Photomask Critical Dimension Metrology in the Scanning Electron Microscope
Michael T. Postek
Critical Dimension (CD) control begins at the photomask. Therefore, photomask metrology is a principal enabler for the development and manufacture of current and future generations of semiconductor devices. With the potential of 100, 65 and 45 nanometer and even smaller linewidths and high aspect ratio structures, the scanning electron microscope (SEM) remains an important tool, which is extensively used in many phases of semiconductor manufacturing throughout the world. The SEM provides higher resolution analysis and inspection than is possible by current techniques using the optical microscope and higher throughputs than scanned probe techniques. Furthermore, the SEM offers a wide variety of analytical modes, each of them contributing unique information regarding the physical, chemical, and electrical properties of a particular specimen, device, or circuit.. MT Postek. in: J Orloff, ed. Handbook of Charged Particle Optics. CRC Press, Inc., New York. 363-399, 1997. . Due to recent developments, scientist and engineers are finding and putting into practice new, very accurate and fast SEM-based measuring methods in research and production of photomasks.
accuracy, CD critical dimension, high pressure, metrology, photomask, precision, scanning electron microscope, SEM