JP2002231606A - Electron beam exposure system and electron lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron beam exposure system, which can expose a pattern on a wafer with accuracy by preventing the expansion and contraction or inflation of a magnetic conductor member which has a lens opening for passing an electron beam due to the temperature fluctuations, by means of cooling functions respectively installed to a plurality of multi-axial electron lenses. SOLUTION: This electron beam exposure system, which exposes patterns on wafer with a plurality of electron beams, is provided with an electron beam generating section which generates plurality of electron beams and a first electron lens section which independently makes the electron beams converge. The electron lens section has a first magnetic conductor section, having a plurality of first lens openings for respectively passing the electron beams, a first coil section which is provided around the conductor section to generate magnetic fields in the first lens openings, and a first cooling section which is provide adjacent to the coil section for cooling the coil section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an electron beam exposure apparatus and an electron lens. In particular, the present invention relates to an electron beam exposure apparatus having a cooling function and an electron lens.

[0002]

2. Description of the Related Art An electron beam exposure apparatus for exposing a pattern on a wafer with a plurality of electron beams is provided with a multi-axis electron lens for independently focusing a plurality of electron beams. The multi-axis electron lens has a coil unit that generates a magnetic field, and a magnetic conductor unit provided with a plurality of lens openings through which a plurality of electron beams pass.

[0003]

In a multi-axis electron lens that independently focuses a plurality of electron beams, a magnetic conductor portion expands and contracts or expands due to heat generated by a coil portion that generates a magnetic field.
There is a problem that the position of the lens opening varies.

Accordingly, an object of the present invention is to provide an electron beam exposure apparatus and an electron lens which can solve the above-mentioned problems. This object is achieved by a combination of features described in the independent claims.
The dependent claims define further advantageous embodiments of the present invention.

[0005]

According to a first aspect of the present invention, there is provided an electron beam exposure apparatus for exposing a pattern on a wafer with a plurality of electron beams, the electron beam generating a plurality of electron beams. A first electron lens unit that independently focuses the plurality of electron beams, wherein the first electron lens unit includes a plurality of first lens openings through which the plurality of electron beams pass. A first magnetic conductor portion, a first coil portion provided around the first magnetic conductor portion and generating a magnetic field in the plurality of first lens openings, and a first coil portion provided adjacent to the first coil portion. And a first cooling unit for cooling the first cooling unit. The electronic lens unit may further include a heat insulating plate provided between the first magnetic conductor unit and the first coil unit.

A second magnetic conductor portion including a plurality of second lens openings through which a plurality of electron beams pass, and a magnetic field is provided around the second magnetic conductor portion to generate a magnetic field in the plurality of second lens openings. A second coil section, a second cooling section provided adjacent to the second coil section, the second cooling section cooling the second coil section, and independently focusing a plurality of electron beams; A cooling control unit that controls the temperatures of the first cooling unit and the second cooling unit may be further provided.

The cooling control section controls the first cooling section and the second cooling section so that the first coil section and the second coil section have substantially the same temperature.
The temperature of the cooling unit may be controlled. The cooling control unit may control the temperatures of the first cooling unit and the second cooling unit such that the first magnetic conductor unit and the second magnetic conductor unit have substantially equal temperature distributions.

The cooling control section controls the temperatures of the first cooling section and the second cooling section to thereby provide a first lens opening provided in the first magnetic conductor section and a second lens conductor section provided in the second magnetic conductor section. The position relative to the second lens opening may be controlled.
The first cooling unit and the second cooling unit may include a cooling passage through which the refrigerant passes, and the cooling control unit may control a flow rate of the refrigerant passing through the cooling passage. The cooling control unit may control the flow rate of the refrigerant based on the current supplied to the first coil unit and the second coil unit.

