The present invention relates to an apparatus for making measurement and inspection of a pattern based on design data on a semiconductor device or the like and the image obtained by a scanning electron microscope. More particularly, it relates to a pattern measurement apparatus for adding identification information to line segments within the electron-microscope image, and managing the pattern-forming line segments based on the identification information.
In recent years, the design data on a semiconductor device has increasingly come into use for the measurement on the semiconductor device by the scanning electron microscope (: SEM). In JP-A-2006-66478 (corresponding to US 2006/0045326), the following embodiment is explained: A pattern matching is performed between line segments based on the design data and contour lines of patterns obtained by the scanning electron microscope. Then, a pattern is measured which is identified by this pattern matching.
Moreover, in JP-A-2000-177961 (corresponding to U.S. Pat. No. 6,768,958), the following embodiment is explained: Pattern edge of a mask pattern on the electron-microscope image is stored into a database, using a standard format such as GDSII.
In JP-A-7-130319 (corresponding to U.S. Pat. No. 5,523,567), there is disclosed a technology for forming an extremely-low-magnification image by mutually connecting a plurality of field-of-views to each other.
A SEM image itself is merely two-dimensional luminance information. Accordingly, the edge represented on the SEM image has none of information about what the edge itself indicates. Consequently, when identifying a pattern of measurement purpose or the like, it becomes necessary to perform position identification by the pattern matching as is explained in JP-A-2006-66478.
Meanwhile, in accompaniment with the microminiaturization of semiconductor devices in recent years, the measurement based on an even-higher-magnification image has become more and more requested. For example, in order to grasp an extent of the pattern correction by OPC (Optical Proximity Correction), it is required to measure a certain part of the pattern which will be modified as a result of being influenced by the OPC pattern. If, however, the measurement is made using the high magnification needed for evaluating a location like this, there occurs the following problem: Namely, it becomes increasingly difficult to involve, within the field-of-view, the entire pattern, or a range of the pattern needed at least for identifying configuration of the pattern.
The acquisition of an image with a high magnification, on the other hand, results in the acquisition of the image in only a narrow field-of-view. As a consequence, it has been found difficult to establish mutual compatibility between the high-magnification observation for high-resolution implementation and the observation in a wide region. In the explanation in JP-A-2000-177961 as well, no disclosure is made concerning a proposal which would be able to simultaneously solve mutually incompatible problems like this. Furthermore, according to the technology disclosed in JP-A-7-130319, on the contrary, such a processing as thinning out scanning lines is performed in order to form the extremely-low-magnification image. Accordingly, this technology is unsuitable for accomplishment of the purpose of the high-magnification observation for high-resolution implementation.