JP2007018860A - Charge reducing apparatus, exposure apparatus, measuring apparatus, and manufacturing method of device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charge reducing apparatus used in an exposing device or a measuring device which irradiates a charged particle beam from a charged particle source to a sample, by applying deflection control by deflection electrodes disposed face to face in a vacuum column to reduce the charge of a portion charged with positive or negative electricity by the charged particle beam in the deflection electrodes, the exposure apparatus and the measuring apparatus equipped with the charge reducing apparatus, and to provide a manufacturing method for a device that uses the exposure device. <P>SOLUTION: This charge reducing device has an electron beam irradiation means to irradiate an electron beam to the charged portion of the deflection electrodes which are charged with positive or negative electricity by the charged particle beam, and a means of changing the irradiation energy of the electron beam. Thereby, charge of the deflection electrodes is reduced; and since even if the deflection electrodes are charged with both positive and negative electricity, two of positive and negative beam sources are not used, but charge can be reduced by using only the electron beam, the constitution of the device can be simplified. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes a charge reducing device used in an exposure apparatus or a measuring apparatus that controls a deflection of a charged particle beam from a charged particle source by a deflection electrode disposed opposite to the inside of a vacuum column and irradiates a sample, and the charge reducing apparatus. The present invention relates to an exposure apparatus, a measurement apparatus, and a device manufacturing method using the exposure apparatus.

Conventionally, for example, Japanese Patent Laid-Open No. 5-291100 (Patent Document 1) proposes a charge removal technique for removing charge by discharge, and generates a charged particle and irradiates a workpiece (sample) with a first discharge; First, the charged region is generated to irradiate the object by separating the discharge region and the object to be processed by the partition and alternately performing the second discharge that is performed so that the object is not irradiated with the charged particles. The same charge removal as before is realized by discharging, and the charge removal of the object to be processed is performed.
Japanese Patent Application Laid-Open No. 11-174008 (Patent Document 2) proposes a mechanism for irradiating charged particles having a charge opposite to that of charging, irradiating the sample with primary charged particles, and releasing the sample from the sample. The charged particle device for detecting secondary charged particles includes a charge removing device that replenishes the charged portion of the sample with a charge opposite in sign to the charged charge to cancel the charge.
These JP-A-5-291100 (Patent Document 1) and JP-A-11-174008 (Patent Document 2) mainly reduce the charging of the sample.
JP-A-5-291100 Japanese Patent Laid-Open No. 11-174008

In an exposure apparatus or microscope in which a charged particle beam is irradiated from an electron source in an almost vacuum column, and passes through the deflecting electrodes arranged opposite to each other to irradiate the sample, each part of the deflecting electrode constituting the apparatus Charged substances such as contamination adhere to the surface, which is charged by a charged particle beam, and the charged particle beam itself used for exposure or observation is affected by this charging. There is a need to reduce it.
Therefore, the present invention is used in an exposure apparatus or a measurement apparatus that irradiates a sample by controlling the deflection of a charged particle beam from a charged particle source with a deflection electrode disposed opposite to the vacuum column. It is an object of the present invention to provide a charge reduction device that reduces the charge of a positively or negatively charged portion, an exposure apparatus including the charge reduction device, a measurement apparatus, and a device manufacturing method using the exposure apparatus.

In order to achieve the above object, an electrification reducing apparatus according to the present invention is an exposure apparatus or a measurement apparatus that irradiates a sample by controlling the deflection of a charged particle beam from a charged particle source by a deflection electrode disposed oppositely in a vacuum column. In the charge reduction device used,
An electron beam irradiation means for irradiating the charged portion of the deflection electrode charged positively or negatively by the charged particle beam with an electron beam;
And means for changing irradiation energy of the electron beam.
Furthermore, the charge reducing device of the present invention is characterized in that the irradiation energy of the electron beam is changed based on a charging potential at a charging portion of the deflection electrode.
Furthermore, in the charge reduction device of the present invention, the electron beam irradiation means includes an electron gun and an acceleration voltage application means, and a desired irradiation energy is obtained by changing the acceleration voltage in the acceleration voltage application means. It is characterized by that.
Furthermore, the charge reducing device of the present invention is characterized in that the electron beam has a lower energy intensity and a larger energy dispersion than the charged particle beam.
Furthermore, the charge reduction device of the present invention is a charge reduction device used in an exposure apparatus or a measurement apparatus that irradiates a sample by controlling the deflection of a charged particle beam from a charged particle source using a deflection electrode disposed opposite to the vacuum column. ,
A reflective portion for reflecting a secondary electron beam when irradiated with the charged particle beam;
The charging of the charged portion is reduced by irradiating the charged portion of the deflection electrode, which is positively or negatively charged by the charged particle beam, with a secondary electron beam from the reflective portion. To do.
Furthermore, in the electrification reducing apparatus of the present invention, the reflection portion is made of Au or Cu as a metal material and CsI or Al ₂ O ₃ as a compound material.
Furthermore, the charge reducing device of the present invention is characterized in that the secondary electron beam has a lower energy intensity and a larger energy dispersion than the charged particle beam.
Furthermore, the exposure apparatus of the present invention includes the above-described charging reduction device.
Furthermore, the measuring device of the present invention includes the above-described charging reduction device.
Furthermore, the device manufacturing method of the present invention includes a step of exposing a sample using the exposure apparatus, and a step of developing the exposed sample.

