Synopsys, Inc.

Apple Inc.

Hua Song

James Patrick Shiely

Qiaolin Zhang

Cheng En Wu

Lawrence S Melvin, Iii

Weiping Fang

Daniel Zhang

Juhwan Kim

Gerard Luk-Pat

Zong Wu Tang

Yuelin Du

Daniel A Podhajny

Yi Zou

Haiqing Wei

Benjamin David Painter

Zongwu Tang

Guangming Xiao

Liming Wang

Alexander Miloslavsky

Irene Y Su

Lantian Wang

Lantiang Wang

Lena Zavyalova

A first set of critical dimension (CD) measurements of resist patterns created by a lithography process and a second set of CD measurements of water patterns created by an etch process may be obtained. A forward etch model and an inverse etch model may be calibrated together by reducing (1) a first prediction error between the second set of CD measurements and a first set of simulated CDs predicted by the forward etch model based on the resist patterns, a second prediction error between the first set of CD measurements and a second set of simulated CDs predicted by the inverse etch model based on the wafer patterns, and a matching error between the forward etch model and the inverse etch model.

Inverse etch model for mask synthesis

Systems and techniques for three-dimension (3D) resist profile aware resolution enhancement techniques are described. 3D resist profile aware resolution enhancement models can be calibrated based on empirical data. Next, the 3D resist profile aware resolution enhancement models can be used in one or more applications, including, but not limited to, lithography verification, etch correction, optical proximity correction, and assist feature placement.

3D resist profile aware resolution enhancement techniques

An item such as a fabric-based item may have a layer of fabric such as a layer of woven fabric. The fabric layer may include warp and weft strands. The fabric may cover keys in a keyboard or may be used in forming other structures in the fabric-based item. Each key may have an illuminated key label. Portions of the fabric may be processed by pressing heated protrusions on a textured mold into polymer optical fibers in the fabric. The protrusions form corresponding light-scattering recesses in cladding portions of the optical fibers. Light-emitting diodes or other light sources may be coupled to respective end surfaces of the optical fibers. The light-emitting diodes emit light that is emitted from the thermally imprinted light-emitting regions formed by pressing the heated protrusions into the optical fibers.

Fabric items with thermally imprinted light-emitting regions

A computer-implemented method includes modeling, using the computer, a photoresist profile in accordance with a magnitude of a gradient of an inhibitor concentration disposed in the photoresist. The photoresist is used during a process to form an integrated circuit. In one embodiment, the computer-implemented method further includes applying the modeled photoresist profile to reduce a distortion in a printed photoresist pattern caused by a response of the photoresist to an electromagnetic wave and/or particle beam during the process.

Method for modeling a photoresist profile

Systems and techniques for using a three-dimension (3D) resist profile aware etch-bias model are described. A 3D resist profile aware etch-bias model can be calibrated based on empirical data. Next, the 3D resist profile aware etch-bias model can be used in one or more applications, including, but not limited to, lithography verification, etch correction, optical proximity correction, and assist feature placement.

3D resist profile aware etch-bias model

Processes and apparatuses are described for modeling and correcting electron-beam (e-beam) proximity effects during e-beam lithography. An uncalibrated e-beam model, which includes a long-range component and a short-range component, can be calibrated based on one or more test layouts. During correction, a first resist intensity map can be computed based on the long-range component of the calibrated e-beam model and a mask layout. Next, a target pattern in the mask layout can be corrected by, iteratively: (1) computing a second resist intensity map based on the short-range component of the calibrated e-beam model and the target pattern; (2) obtaining a combined resist intensity map by combining the first resist intensity map and the second resist intensity map; and (3) adjusting the target pattern based on the combined resist intensity map and the design intent.

Modeling and correcting short-range and long-range effects in E-beam lithography

Mask design techniques for detection and removal of undesirable artifacts in SADP processes using multiple patterns are disclosed. Artifacts or spurs result from lithographic and chemical processing of semiconducting wafers. The spurs are undesirable because they can cause unwanted connections or act as electrical antennas. Spurs are detected using rule-based techniques and reduced by modifying lithographic masks. The severity of the detected spurs is determined, again using rule-based techniques. The effects of detected spurs can be reduced by modifying the decomposition of the drawn patterns into the two masks used for lithography. Mandrel masks are modified by add dummy mandrel material, and trim masks are modified by removing trim material. The resulting multi-pattern arrangement is used to fabricate the critical design elements that make up the semiconductor wafers.

