Standard member for correction, scanning electron microscope using same, and scanning electron microscope correction method

A scanning electron microscope comprising:

• a sample stage for holding a sample or a standard member for calibration;
• an irradiation optical system for scanning an electron beam on the sample on the sample stage;
• a detector for detecting a secondary electron or a reflected electron generated by electron beam scanning;
• a signal processing unit for performing length measurement of the sample by processing an electronic signal obtained from the detector;
• a display unit for displaying a result of length measurement;
• a bias supply for applying voltage for controlling electron beam accelerating voltage to the sample stage;
• and
• a calibration unit for calibrating a magnification of the irradiation optical system based on information about an intensity of the secondary electron or the reflected electron for the standard member for calibration mounted on the sample stage,
• wherein the scanning electron microscope measures a pattern within an observation area based on information about an intensity of a secondary electron or a reflected electron generated by scanning an incident electron ray on the observation area on a measurement sample,
• wherein the standard member for calibration comprises:
• a first pattern area having a convex-concave pattern of a multilayer film cross section formed by laminating different materials periodically at a constant and fixed multi-layer pitch;
• and
• a second pattern area having a convex-concave pattern of a multilayer film cross section formed by laminating different materials at a variable multi-layer pitch which provides varying pitch sizes in one direction,
• wherein the convex-concave patterns of the first pattern area and the second pattern area are arranged adjacently on one axis and at substantially a same height, and
• wherein the variable multi-layer pitch in the second pattern area includes at least one pitch size for coarse adjustment larger than the fixed multi-layer pitch in the first pattern area and at least one pitch size for high-definition adjustment smaller than the fixed multi-layer pitch in the first pattern area.

A scanning electron microscope calibration method for calibrating a scanning electron microscope which measures a pattern within an observation area based on information about an intensity of a secondary electron or a reflected electron generated by scanning an incident electron ray on the observation area on a measurement sample,

• wherein the scanning electron microscope comprises a sample stage for holding a sample or a standard member for calibration, an irradiation optical system for scanning an electron beam on the sample on the sample stage, a detector for detecting a secondary electron or a reflected electron generated by electron beam scanning, a signal processing unit for performing length measurement of the sample by processing an electronic signal obtained from the detector, a display unit for displaying a result of length measurement, a bias supply for applying voltage for controlling electron beam accelerating voltage to the sample stage, and a calibration unit for calibrating a magnification of the irradiation optical system based on information about an intensity of the secondary electron or the reflected electron for the standard member for calibration mounted on the sample stage,
• wherein the standard member for calibration includes a first pattern area having a convex-concave pattern of a multilayer film cross section formed by laminating different materials periodically at a constant and fixed multi-layer pitch, and a second pattern area having a convex-concave pattern of a multilayer film cross section formed by laminating different materials at a variable multi-layer pitch which provides varying pitch sizes in one direction, wherein the convex-concave patterns in the first pattern area and the second pattern area are arranged adjacently on one axis and at substantially a same height,
• wherein the scanning electron microscope calibration method comprising steps of:
• performing a coarse adjustment using a variable multi-layer pitch of a pitch size, in the convex-concave pattern in the second pattern area, larger than the fixed multi-layer pitch in the first pattern area;
• performing a high-definition adjustment using a variable multi-layer pitch of a pitch size, in the convex-concave pattern in the second pattern area, smaller than the fixed multi-layer pitch in the first pattern area;
• and
• comparing the variable multi-layer pitch size and the fixed multi-layer pitch size of either film obtained by the signal processing means with a pitch size obtained beforehand by light or X-ray diffraction and calibrating a magnification of the irradiation optical system so that the difference becomes approximately zero.