AFM lithography combined with optical lithography

Reports on a hybrid method of AFM lithography and optical lithography that increases the drawing speed and decreases the drawing length. Advanced devices, such as quantum ones, have both nanometer-scale structures and large area structures, such as contact pads. It takes a long time to fabricate all the patterns using AFM lithography alone. It is preferable to combine AFM lithography with optical lithography. In this way, AFM lithography is used for nanometer structures only. When this hybrid process is used, the most significant problem is aligning the patterns produced by optical lithography and AFM lithography. To solve this problem, we use small step structures fabricated by slight development on the resist surface, fabricated by optical-lithography exposure. The positional information of the pattern structure in the resist film, fabricated by using optical lithography, is obtained by observing the steps with AFM. The additional patterning is performed by using AFM lithography. Patterns can be observed without exposure, since the force needed to observe the surface and that for the exposure are different.