According to a second aspect of the present invention, there is provided an electron lens for independently focusing a plurality of electron beams, wherein the magnetic lens includes a plurality of lens openings through which the plurality of electron beams pass. , Provided around the magnetic conductor portion,
A coil unit that generates a magnetic field at the plurality of lens openings and a cooling unit that is provided adjacent to the coil unit and cools the coil unit.

The above summary of the present invention does not list all of the necessary features of the present invention, and a sub-combination of these features may also be an invention.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of an electron beam exposure apparatus 100 according to one embodiment of the present invention. The electron beam exposure apparatus 100 uses the electron beam to
And a control system 140 for controlling the operation of each component included in the exposure unit 150.
Is provided.

The exposure unit 150 generates a plurality of electron beams inside the casing 8 and irradiates the wafer 44 with the electron beam forming means 110 for forming a desired cross-sectional shape of the electron beam. It is provided with an irradiation switching means 112 for independently switching whether or not each of the electron beams, and an electron optical system including a wafer projection system 114 for adjusting the direction and size of an image of a pattern transferred to the wafer 44. Exposure unit 1
Reference numeral 50 denotes a stage system including a wafer stage 46 on which a wafer 44 on which a pattern is to be exposed is mounted, and a wafer stage driving unit 48 for driving the wafer stage 46.

The electron beam shaping means 110 includes an electron beam generator 10 for generating a plurality of electron beams, and a first forming member having a plurality of openings for shaping the cross-sectional shape of the electron beam by passing the electron beams. 14th and 2nd
A forming member 22, a first multi-axis electron lens 16 for independently converging a plurality of electron beams, and adjusting a focus of the electron beam;
It has a first shaping deflecting unit 18 and a second shaping deflecting unit 20 for independently deflecting a plurality of electron beams passing through the first shaping member 14.

The first multi-axis electron lens 16 includes a magnetic conductor section including a plurality of lens openings through which a plurality of electron beams pass, a coil section for generating a magnetic field in the plurality of lens openings, and cooling the coil section. And a cooling unit. In addition, a second multi-axis electronic lens 24 and a third multi-axis electronic lens
The fourth, fourth multi-axis electronic lens 36, and fifth multi-axis electronic lens 62 also have the same configuration as the first multi-axis electronic lens 16.

The electron beam generator 10 includes a plurality of electron guns 1.
04 and a substrate 106 on which the electron gun 104 is formed. The electron gun 104 includes a cathode 12 for generating thermoelectrons.
And the cathode 12
And a grid 102 for stabilizing the thermoelectrons generated in the above. It is desirable that the cathode 12 and the grid 102 be electrically insulated. In this embodiment, the electron beam generator 10 forms an electron gun array by providing a plurality of electron guns 104 on a base material 106 at predetermined intervals.

First molded member 14 and second molded member 22
It is preferable that a surface of the substrate to be irradiated with the electron beam has a grounded metal film such as platinum. The cross-sectional shapes of the plurality of openings included in the first forming member 14 and the second forming member 22 may have a spread along the irradiation direction of the electron beam in order to efficiently pass the electron beam. Further, the plurality of openings included in the first molding member 14 and the second molding member 22 are preferably formed in a rectangular shape.

The irradiation switching means 112 independently converges the plurality of electron beams and adjusts the focus of the electron beams, and deflects the plurality of electron beams independently for each electron beam. The electron beam to the wafer 4
4 includes a blanking electrode array 26 for independently switching whether or not to irradiate the electron beam, and an electron beam including a plurality of openings for passing the electron beam and blocking the electron beam deflected by the blanking electrode array 26. Beam shielding member 2
8 is provided. In another embodiment, the blanking electrode array 26 may be a blanking aperture array.

The wafer projection system 114 converges a plurality of electron beams independently to reduce the irradiation diameter of the electron beams.
A multi-axis electron lens 34 and a fourth multi-axis electron lens 3 for independently converging a plurality of electron beams and adjusting the focus of the electron beam
6, a deflecting unit 60 for independently deflecting the plurality of electron beams to desired positions on the wafer 44 for each electron beam, and a fifth unit which functions as an objective lens for the wafer 44 and converges the plurality of electron beams independently. And a multi-axis electron lens 62.