According to the charging removal device of the present invention, the electron beam irradiation means for irradiating the charged portion of the deflection electrode positively or negatively charged by the charged particle beam with the electron beam and the irradiation energy of the electron beam are changed. Means.
For this reason, the charging of the deflection electrode is reduced. For both positive and negative charges, the charge can be reduced using only the electron beam instead of the two positive and negative radiation sources, and the apparatus configuration is simplified.
Furthermore, according to the charge reducing device of the present invention, the apparatus includes a reflection portion that reflects a secondary electron beam when the charged particle beam is irradiated, and the secondary electron beam from the reflection portion is converted into the charged particle. By irradiating the charged portion of the deflection electrode, which is positively or negatively charged by a beam, charging of the charged portion is reduced.
For this reason, the charging of the deflection electrode is reduced, and the charging can be reduced by using only the electron beam instead of the two positive and negative sources for both positive and negative charging, and the apparatus configuration is simplified. .
Further, according to the charge reducing device of the present invention, the electron beam or the secondary electron beam has sufficiently low energy and wide energy dispersion compared to the charged particle beam, and the charge beam is positive or negative. However, the charging potential is sufficiently reduced.
Furthermore, the exposure apparatus and the measurement apparatus of the present invention include the charge reducing device, and the charging of the deflection electrode is reduced.
Furthermore, the device manufacturing method of the present invention comprises a step of exposing a sample using the exposure apparatus and a step of developing the exposed sample, and the charging of the deflection electrode is reduced.

  Hereinafter, the present invention will be described with reference to the drawings based on the embodiments.

FIG. 1 is a configuration diagram of the inside of a column of an electron beam exposure apparatus to which the charge reduction device of Embodiment 1 of the present invention is applied. In some cases, the charge reducing device according to the first embodiment of the present invention is applied to a measuring device such as a microscope instead of the electron beam exposure device.
In a substantially vacuum column 6 constituting an electron beam exposure apparatus, a charged particle beam 2 is irradiated from an electron source (not shown), passes between deflection electrodes 1 and 1 arranged opposite to each other, and irradiates a sample (not shown). Is done. The deflection electrodes 1 and 1 are made of gold, copper, aluminum, platinum, palladium or the like. An electron beam generating source 3 which is an electron beam generating means for removing electrification is a device for generating an electron beam 17. As shown in detail in FIG. 2, the electron beam generating source 3 includes an electron gun 11, a driving high voltage power source 12, and the like. Consists of. The electron gun 11 is composed of a filament and an acceleration Wehnelt, and tungsten or LaB6 is used for the filament as in a normal electron beam generator. The driving high-voltage power source 12 is a power source for generating and accelerating the electron beam 17 from the electron gun 11, and obtains necessary energy dispersion by changing the acceleration voltage with time. The period is set to a sufficiently short time so that charging is eased.
The electron beam 17 is applied to the portion 4 that is positively or negatively charged by the charged particle beam 2 in the deflection electrodes 1, 1, thereby reducing the charging of the charged portion 4. Contamination 5 adheres to the charged portion 4 and is charged by the charged particle beam 2, and the charged particle beam 2 itself used for exposure or observation is affected by this charging. It is necessary to eliminate or reduce as much as possible.

As shown in FIG. 3, the electron beam 17 generated and irradiated from the electron beam generation source 3 has a sufficiently low energy and a wide energy dispersion 7 compared to the energy dispersion 8 of the charged particle beam 2. This energy dispersion 7 can be obtained by periodically changing the voltage of the driving high-voltage power supply 12.
FIG. 4 shows the electron beam-charging responsiveness of the charged portion 4 when the electron beam 17 generated from the electron beam generating source 3 is irradiated. Both positive charging and negative charging appear, and as a result Add up to eliminate charge or relax to charge at a relatively low voltage. By changing the irradiation energy of the electron beam 17 generated from the electron beam generation source 3, the charging voltage changes from positive to negative as shown in FIG.
Therefore, by irradiating the electron beam 17 having the energy distribution 7 having a wide distribution of the region shown in FIG. 3 across the positive and negative, the positive and negative charges are neutralized and the charge is reduced.

