NTT shrinks the world to 60microns
The 60micron-diameter globe was made by writing a map on a micro-sphere made of resin. The smallest pattern is about 10nm in size, corresponding to 2km on the actual earth.
For the nano-filter, a first exposure and development formed the framework and a second formed an array of small holes on the sidewalls of the framework. The smallest holes have a diameter of about 30nm.
The EB system has a resolution down to 10nm, two-axis rotation with accuracy better than 0.1degrees and a focus error of less than 1-2microns. A beam-positioning system detects the outline of a sample using a transmitted-electron signal for accurate placement of patterns.
To measure the focus height, NTT developed a new measurement system that uses a confocal laser microscope. The system makes a height map of a sample, thus enabling the height of any point on the sample to be determined, even if the sample is rotated. In addition, an outline of the shadow of a sample is mapped with a transmission electron detector and patterns are written at the designed position relative to the outline.
NTT plans to develop methods for applying this technique to nanofabrication on various materials, such as semiconductors. In addition, investigations will be carried out to determine how this technique can be used to make new types of nanoelectronic devices.
