| Presentation | 2005-10-14 Study on fabrication of Nb/AlO_x/Nb Josephson Junctions with high critical current densities Takashi SUMIKURA, Hiroyuki AKAIKE, Akira FUJIMAKI, |
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| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | We have been studying a fabrication process for high critical current density (J_c) Nb/AlO_x/Nb Josephson junctions. To fabricate the junctions, a thickness of an Al_2O_3 barrier and an area of a junction have to be reduced. In this work, we have investigated etching conditions for forming counter-electrodes of small junctions. The wafer temperature during the etching was closely related to edge profiles of etched Nb patterns and etching residues. We controlled the profiles and residues by changing the wafer temperature and improved the electrical characteristics of junctions. We also investigated the effects of surface flatness of base Nb layer on the junction characteristics. The flatness depended on the Ar pressure when Nb films were sputtered and flatter Nb films were obtained under lower Ar pressures. We improved the junction characteristics using the flatter Nb films for base layers of junctions. We obtained junctions with a J_c of 13.7kA/cm^2 and a quality parameter V_m of 16.5mV from these improvements. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | Nb/AlO_x/Nb junction / high critical current density / etching conditions / edge profile / base electrodes / flatness |
| Paper # | SCE2005-18 |
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| Conference Information | |
| Committee | SCE |
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| Conference Date | 2005/10/7(1days) |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | |
| Topics (in Japanese) | (See Japanese page) |
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| Paper Information | |
| Registration To | Superconductive Electronics (SCE) |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | Study on fabrication of Nb/AlO_x/Nb Josephson Junctions with high critical current densities |
| Sub Title (in English) | |
| Keyword(1) | Nb/AlO_x/Nb junction |
| Keyword(2) | high critical current density |
| Keyword(3) | etching conditions |
| Keyword(4) | edge profile |
| Keyword(5) | base electrodes |
| Keyword(6) | flatness |
| 1st Author's Name | Takashi SUMIKURA |
| 1st Author's Affiliation | Nagoya University() |
| 2nd Author's Name | Hiroyuki AKAIKE |
| 2nd Author's Affiliation | Nagoya University |
| 3rd Author's Name | Akira FUJIMAKI |
| 3rd Author's Affiliation | Nagoya University |
| Date | 2005-10-14 |
| Paper # | SCE2005-18 |
| Volume (vol) | vol.105 |
| Number (no) | 334 |
| Page | pp.pp.- |
| #Pages | 6 |
| Date of Issue | |