Desigen And Analysis Of A Holder For Contact Localized SP Direct Writing Lithography

Optical lithography has played a key role in the progress of semiconductor manufacturing industry. But the resolution of conventional photolithography is limited by Abbe’s diffraction. With the development of near-field optics, near-field optics lithography provides a new route to overcome the diffraction and achieve a high resolution. However, the transmittance of the light is too low to get a high image contrast. Recently, near-field lithography developed on the basis of surface plasmon polaritons(SPPs) can enhance the transmittance of light to improve the resolution and image contrast of near-field lithography. As one type of plasmonic photolithography, plasmonic direct writing nanolithography is a maskless lithography method, it can be used to fabricate arbitrary patterns. And the system of plasmonic direct writing lithography is simple and low cost. These advantages makes it becomes a perfect nanolithography method.Scan probe lithography is an important lithography technique belonging to direct writing lithography. In general, a cantilever-tip-based probe is used for direct writing lithography. While the cantilever is easily deformed when the force is applied at the tip of probe, the bending of cantilever leads to the tip positioning problem. In this paper, we designed a circle spring with four fixed-fixed arms to hold the probe and it can achieve higher positioning accuracy in the process of direct writing lithography. An arc-shaped arm was designed to increase the length of arm and reduce the stiffness of circle spring. Analysis the positioning accuracy of cantilever probe in the approach mode and scan mode theoretically and compare the lateral tip displacement of circle probe and cantilever probe in the two modes. The circle probe both has higher positioning accuracy in its approach model and scan mode than a cantilever probe.ANSYS14.0 was used to make a dynamic simulation about the application of circle spring in the localized surface plasmonic direct writing nanolithography. In the process of lithography, the force caused by deformation of circle spring can ensure the probe contact with the photoresist intimately. In approach mode, circle spring maintains probe vertically and has no deflection; in scan mode, circle spring maintains the probe has the same deflection angle; with the same displacement load and scan speed, the probe has the same deflection angles around the xy plane when probe scan on the surface of photoresist in different directions. Using the adaptability of circle spring, the probe can intimately contact with the surface of photoresist in 1.5′ angle variation range within the maximum displacement load limited by allowed inclination of direct writing probe.Completed the design of experimental system for localized surface plasmonic direct writing nanolithography, completed selection and purchasing of the important equipment used in the system, and finalized the detection scheme to detect the deformation of contact probe in the process of lithography.