Nuflare Technology, Inc.

Haruyuki Nomura

Noriaki Nakayamada

Munehiro Ogasawara

Takashi Kamikubo

The disclosure relates to a multiple charged particle beam writing apparatus that includes a dose representative value calculator that determines a representative dose for each mesh region irradiated by multiple beams. A calculation processor computes the temperature rise in a mesh region of interest due to beam irradiation, using a convolution of the dose values and a thermal spread function. An effective temperature calculator repeats this process while shifting the processing region along the stripe to obtain multiple temperature rises of the mesh area of interest and calculate a representative value of the multiple temperature rises as an effective temperature of the mesh area of interest. Based on the effective temperature, a dose corrector adjusts the beam doses to compensate for resist heating effects.

Multiple charged particle beam writing apparatus, multiple charged particle beam writing method, and computer readable recording media storing program

In a charged particle beam writing method according to an embodiment, a charged particle beam is deflected by a deflector, and a pattern is written by irradiating, with the charged particle beam, a substrate having a resist film formed thereon. The method includes irradiating a pattern region, in which a pattern is to be formed, with a beam at a first dose, irradiating at least part of a non-pattern region, in which a pattern is not to be formed, with the charged particle beam at a second dose, at which the resist film is not dissolved away, and determining the second dose based on the first dose and a charge amount of the resist film corresponding to a pattern density of the pattern region, wherein a charge amount difference between the pattern region and a non-dissolution irradiation region, which is irradiated at the second dose, is smaller than that obtained when the second dose is zero.

Charged particle beam writing method, charged particle beam writing apparatus, and computer-readable recording medium

In one embodiment, a charged particle beam writing method includes transferring a substrate to a writing chamber of a charged particle beam writing apparatus by use of a transfer mechanism while maintaining each of the writing chamber and the transfer mechanism at a predetermined temperature, calculating correction amounts for charged particle beams based on correction data for charged particle beam irradiation positions each associated with a previously obtained elapsed time from a predetermined starting point in time of transfer of the substrate and the elapsed time at a point in time of irradiation with each of the charged particle beams, and applying the charged particle beams to positions corrected based on the calculated correction amounts for the charged particle beams to write a pattern on the substrate.

Charged particle beam writing method and charged particle beam writing apparatus

Position shifts caused by charging phenomena can be corrected with high accuracy. A charged particle beam writing apparatus includes an exposure-amount distribution calculator calculating an exposure amount distribution of a charged particle beam using a pattern density distribution and a dose distribution, a fogging charged particle amount distribution calculator calculating a plurality of fogging charged particle amount distributions by convoluting each of a plurality of distribution functions for fogging charged particles with the exposure amount distribution, a charge-amount distribution calculator calculating a charge amount distribution due to direct charge using the pattern density distribution, the dose distribution, and the exposure amount distribution, and calculating a plurality of charge amount distributions due to fogging charge using the plurality of fogging charged particle amount distributions, a position shift amount calculator calculating a position shift amount of a writing position based on the charge amount distribution due to direct charge and the plurality of charge amount distributions due to fogging charge, a corrector correcting an exposure position using the position shift amount, and a writer exposing the corrected exposure position to a charged particle beam.

Charged particle beam writing apparatus, charged particle beam writing method, and a non-transitory computer-readable storage medium

In a charged particle beam writing method according to one embodiment, a deflector is caused to deflect a charged particle beam and a pattern is written by irradiating a substrate with the charged particle beam. The charged particle beam writing method includes calculating a charge amount distribution based on a charge amount of a beam irradiation region on the substrate immediately after irradiation with the charged particle beam and a diffusion coefficient for electric charge of the substrate, calculating a position shift distribution of the charged particle beam on the substrate based on the charge amount distribution, and correcting an irradiation position of the charged particle beam based on the position shift distribution.

A charged-particle beam writing apparatus includes a writing chamber to house a stage having a writing object placed thereon, a beam irradiator to irradiate a charged particle beam to the writing object placed on the stage, a stage driver to move the stage, a temperature distribution calculator to calculate temperature distribution of the writing object caused by a heat source in the writing chamber, based on movement history information of the stage, a deformed amount calculator to calculate a deformed amount of the writing object based on a constraint condition of the writing object placed on the stage and the calculated temperature distribution, and a position corrector to correct an irradiation position of the charged particle beam to the writing object based on the calculated deformed amount. The beam irradiator irradiates the charged particle beam based on the irradiation position corrected by the position corrector.

Charged-particle beam writing apparatus and charged-particle beam writing method

A parameter acquiring method for dose correction of a charged particle beam includes writing evaluation patterns on a substrate coated with resist; writing, while varying writing condition, a peripheral pattern on a periphery of any different one of the evaluation patterns, after an ignorable time as to influence of resist temperature increase due to writing of an evaluation pattern concerned has passed; and calculating a parameter for defining correlation among a width dimension change amount of the evaluation pattern concerned, a temperature increase amount of the evaluation pattern concerned, and a backscatter dose reaching the evaluation pattern concerned, by using, under each writing condition, a width dimension of the evaluation pattern concerned, the temperature increase amount of the evaluation pattern concerned at each shot time, and the backscatter dose reaching the evaluation pattern concerned from each shot.

Method for acquiring parameter for dose correction of charged particle beam, charged particle beam writing method, and charged particle beam writing apparatus

In one embodiment, a charged particle beam writing apparatus includes a current limiting aperture, a blanking deflector switching between beam ON and beam OFF so as to control an irradiation time by deflecting the charged particle beam having passed through the current limiting aperture, a blanking aperture blocking the charged particle beam deflected by the blanking deflector in such a manner that the beam OFF state is entered, and an electron lens disposed between the current limiting aperture and the blanking aperture. A lens value set for the electron lens is substituted into a given function to calculate an offset time. The offset time is added to an irradiation time for writing a pattern to correct the irradiation time. The blanking deflector switches between the beam ON and the beam OFF based on the corrected irradiation time.

A charged particle beam writing apparatus includes a limiting aperture member at the downstream side of the emission source, arranged such that its height position can be selectively adjusted, according to condition, to be one of the n-th height position (n being an integer of 1 or more) based on the n-th condition depending on at least one of the height position of the emission source and an emission current value, and the (n+m)th height position (m being an integer of 1 or more) based on the (n+m)th condition depending on at least one of the height position of the emission source and the emission current value, and a shaping aperture member at the downstream side of the electron lens and the limiting aperture member to shape the charged particle beam by letting a part of the charged particle beam pass through a second opening.

Charged particle beam writing apparatus and charged particle beam writing method

An electron beam writing apparatus includes an electron gun system to emit an electron beam, a height adjustment unit, arranged at the downstream side compared to the electron gun system with respect to the optical axis direction, to variably adjust a height position of the electron gun system, an electron lens, arranged at the downstream side compared to the height adjustment unit with respect to the optical axis direction, to converge the electron beam, a lens control unit to control, for each variably adjusted and changed height position of the electron gun system, the electron lens such that the electron beam forms a crossover at a predetermined position, and an objective lens, arranged at the downstream side compared to the electron lens with respect to the optical axis direction, to focus the electron beam having passed the electron lens.

Growing community of inventors

Yokohama, Japan

Haruyuki Nomura