Title:
CONTROLLING METHOD OF GAP BY DIFFRACTION GRATING
Document Type and Number:
Japanese Patent JPS60173835
Kind Code:
A
Abstract:
PURPOSE:To control a gap easily with high accuracy by mounting a diffraction grating to a first body, the gap thereof must be controlled, and a reflective surface to a second body and detecting the gap between both bodies from the intensity of diffracted beams diffracted and reflected by these diffraction grating and reflective surface. CONSTITUTION:Beams projected onto a diffraction grating mark 11 prepared on a mask 10 are reflected by a reflecting makr 14 prepared on a wafer 13 held on a wafer stage 12, and pass through the diffraction grating mark 11 again. Beams diffracted and reflected by both these marks are changed into a large number of plus and minus diffracaed beams diffracted in the direction symmetrical to incident beams. Plus and minus primary diffracted beams in a large number of diffracted beams are reflected by a half mirror 15, and each introduced to photodetectors 17, 18 by condenser lenses 16. Plus and minus primary diffracted beams are converted into diffracted-besm intensity I+1 and I-1 in a photoelectric manner by the photodetectors 17, 18, and signal-processed by a signal processing control section 19 and turned into driving signals for a mask stage 9 and the wafer stage 12, thus controlling a gap between the mask and the wafer.
Inventors:
UNE ATSUNOBU
INOSHIRO MAKOTO
TAKEUCHI NOBUYUKI
DEGUCHI KIMIKICHI
INOSHIRO MAKOTO
TAKEUCHI NOBUYUKI
DEGUCHI KIMIKICHI
Application Number:
JP1469284A
Publication Date:
September 07, 1985
Filing Date:
January 30, 1984
Export Citation:
Assignee:
NIPPON TELEGRAPH & TELEPHONE
International Classes:
G01B11/14; G03F7/20; G03F9/00; H01L21/027; (IPC1-7): G03F7/20
Domestic Patent References:
| JPS5698829A | 1981-08-08 | |||
| JPS57139925A | 1982-08-30 | |||
| JPS57109335A | 1982-07-07 | |||
| JPS54101676A | 1979-08-10 |
Attorney, Agent or Firm:
Takashi Sawai