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Mask Registration Metrology Systems

LMS IPRO7 LMS IPRO6 LMS IPRO5
LMS IPRO7

Product Description

The LMS IPRO7 mask registration metrology tool is designed to accurately verify pattern placement performance of reticles for the 7nm node. It offers comprehensive characterization of reticle pattern placement error, which is a direct contributor to intra-field wafer overlay error. As several papers indicate1, due to different mask registration performance of targets and on-device features, it is mandatory to characterize the reticle contribution to intra-field wafer overlay on on-device patterns. KLA-Tencor’s proprietary model-based metrology algorithm allows the LMS IPRO7 mask metrology system to accurately measure placement error for on-device pattern features, and thus characterize real mask contribution to intra-field overlay.

Based on the industry-proven IPRO platform, the LMS IPRO7 mask registration metrology system achieves its industry-leading performance by incorporating several new or improved features:

  • New operating mode provides highly accurate on-device measurement of reticle registration error with industry-leading cycle time for comprehensive reticle qualification
  • Significantly improved measurement performance over the LMS IPRO6 enables development and production of reticles at the ≤7nm design node
  • Fast and accurate model-based image processing algorithms for on-device pattern metrology to detect and characterize pattern dependent placement error
  • Optical resolution enables measurement of all immersion masks and development and production of EUV masks
  • Registration measurement on 193i reticles with and without pellicles
  • High-throughput mode enables more comprehensive reticle and e-beam qualification at the same cycle time for production masks
  • Registration metrology on resist test masks enables feed forward of mask registration data to 5D Analyzer® for optimized intra-field scanner corrections
  • Automated pattern selection from design capability allows for easy generation of on-device measurement jobs with 1000 or more OPC’ed sites
  • Field-proven EUV mask capability for 7 nm node development
  • Field upgradability from the previous generation model protects customer’s capital investment

Applications

Mask OQC: When a mask is shipped, many IC fabs now require that densely sampled registration data - not just a 3-sigma value - are provided along with the mask. A single number is no longer sufficient to characterize a mask, given the tight wafer overlay specifications driven by challenging 7nm lithography technologies. Likewise, an under-sampled mask can harbor an unrecognized pattern registration excursion—which can result in a major yield hit for the IC fab. Sufficient sampling however requires accurately measuring on-device patterns inside the active array. LMS IPRO7’s unique proprietary model-based measurement algorithm enables highly accurate measurements of any feature.

The LMS IPRO7 mask metrology system delivers the capabilities needed for a mask manufacturer to provide a registration characterized mask to the fab on schedule—and allows both the mask shop and fab to have confidence that the mask registration is good.

Mask writer qualification and monitoring: Today’s mask writers are able to incorporate sub-nm pattern placement corrections. In order to take advantage of this capability, pattern placement error must be measured accurately with high sampling frequency. LMS IPRO7 supplies the automation performance, high throughput, and analytical software needed to fully characterize reticle pattern placement error. Based on these data the performance of the mask writer can be verified and adjustments performed if required, so that fewer problems are discovered at outgoing quality control (OQC).

Mask process development and monitoring: LMS IPRO7 is the only mask registration metrology system to offer flexible, automated on-device metrology, industry-leading performance, and the ability to take through-pellicle (193i masks) measurements. In order to envision and correct pattern dependent registration error, the LMS IPRO7 provides accurate measurement capability on actual on-device features.

Furthermore, the LMS IPRO7 is the only DUV illumination-based registration tool which enables measurement on resist masks in order to separate e-beam error from process deviations.

Wafer patterning control: As part of the 5D Patterning Control Solution™, LMS IPRO7 reticle data can be directly uploaded to the industry standard 5D Analyzer software to assess the mask’s contribution to wafer overlay error. Thus, on-device data can be fed forward to the wafer fab’s lithography module and used for optimized scanner corrections that can improve intra-field wafer overlay yield.

REFERENCE

  • LMS IPRO6 Mask metrology system for the 10nm design node
  • LMS IPRO5 Mask metrology system for the 16nm design node
LMS

“Mask contribution to intra-field wafer overlay”, SPIE 90501Q / 2014 (YMS: http://www.ymsmagazine.com/); and “In-Die Registration Measurement Using Novel Model-Based Approach for Advanced Technology Masks”, PMJ 2014

KLA-Tencor supports the need for registration metrology on flexible substrates, e.g., 5009 5” (127mm) and 6025 6” (152mm) reticles, with new and used LMS IPRO4 systems. For more information, please contact your local KLA-Tencor organization or fill in our inquiry form.

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