Impact of the OMOG substrate on 32 nm mask OPC inspectability, defect sensitivity, and mask design rule restrictions

Badger, Karen; Kodera, Yutaka; Gallagher, Emily; Lawliss, Mark

doi:10.1117/12.801951

Cited by 8 publications

(8 citation statements)

References 5 publications

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“…The phase interference effect, or amount of ringing contributes to the perceived optical size of the image, as seen by the inspection tool. As was demonstrated in early testing when standard OMOG was first introduced, sensitivity appears to be dependent more on the defect's impact on CD rather than on defect size [2]. It follows that if the perceived image size can be made to appear smaller, the same size defect would have a greater impact on CD.…”

Section: Thin Omog Defect Sensitivitymentioning

confidence: 91%

“…During our investigation of this reflect light contrast difference at 193 nm wavelength, we discovered a fair amount of phase interference effect at 193 nm for standard OMOG that is not present at 257 nm on either attenuator, nor is it present at 193 nm on thin OMOG. This phase interference effect (referred to as 'ringing') is a condition also seen on 193 nm attenuated phase shift attenuators and is believed to contribute to increased defect sensitivity [2]. At 193 nm wavelength for standard OMOG, there is a 1.2X difference in reflectivity between quartz and the attenuator, whereas for thin OMOG that difference, also at 193 nm wavelength, is 6.8X, resulting in less ringing.…”

Section: Thin Omog Defect Sensitivitymentioning

confidence: 98%

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The impact of a thinner binary mask absorber on 22nm and beyond mask inspectability and defect sensitivity

Badger¹,

Seki

2011

SPIE Proceedings

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As part of 20 nm/22 nm process development, an evaluation was performed to determined the impact of Thin OMOG on mask inspection. Despite significant improvements in mask inspectability and reduced database modeling errors, thin OMOG demonstrated lower defect sensitivity as compared to Standard OMOG at the same inspection conditions (calibration, sensitivity). Stack height aside, the primary difference between standard and thin OMOG is attenuator reflectivity. It is surmised that the reduction in sensitivity is due to a lower reflected light contrast on thin-OMOG. This characteristic was noted for both 257 nm and 193 nm inspection wavelengths.In addition to the reduction in defect sensitivity, an unexpected phase interference was noted at the image edge with a 193 nm inspection wavelength, for Standard OMOG, but not for Thin OMOG. This interference, or undershoot is due in part to the low difference in reflectivity and phase between the quartz and the attenuator on the Standard OMOG substrate. This difference is more than five times greater for the Thin OMOG attenuator.The primary focus of this paper is on the characterization of thin OMOG relative to the interaction between attenuator reflectivity, image quality, database modeling and tool calibrations as they relate to mask inspectability and defect sensitivity. This paper will also address the changes required to compensate for the loss of sensitivity induced by the introduction of the thin OMOG absorber.

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Section: Thin Omog Defect Sensitivitymentioning

confidence: 91%

Section: Thin Omog Defect Sensitivitymentioning

confidence: 98%

The impact of a thinner binary mask absorber on 22nm and beyond mask inspectability and defect sensitivity

Badger¹,

Seki

2011

SPIE Proceedings

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“…Recent studies suggest that defect inspection and repair capabilities are considered as significant factors to deal with the scaling down in feature size. [1][2][3] As stated in another recent study, currently mainly tools adopting existing photomask inspection technologies are applied for EUV mask defect inspection. 4 Above all, NPI6000EUVα developed with SELETE adopting various types of polarization is considered as the most promising tool for volume production of Photomasks with feature size of HP22nm and beyond.…”

Section: Introductionmentioning

confidence: 99%

Defect inspection and repair performance comparisons between EUV and conventional masks

et al. 2010

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Two types of blanks, EUV A and EUV B, are the leading EUV blanks contenders. They are evaluated and compared with OMOG blank for their suitability as a photomask blanks. For defect inspection evaluation, contrast for pattern image and sensitivity for detection were evaluated using the newly developed inspection tools. With these tools, it is learnt that the sensitivity varies according to a set of conditions. For repair performance evaluations, EUV mask was assessed through E-beam repair tools, those that are most widely used. The results on both types of masks demonstrate good repair shape that is almost same quality as repair on OMOG mask. Moreover, under the two types of repair conditions used in this study, no degradation on pattern was found for the optimized condition as result of repair work.

