Three-dimensional nanofabrication with 10-nm resolution

We have devised three-dimensional (3D) nanofabrication technology using electron-beam (EB) lithography and a sample-rotation drive. Ten-nm resolution of patterning over a 3D sample and 3D fabrication was achieved by precise control of beam focusing for patterns divided based on the depth of focus of the EB. The focus control is carried out using an offline height-measurement system we developed, which provides focusing error of less than 2 μm. The depth of focus was accurately derived using the wave optical method. We have demonstrated these techniques and the resulting resolution by making the world's smallest globe, which shows the minimum feature size of 10nm over the world map.