Title :
Analysis of alignment modeling for Nikon steppers
Author :
He, Feng ; Wang, Jun ; Wu, Zhiming ; Jiang, Yadong ; Yuan, Kai
Author_Institution :
State Key Lab. of Electron. Thin Films & Integrated Devices, Univ. of Electron. Sci. & Technol. of China, Chengdu, China
Abstract :
The alignment system, as one of key component for stepper, developed rapidly in the last few years because of huge requirement on advanced exposing tools for VLSI and MEMS. Alignment accuracy is mainly affected by errors coming from mark deformations and optical system. In this paper, we combined mathematical model of Nikon stepper alignment optical system and analyzed alignment errors of Nikon stepper caused by mark deformation in different processes. The model was verified by different experiments. Finally some improvement process is put forward to enhance alignment accuracy.
Keywords :
integrated circuit manufacture; optical design techniques; photolithography; wafer-scale integration; Nikon steppers; alignment modeling; mark deformation; Etching; Gratings; Mathematical model; Optical diffraction; Optical films; Optical interferometry; Optical sensors; Semiconductor device modeling; Signal processing; Very large scale integration;
Conference_Titel :
Physical and Failure Analysis of Integrated Circuits, 2009. IPFA 2009. 16th IEEE International Symposium on the
Conference_Location :
Suzhou, Jiangsu
Print_ISBN :
978-1-4244-3911-9
Electronic_ISBN :
1946-1542
DOI :
10.1109/IPFA.2009.5232634
