Practical approach for AAPSM image imbalance correction for sub-100-nm lithography

Cho, Hung Lin; Lin, Shu; Hsieh, F.; Kroyan, Armen; Liu, Huayu; Huang, Jian; Hsu, Steven; Huang, I. H.; Lin, B. N.; Hung, Kuei-Chun

doi:10.1117/12.504393

Cited by 3 publications

(2 citation statements)

References 7 publications

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“…The experimental results confirm the simulation prediction that an optimal combination of shifter width bias with undercut can be used effectively to correct the image intensity imbalance 6 . Problems in the process of manufacturing alternating PSM mask have been solved, including three essential factors, which are overlay of 2nd writing, the profile of quartz dry etching and depth control 7 .…”

Section: Introductionsupporting

confidence: 87%

Extension of ArF lithography for poly gate patterning of 65-nm generation and beyond

et al. 2004

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Due to the existing problems and delay of 157nm lithography tool, extension of the ArF (193nm) lithography process with resolution enhancement techniques (RET) should be considered for the 65nm generation lithography and beyond. The mature double-exposure lithography process based on dark-field alternating phase-shift mask (PSM) is one of the promising RET candidates, which is proven to be one of the production-ready strong phase-shifting techniques for current and future IC generations.In this paper, poly gate patterning with the minimum pitch of 160nm has been demonstrated with high numeric aperture (NA) and small partial coherence of ArF lithography along with a dark-field alternating PSM. For poly gate patterning of 65nm generation, optimum illumination settings are found for minimum pitch of 160nm. Through-pitch common process windows for gates with 65nm after-development-inspection (ADI) critical dimension (CD) at minimum pitch of 160nm can be reached larger than 0.30um depth of focus (DOF), which can be used for 65nm node production. Through-pitch proximity can be compensated by optical proximity correction (OPC). Line edge roughness (LER) can be improved a little by this dark-field alternating PSM technique. LER is found of strong aerial image contrast dependency. Shifter width is also chosen as optimum value to obtain the largest process windows and minimize the phase conflicts. 193nm Hi-NA or liquid immersion lithography is suggested to push the alternating PSM resolution limitation.

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Section: Introductionsupporting

confidence: 87%

Extension of ArF lithography for poly gate patterning of 65-nm generation and beyond

et al. 2004

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“…Structure of alternating aperture phase shifting mask (Alt-PSM) has been discussed and a lot of investigations on optimization were reported because structural detail has a large influence on the wafer printing performance [1][2][3][4][5][6][7][8]. In our previous works [2][3][4], we have discussed the characteristic of several Alt-PSM structures in 90-65nm nodes.…”

Section: Introductionmentioning

confidence: 99%

Optimization of Alt-PSM structure for 45nm node ArF immersion lithography

et al. 2005

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Alternating Aperture Phase Shifting Mask (Alt-APSM) has been expected as one of the practical techniques for 45nm node ArF lithography. We have already discussed and proposed the Single trench with undercut (UC) and bias structure is the primary candidate for 65nm node Alt-APSM structure. In fact, we have selected this structure as a standard in production for 65nm node Alt-PSM. For the 45nm node, according to the design shrinkage, mask rule such as MRC which specify minimum chrome CD between 0 and pi degree apertures and etc. is getting tighter. So, we need to consider about single trench with no undercut and bias structure. Such two types of structure are the candidates for 45nm node Alt-APSM. Exposure conditions will be considered as 0.9 or higher NA and the immersion technology as well.In this work, we will discuss about 45nm node Alt-PSM structure in terms of lithographic performance by using 3D rigorous optical simulation software. Two types of structure, single trench with UC and bias, and single trench with No UC and bias are compared. We examined the following items to find optimum Alt-PSM structure, 0/pi space bias to minimize CD difference at the wafer, quartz depth to optimize effective phase and optical proximity correction (OPC) to adjust printed line CD in through pitch condition. Wafer printing performance will be evaluated by the stability of line CD and 0-pi CD difference, contrast, NILS, phase angles, MEEF, ED-window and gate position shift.

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