The control system 140 includes an overall control unit 130 and an individual control unit 120. The individual control unit 120 includes an electron beam control unit 80, a multi-axis electron lens control unit 82, a shaping deflection control unit 84, and a blanking electrode array control unit 86.
And a deflection controller 92 and a wafer stage controller 96. The general control unit 130 is, for example, a workstation, and performs general control of each control unit included in the individual control unit 120. The electron beam controller 80 controls the electron beam generator 10. The multi-axis electron lens control unit 82
The multi-axis electron lens 16, the second multi-axis electron lens 24, the third multi-axis electron lens 34, the fourth multi-axis electron lens 36, and the fifth
Each of the multi-axis electron lenses 62 supplies a current to the respective multi-axis electron lens so as to focus the electron beam at a desired position.

The shaping / deflecting controller 84 includes a first shaping / deflecting unit 1.
8 and the second shaping deflection unit 20 are controlled. The blanking electrode array control unit 86 controls the voltage applied to the deflection electrodes included in the blanking electrode array 26. The deflection control unit 92 controls a voltage applied to the deflection electrodes included in the plurality of deflectors included in the deflection unit 60. The wafer stage control unit 96 controls the wafer stage drive unit 48 to move the wafer stage 46 to a predetermined position.

The electron beam exposure apparatus 10 according to the present embodiment
The operation of 0 will be described. First, the electron beam generator 1
0 generates multiple electron beams. In the electron beam generator 10, the generated electron beam is applied to the first forming member 14 to be formed.

The first multi-axis electron lens 16 independently converges a plurality of rectangularly shaped electron beams, and
The focus adjustment of the electron beam with respect to 2 is performed independently for each electron beam. The first shaping / deflecting unit 18 deflects a plurality of rectangularly shaped electron beams to a desired position with respect to the second shaping member independently for each electron beam. Second forming deflection unit 2
0 deflects the plurality of electron beams deflected by the first shaping / deflecting unit 18 in a direction substantially perpendicular to the second shaping member 22 independently for each electron beam. The second forming member 22 including a plurality of openings having a rectangular shape is used to form a plurality of electron beams having a rectangular cross section applied to each opening into a desired rectangular cross section to be irradiated on the wafer 44. It is further shaped into an electron beam.

The second multi-axis electron lens 24 independently converges a plurality of electron beams, and adjusts the focus of the electron beam on the blanking electrode array 26 independently for each electron beam. The electron beam focused by the second multi-axis electron lens 24 passes through a plurality of apertures included in the blanking electrode array 26.

The blanking electrode array controller 86 controls whether or not to apply a voltage to the deflection electrodes formed in the blanking electrode array 26 and provided near each aperture. The blanking electrode array 26 switches whether or not to irradiate the wafer 44 with the electron beam based on the voltage applied to the deflection electrode.

The electron beam that is not deflected by the blanking electrode array 26 has its electron beam diameter reduced by the third multi-axis electron lens 34 and passes through an opening included in the electron beam shielding member 28. The fourth multi-axis electron lens 36
A plurality of electron beams are independently converged, and the focus of the electron beam with respect to the deflecting unit 60 is adjusted independently for each electron beam. The focused electron beam is incident on a deflector included in the deflecting unit 60. You.

A deflection controller 92 controls a plurality of deflectors included in the deflection unit 60 independently. The deflecting unit 60 deflects the plurality of electron beams incident on the plurality of deflectors to a desired exposure position on the wafer 44 independently for each electron beam. The focus of the plurality of electron beams that have passed through the deflecting unit 60 with respect to the wafer 44 is adjusted by the fifth multiaxial electron lens 62,
The wafer 44 is irradiated.

