Modern Scanning Electron Microscopy. 2. Test Objects for Scanning Electron Microscopy

A review of the test objects intended to calibrate scanning electron microscopes and study the secondary-electron emission of a solid-body relief surface using scanning electron microscope is carried out. The test objects are divided according to two parameters: the form of the relief and relief structure. As regards the form of the relief, the test objects are divided into single, pitch, and periodic structures. As regards the relief structure, the test objects are divided into objects with rectangular profiles and those with trapezoidal profiles with large and small angles of side-wall inclination. Examples of such test objects are given. Their characteristics and methods for parameter certification are described. The advantages and disadvantages of test objects are considered. It is shown that tests objects with pitch structures consisting of trapezoidal grooves with large angles of side-wall inclination have the best characteristics. The test objects are produced in single-crystal silicon with {100} surface orientation by means of the method of the liquid anisotropic etching of silicon. These test objects allow the determination of all characteristics of scanning electron microscopes affecting the measurement of the linear sizes of relief structures used in microelectronics and nanotechnology. If they are used, it is possible to make correlation measurements, which increase the calibration accuracy for scanning electron microscopes tenfold.