APPARATUS FOR MEASURING SURFACE HEIGHT OF SAMPLE IN CHARGED PARTICLE RAY APPARATUS

摘要

PURPOSE:To measure titled height in extremely high precision and to make an apparatus small-sized by providing at least one image forming lense along the axis crossing with the fixed angle against the axis of a charged particle beam at the vicinity of a sample surface. CONSTITUTION:Electrons emitted from an electron gun 1 are focused by a focusing lense 2, and projected on a cross section shaping slit 3. The electrons passed through the slit 3 are formed an image by the image forming lense 4 and the contracted image of the slit 3 is projected on a sample (wafer) 5. An XY deflector 6 is placed along the passage of the electron ray so that the shaped electron beam is scanned on the sample 5. The pattern signal is impressed to the deflector 6 by a computer 8 through an amplifier 7, and the desired IC pattern is drawn on a semiconductor wafer. Consequently, the measurement of extremely high precision is made possible and the size of the apparatus is made small.