Various methods and systems for utilizing design data in combination with inspection data are provided. One computer-implemented method for binning defects detected on a wafer includes comparing portions of design data proximate positions of the defects in design data space. The method also includes determining if the design data in the portions is at least similar based on results of the comparing step. In addition, the method includes binning the defects in groups such that the portions of the design data proximate the positions of the defects in each of the groups are at least similar. The method further includes storing results of the binning step in a storage medium.

Methods and systems for utilizing design data in combination with inspection data

This tutorial introduces the reader to the basic concepts of optical lithography, derives fundamental resolution limits, reviews the challenges facing future technology nodes, explains the principles of resolution enhancement techniques and their impact on chip layout, and discusses layout optimization considerations.

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Layout impact of resolution enhancement techniques: impediment or opportunity?

The implementation of alternating phase shifted mask lithography for the poly-conductor level of IBM's leading edge 65nm microprocessor is described. Very broad and 'resolution-enhancement-technology generic' design rules, referred to as radical design restrictions, are demonstrated to be key enablers of alternating phase shifted mask design. The benefit of these radical design restrictions over conventional design rules and other alternating phase shifted mask design approaches is detailed for key aspects of the design flow.

High-performance circuit design for the RET-enabled 65-nm technology node

We use the gradient of the image slope and gradient of the edge placement error (EPE) in order to improve both slope and EPE during OPC. The EPE gradient taken with respect to edge position is normally called MEEF or the MEEF matrix. Use of the gradient of image slope with respect to change in edge position was introduced by Granik as the “contrast matrix.” Whereas traditional OPC techniques focus on EPE alone (pattern fidelity), we broaden the scope of OPC to maximize slope for improved image robustness and to maximize process window.

Using OPC to optimize for image slope and improve process window

Various methods and systems for determining a position of inspection data in design data space are provided. One computer-implemented method includes determining a centroid of an alignment target formed on a wafer using an image of the alignment target acquired by imaging the wafer. The method also includes aligning the centroid to a centroid of a geometrical shape describing the alignment target. In addition, the method includes assigning a design data space position of the centroid of the alignment target as a position of the centroid of the geometrical shape in the design data space. The method further includes determining a position of inspection data acquired for the wafer in the design data space based on the design data space position of the centroid of the alignment target.

Methods and systems for determining a position of inspection data in design data space

Sub-resolution assist features (SRAF) have been shown to provide significant process window enhancement and across chip line-width variation reduction when used in conjunction with modified illumination lithography. Work previously presented at this conference has focused on the optimization of sraf design rules that specify the predominantly one dimensional placement and width of assist features as a function of layout pitch. This paper will recount the optimization of SRAF style options that specify how SRAF are to behave in realistic two dimensional circuit layouts. Based on the work done to strike the correct balance between sraf manufacturability, CAD turnaround time, and lithographic benefit in IBM's early product implementation exercises, the evolution of sraf style options is presented. Using simulation as well as exposure data, this paper explores the effect of various two dimensional sraf layout solutions and demonstrates the use of model based verification in the optimization of sraf style options.

Optimizing style options for subresolution assist features

An automated system for analyzing mask defects in a semiconductor manufacturing process is presented. This system combines results from an inspection tool and design layout data from a design data repository corresponding to each mask layer being inspected with a computer program and a predetermined rule set to determine when a defect on a given mask layer has occurred. Mask inspection results include the presence, location and type (clear or opaque) of defects. Ultimately, a determination is made as to whether to scrap, repair or accept a given mask based on whether the defect would be likely to cause product failure. Application of the defect inspection data to the design layout data for each mask layer being inspected prevents otherwise acceptable wafer masks from being scrapped when the identified defects are not in critical areas of the mask.

Mask defect analysis system

A mask/wafer control structure and an algorithm for placement thereof provide for data placement of measurement control structures, called a PLS, Process limiting Structure, on a mask and a plurality of chips on the wafer which provide for tighter control of both mask manufacture and wafer production by providing the most critical design structures for measurement during creation of the mask, and in the photolithography and etch processes. The PLS structures are located at multiple locations throughout the chip, and so they receive the same data preparation as the chip, and measurement tools are able to measure the same features at each fabrication step from fabrication of the mask to final formation of the etched features. Manufacturing control and the interlock between the wafer fabrication and the mask fabrication are enhanced, allowing for improved quality of the final product.

Joshua J. Krueger

Papers

Optimizing style options for subresolution assist features

Mask defect analysis system

Mask/wafer control structure and algorithm for placement