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“…Due to its binary nature, OMOG demonstrates many advantages over 6% EAPSM such as improved resolution and CD uniformity and an improvement in the inspectability [4][5][6] . Since the early 1990's Hi-T films were presented as an extension of the 6% EAPSM technology that provided many benefits leading to an improvement in the process window over 6% EAPSM [7][8][9][10][11][12] .…”

Section: Introductionmentioning

confidence: 99%

Impact of new MoSi mask compositions on processing and repair

2010

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The mask industry has recently witnessed an increasing number of new MoSi mask blank materials which are quickly replacing the older materials as the standard in high end mask shops. These new materials, including OMOG (opaque MoSi on glass) and high transmission (Hi-T) films, are driven foremost by the need to reduce feature size through resolution enhancement techniques (RET). The subject of this paper is a new low stress, Hi-T material which addresses the challenges presented by transitioning to smaller technology nodes including difficulties with pattern transfer, cleaning and repair. This material, based on currently employed MoSi films, eliminates process steps and utilizes a thinner overall substrate stack than currently used Hi-T schemes allowing an increase in critical dimension (CD) uniformity and feature resolution and more robustness due to a lower aspect ratio. While this new material is MoSi based the small compositional change requires, in some cases, a significant change in processing. Among the most impacted areas are the etch, clean and repair steps. Given the potential for defects to manifest on masks, repair is an invaluable step that can significantly impact the overall yield and lead to a reduction in cycle time 1 . The Carl Zeiss MeRiT ® electron beam mask repair line provides the most advanced repair capabilities allowing a wide range of repairs to be performed on a number of mask types 2 . In a joint effort between MP Mask Technology Center LLC and Carl Zeiss SMT, this paper focuses on the benefits of the new Hi-T mask blank and the challenges it presents to the repair community. The differences between the new low stress, Hi-T material and current Hi-T technologies are presented and on site compositional analysis is performed with x-ray photoelectron spectroscopy (XPS) to illuminate the compositional differences. The development of a repair process for the new material utilizing the on-site Carl Zeiss MeRiT ® MG 45 is presented along with several repairs and their AIMS™ results. KEYWORDSMeRiT ® MG45, AIMS™ 45-193i, mask repair, defect repair, new MoSi materials, Hi-T, high transmission INTRODUCTIONEmbedded attenuated phase shift mask (EAPSM) technology is one of the most utilized RETs in high end mask shops today. The use of MoSi films which allow a small amount of the incident light to be transmitted through the opaque material, commonly 6% at a 180 degree phase shift with respect to the clear regions, allows for higher contrast and the ability to pattern smaller, more complex features than binary masks 3 . However, as the limits of this technology are currently being pushed the need to further reduce feature size and improve the process window has sparked interest in a number of new MoSi based films in order to bridge the gap between current mask manufacturing capabilities and the next technology. The importance of extending MoSi based materials as far as possible can be understood when considering the industry infrastructure. All current tools, materials and processes such as ...

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Impact of the OMOG substrate on 32 nm mask OPC inspectability, defect sensitivity, and mask design rule restrictions

Cited by 8 publications

References 5 publications

The impact of a thinner binary mask absorber on 22nm and beyond mask inspectability and defect sensitivity

The impact of a thinner binary mask absorber on 22nm and beyond mask inspectability and defect sensitivity

Defect inspection and repair performance comparisons between EUV and conventional masks

Impact of new MoSi mask compositions on processing and repair

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