Focus correcting method and method of manufacturing semiconductor device
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorToshifumi Suganaga
Life of this patent
Estimating the term…
Abstract
Disclosed herein is how to obtain the magnitude of focus deviation and the direction of the deviation directly from a focus measuring mark. The magnitude of focus deviation is measured from the length of the focus measuring mark (3) in the elongate direction. The length of a tapered part (20) of the focus measuring mark (3) in which the resist gradually becomes thinner is measured from the secondary electron signal waveform of a scanning electron microscope. The direction of the focus deviation is obtained from the measured length of the tapered part (20).
Claims10
A focus correcting method for use in an aligner capable of adjustment of focus position by setting a focusing value, comprising the steps of:
- (a) forming a resist pattern with at least one focus measuring mark by exposing a resist by said aligner;
- (b) measuring length of said at least one focus measuring mark in elongate direction;
- (c) measuring length of a tapered part of said at least one focus measuring mark in which said resist becomes thinner toward an end of said at least one focus measuring mark;
- and
- (d) determining a magnitude of deviation from a best focus on the basis of a measurement in said step (b) and also determining direction of said deviation from said best focus on the basis of a measurement in said step (c) to obtain a deviation amount from said best focus, and then setting said focusing value on the basis of said deviation amount from said best focus.
A method of manufacturing a semiconductor device using an aligner in which focus is corrected by using a given focus correcting method and focus position can be adjusted by setting a focusing value, comprising the steps of:
- (a) setting the focusing value;
- and
- (b) manufacturing semiconductor devices by using the aligner in which the focus position is adjusted by setting said focusing value;
- wherein said step (a) comprises the steps of,
- (c) forming a resist pattern with at least one focus measuring mark by exposing a resist by said aligner;
- (d) measuring length of said at least one focus measuring mark in elongate direction;
- (e) measuring length of a tapered part of said at least one focus measuring mark in which said resist becomes thinner toward an end of said at least one focus measuring mark;
- and
- (f) determining a magnitude of deviation from a best focus on the basis of a measurement in said step (d) and also determining direction of said deviation from said best focus on the basis of a measurement in said step (e) to obtain a deviation amount from said best focus, and then setting said focusing value on the basis of said deviation amount from said best focus.
Dependencies are inferred from the claim text.