Due to the lithography demanding high performance in projection of semiconductor mask to wafer, the lens has to be almost free in spherical and coma aberration, thus, in situ optical testing for diagnosis of lens performance has to be established to verify the performance and to provide the suggesting for further improvement of the lens, before the lens has been build and integrated with light source. The measurement of modulation transfer function of critical dimension (CD) is main performance parameter to evaluate the line width of semiconductor platform fabricating ability for the smallest line width of producing tiny integrated circuits. Although the modulation transfer function (MTF) has been popularly used to evaluation the optical system, but in lithography, the contrast of each line-pair is in one dimension or two dimensions, analytically, while the lens stand along in the test bench integrated with the light source coherent or near coherent for the small dimension near the optical diffraction limit, the MTF is not only contributed by the lens, also by illumination of platform. In the study, the partial coherence modulation transfer function (PCMTF) for testing a lithography lens is suggested by measuring MTF in the high spatial frequency of in situ lithography lens, blended with the illumination of partial and in coherent light source. PCMTF can be one of measurement to evaluate the imperfect lens of lithography lens for further improvement in lens performance.
Smartphone require limit space for image system, current lens, used in smartphones are refractive type, the effective focal length is limited the thickness of phone physical size. Other, such as optro-electronics sensing chips, proximity optical sensors, and UV indexer chips are integrated into smart phone with limit space. Due to the requirement of multiple lens in smartphone, proximity optical sensors, UV indexer and other optro-electronics sensing chips in a limited space of CPU board in future smart phone, optro-electronics 3D IC’s integrated with optical lens or components may be a key technology for 3 C products. A design for reflective lens is fitted to CMOS, proximity optical sensors, UV indexer and other optro-electronics sensing chips based on 3-D IC. The reflective lens can be threes times of effective focal lens, and be able to resolve small object. The system will be assembled and integrated in one 3-D IC more easily.
High efficiency coupling of the array of UV light diode light source could be able to replace the traditional mercury light source, while mercury light source requires a large amount of electricity, condenser optics and volume, with hazard environmental issue. It is an urgent need for further requirement of light source for lithography. Although array UVLED could be a replacement of light sources of lithography, there are some existent optical parameters that not fit for optical coupling, such as large divergent cone angle of single chip and half divergent angle of array, which are weak the possibility of application in lithography. Before the broadly accepted by lithography, those shortages have to be overcome. Some techniques, such as designing small divergent cone angle of single chip, or eliminating divergent angle have suggested by fly eye and other methods, yet all of those methods, only improve the coupling efficiency and uniformity of emitted surface in some limited extent. The project is to develop a high coupling efficiency of the optical system used in the array of UV light diodes, which can make the high coupling efficiency, despite UVLED has a small size and large divergent angle. The optical design of illumination has carried out for array UVLED, an illumination optics has designed based on Koehler type illumination, and it has shown reducing the divergent angle to increase in coupling efficiency between the Array UVLED to the mask of lithography. The uniformity of average power has shown excellently fitted for high quality lithography in direct exposure or lens exposure.
An ultrashort throw liquid crystal on silicon (LCoS) projector for home cinema, virtual reality, and automobile heads-up display has been designed and fabricated. To achieve the best performance and highest-quality image, this study aimed to design wide-angle projection optics and optimize the illumination for LCoS. Based on the telecentric lens projection system and optimized Koehler illumination, the optical parameters were calculated. The projector’s optical system consisted of a conic aspheric mirror and image optics using either symmetric double Gauss or a large-angle eyepiece to achieve a full projection angle larger than 155 deg. By applying Koehler illumination, image resolution was enhanced and the modulation transfer function of the image in high spatial frequency was increased to form a high-quality illuminated image. The partial coherence analysis verified that the design was capable of 2.5 lps/mm within a 2 m×1.5 m projected image. The throw ratio was less than 0.25 in HD format.
The critical dimension(CD) is main factor to determine the line width of semiconductor equipment fabricating ability for the smallest line width of produced electronic components. Modulation transfer function(MTF) has been popularly used to evaluation the optical system, due to the contrast of each line-pair in dimension analytically, however, while the light source is coherent or near coherent for the small dimension near the optical diffraction limit, the MTF is hard to achieve consistently. The study of ultra-violet partial coherence modulation transfer function is to calculate the 1-D and 2-D the line with anoptical design program, to estimate the MTF near the size of diffraction limit. It provides fabricating parameter for a 1-to-1 TSV lithographic system. By applying partial coherence analysis, the optimized relative numerical aperture (RNA) has found. As the system is built, the optimized performance should be expected.
In the past decade, the display format from (HD，High Definition) through Full HD(1920X1080)，to UHD(4kX2k), mainly guides display industry to two directions: one is liquid crystal display(LCD) from 10 inch to 100 inch and more, and the other is projector. Although LCD has been popularly used in market; however, the investment for production such kind displays cost more money expenditure, and less consideration of environmental pollution and protection. The Projection system may be considered, due to more viewing access, flexible in location, energy saving and environmental protection issues.
The topic is to design and fabricate a short throw factor liquid crystal on silicon (LCoS) projection system for cinema. It provides a projection lens system, including a tele-centric lens fitted for emitted LCoS to collimate light to enlarge the field angle. Then, the optical path is guided by a symmetric lens. Light of LCoS may pass through the lens, hit on and reflect through an aspherical mirror, to form a less distortion image on blank wall or screen for home cinema. The throw ratio is less than 0.33.
The design and fabrication of common optical components lithography Lens has been carried out for a 1 to 1 stepper. The specification of lens is fulfilled the 3-D lithography system as 2 micron in resolution for 1 inch x 2.8 inches system. The lens has been sophistically designed by dual path in a triplet to reduce the number of components. A single aspherical surface has been applied to reduce the aberration to diffraction limit in lens. The well-made shapes of lens have been suggested. Then, the fabrication of lens has been in the process. Finally, the optical axis of tolerance optical mechanical mountings for lens system in assembly has been analyzed, and valuable for assembly and fabrication.