A technology for detecting defects in a chip at the stage of creating the cells
April 20, 2009, 11:14 am
Toshiba Corp. developed a technology for detecting points of overheating (hotspot) lithography at the crystal at the stage of creating a cell and provided details on Photomask Japan 2009. Toshiba uses this technology in the production of chips by the norms of 45 nm or more. The process of examination to identify points of overheating called lithography verification of conformity (lithography compliance check, LCC), has two stages. During the first phase occurs LCC cell, where lithography simulation is performed on the basis of the pattern mask cell, which is an optical proximity effect correction (optical proximity correction, OPC). As a result, the simulation is determined by the contour (the pattern transferred to the silicon), taking into account the influence of neighboring structures in the cell. In the absence of defects check arrives at the chip level. In contrast to the examination cell, lithographic simulation with LCC over the entire chip covers a broad area that requires more processing time. As development occurs in the direction of miniaturization, the processing time increases due to more complex OPC. Nevertheless, the problems found at the chip level, LCC, is often difficult to correct, because the process of creating chips now coming to a certain stage. Toshiba uses two technologies called hot point (warm spot) and a universal pattern (universal pattern) and developed a method for detecting points of overheating at the level of the chip at the manufacturing stage in a short period of time. Teplou point is called an area which does not incur any problems at the level of the cell, but can lead to trouble in the chip. New method simultaneously detects the point of overheating and warm with the help of a simulation of lithography in the LCC at the level of the cell. If not found problems in lithography simulation, using the universal template, which means that the point of the kind will not be in a state of overheating. To find a form that can be used as a universal template, Toshiba has experienced many forms, and found that all the most versatile template. During the presentation, Toshiba is not disclosed such details as the criterion for selection of points, and overheating of the size of a universal template. Nevertheless, it can be called a significant advance in the way of simplification of LCC, which will play an increasingly important practical role in the further miniaturization of the production.