摘要:
A system for inspecting a pattern shape operates to detect secondary electrons from a specimen by irradiation of a focused electron beam and perform arithmetic processing on this detected signal. The detected signal waveform is divided into a plurality of regions on the basis of a variation of the signal quantity. The size of the divided regions is used for quantitative evaluation of a three dimensional shape of the specimen. This system, especially by displaying measurement results of the pattern shape for each divided signal waveform (bottom width in the final shape, resist bottom width, etching shift quantity, and etching slope-angle component by the exposure), permits an easy check on which a component varies and how the component varies in all shape variations. With this arrangement, a pattern cross section information effective in determining etching process conditions can be acquired using images by an in-line SEM capable of nondestructive observation.
摘要:
This invention provides a method of measuring semiconductor pattern dimensions capable of realizing a stable and highly precise pattern dimension measurement technique even when the pattern cross-sectional shapes are changed and making the calculation amount relatively small to reduce the calculation time. More specifically, the relationship between cross-sectional shapes of a pattern and measurement errors in a specified image processing technique is evaluated in advance by the electron beam simulation in a pattern measurement system in a length measuring SEM, and in the actual dimension measurement, dimensions of an evaluation objective pattern are measured from image signals of a scanning electron microscope, and errors of the dimensional measurement of the evaluation objective pattern are estimated and revised based on the relationship between cross-sectional shapes of a pattern and measurement errors evaluated in advance, thereby realizing highly precise measurement where dimensional errors depending on pattern solid shapes are eliminated.
摘要:
This invention provides a method of measuring semiconductor pattern dimensions capable of realizing a stable and highly precise pattern dimension measurement technique even when the pattern cross-sectional shapes are changed and making the calculation amount relatively small to reduce the calculation time. More specifically, the relationship between cross-sectional shapes of a pattern and measurement errors in a specified image processing technique is evaluated in advance by the electron beam simulation in a pattern measurement system in a length measuring SEM, and in the actual dimension measurement, dimensions of an evaluation objective pattern are measured from image signals of a scanning electron microscope, and errors of the dimensional measurement of the evaluation objective pattern are estimated and revised based on the relationship between cross-sectional shapes of a pattern and measurement errors evaluated in advance, thereby realizing highly precise measurement where dimensional errors depending on pattern solid shapes are eliminated.
摘要:
A system for inspecting a pattern shape operates to detect secondary electrons from a specimen by irradiation of a focused electron beam and perform arithmetic processing on this detected signal. The detected signal waveform is divided into a plurality of regions on the basis of a variation of the signal quantity. The size of the divided regions is used for quantitative evaluation of a three dimensional shape of the specimen. This system, especially by displaying measurement results of the pattern shape for each divided signal waveform (bottom width in the final shape, resist bottom width, etching shift quantity, and etching slope-angle component by the exposure), permits an easy check on which a component varies and how the component varies in all shape variations. With this arrangement, a pattern cross section information effective in determining etching process conditions can be acquired using images by an in-line SEM capable of nondestructive observation.
摘要:
A method of measuring pattern dimensions includes evaluating a relationship between cross-sectional shapes of a pattern and measurement errors of a pattern in a specified image processing technique, and conducting an actual measurement in which dimension measurement of an evaluation objective pattern from image signals of a microscope is carried out, and revising errors of the dimension measurement of the evaluation objective pattern based on the relationship between the cross-sectional shapes of a pattern and the measurement errors of a pattern previously evaluated.
摘要:
To realize a method for detecting variations in conditions (drift of the exposure and drift of the focus) in exposure equipment at a product wafer level in lithography process, the process is specified in such a way that calculation results of feature quantities such as electron beam images, line profiles, dimensions, etc. under various sets of the exposure and the focus are stored as a library, and an electron beam image of the product wafer is compared with these pieces of data in the library so that detection of drifts of the exposure and the focus a check of the results on the screen can easily be performed.
摘要:
A method of measuring pattern dimensions includes evaluating a relationship between cross-sectional shapes of a pattern and measurement errors of a pattern in a specified image processing technique, and conducting an actual measurement in which dimension measurement of an evaluation objective pattern from image signals of a microscope is carried out, and revising errors of the dimension measurement of the evaluation objective pattern based on the relationship between the cross-sectional shapes of a pattern and the measurement errors of a pattern previously evaluated.
摘要:
In monitoring of an exposure process, a highly isolative pattern greatly changed in a shape of cross section by fluctuations in the exposure dose and the focal position is an observation target. Especially, to detect a change in a resist shape of cross section from a tapered profile to an inverse tapered profile, one of the following observation methods is employed to obtain observation data: (1) a tilt image of a resist pattern is imaged by using tilt imaging electron microscopy, (2) an electron beam image of a resist pattern is imaged under imaging conditions for generating asymmetry on an electron beam signal waveform, and (3) scattering characteristic data of a resist pattern is obtained by an optical measurement system. The observation data is applied to model data created beforehand in accordance with the exposure conditions to estimate fluctuations in the exposure dose and the focal position.
摘要:
Size characteristic quantities are measured at a plural locations. The size characteristic quantities include edge widths, pattern widths, and/or pattern lengths of the electron-beam images of a resist-dropout pattern and a resist-remaining pattern that are located such that the effective exposure quantities differ depending on the places. With the predetermined measurement errors added thereto, the size characteristic quantities are compared with model data that has been created in advance and that causes various exposure conditions to be related with the size characteristic quantities measured under these various exposure conditions. This comparison makes it possible not only to estimate deviation quantities in the exposure quantity and the focal-point position from the correct values, but also to calculate ambiguity degrees of the estimated values. This, allows the implementation of a proper monitoring/controlling of the exposure-condition variations (i.e., the deviations in the exposure quantity and the focal-point position) in the lithography process.
摘要:
The present invention relates to a method and apparatus for measuring a three-dimensional profile using a SEM, capable of accurately measuring the three-dimensional profile of even a flat surface or a nearly vertical surface based on the inclination angle dependence of the amount of secondary electron image signal detected by the SEM. Specifically, a tilt image obtaining unit obtains a tilt image (a tilt secondary electron image) I(2) of flat regions a and c1 on a pattern to be measured by using an electron beam incident on the pattern from an observation direction φ(2). Then, profile measuring units presume the slope (or surface inclination angle) at each point on the pattern based on the obtained tilt image and integrate successively each presumed slope value (or surface inclination angle value) to measure three-dimensional profiles S2a and S2c. This arrangement allows a three-dimensional profile to be accurately measured.