During the exposure process, the wafer stage controller 96
Moves the wafer stage 48 in a certain direction. The blanking electrode array control unit 86 determines apertures through which the electron beam passes based on the exposure pattern data, and performs power control on each aperture. In accordance with the movement of the wafer 44, an aperture for passing the electron beam
Then, by deflecting the electron beam by the deflecting unit 60, a desired circuit pattern can be exposed on the wafer 44.

FIG. 2 shows the configuration of the first multi-axis electron lens 16 according to the present embodiment. FIG. 2A is a top view of the first multi-axis electron lens 16. FIG. 2B is a cross-sectional view of the first multi-axis electron lens 16. The first multi-axis electron lens 16 has a lens magnetic conductor 20 provided with a plurality of lens openings 204 through which a plurality of electron beams respectively pass.
2 and a coil portion 21 provided around the lens magnetic conductor portion 202 and generating a magnetic field in the plurality of lens openings 204.
2, a coil portion magnetic conductor portion 200 provided so as to surround the coil portion 212, a cooling portion 208 provided adjacent to the coil portion 212 to cool the coil portion 212, a coil portion 212 and a lens portion magnetic conductor portion And a heat insulating plate 210 provided between the heat insulating plate 202 and the heat insulating plate 202.

The cooling section 208 is a cooling passage 2 through which the refrigerant passes.
The cooling unit 206 is cooled by supplying a cooling medium to the cooling path 206, and cools the coil unit 212.
Therefore, it is preferable that the cooling unit 208 is formed of a material having a high thermal conductivity, such as copper. Further, the contact surface between the cooling section 208 and the coil section 212 is preferably wide, and the cooling section 208 is preferably pressed by the coil section 212. Further, it is preferable that the heat insulating plate 210 is provided so as not to contact the coil portion 212. Insulation board 21
A value of 0 can shield heat generated from the coil portion 212 and prevent the heat from being transmitted to the lens portion magnetic conductor portion 202.

FIG. 3 shows the cooling units 208, 220, 222,
4 shows a supply system for supplying a refrigerant to 224, 226; The electron beam exposure apparatus 100 includes a coolant supply unit 214a that supplies a coolant to the cooling unit 208 of the first multi-axis electron lens 16,
A coolant supply unit 214b for supplying a coolant to the cooling unit 220 of the second multi-axis electron lens 24; a coolant supply unit 214c for supplying a coolant to the cooling unit 222 of the third multi-axis electron lens 34; A refrigerant supply unit 214d that supplies a refrigerant to the 36 cooling units 224, and a refrigerant supply unit 214e that supplies a refrigerant to the cooling unit 226 of the fifth multi-axis electron lens 62;
Temperature acquisition unit 2 for acquiring the temperature of first multi-axis electron lens 16
16a, a temperature acquisition unit 216b for acquiring the temperature of the second multi-axis electron lens 24, a temperature acquisition unit 216c for acquiring the temperature of the third multi-axis electron lens 34, and the fourth multi-axis electron lens 3.
6, a temperature acquisition unit 216d that acquires the temperature of the fifth multi-axis electron lens 62,
Refrigerant supply parts 214a, 214b, 214c, 214d,
And 214e are the cooling units 208, 220, 220, 22
4, and a cooling control unit 218 that adjusts the flow rate of the refrigerant to be supplied to the cooling units 208, 220, 220, 224, and 226.

Temperature acquisition units 216a, 216b, 216
c, 216d, and 216e are respectively the coil part 212 of the first multi-axis electron lens 16 and the second multi-axis electron lens 2
4, the coil section 240 of the third multi-axis electronic lens 36, the coil section 242 of the fourth multi-axis electronic lens 36,
It is preferable to obtain the temperatures of the coil section 244 of the fifth multi-axis electron lens 62 and the respective temperatures. Further, the temperature acquisition units 216a, 216b, 216c, 216d, and 216
e is a magnetic conductor part 202 of the first multi-axis electron lens 16, a magnetic conductor part 246 of the second multi-axis electron lens 24,
In each of the magnetic conductor section 248 of the third multi-axis electron lens 34, the magnetic conductor section 250 of the fourth multi-axis electron lens 36, and the magnetic conductor section 252 of the fifth multi-axis electron lens 62, the temperatures at a plurality of locations are measured. It is preferable to obtain the temperature distribution of each magnetic conductor.

