A method and apparatus for creating a phase shifting mask and a structure mask for shrinking integrated circuit designs. One embodiment of the invention includes using a two mask process. The first mask is a phase shift mask and the second mask is a single phase structure mask. The phase shift mask primarily defines regions requiring phase shifting. The single phase structure mask primarily defines regions not requiring phase shifting. The single phase structure mask also prevents the erasure of the phase shifting regions and prevents the creation of undesirable artifact regions that would otherwise be created by the phase shift mask. Both masks are derived from a set of masks used in a larger minimum dimension process technology.

Phase shifting circuit manufacture method and apparatus

A device for emitting radiation at a predetermined wavelength is presented. This device has a cavity with an active layer in which said radiation is generated by charge carrier recombination. The edges of the device define the region or space for radiation and/or charge carrier confinement. At least one of the edges of this cavity has a substantially random grating structure. The edge of the device has substantially random grating structure and can extend as at least one edge of a waveguide forming part of this radiation emitting device. The radiation emitting device of the present invention can have a cavity comprising a radiation confinement space that includes confinement features for the charge carriers confining the charge carriers to a subspace being smaller than the radiation confinement space within the cavity. The emitting device can comprise at least two edges forming, in cross-section, a substantially triangular shape. The angle between these two edges is smaller than 45°. At least one of the two edges has a transparent portion. the devices according to the present invention can be arranged in arrays.

Method of manufacturing surface textured high-efficiency radiating devices and devices obtained therefrom

Techniques are provided for extending the use of phase shift techniques to implementation of masks used for complex layouts in the layers of integrated circuits, beyond selected critical dimension features. The method includes identifying features for which phase shifting can be applied, automatically mapping the phase shifting regions for implementation of such features, resolving phase conflicts which might occur according to a given design rule, and application of assist features and proximity correction features. The method includes applying an adjustment to a phase shift mask pattern including a first and a second phase shift window, and a control chrome with a control width, and/or to a trim mask pattern having a trim shape with a trim width based upon one or both of a rule based correction and a model based correction to improve a match between a resulting exposure pattern and a target feature.

Phase shift masking for complex patterns with proximity adjustments

Layout processing can be applied to an integrated circuit (IC) layout using a shape-based system. A shape can be defined by a set of associated edges in a specified configuration. A catalog of shapes is defined and layout processing actions are associated with the various shapes. Each layout processing action applies a specified layout modification to its associated shape. A shape-based rule system advantageously enables efficient formulation and precise application of layout modifications. Shapes/actions can be provided as defaults, can be retrieved from a remote source, or can be defined by the user. The layout processing actions can be compiled in a bias table. The bias table can include both rule-based and model-based actions, and can also include single-edge shapes for completeness. The scanning of the IC layout can be performed in order of increasing or decreasing complexity, or can be specified by the user. The appropriate layout processing actions are applied to matching portions of the IC layout to form the corrected photomask layout. This process can be sequential or batch mode. Shape and action conflicts can be resolved by marking identified/modified elements or by designing rules for orderly resolution of any inconsistencies or overlaps.

General purpose shape-based layout processing scheme for IC layout modifications

Phase information is incorporated into a cell-based design methodology Standard cells have four edges: top, bottom, left, and right The top and bottom edges have fixed phase shifters placed, eg 0 A given cell C will have a phase set created with two versions: 0-180 (left-right) as well as 180-0 Alternatively, the same phase set: 0—0 and 180—180 could be created for a cell The phase sets are selected based on the ability to phase shift the features within the cell C By creating a phase set for most of the cells of a cell library, standard cell placement and routing techniques can be used and phase can then be quickly assigned using a simple ripple technique This ensures a phase compliant design upfront for the standard cell areas In some instances, phase sets are created for every cell in a library

Standard cell design incorporating phase information

A resist pattern is formed with a phase-shifting mask 4 in which transparent regions through an opaque region are different 180° in phase from one another. In this case, when positive resist 1 is subjected to exposure, the widths of the opaque regions 5A and 5B of the mask 4 are changed according to a pattern adjacent thereto, so that a fine pattern having the same line width is formed with high accuracy.

Photo mask and pattern forming method

An application of alternating phase-shifting mask to 0.16 micrometers logic gate patterns is studied. A double exposure method using positive resist in KrF excimer laser lithography is applied to obtain random gate patterns. To optimize the exposure conditions, proximity effects for 0.16 micrometers line patterns under various combinations of NA and (sigma) are examined using an aerial image simulator. To control the linewidth in +/- 10% CD, mask bias according to the space width and the mask pattern with two adjacent apertures which transfers an isolated line are applied. By using these techniques, 0.16 micrometers logic gate patterns including SRAM are demonstrated.

Application of alternating phase-shifting mask to 0.16 μm CMOS logic gate patterns

An optical proximity correction algorithm based on statistical methodology is developed. The response surface function (RSF) for the CD in the lithographic process is extended by introducing variables for the mask pattern size. The values of process parameters and mask pattern size are concurrently optimized by using the RSF. This methodology allows design for manufacturability, considering error distributions of process parameters such as focus position and exposure dose. The algorithm is applied to a DRAM cell pattern. The result indicates the annular illumination with larger coherency than that of the conventional illumination improve the CD limited yield.

Koji Matsuoka

Papers

Photo mask and pattern forming method

Application of alternating phase-shifting mask to 0.16 μm CMOS logic gate patterns

Optical proximity correction in DRAM cell using a new statistical methodology