Research and Design of Nanoimprint Lithography Alignment System : Application of Image Detection and Laser Interferometer in Multi-layer Nanoimprint system
Date Issued
2005
Date
2005
Author(s)
YUAN, CHI-WEI
DOI
zh-TW
Abstract
As semiconductor vendors strive to reduce the feature sizes of integrated circuits, the need for next-generation lithography (NGL) tools increases. The escalating cost of these tools for conventional optical and extreme ultraviolet (EUV) lithography is driven in part by the need for complex optical sources and optics. The cost for a single NGL tool could exceed $50 million in the next few years, a prohibitive figure for many companies and laboratories. Nanoimprint offers a low-cost alternative method for printing sub-100 nm features with great potential accuracy, high resolution, and reductivity. Overlay with alignment precision in the range of the resolution is mandatory for a large number of applications. Specific process details of UV nanoimprint lithography (UV-NIL) offer three main advantages to reach the overlay accuracy required. First, the transparent imprint molds allow one to adopt alignment techniques developed for optical or x-ray lithography. Second, the absence of thermal cycles in UV-NIL enhances the overlay accuracy principally and is favorable for optical interferometric techniques. Third, prior to UV curing the imprint resist remains in a state of low viscosity, allowing fine alignment in contact mode. Alignment errors that may occur during lowering of the imprint mold to the substrate surface and the imprint into the resist can be corrected within certain margins. The extremely small gap as well as the strong parallelism between mold and resist surface enhances signal quality and the achievable resolution. In this contribution, this paper presents some details of an alignment technique constructed by grating mark on mold and wafer. This method is like grating interferometry, but the tiny distance between mold and wafer let the theory and result totally different. Even based on different theory, both methods can provide high accuracies under 100nm.
Subjects
奈米壓印
疊對技術
位移平台
繞射式光學尺
nano-imprint
lithography
overlap control
precision alignment
diffractive laser encoder
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-94-R92525014-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):bc494ccf04661205c0ef85574154c717