| 摘要 |
PURPOSE:To improve the precision of the pattern of a mask by measuring reflected light or transmitted light of a light shield plate and detecting the end point of etching when the light shield film on a glass substrate is etched selectively. CONSTITUTION:A mask plate 44 is obtained by fixing the glass substrate to which the light shield film is adhered and performing a dry etching treatment. A plate 44 is rotatable together with a disk 45 and a slit 45a formed at its peripheral edge part is detected by a photosensor 46 to detect the angle of rotation of the plate 44. A laser diode 41 is controlled by a pulse oscillator 52 and laser light is converged by a lens 22 and reflected to the plate 44. The reflected light is further reflected by a half-mirror 32, converted photoelectrically, and transmitted to a lock-in analyzer 57. The output of an amplifier 57 is held by a sample holding circuit 53 until a synchronous input is obtained from a delay circuit 55 and outputted when the synchronous input is obtained. Thus, mask conditions are set with high precision. |
