Showing papers by "Kenji Saitoh published in 2002"

Exposure method and apparatus

Abstract: There is provided an exposure method that includes the steps of forming a phase shift mask having a desired pattern and a cyclic dummy pattern overlaid onto the desired pattern, a part of the desired pattern to be resolved by effects of the dummy pattern being thicker than the dummy pattern's line width, illuminating the phase shift mask by using illumination light having a peak near or on an optical axis in an intensity distribution to transfer the desired pattern onto the exposure plane by projecting light having passed through the phase shift mask onto the exposure plane.

Method for setting mask pattern and its illumination condition

Abstract: A method for setting a mask pattern and an illumination condition suitable for an exposure method for using plural kinds of light to illuminate a mask that arranges a predetermined pattern and an auxiliary pattern smaller than the predetermined pattern, so as to resolve the predetermined pattern without resolving the auxiliary pattern on a target via a projection optical system includes the steps of forming data for the predetermined pattern, forming data for the auxiliary pattern, and setting the illumination condition for defining an effective light source of illumination using the plural kinds of light.

Challenging the limit of single mask exposure

Abstract: IDEALSmile is introduced as a new exposure technique. Since we have realized k 1 equals 0.29, k 1 equals 0.32 optical lithography is now achievable. In this paper IDEALSmile is targeted for contact hole patterns. The results validate that it is possible to simultaneously fabricate 110 nm (k 1 0.32) half-pitch dense and isolated contact hole patterns using Canon FPA-5000ES3 (KrF, NA equals 0.73). Furthermore, our experimental results also show that it is possible to fabricate different half-pitch patterns at the same exposure dose, which is impossible by conventional methods. Since these results are obtained using binary mask and the modified illumination with single exposure, there are no concerns with regards to decrease in throughput and increase in cost of ownership. By attaining k 1 equals 0.32 for contact hole patterns using binary mask with single exposure, printing 100 nm contact hole patterns can be achieved with single exposure using KrF lithography, such as the Canon FPA-5000ES4 (KrF, NA equals 0.80) scanner which will soon make its market debut. ArF or F2 lithography is effective as for contact hole patterns below the 100 nm node. There is no doubt that optical microlithography will continue for some time.

New resolution enhancement method realizing the limit of single mask exposure

Abstract: IDEALSmile is introduced as a new exposure technique that realizes k 1 =0.29. In this paper IDEALSmile is targeted for contact hole patterns (C/H). The results validate that it is possible to simultaneously expose not only k 1 =0.32 half-pitch dense and isolated C/H patterns, but also different pitches using Canon FPA-5000ES3 (KrF, NA=0.73), which is impossible by conventional methods. Since these results are obtained using a binary mask and modified illumination with single exposure, there are no concerns with regards to a decrease in throughput and an increase in cost of ownership. However, one of the issues in fabricating C/H patterns is the mask error enhancement factor (MEEF). Our simulation has shown that IDEALSmile exhibits good MEEF. Although there are questions regarding optical microlithography for critical C/H patterning, the IDEALSmile exposure method has the potential to be the solution. By attaining k 1 =0.32, printing 100nm C/H patterns can be achieved with a single exposure using KrF lithography, such as the Canon FPA-5000ES4 (KrF, NA=0.80). Furthermore, the IDEALSmile technique using ArF or F2 lithography will be effective for C/H patterns below the 100nm node. There is no doubt that optical microlithography will continue for some time.

Mask manufacturing method

Abstract: A method for forming, on a mask, a mask pattern used for exposure. The mask pattern includes a first pattern that blends plural types of patterns, and second pattern that is smaller in size than the first pattern. The mask pattern is arranged on the mask so that the first pattern may be resolved and the second pattern is restrained from being resolved. The method includes the steps of classifying the first pattern into one of a periodic pattern having at least three elements having two equal intervals in at least one direction among two orthogonal directions, an isolated pair pattern that does not belong to the periodic pattern and includes a pair of elements arranged in at least one direction among the two orthogonal directions, and an isolated element that does not belong to the isolated pair pattern and includes only one element without constituting any pair in any of the two orthogonal directions, arranging the second pattern for the isolated pair pattern, arranging the second pattern for the isolated element, and arranging the second pattern for the periodic pattern.

Method of manufacturing mask

Abstract: PROBLEM TO BE SOLVED: To provide a method of manufacturing a mask capable of forming by exposure a contact hole pattern which has a fine hole diameter and in which the contact holes ranging from isolated contact holes to contact hole arrays coexist with high resolution and without replacing the mask. SOLUTION: In the method of forming a mask pattern for exposure, a first pattern in which a plurality of kinds of patterns are intermingled and a second pattern whose dimensions are smaller than those of the first pattern are arranged on the mask in such a manner that the first pattern is resolved and the resolution of the second pattern is suppressed. COPYRIGHT: (C)2004,JPO