Proceedings Article | 9 April 2020
KEYWORDS: Light sources, Lithography, Scanners, Electroluminescence, Semiconducting wafers, Copper indium disulfide, Projection systems, Chromatic aberrations, Optical lithography, Photomasks
In modern semiconductor lithography world, doubtlessly, scanners using DUV as light source still be main work horses to push physical limits of semiconductor devices to a new level. Meanwhile, as the semiconductor devices diversified to many different types, for example, logic, DRAM, NAND ash, CMOS Image Sensor (CIS), etc., lithography performances needed are also diversified. For example, CH/VIA layers in the-state-of-the-art logic processes require improved lithography Process Window (PW) due to their shallow Depth of Focus (DOF). On the other hand, engineers working in the field of modern 3D-NAND ash memory and CIS lithography are needed to deal with problems induced by thick resists. Efforts by chip makers, scanner vendors solved the problems in some degree. For example, focus drilling multi-exposure, has improved DOF of some specific layers substantially. But all these approaches have some kinds of issues, such as, throughput losses, etc. As a light source maker, we believe we can make unique contributions to solve the issues. In this report, we are going to show that our advanced Spectral Engineering (SE), a cost-effective way, can provide chip makers with an alternative to cope with the challenges stated above.
