JPS6123317A - Charged particle beam apparatus - Google Patents

Abstract

PURPOSE:To accurately irradiate charged particle beam onto a material to be irradiated even when a stage has an inherent vibration by controlling the charged particle beam depending on a correction signal obtained through integration of only the frequency components based on the inherent vibration of the stage among output signals of an accelerometer. CONSTITUTION:A signal detected by an accelerometer 7 is amplified by an amplifier 7 and is then applied to a band-pass filter 9 which allows only the component based on the inherent vibration of stage 6 to pass through. The inherent vibration component of stage obtained through this filter 9 is integrated twice by a first integration circuit 10 and a second integral circuit 11, resulting in displacement based on the inherent vibration of the stage. After adjustment of amplitude with an amplitude adjusting amplifier 12, this signal is applied to an adder circuit 13 as a correction signal which cancels displacement of stage due to the vibration and is added with a drawing signal sent form a computer 14, and applied to a deflector 4 as a deflection signal for electron beam, whereby electron beam is irradiated accurately to the position on the drawing material 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention is directed to a charged particle beam suitable for use in, for example, an electron beam lithography system that requires irradiation of a charged particle beam onto a predetermined position of a material. Regarding line equipment.

[Prior Art] In an electron beam drawing apparatus, if there is a movement error of a stage on which a material to be drawn is placed, ultrafine figures cannot be drawn with high precision. In the technique described in Japanese Patent Publication No. 49-24519, a mirror of a laser interferometer is fixed to a stage on which a material is placed, and the amount of movement and variation of the stage is measured by the laser interferometer. This measured moving mouth,
A signal corresponding to the amount of variation is supplied to an electron beam deflection means, and the movement error of the stage is corrected by deflecting the electron beam.

[Problems to be Solved by the Invention] By the way, the stage on which the material is placed is configured to be movable within the drawing chamber, and therefore the stage has a unique frequency that corresponds to the structure of the stage and is vibrating against the column. Although the displacement due to the natural vibration of this stage is several nanometers or less, when writing is performed with nanometer precision, the displacement of the stage, that is, the material due to this natural vibration, cannot be ignored. However, the above-mentioned correction technique using a laser interferometer is limited by the wavelength of the laser used, and the correction resolution of this technique is 5nlIIPi! degree. With this resolution of 5 nm, it is not possible to detect the displacement due to natural vibration, so naturally it is not possible to correct the displacement, and if a nanometer line width is drawn, the linearity of the drawn line will be impaired. Become.

Therefore, the main object of the present invention is to provide a charged particle beam device capable of drawing nanometer figures.

[Means for Solving the Problems] A charged particle beam device based on the present invention includes means for generating a charged particle beam to be irradiated onto a material, and for moving the irradiation position of the charged particle beam on the material. charged particle beam deflection means;
A stage on which the material is placed, a means for driving the stage, an accelerometer installed on the stage, a bandpass filter to which the output signal of the accelerometer is supplied, and a bandpass filter that receives the output signal of the filter. The method is characterized in that the charged particle beam deflecting means deflects the charged particle beam irradiated onto the material based on the integrated signal.

[Example] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The drawing shows a charged particle beam lithography apparatus using the present invention, and numeral 1 in the drawing is an electron gun. The electron beam generated from the electron gun and accelerated is ttA Fl,
It is narrowly focused on 3. The electron beam irradiation position on the material 3 is changed depending on the voltage applied to the electrostatic deflector 4. The material 3 is placed on a stage 6 that is moved by a drive mechanism 5. An accelerometer 7 is attached to the stage 6, and an output signal of the acceleration 7 is supplied to an amplifier 8. The signal amplified by the amplifier 8 is filtered by a bandpass filter 9 so that only signals of specific frequency components are passed to the first integrating circuit 10 . The signal is supplied to the second integration circuit 11 and integrated twice. The output signal of the second integration circuit 11 is supplied to an addition circuit 13 via an amplitude adjustment amplifier 12. The adding circuit 13 is supplied with a drawing signal from a computer 14 (which controls the stage drive mechanism 4, etc.) via a D-A converter 15, and the adding circuit 13 receives the drawing signal and the amplitude adjustment amplifier. The correction signal from 12 is added and supplied to the electrostatic deflector 4. Note that each circuit, such as the electrostatic deflector, accelerometer, bandpass filter, and integration circuit, is actually provided for the X direction and the Y direction, but for the sake of simplicity, only one will be shown. Illustrated.

In the configuration as described above, drawing of the material 3 is performed by moving the stage 6 and deflecting the electron beam based on the supply of drawing signals from the computer 14 to the deflector 4.

