Abstract: Methods and systems for performing model-less measurements of semiconductor structures based on scatterometry measurement data are described herein. Scatterometry measurement data is processed directly, without the use of a traditional measurement model. Measurement sensitivity is defined by the changes in detected diffraction images at one or more non-zero diffraction orders over at least two different illumination incidence angles. Discrete values of a scalar function are determined directly from measured images at each incidence angle. A continuous mathematical function is fit to the set of discrete values of the scalar function determined at each incidence angle. A value of a parameter of interest is determined based on analysis of the mathematical function. In some embodiments, the scalar function includes a weighting function, and the weighting values associated with weighting function are optimized to yield an accurate fit of the mathematical function to the scalar values.

Abstract: The present disclosure discloses a method and apparatus for storing data. A specific embodiment of the method includes: judging whether a remaining storage space in a compressed data page is greater than a storage space threshold, in response to to-be-stored data to be written to the compressed data page in a cache storage region of a database; if not, determining a non-compressed data page among the non-compressed data pages for generating the compressed data page; and compressing the determined non-compressed data page to generate the compressed data page. This embodiment achieves the generation of the compressed data page in advance, such that each time the data is written to the compressed data page, it is ensured that there is enough storage space in the compressed data page to store the written data, thus reducing the system overhead when writing the data to the compressed data page, enhancing the writing efficiency of the system.

Abstract: The present disclosure discloses a method and apparatus for storing data. A specific embodiment of the method includes: judging whether a remaining storage space in a compressed data page is greater than a storage space threshold, in response to to-be-stored data to be written to the compressed data page in a cache storage region of a database; if not, determining a non-compressed data page among the non-compressed data pages for generating the compressed data page; and compressing the determined non-compressed data page to generate the compressed data page. This embodiment achieves the generation of the compressed data page in advance, such that each time the data is written to the compressed data page, it is ensured that there is enough storage space in the compressed data page to store the written data, thus reducing the system overhead when writing the data to the compressed data page, enhancing the writing efficiency of the system.