Printer

Abstract

Abstract PURPOSE:To provide a printer easy to adjust the focus and inexpensive, by designing a printer in which the focus of the image forming optical system is adjusted by varying the wavelength of the light from a light source. CONSTITUTION:The laser beam generated from an excimer laser oscillator 1 is passed through an illuminating optical system 2 to irradiate a mask 3 so that the pattern on the mask 3 is transferred to a wafer 6 as an object of printing by a projecting lens 4. The image forming position of the lens 4 is detected by a focus position detector 5a. When the image forming position of the projecting lens 4 is off the surface of the wafer 6, the amount by which the surface of the wafer 6 is offset from the image forming position of the lens 4 is detected, and the detected offset amount is transmitted to a feedback control system 7 for automatic focusing. The control system 7 calculates an amount of change of the wavelength of light from the light source which corresponds to the offset amount and changes the wavelength of the laser beam from the excimer laser oscillator 1 by injection locking to effect adjustment such that the image forming position of the projecting lens 4 is coincident with the surface of the wafer 6.

Inventors

• 👤 Haruna Kawashima
• 👤 春名 川島
• 👤 Akiyoshi Suzuki
• 👤 章義 鈴木

Bibliographic Details