High-Accuracy Proximity Effect Correction for Mask Writing

Abe, Takayuki; Hattori, Yoshiaki; Iijima, Takafumi; Anze, Hirohito; Oogi, Susumu; Kamikubo, Takashi; Tsuchiya, Seiichi; Shimizu, Masaharu; Matsuki, Kazuto; Inoue, Hideo; Tojo, Toru; Takigawa, Tadahiro

doi:10.1143/jjap.46.826

Cited by 30 publications

(33 citation statements)

References 14 publications

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“…There are even no patterns at all in the case of positive resist. Of course there are several ways to improve the dose modulation method, like by increasing the number of available doses to get finer dose allocation or by increasing the number of Gaussian functions in the PSF to get a model that better matches the scattering of electrons 10 , or by using more accurate modelling and algorithms for dose allocation 11,12,13 . Another solution is to implement geometrical correction 5,14 .…”

Section: Current Correction Methodsmentioning

confidence: 99%

New writing strategy in electron beam direct write lithography to improve critical dense lines patterning for sub-45nm nodes

Martin

Manakli

Icard

et al. 2009

25th European Mask and Lithography Conference

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Electron beam direct write lithography is known for its high resolution capabilities, which enables studies ahead of the technology in production. That is why this technique is used for many years in laboratories for R&D. Recently it was shown that electron beam lithography can be integrated within the flows of the microelectronics industry for prototyping applications, low volume production and to support optical lithography for ASIC manufacturing. Moreover recent lithography workshops highlighted that the multi beam solution is identified as one potential technique for next generation lithography techniques to meet the requirements of sub-32nm technological nodes. The present proximity correction methods for electron beam lithography are based on the standard dose modulation principle. However these methods cannot properly ensure a sufficient control of the patterning of the most critical designs. To push the resolution capability of electron beam lithography, a new correction method is proposed. It consists in a multiple pass exposure strategy. For example instead of patterning a line in one pass (standard exposure), the pattern is split in several basic blocks with potential overlaps exposed in several passes and with an adapted dose. Compared to standard exposure, this solution provides an improved process window and a better control of the critical dimensions. We could achieve energy latitude of 22.2% and we improved the line edge roughness by 27% on 45nm dense lines (line width equal to space) with this method.

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Section: Current Correction Methodsmentioning

confidence: 99%

New writing strategy in electron beam direct write lithography to improve critical dense lines patterning for sub-45nm nodes

Martin

Manakli

Icard

et al. 2009

25th European Mask and Lithography Conference

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“…The coarse graining method including the pattern density method 21) and the representative figure method 19,20,[22][23][24][25][26][27] have been used for the proximity effect correction. These methods use the characteristic features of a pattern, such as pattern density, to correct the proximity effect, instead of using the figures of the LSI pattern themselves.…”

Section: Coarse Graining Methodsmentioning

confidence: 99%

Proximity Effect Correction for Mask Writing Taking Resist Development Processes into Account

Abe¹,

Matsumoto

Shibata³

et al. 2009

Jpn. J. Appl. Phys.

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In this paper, a proximity effect correction method for mask fabrication with taking into account resist development processes is proposed. The idea of our method is that the figure size of a developed resist is determined using a suitable function of exposure dose and the normalized deposited energy by backscattering electrons, under the assumption of high acceleration voltage electron beam mask writing. This suitable function should be determined empirically to include the effects of resist development process, and is called development process function in this paper. Methods of deriving the development process function, proximity effect correction equation, and optimum correction dose from the equation are proposed. To check the accuracy of our method, a sample model of development process function is introduced under the condition that the conventional threshold model has an intrinsic error of 8 nm. The method proposed in this paper is found to be able to suppress the correction error of this sample model to less than 1 and 0.2 nm by two and three iterations, respectively. The method proposed in this paper is expected to provide high accuracy proximity effect correction in future mask fabrication.

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“…Especially, taking only long range backscattering into account in the correction can lead to errors that would increase when the real process effects behave with increased mid-range effects. For the sake of the demonstration, we chose a virtual process A dose correction handling long range backscattering only [2] is applied to the test layout. The correction and the verification are run with different models (each one is supposed to be an image of a real process …”

Section: Evaluation Of Correction Accuracymentioning

confidence: 99%