsuo

ABSTRACTCluster ion beam processes can produce high rate sputtering with low damage in comparison with monomer ion beam processes. Especially, it is expected that extreme high rate sputtering can be obtained using reactive cluster ion beams. Reactive cluster ion beams, such as SF6, CF4, CHF3, and CH2F2, were generated and their cluster size distributions were measured using Time-of-Flight (TOF) method. Si substrates were irradiated with the reactive cluster ions at the acceleration energy of 5–65 keV. Each sputtering yield was increased with acceleration energy and was about 1000 times higher than that of Ar monomer ions. The sputtering yield of SF6 cluster ions was about 4600 atoms/ion at 65 keV. With this beam, 12 inches wafers can be etched 0.5 μm per minute at 1 mA of beam current. The TOF measurement showed that the size of SF6 cluster was about 550 molecules and the number of fluorine atoms in a SF6 cluster was about 3300. If the sputtered product was SiF, the yield has to be less than 3300 atoms/ion. These results indicate that the reactive cluster ions etch targets not only chemically, but also physically. This high-speed processing with reactive cluster ion beam can be applied to fabricate nano-devices.


2007 ◽  
Vol 1020 ◽  
Author(s):  
Gikan Takaoka ◽  
Masakazu Kawashita ◽  
Takeshi Okada

AbstractIn order to investigate the interactions of methanol cluster ion beams with solid surfaces, Si substrates and SiO2 films were irradiated at different acceleration voltages. The sputtered depth increased with increase of the acceleration voltage. When the acceleration voltage was 9 kV, the sputtered depths of Si and SiO2 at a dose of 1×1016ions/cm2 were 1497.1 nm and 147.8 nm, respectively. The selectivity between Si and SiO2 surfaces arose from the volatility of the reaction products. Furthermore, the sputtering yield for the Si surface was approximately seven hundreds times larger than that by Ar monomer ion beams. This suggested that chemical sputtering was predominant for the methanol cluster ion irradiation. In addition, the etching and cleaning process by the methanol cluster ion irradiation was performed on the Si surfaces contaminated with a small amount of metal particles such as Au and Al. Thus, methanol cluster ion beams have unique characteristics such as surface etching and cleaning with high sputtering yield and smooth surface.


2003 ◽  
Vol 792 ◽  
Author(s):  
Toshio Seki ◽  
Jiro Matsuo

ABSTRACTCluster ion beam processes can produce high rate sputtering with low damage in comparison with monomer ion beam processes. Especially, it is expected that extreme high rate sputtering can be obtained using reactive cluster ion beams. High current SF6 cluster ion beams were recently obtained with new modifications in the basic cluster ion beam technique. The cluster size distribution was measured with Time-of-Flight (TOF) method and the mean size of cluster was about 500 molecules. Si substrates were irradiated with SF6 cluster ions at the acceleration energy of 5–45 keV. Sputtering yield with SF6 cluster ions was increased with acceleration energy and was about 2300 atoms/ion at 45 keV. The sputtering yield was about 1000 times higher than that of Ar monomer ions and was also higher than that of Ar cluster ions. It was found that reactive sputtering occurred with SF6 cluster ion irradiation. These results indicate that high-speed fabrication can be realized with reactive cluster ion irradiation at high energy.


2012 ◽  
Vol 116 (44) ◽  
pp. 23735-23741 ◽  
Author(s):  
Li Yang ◽  
Martin P. Seah ◽  
Ian S. Gilmore

2019 ◽  
Vol 3 (2) ◽  
pp. 8 ◽  
Author(s):  
Yoshihiro Hase ◽  
Katsuya Satoh ◽  
Atsuya Chiba ◽  
Yoshimi Hirano ◽  
Shigeo Tomita ◽  
...  

Cluster ion beams have unique features in energy deposition, but their biological effects are yet to be examined. In this study, we employed bacterial spores as a model organism, established an irradiation method, and examined the lethal effect of 2 MeV C, 4 MeV C2, and 6 MeV C3 ion beams. The lethal effect per particle (per number of molecular ions) was not significantly different between cluster and monomer ion beams. The relative biological effectiveness and inactivation cross section as a function of linear energy transfer (LET) suggested that the single atoms of 2 MeV C deposited enough energy to kill the spores, and, therefore, there was no significant difference between the cluster and monomer ion beams in the cell killing effect under this experimental condition. We also considered the behavior of the atoms of cluster ions in the spores after the dissociation of cluster ions into monomer ions by losing bonding electrons through inelastic collisions with atoms on the surface. To the best of our knowledge, this is the first report to provide a basis for examining the biological effect of cluster ions.


2008 ◽  
Author(s):  
Noriaki Toyoda ◽  
Iaso Yamada ◽  
Edmund G. Seebauer ◽  
Susan B. Felch ◽  
Amitabh Jain ◽  
...  

2011 ◽  
Vol 36 (3) ◽  
pp. 309-312 ◽  
Author(s):  
K. Ichiki ◽  
S. Ninomiya ◽  
T. Seki ◽  
T. Aoki ◽  
J. Matsuo

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