US 5,315,123 AGranted

Electron beam lithography apparatus

AssigneeHitachi, Ltd.

InventorsHiroyuki Itoh, Minoru Sasaki

Life of this patent

Estimating the term…

Loading patent…

Abstract

Drift values of exposure position of an electron beam are obtained through detection of a reference mark on a sample stage and a drift characteristic formula which expresses the exposure positions of the electron beam is corrected by using a plurality of the drift values. The electron beam is controlled to expose some lithographic pattern by estimating the exposure position in real time at which the electron beam is irradiated at the estimated exposure position based on the drift characteristic formula without detecting the reference mark, and further to expose other lithographic pattern by calculating the exposure position based on the drift characteristic formula by detecting the reference mark. The measuring of the drift which takes much time are partly taken place at few limitted positions and the correction of the exposure positions is effectively in a short time.

Claims21

Dependent claims

An electron beam lithography apparatus for obtaining lithographic patterns on a sample by applying an electron beam thereon, comprising:

a means for obtaining drift values of an exposure position of the electron beam by detecting reflected electron signals obtained by irradiating the electron beam on a reference mark on a sample stage;
a memory for storing a plurality of position drift values of the electron beam;
a means for calculating a drift characteristic formula which expresses the exposure positions of the electron beam by using a plurality of drift values from the memory;
a deflection correcting circuit for correcting the exposure positions based on the drift characteristic formula in real time at which the electron beam is irradiated;
and
means for controlling the electron beam based on the exposure positions by estimating some of the exposure positions in the real time at which the electron beam is irradiated based on the drift characteristic formula, and by calculating other of the exposure positions based on the drift characteristic formula by detecting the reference mark.

3 more elements

Dependencies are inferred from the claim text.