FINE DIMENSION MEASURING DEVICE

• Main Author: MATSUDA KIMIHIRO
• Format: Patent
• Language: English
• Published: 02.05.1990
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; PHYSICS; SEMICONDUCTOR DEVICES; TESTING

PURPOSE:To improve the measuring accuracy of a pattern by providing a stage on which a semiconductor wafer is placed, a measuring part having an objective lens, an arithmetic processing part and a control part. CONSTITUTION:The dimension of the pattern on the same part of the wafer 4 is measured plural times at a focusing position whose height is H1. The measured value is processed in the arithmetic processing part 8 every time measurement is completed and the reproducing accuracy of the measurement which is repeated for the same focusing position is stored. Then, a driving signal is transmitted through a central control part 9 and a stage control part 10 and the stage 5 is moved by a stage driving part 6 to the focusing position whose height is H2, where the measurement is performed plural times and the reproducing accuracy of the repeated measurement is calculated and stored. Thereafter, the measurement is repeated n-times optionally in the same way. The arithmetic processing part 8 selects the focusing position which is the most excellent in reproducibility out of the reproducing accuracy of each focusing position. In order to get the selected focusing position, the signal is transmitted from the control part 9 to the driving part 6 and the measurement of the dimension of the respective points in the wafer 4 which is set at the optimum focusing position is started.