| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2006: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2005: ¥2,700,000 (Direct Cost: ¥2,700,000)
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| Research Abstract |
1. AFM lithography on insulating substrates:
In the present study, we employed a lithography method using an AFM cantilever to fabricate nano-size structures. By an application of a voltage pulse during the AFM imaging. Au atoms on the tip was deposited on a substrate to form a nano-size dot. We tried to fabricate a nano-size Au wire by repetitive dot formation. So far, in the AFM lithography, a Au-coated cantilever is used in the tapping mode AFM. In our study, we used a Au-tip cantilever, which we developed by ourselves and whose diameter is smaller than a coated one by a factor of 5 to 10, in non-contact mode, whose force sensitivity is higher than the tapping mode. Using the new system, we successfully fabricated a nano-size pattern with Au dots.
2. development of metal-tip cantilever for the AFM lithography
In the AFM lithography, a Si cantilever on which metal thin film is deposited is usually employed, but the probe has problems such as dull tip apex and limited amount of the deposited material. In order to solve the problems, we developed a new cantilever which has a metal-wire tip. First, a metal wire whose diameter is 5-10μm was attached on a cantilever using a micromanipulator under an optical microscope, and then the wire was cut and sharpened by focused ion beam (FIB). The sharpness of the tip was checked with TEM and also by the AFM observation and found that the tip works well as a probe of non-contact AFM.
3. development of low-temperature AFM unit
In order to fabricate atomic-scale structures, precise and stable control of probe position is highly required and thus operation in low temperature is highly desired. We modified our low-temperature (>2.8K) ultrahigh vacuum STM and successfully operated it as an AFM. Atomically resolved AFM images of the Si(111) 7x7 surface were clearly observed at 5K.
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