Contact hole formation by multiple exposure technique in ultralow-k 1 lithography

Nakamura, Hiroko; Onishi, Yasunobu; Satõ, Kazuya; Tanaka, Satoshi; Motomizu, Shoji; Hashimoto, Koji; Inoue, Soichi

doi:10.1117/12.535114

Cited by 14 publications

(16 citation statements)

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“…To coat a second positive tone resist on top of a patterned first positive tone resist requires a step to prevent intermixing of these two resists. The typical step reported in the literature is to UV cure the first resist [4][5][6] . In this process, an extra UV curing tool is required.…”

Section: Introductionmentioning

confidence: 99%

“…Major challenges for the multilayer resist systems for DE are: 1) no intermixing between 2 resist layers, 2) no substantial distortion of the resist images of each resist layer in the bake and developing processes, and 3) performing well in meeting or exceeding the lithographic requirements by each resist layer. Typical examples of DE using 2 layer resists are pitch splitting technique developed for dense lines 2,3 and cross grid contact hole printing [3][4][5][6] . To coat a second positive tone resist on top of a patterned first positive tone resist requires a step to prevent intermixing of these two resists.…”

Section: Introductionmentioning

confidence: 99%

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Resist freezing process for double exposure lithography

Chen

Huang

et al. 2008

Advances in Resist Materials and Processing Technology XXV

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In this study, we have developed a thermal freezing process to prevent intermixing between 1 st patterned positive resist and 2 nd positive resist. Based on solvent solubility switch characteristic of polymer after higher temperature bake, a prototype of polymer consisting of methyladmantane mathacrylate, norbornanecarbo lactone mathacrylate and hydroxyl admantane mathacrylate was selected for resist-on-resist double exposure experiment to prevent the intermixing between layers. Photo sensitivity shifting of this prototype resist after post develop bake further facilitates the design by preventing 1st layer resist distortion from 2nd exposure. Lastly, through composition and formulation optimization, 35nm L/S patterns were successfully demonstrated by using a 1.2NA stepper.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Resist freezing process for double exposure lithography

Chen

Huang

et al. 2008

Advances in Resist Materials and Processing Technology XXV

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“…Without stabilization, the first resist pattern will swell or dissolve on application of the second resist film, or undergo additional exposure and development during the patterning of the second resist. Numerous chemical, 3,6,[9][10][11][12][13] photochemical, [1][2][3][4]14 thermal, 8 and ion-beam 5,7,15 stabilization methods have recently been described.…”

Section: Introductionmentioning

confidence: 99%

“…1͒. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] Stabilization of the first photoresist pattern before processing of the second resist pattern is necessary in double imaging. Without stabilization, the first resist pattern will swell or dissolve on application of the second resist film, or undergo additional exposure and development during the patterning of the second resist.…”

Section: Introductionmentioning

confidence: 99%

Cure-induced photoresist distortions in double patterning

Wallow

Rayasam

Yamaguchi

et al. 2009

J. Micro/Nanolith. MEMS MOEMS

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Many processes are under evaluation as simplifications to current double patterning methods. Reduction in process complexity and cost may be achieved by use of track-based photoresist stabilization methods that eliminate one etch step by allowing a second resist to be patterned over a first resist. Examples of stabilization methods using numerous curing processes have been reported. At least some resist shrinkage during stabilization appears to be generally observed for these methods. We evaluate the link between shrinkage and three-dimensional pattern distortions at line ends and elbow corners using experimental and simulation-based methods. A 172-nm UV resist curing process was used to produce controlled shrinkage ranging from 5% to 30%: shrinkage was correlated with resist distortions. At cure dose sufficient to stabilize the resist, shrinkage of approximately 23% results in measured line-end pullback and elbow displacement of approximately 16% and 13% of nominal linewidth respectively, when measured at resist half-height. Finite element analysis of resist beam structures produces shrinkage distortions that are in good qualitative and semiquantitative agreement with these measurements and thus appears to provide a provisionally general and useful method for predicting pattern distortions that arise during cure-based resist stabilization methods used in double imaging.

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“…UV light 2,4) and ion implantation 5) were used. The merit of the method is that only one process is added to the conventional process as a resist insoluble treatment.…”

Section: Introductionmentioning

confidence: 99%

Ion implantation as insoluble treatment for resist stacking process

Nakamura

Shibata

Rikimaru

et al. 2008

Advances in Resist Materials and Processing Technology XXV

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With regard to the resist stacking process, it was proposed that the implantation of ions whose acceleration voltage was below 50 kV could make the lower-layer resist insoluble for the upper-layer resist patterning process. But the lower-layer resist pattern was observed to be peeled off in a pattern. In another type of the pattern whose lower-layer pattern was fastened by the upper-layer pattern, there were caves in the bottom of the lower-layer resist pattern. From the calculation of the projected range of the ions, it was found that the ions cannot reach the bottom of the lower-layer resist pattern, so that the bottom of the lower-layer resist was not hardened. The peeling-off was due to the dissolution of the bottom in the lower-layer resist during the development of the upper-layer resist pattern. When the acceleration voltage of the implanted ions is set so that the projected range of the ions is larger than the resist thickness, the lower-layer resist can be made effectively insoluble for the upper-layer resist patterning process. The ion implanted pattern can be used as the etching mask. Moreover, the ions can be prevented from penetrating the film to be etched by adjusting the acceleration voltage.

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Contact hole formation by multiple exposure technique in ultralow-k 1 lithography

Cited by 14 publications

References 0 publications

Resist freezing process for double exposure lithography

Resist freezing process for double exposure lithography

Cure-induced photoresist distortions in double patterning

Ion implantation as insoluble treatment for resist stacking process

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