Abstract: Improvements in the fabrication of integrated circuits are driven by the decrease of the size of the features printed on the wafers. Current lithography techniques limits have been extended through the use of phase-shifting masks, off-axis illumination, and proximity effect correction. More recently, liquid immersion lithography has been proposed as a way to extend even further the limits of optical lithography. This invention described a methodology based on contact or proximity printing using a projection lens to define the image of the mask onto the wafer. As the imaging is performed in a solid material, larger refractive indices can be obtained and the resolution of the imaging system can be increased.

Abstract: The manufacturing of integrated circuits relies on the use of optical proximity correction (OPC) to correct the printing of the features on the wafer. The data is subsequently fractured to accommodate the format of existing mask writer. The complexity of the correction after OPC can create some issues for vector-scan e-beam mask writing tools as very small slivers are created when the data is converted to the mask write tool format. Moreover the number of shapes created after fracturing is quite large and are not related to some important characteristics of the layout like for example critical areas. A new technique is proposed where the order of the OPC and fracturing steps is reversed. The fracturing step is done first in order to guarantee that no slivers are created and that the number of shapes is minimized. The shapes created can also follow the edges of critical zones so that critical and non-critical edges can be differentiated during the subsequent OPC step.

Abstract: Improvements in the fabrication of integrated circuits are driven by the decrease of the size of the features printed on the wafers. Current lithography techniques limits have been extended through the use of phase-shifting masks, off-axis illumination, and proximity effect correction. More recently, liquid immersion lithography has been proposed as a way to extend even further the limits of optical lithography. This invention described a methodology based on contact printing using a projection lens to define the image of the mask onto the wafer. As the imaging is performed in a solid material, larger refractive indices can be obtained and the resolution of the imaging system can be increased.

Abstract: A decoder generally comprising a branch metrics circuit and a state metrics circuit. The branch metrics circuit may be configured to generate a plurality of branch metric signals. The state metrics circuit may be configured to (i) add the branch metric signals to a plurality of state metric signals to generate a plurality of intermediate signals, (ii) determine a next state metric signal to the state metric signals, (iii) determine a normalization signal in response to the intermediate signals, and (iv) normalize the state metric signals in response to the normalization signal.

Abstract: A method for determining whether a defect that is detected by photomask inspection will adversely affect a semiconductor device, such as a wafer. The method has the ability of relating defect specifications directly to device performance and wafer yields, and assessing the impact of combining the defect with the critical dimension error using standard inspection tools.

Abstract: A method for determining if an undesirable feature on a photomask will adversely affect the performance of the semiconductor integrated circuit device that the mask is being used to create. The method includes inspecting the photomask for undesirable features and analyzing the designed features close to the defects. This analysis is performed on lithographic images that represent the image that is transferred onto the semiconductor wafer by the lithography process. This analysis takes into account the effect of variations that are present in the lithography process. Through knowledge of the effects of variations in mask critical dimension of a feature on the lithographic image of that feature, the analysis results in the assignment of an equivalent critical dimension error to the defect. This equivalent critical dimension error is then compared to the mask critical dimension error specification to determine whether or not the defect will adversely affect the device.