Performance of the magnetron sputtering apparatus equipped with 60 mm  superconducting bulk magnet

Abstract

The performance of the planar magnetron sputtering apparatus with the use of a c-axis oriented single-domain Sm123 bulk superconductor with 60 mm in diameter is discussed. A high magnetic field of 4.2 T at the surface of the superconductor coupled with a high electric field of maximum 6 kV enabled us to discharge even at the Ar gas pressure of 1 × 10−3 Pa. A target-to-substrate distance could be extended to 30 mm under low pressures of 10−2–10−3 Pa to allow the deposition with an incidence angle normal to a substrate. The discharging characteristics of Cu, Ni, Fe, Al and carbon targets in the pressure range over 10−1 to 10−3 Pa were studied under different target voltages. The deposition rates of 0.063 nm s−1 (or 38 Å min−1) and 0.013 nm s−1 (or 8 Å min−1) were achieved for Cu and Fe targets with 3 mm in thickness, respectively, under the Ar pressure of 6.6 × 10−2 Pa.

Enhancement of Trapped Field and Total Trapped Flux on High Temperature Bulk Superconductor by a New Pulse-Field Magnetization Method

“…As a practical application of REBaCuO bulk superconductors (RE: rare-earth element or yttrium), a highstrength superconducting bulk magnet has been intensively developed by pulse-field magnetization (PFM) as well as the conventional field-cooled magnetization (FCM). 1) The trapped field B T P obtained by PFM was, however, considerably smaller than that attained by FCM below 77 K due to the large temperature rise (ÁT) caused by the dynamical motion of the magnetic fluxes. 2) Several approaches have been successfully performed to enhance B T P including an iteratively magnetizing pulsed-field method with reducing amplitude (IMRA) 3) and a multipulse technique with stepwise cooling (MPSC).…”

Construction of superconducting bulk magnet magnetron sputtering apparatus for fabrication of highly reflective optical mirrors

“…As a superconducting bulk magnet, we employed the Ø60 mm c-axis oriented single-domain Sm123 bulk superconductor synthesized in the oxygen-controlled melt-growth (OCMG) method by adding 20 wt% Ag 2 O and 0.5 wt% Pt to the powders mixed with the ratio Sm123:Sm211 = 3:1 [5][6][7][8][9]. In the present work, however, the two Gd123 bulks of 60 mm in diameter were purchased from Nippon-Steel Co.…”

“…Mizutani et al [5][6][7][8][9][10] constructed a superconducting magnetron sputtering apparatus by installing the magnetized bulk superconductor in place of the Nd-Fe-B permanent magnet. A bulk superconductor cooled by a refrigerator down to about 30 K was magnetized and subsequently inserted below a target plate in order to confine the plasma immediately above it.…”

Fabrication of Mo/Si multilayer mirrors for extreme ultraviolet lithography by means of superconducting bulk magnet magnetron sputtering

“…A superconducting magnetron sputtering apparatus was constructed by installing the magnetized bulk superconductor in place of the Nd-Fe-B permanent magnet [5][6][7][8][9][10][11][12]. It can capture much denser plasma over the target than a conventional magnetron sputtering as a result of the generation of an extremely strong magnetic field by the magnetized bulk superconductor.…”

“…It can capture much denser plasma over the target than a conventional magnetron sputtering as a result of the generation of an extremely strong magnetic field by the magnetized bulk superconductor. The degree of plasma confinement has been evaluated by using a parameter B max == , magnetic field being defined on the target as that directed parallel to its surface and, hence, possessing a vanishing vertical or z-component [5][6][7][8][9][10][11][12].…”