Research Of Liquid Crystal Photoalignment Technology Based On DMD Digital Mask Lithography

With the rapid development of the liquid crystal optoelectronic technology,microelectronics,micro-optical technology,the device information age of miniaturization,integration,technical requirements for lightweight,liquid crystal display technology has been constantly improving and upgrading.It has shown a very broad application prospects in optical communications,optical computing,optical interconnects,and many other high-tech fields.With the need for low cost and flexible manufacturing of liquid crystal devices In lithography,Maskless lithography has become a research hotspot.This paper is based on the basic structure and double exposure interference theory of projection lithography system of DMD digital mask lithography machine,combining the feasibility of projection lithography systems with the flexibility of programmable digital liquid crystal devices,instead of the conventional mask lithography,producing an ideal micro-optical element by exposing a digital mask pattern.It achieves reproducible lithography and reduces the cost of mask printing.It has obvious advantages over other lithography technologies.Therefore,this paper is based on the following research:(1)The internal basic structure and photolithography process of the DMD digital mask lithography machine were studied.It used reasonable optics to test the resolution of the instrument.Two-dimensional liquid crystal gratings were used for polarization imaging on a glass substrate,and three kind of liquid crystal grating digital mask patterns were exposed under three DMD two-fold,five-fold,and ten-fold objective lenses.The approximate period range is measured under an optical microscope,and the resolution value of each lens is finally obtained.(2)According to the principle and function of the basic structure of the liquid cry stal device,we made a chess structure and a depolarizer structure under the DMD.After rotating a particular polarization angle,the four complementary chess patterns can be obtained with a clear border pattern under an optical microscope.When the polarizer is rotated,and the adjacent squares have obvious light and dark changes.The depolarizer is a kind of patterned retarder,which can reduce the polarization of the emitted light and convert polarized light into non-polarized light.The experiment verifies that it can be produced by using four pixel liquid crystal grating structure diagram polarizing a certain angle.After the polarizer rotates,the optical axis moves with it to obtain a dynamic pattern.After detection,it can convert line polarization into random polarized light,which conforms to the photoelectric characteristic of the airspace depolarizer.