The Development And Application Of Laser Interference Lithography Process Research

Laser interference lithography (LIL) is method which can be used to fabricate micrometer and sub-micrometer periodic and quasi-periodic patterns over large areas on materials. Comparing with other types of lithographic technologies, LIL is very useful considering it is a simple process to achieve large area, uniform definition and high throughput at low cost, has attracted a lot of attention. This technique is a maskless process capable of generating homogeneous nanostructures of lines and dots in large areas, which is either impossible or time/cost consuming with other lithography techniques. The structures fabricated by this method show novel physics, photonics and biology phenomenon, which can be used as nanoimprint templates, photonic crystals and biosensors.People have studied LIL technology for many years, currently a lot of good results have been got, foreign scientists fabricate large area and small scale nanostructure in high quality, and they proved the application potential of this technology. However there are still many problems like poor quality and high costs for example. In this work, we build a set of LIL equipment based on international popular Loyld’s-Mirror laser interference lithography, and do the following innovative research.1. Besides of the expensive and special photoresist and anti-reflection coating in overseas studies, we first fabricate high quality nanostructure on cheap photoresist made in our country. This method is maskless, do not need expensive lens and new light source with short wavelength. Initial experiments results show the large area sub-miron periodic grating, dot arrays and cone array patterns can be fabricated by this process, which establishes the exciting foundation for the nanostructure fabrication. We studied the characteristics of four different photoresists and the pattern transfer process, the results set a good foundation for the further studies of LIL.2. Based on the nanostructures fabricated by LIL, we systematic studied the application of these nanostructures. Our experiments show that the nano-tip structures fabricated by the combined LIL and RIE process deliver satisfactory hydrophobic tendencies when the periods fall into the submicron scale. The nanobump structures with a Au thin top layer shows strong surface plasmon resonance tunable by changing the period of the structures and the light incident angle.3. For LIL to be widely applied, we studied some new process and applications of LIL, including backside exposure, multiple resist structure process, pattern transfer by casting, biosensing and new semiconductor transistor etc. The results of these experiments shows great application potential of LIL, which prove LIL can be used in a broader fields.All the results prove the LIL is a very powerful method for fabricating large area nanostructures, besides the value of scientific, LIL method shows extremely well application prospect.