Metrology methods and targets are provided for reducing or eliminating a difference between a device pattern position and a target pattern position while maintaining target printability, process compatibility and optical contrast—in both imaging and scatterometry metrology. Pattern placement discrepancies may be reduced by using sub-resolved assist features in the mask design which have a same periodicity (fine pitch) as the periodic structure and/or by calibrating the measurement results using PPE (pattern placement error) correction factors derived by applying learning procedures to specific calibration terms, in measurements and/or simulations. Metrology targets are disclosed with multiple periodic structures at the same layer (in addition to regular target structures), e.g., in one or two layers, which are used to calibrate and remove PPE, especially when related to asymmetric effects such as scanner aberrations, off-axis illumination and other error sources.

A method at tuning a lithographic process for a particular patterning device. The method includes: obtaining wavefront data relating to an objective lens of a lithographic apparatus, the wavefront data measured subsequent to an exposure of a pattern on a substrate using the particular patterning device; determining a pattern specific wavefront contribution from the wavefront data and a wavefront reference, the pattern specific wavefront contribution relating to the patterning device; and tuning the lithographic process for the particular patterning device using the pattern specific wavefront contribution.

A layout geometry of a lithographic mask is received. The layout geometry includes at least one shape having one or more rounded corners. The layout geometry is partitioned into a plurality of feature images, for example as selected from a library. The feature images include at least one mask corner rounding (MCR)-corrected feature image that accounts for the rounded corners of the shape. The feature images have corresponding mask 3D (M3D) filters, which represent the electromagnetic scattering effect of that feature image for a given source illumination. The mask function contribution from each of the feature images is calculated by convolving the feature image with its corresponding M3D filter. The mask function contributions are combined to determine a mask function for the mask illuminated by the source illumination.

A method of forming a resist pattern includes applying a photoresist to first and second regions of a processing target to form a resist layer. The processing target includes a stacked body of alternately stacked first and second layers. The first region includes an upper surface of the stacked body, and the second region includes a recess extending into the stacked body from the upper surface. The resist layer is then patterned with light passed through a multi-gradation mask including a partial translucent feature at an outer perimeter of the recess, a light shielding feature corresponding in position to the recess, and a translucent feature surrounding the partial translucent feature. A resist pattern is formed including an overhang portion extending above a portion of the recess.

Disclosed are a photomask, an exposure apparatus, and a method of fabricating a three-dimensional semiconductor memory device using the same. The photomask may include a mask substrate, a first mask pattern on the mask substrate, and an optical path modulation substrate. The optical path modulation substrate may include a first region on a portion of the first mask pattern, and a second region on another portion of the first mask pattern. The second region has a thickness that is less than a thickness of the first region.

A method is provided. The method includes forming a shrink material layer over a substrate including a photoresist pattern. The method also includes exposing the substrate with the shrink material layer to an activating radiation via a grey-tone mask that provides a predetermined light transmittance profile for the activating radiation. The method also includes removing at least a portion of the shrink material layer.

A method, includes, in part, defining a continuous signal, defining a threshold value, calibrating the continuous signal and the threshold value from measurements made on edges of one or more patterns on a mask and corresponding edges of the patterns on a wafer, convolving the continuous signal with a kernel to form a corrected signal, and establishing, by a processor, a probability of forming an edge at a point along the corrected signal in accordance with a difference between the value of the corrected signal at the point and the calibrated threshold value. The kernel is calibrated using the same measurements made on the patterns' edges.

An electronic device includes a substrate having contact pads disposed thereon and traces interconnecting the contact pads. A first integrated circuit (IC) die is mounted on the substrate and includes a predefined set of circuit components arranged on the first IC die in a first geometrical pattern, which is non-symmetrical under reflection about a given axis in a plane of the die. A second IC die is mounted on the substrate and includes the predefined set of circuit components arranged on the second IC die in a second geometrical pattern, which is a mirror image of the first geometrical pattern with respect to the given axis.

Feature images representing a layout geometry of a lithographic mask are received. Mask function (MF) contributions from individual feature images are calculated by convolving the feature image with a corresponding three-dimensional mask (M3D) filter. The M3D filters represent an electromagnetic scattering effect of that feature image. At least one M3D filter also accounts for effects arising from a fabrication process for the lithographic mask.

In some aspects, an integrated model accounts for effects from both the mask fabrication process and the wafer lithography process. The aerial image incident on the wafer, the pattern printed on the wafer, and/or measures of the foregoing are estimated using an integrated three-dimensional mask (M3D) model, as follows. The shapes in the mask fabrication description are partitioned into feature images. Each feature image is convolved with a corresponding M3D filter. The M3D filter represents an electromagnetic scattering effect of that feature image in the wafer lithography process, and the feature image and/or M3D filter account for effects on the layout geometry from the mask fabrication process. This is done without estimating the mask pattern printed on the lithographic mask. The mask fabrication description is modified based on differences between the estimated lithography results and corresponding target results.