Alignment Focus Optimization and Image Contrast

Autor:	Ayako Sugaya
Rok vydání:	2005
Předmět:	Computer science business.industry ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION General Engineering Phase (waves) General Physics and Astronomy Image contrast Image (mathematics) Optics Position (vector) Duty cycle Image alignment business Focus (optics)
Zdroj:	Japanese Journal of Applied Physics. 44:5970
ISSN:	1347-4065 0021-4922
DOI:	10.1143/jjap.44.5970
Popis:	In LSI mass production, an alignment sensor must be installed in an exposure system to detect the pattern position accurately even if the pattern condition is changed. To satisfy such a requirement, the defocus effect of improving the image contrast is studied. Particularly under optical conditions with large illumination σ, the theory of image profile change induced by defocus is clarified in this paper. For a field image alignment sensor (FIA) with large illumination σ, FIA focus optimization (FFO) is developed as a technique that realizes alignment with both high accuracy and better image contrast by optimized defocus. FFO makes this possible regardless of the pattern phase and/or pattern duty ratio. The effects are confirmed by simulations and experiments. The versatile advantages of FFO for LSI production are confirmed.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c565e62c43ce1588dc1e0b0c978432fa https://doi.org/10.1143/jjap.44.5970 Zobrazit plný text záznamu