Apparatus and method for electron beam lithography and semiconductor device

A method for electron beam lithography wherein electron beam is applied to a shaping window of a first aperture mask;

• an electron beam image from the shaping window is deflected and controlled by a shaping deflector having a function for effecting correction based on beam size correction formulae in which correction values for longitudinal and lateral widths are functions of two set values of the longitudinal and lateral widths to project the electron image upon a variable shaping window or a simultaneous shaping window of a second aperture mask in a displaced position, thereby forming an electron beam image in a different size and drawing a pattern in an arbitrary size on a sample by the electron beam image thus formed, the method comprising:
• a first step of varying the longitudinal and lateral widths of a beam size in a one-dimensional manner using a predefined reference size as a reference respectively, combining the longitudinal and lateral widths varied in the one-dimensional manner variously to vary the beam size in a two-dimensional manner and measuring current amount each time each set value is varied;
• a second step of estimating a measured value corresponding to each set value from the current amount obtained in the first step;
• a third step of calculating an offset amount of the measured value for each set value obtained in the second step from the set value;
• and
• a fourth step of obtaining optimum values of the constants of the beam size correction formulae such that the offset amount of each set value obtained in the third step is minimized or such that conformity to the size of the pattern to be transferred to the sample is achieved and providing feedback of the optimum values to the beam size correction formulae.

A semiconductor device fabricated using an apparatus for electron beam lithography wherein electron beams are applied to a shaping window of a first aperture mask, an electron beam image from the shaping window is deflected and controlled by a shaping deflector having a function for effecting correction based on beam size correction formulae in which correction values for longitudinal and lateral widths are functions of two set values for the longitudinal and lateral widths to project the electron beam image upon a variable shaping window or a simultaneous shaping window of a second aperture mask in a displaced position, thereby forming an electron beam image in a different size and drawing a pattern in an arbitrary size on a sample by using the electron beam image thus formed;

• a first step of varying the longitudinal and lateral widths of a beam size in a one-dimensional manner using a predefined reference size as the reference respectively, combining the longitudinal and lateral widths in the one-dimensional variations variously to vary the beam size in a two-dimensional manner and measuring current amount each time each set value is varied;
• a second step of estimating a measured value corresponding to each set value from the current amount obtained in the first step;
• a third step of calculating an offset amount of the measured value for each set value obtained in the second step from the set value;
• and
• a fourth step of obtaining optimum values of the constants of the beam size correction formulae such that the offset amount for each set value obtained in the third step is minimized or such that conformity to the size of the pattern to be transferred to the sample is achieved and providing feedback of the optimum values to the beam size correction formulae.