Next, referring to FIG. 5, a description will be given of an electrification reducing apparatus according to Embodiment 2 of the present invention.
The charge reduction device according to the second embodiment of the present invention is illustrated by passing a charged particle beam 2 from an electron source (not shown) in a substantially vacuum column 6 and passing between deflecting electrodes 1 and 1 arranged opposite to each other. The present invention is applied to an exposure apparatus that irradiates a sample that is not performed. In some cases, the charge reduction device according to the second embodiment of the present invention may be applied to a measurement device such as a microscope instead of the exposure device.
The deflection of the charged particle beam 2 is controlled by the deflection electrodes 1 and 1 and the deflectors 9 and 9. For example, the reflective parts 10 and 10 made of Au or Cu as the metal material and CsI or Al ₂ O ₃ as the compound material are irradiated with the charged particle beam 2 and reflected. The secondary electron beam 2 a reflected from the reflective parts 10, 10 is irradiated on the part 4 charged positively or negatively by the charged particle beam 2 in the deflection electrode 1, 1. Reduce electrification.
Here, the secondary electron beam 2a has a sufficiently low energy and a wide energy dispersion compared to the charged particle beam 2.
In some cases, an exposure apparatus and a measuring apparatus such as a microscope include the charge reduction apparatuses according to the first and second embodiments of the present invention.

Next, with reference to FIG. 6, a device manufacturing method according to a third embodiment of the present invention in which a semiconductor device is manufactured using the exposure apparatus provided with the charge reducing apparatus according to the first and second embodiments of the present invention will be described.
FIG. 6 shows a manufacturing flow of a microdevice (a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a micromachine, etc.).
In step 1 (circuit design), a semiconductor device circuit is designed. In step 2 (exposure control data creation), exposure control data for the exposure apparatus is created based on the designed circuit pattern. On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the wafer and the exposure apparatus to which the prepared exposure control data is input. The next step 5 (assembly) is referred to as a post-process, and is a process for forming a semiconductor chip using the wafer produced in step 4, such as an assembly process (dicing, bonding), a packaging process (chip encapsulation), and the like. including. In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. Through these steps, the semiconductor device is completed and shipped (step 7).

  In recent years, fine processing technology has been developed, and sub-micron pattern accuracy is required in exposure apparatuses, and the same level of accuracy is required in microscopes. Since charging problems are related to accuracy problems, control of fine charged particles is required. Need. For this reason, the charge reducing device of the present invention is applied to an exposure apparatus in which a charged particle beam is irradiated from an electron source onto a sample or a vacuum column constituting a microscope, and the charge is reduced.

It is a block diagram of the inside of a column of an electron beam exposure apparatus to which the charge reducing device of Embodiment 1 of the present invention is applied. It is a block diagram of the electron beam generation source for the charge removal which comprises Example 1 of this invention. It is explanatory drawing of an example of the energy dispersion | distribution of the electron beam which the electron beam generation source for electrification which comprises Example 1 of this invention generate | occur | produces. It is explanatory drawing of the electron beam-charging responsiveness of the charged site | part when irradiated with the electron beam generated from the electron beam generation source in Example 1 of this invention. It is a block diagram inside the column of the electron beam exposure apparatus to which the charge reduction apparatus of Example 2 of this invention is applied. It is explanatory drawing of the flow of the device manufacturing method of Example 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Deflection electrode 2 Charged particle beam 2a Secondary electron beam 3 Electron beam generation source 4 Charged part 5 Contamination 6 Column 9 Deflector 10 Reflection part 11 Electron gun 12 Drive high voltage power supply

Claims (10)

In a charge reduction device used in an exposure apparatus or a measurement apparatus that irradiates a sample by controlling the deflection of a charged particle beam from a charged particle source by a deflection electrode disposed opposite to the inside of a vacuum column.
An electron beam irradiation means for irradiating the charged portion of the deflection electrode charged positively or negatively by the charged particle beam with an electron beam;
And a means for changing the irradiation energy of the electron beam.   The charging reduction device according to claim 1, wherein irradiation energy of the electron beam is changed based on a charging potential at a charging portion of the deflection electrode.   3. The electron beam irradiation means includes an electron gun and an acceleration voltage application means, and a desired irradiation energy is obtained by changing an acceleration voltage in the acceleration voltage application means. The charge reducing device described in 1.   The charge reduction device according to claim 1, wherein the electron beam has lower energy intensity and greater energy dispersion than the charged particle beam. In a charge reduction device used in an exposure apparatus or a measurement apparatus that irradiates a sample by controlling the deflection of a charged particle beam from a charged particle source by a deflection electrode disposed opposite to the inside of a vacuum column.
A reflective portion for reflecting a secondary electron beam when irradiated with the charged particle beam;
The charging of the charged portion is reduced by irradiating the charged portion of the deflection electrode, which is positively or negatively charged by the charged particle beam, with a secondary electron beam from the reflective portion. To reduce charge. The charging reduction device according to claim 5, wherein the reflection portion is made of any one of Au, Cu, CsI, and Al ₂ O ₃ .   The charge reducing device according to claim 5 or 6, wherein the secondary electron beam has lower energy intensity and larger energy dispersion than the charged particle beam.   An exposure apparatus comprising the charge reducing device according to claim 1.   A measuring device comprising the charge reducing device according to claim 1.   A device manufacturing method, comprising: exposing a sample using the exposure apparatus according to claim 8; and developing the exposed sample.

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