Detection and removal of self-aligned double patterning artifacts

Mask design techniques for sharp corner printing in liquid crystal displays are disclosed using multiple patterns. The viewing angle and color quality of thin film transistor liquid crystal displays are largely dependent upon electrode corner sharpness as patterned in a given metal layer. Depending on design style, critical elements include convex angles, concave angles, or both convex and concave angles. Angle sharpness is dependent upon the resolution limit of a given exposure system. Since critical design element requirements exceed the capabilities of one mask, two or more masks are implemented. The determination of critical pattern features within a given layer identifies angles that are problematic for fabrication. The critical pattern features are decomposed into multiple mask layers. The resulting multi-pattern arrangement is used to fabricate the critical design elements that make up the needed angles.

Multi-patterning for sharp corner printing

Systems and techniques for modeling the EUV lithography shadowing effect are described. Some embodiments described herein provide a process model that includes an EUV lithography shadowing effect component. Polygon edges in a layout can be dissected into a set of segments. Next, the EUV lithography shadowing effect component can be used to bias each segment. The modified layout having the biased segments can then be used as input for other components in the process model.

Modeling EUV lithography shadowing effect

One embodiment of the present invention provides a system that accurately models polarization states of an illumination source in an optical lithography system for manufacturing integrated circuits. During operation, the system starts by receiving a two-dimensional (2D) grid map for an illumination source pupil in the optical lithography system. The system then constructs a source-polarization model for the illumination source by defining a polarization state at each grid point in the grid map. Next, the system enhances a lithography model for the optical lithography system by incorporating the source-polarization model into the lithography/OPC model.

Modeling an arbitrarily polarized illumination source in an optical lithography system

Extreme ultraviolet (EUV) lithography flare calculation and compensation is disclosed herein. A method of calculating flare for a mask for use in EUV lithography includes decomposing the flare power spectrum density (PSD) into a low frequency component and a high frequency component. Further, the method includes receiving a plurality of layouts in a flare map generator. Each of the plurality of layouts corresponds to a chip pattern location on the mask. Moreover, the method includes generating, using the flare map generator, a low frequency flare map for the mask from the low frequency component by using fast Fourier transform (FFT).

EUV lithography flare calculation and compensation

One embodiment of the present invention provides a system that determines image intensity at a location in a photoresist (PR) layer on a wafer. During operation, the system receives a set of masks which were used to generate one or more patterned layers of a multilayer structure on the wafer, wherein a patterned layer includes a set of reflectors on a top surface of the patterned layer, which correspond to patterns in a patterned-layer mask in the set of masks, wherein a reflector reflects light from a light source during a photolithography process. The system then generates a first virtual mask based on the first mask and the patterned-layer mask, wherein the first virtual mask uses a clear area to model a reflector in the set of reflectors. Next, the system determines the image intensity value at the location on the PR layer based at least on the first mask and the first virtual mask.

Modeling thin-film stack topography effect on a photolithography process

One embodiment of the present invention provides a system that performs lithography verification for a double-patterning process on a mask layout without performing a full contour simulation of the mask layout. During operation, the system starts by receiving a first mask which is used in a first lithography step of the double-patterning process, and a second mask which is used in a second lithography step of the double-patterning process. Note that the first mask and the second mask are obtained by partitioning the mask layout. Next, the system receives an evaluation point on the mask layout. The system then determines whether the evaluation point is exclusively located on a polygon of the first mask, exclusively located on a polygon of the second mask, or located elsewhere. The system next computes a printing indicator at the evaluation point for the mask layout based on whether the evaluation point is exclusively located on a polygon of the first mask or exclusively located on a polygon of the second mask.

Method and system for performing lithography verification for a double-patterning process

One embodiment provides a system for using a database to quickly identify a manufacturing problem area in a layout. During operation, the system receives a first check-figure which identifies a first area in a first layout, wherein the first area is associated with a first feature. Next, the system determines a first sample using the first check-figure, wherein the first sample represents the first layout's geometry within a first ambit of the first check-figure, wherein the first sample's geometry is expected to affect the shape of the first feature. The system then performs a model-based simulation using the first sample to obtain a first simulation-result which indicates whether the first feature is expected to have manufacturing problems. Next, the system stores the first simulation-result in a database which is used to quickly determine whether a second feature is expected to have manufacturing problems.

Method and apparatus for using a database to quickly identify and correct a manufacturing problem area in a layout

A computer is programmed to perform lithography simulation at a number of locations in a transverse direction relative to a length of a feature of an IC design, to obtain simulated intensities at the locations. The computer is further programmed to determine constants of a predetermined formula that models a trend of the simulated intensities as a function of distance (in the transverse direction), by curve-fitting. The computer is also programmed to compute a value ('CD predictor') based on the just-determined constants, the formula and a known threshold intensity for a given position along the feature's length. The just-described process, of lithography-simulation, followed by curve-fitting, followed by CD predictor computation, is repeatedly performed to obtain a number of CD predictors at a corresponding number of positions along the feature's length. The CD predictors are used to identify a position of a critical dimension, for use in, for example, layout verification.

Growing community of inventors

San Jose, CA, United States of America

Hua Song