Here, when the stage 6 is vibrating at a unique frequency f, the stage displacement ff1A due to the vibration, the vibration speed ■, and the vibration acceleration α are the amplitude of the vibration 2Ao and the angular velocity of the vibration ω(2πf ), it can be expressed as follows.

, A=Ao sin ωt ■=ωAOCO5ωt α−=A′oω2 sin(I)t Therefore, if the acceleration of the vibration is known, the amount of displacement due to the vibration can be determined by integrating the acceleration twice. In this embodiment, the signal detected by the accelerometer 7 is amplified by an amplifier 8 and then fed to a bandpass filter 9 that passes only components due to the natural vibrations of the stage. The stage natural vibration component obtained by the filter 9 is transmitted to a first integrating circuit 10. Second
It is integrated twice by the integrating circuit 11 to determine the amount of displacement based on the natural vibration of the stage. The amplitude of the signal corresponding to the amount of displacement is adjusted by the amplitude adjustment amplifier 12, and then supplied to the addition circuit 13 as a correction signal to cancel the displacement of the stage due to the vibration, and then sent to the computer 14.
is added to the drawing signal from. Since the added signal is supplied to the deflector 4 as an electron beam deflection signal, it is not affected by the displacement of the stage based on the natural vibration of the stage.
- It becomes possible to irradiate an accurate position of the drawing material 3 with an electron beam. Here, the maximum displacement amount 2Ao of the stage due to the natural vibration of the stage is the frequency f lfi 70Hz of the natural vibration of the stage, and the acceleration α is α−1On+oa
If l (10x 10-3 cm/2), then 2A-2α/2πf -2x10x10J3/ (2xπX70)2= 1
,07×10-7 Cm. Some accelerometers have a resolution of 1 moal, and therefore, according to the present invention, it is possible to detect displacements of 1 nanometer or less, which is impossible with the laser interference screen 1. The signal corresponding to this detected displacement is the material vj of the electron beam.
It is used to change the irradiation position on the
The electron beam can be irradiated to a precise position on the material 1, and ultrafine figures can be drawn with nanometer precision.

Furthermore, above)! In the embodiment described above, a configuration was shown in which an accelerometer was simply attached to the stage in order to obtain a correction signal for the displacement of the stage, but in reality, the displacement of the stage,
The amount of movement is also measured by a laser interferometer as in the past, and the displacement of the stage outside the stage's natural vibration J,
The movement is corrected by this laser interference correction system. Also, the embodiment described above can be modified in many ways. For example, a correction signal obtained by integrating the signal from the accelerometer twice is used. Although the configuration is such that it is added to the drawing signal and supplied to a single deflector, it is also possible to install two types of deflectors, one to supply the IW image signal, and the other to supply the correction signal. Furthermore, although one accelerometer is provided in one direction, if there are multiple natural vibrations of the stage, multiple detection systems such as accelerometers may be installed for each natural vibration with a different frequency. The amount of displacement of the stage due to each vibration can be detected by either setting up a [J] or by supplying the output signal of one acceleration t1 to multiple band-pass filters with different passbands, and then detecting the amount of displacement of the stage due to each vibration. The electron beam may be deflected.Furthermore, although the present invention has been described using an example of an electron beam lithography system, the present invention can also be applied to an ion beam lithography system, and can also be applied to ultra-high resolution It can also be used in a control system for a stage of a scanning electron microscope or the like.

[Effect 1] As described in detail above, the present invention uses an accelerometer, integrates only the frequency component based on the natural vibration of the stage of the output signal of the accelerometer, and generates a correction signal of 1q based on this correction signal. Since the stage is configured to control the charged particle beam, even if the stage has natural vibration, the charged particle beam can be accurately irradiated onto the irradiated material.

[Brief explanation of drawings]

The accompanying drawings are diagrams showing an electron beam lithography apparatus that is an embodiment of the present invention. 1... Electron gun 2... Focusing lens 3... Material to be drawn 4... Deflector 5... Drive mechanism 6
...Stage 7...Accelerometer 8...Amplifier 9...Band pass filter 10.11...Integrator circuit 12...Amplitude adjustment amplifier 13...Addition circuit 14...Computer 15.
・・D-A converter patent E) Mr. Ito, Representative of JEOL Co., Ltd.

Claims (1)

[Claims] means for generating a charged particle beam to be irradiated onto a material; a charged particle beam deflection means for moving the irradiation position of the charged particle beam on the material; a stage on which the material is placed; an accelerometer provided on the stage; a bandpass filter to which an output signal of the accelerometer is supplied; and a means for integrating the output signal of the filter; A charged particle beam device configured to deflect a charged particle beam irradiated onto the material by the charged particle beam deflection means.