Abstract: The Hessian (second derivative) of the image log slope (ILS) can be quickly and accurately calculated without the need to use approximate methods from the gradient of the ILS with respect to mask transmission and source intensity. The Hessian has been traditionally calculated using a finite-difference approach. Calculating the Hessian through a finite-difference approach is slow and is an approximate method. The gradient of the ILS improves the speed of calculation of the Hessian, and thus accelerated SMO operation is realized. The results of ILS evaluation can be used in design for manufacturing (DFM) to suggest changes in the design rules to improve imaging. For a fixed illumination, this information can help remove forbidden pitches and help select design rules for 1-D and 2-D patterns on a mask design layout.

Abstract: A method of decomposing a target pattern containing features to be printed on a wafer into multiple patterns. The method includes the steps of: (a) defining a region of influence which indicates the minimum necessary space between features to be imaged; (b) selecting a vertex associated with a feature of the target pattern; (c) determining if an edge of another feature is within the region of influence with respect to the vertex; and (d) splitting the another feature into two polygons if the edge of another feature is within the region of influence.

Abstract: A method of decomposing a target pattern containing features to be printed on a wafer into multiple patterns. The method includes the steps of: (a) defining a region of influence which indicates the minimum necessary space between features to be imaged; (b) selecting a vertex associated with a feature of the target pattern; (c) determining if an edge of another feature is within the region of influence with respect to the vertex; and (d) splitting the another feature into two polygons if the edge of another feature is within the region of influence.

Abstract: A method of decomposing a target pattern containing features to be printed on a wafer into multiple patterns. The method includes the steps of: (a) defining a region of influence which indicates the minimum necessary space between features to be imaged; (b) selecting a vertex associated with a feature of the target pattern; (c) determining if an edge of another feature is within the region of influence with respect to the vertex; and (d) splitting the another feature into two polygons if the edge of another feature is within the region of influence.

Abstract: Optimization of illumination for a full-chip layer is disclosed. A pitch frequency of the full-chip layer is determined so as to generate a pitch frequency histogram of the full-chip layer. The pitch frequency indicates how often a given pitch occurs in the full-chip layer. The pitch frequency histogram is equated to be the first eigenfunction from the sum of coherent system representation of a transformation cross coefficient. An integral equation for the first eigenfunction of the transformation cross coefficient is solved so as to define the optimal illumination for imaging the full-chip layer.

Abstract: A method of decomposing a target pattern containing features to be printed on a wafer into multiple patterns. The method includes the steps of: (a) defining a region of influence which indicates the minimum necessary space between features to be imaged; (b) selecting a vertex associated with a feature of the target pattern; (c) determining if an edge of another feature is within the region of influence with respect to the vertex; and (d) splitting the another feature into two polygons if the edge of another feature is within the region of influence.

Abstract: Model OPC is developed based on eigen decomposition of an aerial image expected to be produced by a mask pattern on a surface of a resist. With the eigen decomposition method the aerial image intensity distribution around a point (x, y) is accurately described in the model. A scalar approach may be used in the eigen decomposition model which treats the light wave through the mask as a scalar quantity. A eigen decomposition alternatively may use a vector approach which utilizes a vector to describe the light wave and the pupil function. A predicted SPIF may be generated from the aerial image which may be used to verify the mask modeling process by comparing the predicted SPIF to an experimentally determined SPIF. The model OPC, once calibrated, may be used to evaluate performance of a mask and refine features of the mask.

Abstract: A means for selectively elevating a presser foot out of pressure contact with a work material when a sewing needle extends through the work material. The device includes a needle bar lever pivotally supported by the sewing machine frame and having an operative connection to the endwise shiftable needle bar for implementing oscillation thereof. A lug extending from the needle bar lever may cooperate with the second end of a lift lever having a first end operatively connected with the presser foot of the sewing machine. The lift lever is carried on a selectively shiftable pintle supported by the sewing machine frame, the pintle having a first shiftable position in which the lug extending from the needle bar lever does not engage with the second end of the lift lever and a second shiftable position in which the lug does engage with the second end of the lift lever whereby the lug will effect rotation of the lift lever and have the first end elevate the presser foot out of pressure contact with the work material.

Abstract: An electronically controlled sewing machine includes the capability for sewing extended bight width patterns. When certain bight width data is recognized as needle shift data, an indication of same is provided to the sewing machine operator.

Abstract: An arrangement for indicating to an operator whether a selected stitch length is within, below or above a preferred range for a selected pattern in a multiple pattern sewing machine includes a slide contact board and a group of slide contacts connected to a stitch length selection lever. The different patterns are grouped in accordance with preferred stitch length ranges, each group having associated therewith one of the slide contacts on the lever. The slide contact board is arranged to define the preferred ranges so that for each of the pattern groups, a circuit is completed to energize a low LED if the selected stitch length is below the preferred range; to energize an in-range LED if the selected stitch length is within the preferred range; and to energize the high LED if the selected stitch length is above the preferred range.