1992 Fiscal Year Final Research Report Summary
Microfabrication and Joining by Field Evaporation Mechanism
| Project/Area Number |
03805063
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
溶接工学
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| Research Institution | Osaka University |
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Principal Investigator |
YASUDA Kiyokazu Osaka University, Facutly of Engineering, Assistant, 工学部, 助手 (00210253)
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| Co-Investigator(Kenkyū-buntansha) |
FUJIMOTO Kouzou Osaka University, Facutly of Engineering, Assistant Professor, 工学部, 助教授 (70135664)
NAKATA Syuji Osaka University, Facutly of Engineering, Professor, 工学部, 教授 (90029075)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Microfabrication / Microjoining / Scanning tunneling microscope / STM / Field evaporation / Surface modification / Silicon |
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| Research Abstract |
The purpose of this research is to clarify mechanism of surface modification in nanometer scale by field evaporation and melting process using scanning tunneling microscope in air. The tip used in the experiment was produced by electrochemical etching with DC power supply. The tip with curvature 33*10nm and aspect ratio 2.2 was produced when etching voltage is 40V. In order to prevent tip surface from oxidation whcih causes degradation of resolution and stability, tip was coated with gold thin film by vacuum deposition. The tip was very stable in air with high resolution of atomic scale (HOPG) even after 1 week. In experiment of biasing voltage to sample for surface modification, etching of sample (Si) was observed when negative voltage was applied to the sample. The depth of etching region was proportional to the power of bias voltage. This results mean that surface modification was caused by electric field, not by mechanical contact. With positive bias voltage to sample no surface modification occured, presumably caused by Shottoky effect of Ntype Si. From I-S (tunnel current - gap distance) characteristics of modified region mean barriar height psi_m was decreased as number of scanning frame was increased. This effect was rusulted by surface oxidation of silicon.
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