A method of exposing a wafer to a high-tilt angle ion beam and an apparatus for performing the same are disclosed. In an embodiment, a method includes forming a patterned mask layer over a wafer, the patterned mask layer including a patterned mask feature; exposing the wafer to an ion beam, a surface of the wafer being tilted at a tilt angle with respect to the ion beam; and moving the wafer along a scan line with respect to the ion beam, a scan angle being defined between the scan line and an axis perpendicular to an axis of the ion beam, a difference between the tilt angle and the scan angle being less than 50°.

A method of simulating a pattern to be imaged onto a substrate using a photolithography system, the method includes obtaining a pattern to be imaged onto the substrate, smoothing the pattern, and simulating an image of the smoothed pattern. The smoothing may include application of a graphical low pass filter and the simulating may include application of edge filters from an edge filter library.

A method for improving a process model by measuring a feature on a printed design that was constructed based in part on a target design is disclosed. The method includes obtaining a) an image of the printed design from an image capture device and b) contours based on shapes in the image. The method also includes identifying, by a pattern recognition program, patterns on the target design that include the feature and determining coordinates, on the contours, that correspond to the feature. The method further includes improving the process model by at least a) providing a measurement of the feature based on the coordinates and b) calibrating the process model based on a comparison of the measurement with a corresponding feature in the target design.

A method including: obtaining a thin-mask transmission function of a patterning device and a M3D model for a lithographic process, wherein the thin-mask transmission function is a continuous transmission mask (CTM) and the M3D model at least represents a portion of M3D attributable to multiple edges of structures on the patterning device; determining a M3D mask transmission function of the patterning device by using the thin-mask transmission function and the M3D model; and determining an aerial image produced by the patterning device and the lithographic process, by using the M3D mask transmission function.

Disclosed is a method of determining a characteristic of interest, in particular focus, relating to a structure on a substrate formed by a lithographic process, and an associated patterning device and lithographic system. The method comprises forming a modified substrate feature on the substrate using a corresponding modified reticle feature on a patterning device, the modified substrate feature being formed for a primary function other than metrology, more specifically for providing a support for a vertically integrated structure. The modified reticle feature is such that said modified substrate feature is formed with a geometry dependent on the characteristic of interest during formation. The modified substrate feature can be measured to determine said characteristic of interest.

A method of exposing a wafer to a high-tilt angle ion beam and an apparatus for performing the same are disclosed. In an embodiment, a method includes forming a patterned mask layer over a wafer, the patterned mask layer including a patterned mask feature; exposing the wafer to an ion beam, a surface of the wafer being tilted at a tilt angle with respect to the ion beam; and moving the wafer along a scan line with respect to the ion beam, a scan angle being defined between the scan line and an axis perpendicular to an axis of the ion beam, a difference between the tilt angle and the scan angle being less than 50°.

A system includes a plate configured for mounting of a reflective extreme ultra-violet (EUV) mask thereon and a zone plate configured to divide EUV light into zero-order light and first-order light and to pass the zero-order light and the first-order light to the reflective EUV mask. The system further includes a detector configured to receive EUV light reflected by the EUV mask and including a zero-order light detection region configured to generate a first image signal and a first-order light detection region configured to generate a second image signal, and a calculator configured to generate a compensated third image signal from the first image signal and the second image signal. The third image signal may be used to determine a distance between mask patterns of the EUV mask.

Embodiments described herein comprise extreme ultraviolet (EUV) reticles and methods of forming EUV reticles. In an embodiment, the reticle may comprise a substrate and a mirror layer over the substrate. In an embodiment, the mirror layer comprises a plurality of alternating first mirror layers and second mirror layers. In an embodiment, a phase-shift layer is formed over the mirror layer. In an embodiment, openings for printable features and openings for non-printable features are formed into the phase-shift layer. In an embodiment, the non-printable features have a dimension that is smaller than a dimension of the printable features.

A method of fabricating gratings with variable grating depths including depositing a first grating material layer with a uniform thickness profile on a substrate, forming an etch mask layer having a variable thickness profile on the first grating material layer, etching the etch mask layer and the first grating material layer to change the uniform thickness profile of the first grating material layer to a non-uniform thickness profile, forming a patterned hard mask on the first grating material layer, and etching, using the patterned hard mask, the first grating material layer to form a grating with a variable depth in the first grating material layer.

A maskless, extreme ultraviolet (EUV) lithography scanner uses an array of microlenses, such as binary-optic, zone-plate lenses, to focus EUV radiation onto an array of focus spots (e.g. about 2 million spots), which are imaged through projection optics (e.g., two EUV mirrors) onto a writing surface (e.g., at 6X reduction, numerical aperture 0.55). The surface is scanned while the spots are modulated to form a high-resolution, digitally synthesized exposure image. The projection system includes a diffractive mirror, which operates in combination with the microlenses to achieve point imaging performance substantially free of geometric and chromatic aberration. Similarly, a holographic EUV lithography stepper can use a diffractive photomask in conjunction with a diffractive projection mirror to achieve substantially aberration-free, full-field imaging performance for high-throughput, mask-projection lithography. Maskless and holographic EUV lithography can both be implemented at the industry-standard 13.5-nm wavelength, and could potentially be adapted for operation at a 6.7-nm wavelength.