Lsi Logic Corporation

Lsi Corporation

Sergei Rodin

Stanislav V Aleshin

Marina Igorevna Medvedeva

Marina M Medvedeva

Eugeni E Egorov

Evgueny E Egorov

Ilya Golubtsov

Ranko L Scepanovic

Nadya Strelkova

Sergey V Uzhakov

A method and system is provided for automatically recognizing geometric points of features in a target design for OPC mask quality calculation. For each feature in the target design, x, y points comprising the feature are traversed and each neighboring pair of points is connected to define respective segments, wherein a set of contiguous segments form a step if the x values of the segments/points all increase or decrease and the same is true for the y values. Physical characteristics of the segments of the respective features are determined by comparing lengths of the segments to one another and to threshold values. Locations of quality measuring points are then determined along particular ones of the segments based on the physical characteristics.

Automatic recognition of geometric points in a target IC design for OPC mask quality calculation

The present invention is directed to a method and apparatus for optimizing fragmentation of integrated circuit boundaries for optical proximity correction (OPC) purposes. The present invention may balance the number of vertices and the 'flexibility' of the boundary and may recover fragmentation according to the process intensity profile along the ideal edge position to obtain the best decision for OPC.

Method and apparatus for optimizing fragmentation of boundaries for optical proximity correction (OPC) purposes

The present invention provides a method and system for analyzing the quality of an OPC mask. The method includes receiving a target layer from a target design, receiving an OPC mask layer from the OPC mask. The method also includes classifying each cell of at least one of the target layer and the OPC mask layer as either repeating or non-repeating, and for each repeating cell, recognizing geometric points in the target layer to determine quality measuring groups. The method also includes simulating the OPC mask layer based on the quality measuring groups, measuring edge placement errors (EPEs) based on at least one of the geometric points, and providing an EPE layer representing EPEs greater than an EPE threshold.

Method and system for analyzing the quality of an OPC mask

A method and system is provided for performing edge correction on a mask design. Aspects of the invention include initially fragmenting boundaries of the mask design for optical proximity correction, whereby edge segments of the boundaries are moved by a distance value; interpreting the moved edge segments by defining a new endpoint for respective pairs of neighboring edge segments that meet at an angle, the endpoint being a location of where lines on which the edge segments lie intersect, wherein the new endpoint is used to create a smoothed feature, resulting in a smoothed OPC mask; calculating distances between all pairs of comparable edge segments of the smoothed OPC mask; comparing the distances to a design rule limit; for each edge segment having a distance that exceeds the design rule limit, decreasing the segment's distance value; and optimizing the mask design by repeating the above steps until no distance violations are found.

OPC edge correction based on a smoothed mask design

The present invention is directed to a method and apparatus for making mask edge corrections using a gradient method for high density chip designs. The present invention uses a newly defined cost function.

Gradient method of mask edge correction

A method and system for simply and efficiently correcting sidelobe formation is disclosed. The method for reducing sidelobe formation in an aerial image created from an attenuated phase shift mask used in photolithography includes the steps of: a) generating a density map for an input design having a set of nodes identified as being outside of a periphery of the input design; b) examining the aerial image using the density map to compare an image intensity of the aerial image at a plurality of locations, each location corresponding to one node of the set of nodes; c) marking a node of the density map when the image intensity at the corresponding location of the aerial image satisfies a threshold intensity criterion and a separation distance criterion to create a set of marked nodes; and d) masking each node of the set of marked nodes.

Sidelobe correction for attenuated phase shift masks

A method of finding an optically periodic structure in a cell layer of an integrated circuit design includes receiving as input a physical representation of a cell layer of an integrated circuit design, finding reference coordinates of a selected portion of the cell layer from the physical representation of a cell layer, selecting an initial element located nearest to the reference coordinates, and constructing a base structure that includes the initial element and a minimum number of elements in the physical representation of the cell layer wherein the base structure may be replicated at an X-offset and a Y-offset to fill the entire selected portion so that for each element in each replica of the base structure there is an identical element at identical coordinates in the physical representation of the cell layer.

Growing community of inventors

Moscow, Russia

Sergei Rodin