The cooling control section 218 includes a coil section 212 of the first multi-axis electron lens 16, a coil section 238 of the second multi-axis electron lens 24, and a coil section 2 of the third multi-axis electron lens 34.
40, a coil part 242 of the fourth multi-axis electron lens 36,
The cooling units 208, 220, 222, 2
It is preferable to control the temperatures of 24 and 226. The cooling control unit 218 includes a magnetic conductor 202 of the first multi-axis electron lens 16, a magnetic conductor 246 of the second multi-axis electron lens 24, and a magnetic conductor 24 of the third multi-axis electron lens 34.
8, a magnetic conductor 250 of the fourth multi-axis electron lens 36,
The cooling units 208, 220, 22 are arranged such that the temperature distribution is substantially equal to that of the magnetic conductor 252 of the fifth multi-axis electron lens 62.
Preferably, the temperatures of 2, 224 and 226 are controlled.

Further, the cooling control unit 218
By controlling the temperatures of 8, 220, 222, 224, and 226, a lens opening 204 provided in the magnetic conductor 202, a lens opening 228 provided in the magnetic conductor 246, and a magnetic conductor 248 are provided. It is preferable to control the relative positions of the lens opening 230 provided in the magnetic conductor 250, the lens opening 232 provided in the magnetic conductor 250, and the lens opening 234 provided in the magnetic conductor 252. In addition, the cooling control unit 218 includes the coil units 212 and 23
The flow rate of the supplied refrigerant may be controlled based on the current supplied to 8, 240, 242, and 244.

According to the electron beam exposure apparatus 100 of the present embodiment, the first multi-axis electron lens 16, the second multi-axis electron lens 24, the third multi-axis electron lens 34, the fourth multi-axis electron lens 3
By providing a cooling function to the sixth and fifth multi-axis electron lenses 62 to reduce or uniform the deformation of the magnetic conductor member due to temperature fluctuation, the relative opening of the lens opening provided in the magnetic conductor member is reduced. The positions can be matched between the plurality of magnetic conductor members, and the wafer can be irradiated with a plurality of electron beams with high accuracy.

The cooling control unit 218 is connected to the temperature acquisition unit 2
16a, 216b, 216c, 216d, and 216e
In order to control the temperatures of the cooling units 208, 220, 222, 224, and 226 based on the temperatures of the respective multi-axis electron lenses obtained by the above, when different currents are supplied to the respective multi-axis electron lenses, Also, the relative positions of the lens openings provided in the magnetic conductor member can be matched between the plurality of magnetic conductor members, and the wafer can be irradiated with a plurality of electron beams with high accuracy.

As described above, the present invention has been described using the embodiments. However, the above embodiments do not limit the claimed invention, and all combinations of the features described in the embodiments are not limited to the invention. Is not necessarily essential to the solution of the above. Further, the technical scope of the present invention is not limited to the scope described in the above embodiment. Various changes or improvements can be added to the above embodiment. It is apparent from the description of the appended claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

[0037]

As is apparent from the above description, according to the electron beam exposure apparatus of the present invention, a magnetic conductor in which a plurality of multiaxial electron lenses are provided with a cooling function and a lens opening through which an electron beam passes is provided. It is possible to reduce the expansion and contraction or expansion due to the temperature fluctuation of the member, and to accurately expose the pattern on the wafer.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an electron beam exposure apparatus 100 according to one embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a first multi-axis electron lens 16;

FIG. 3 is a diagram illustrating a supply system that supplies a cooling medium to cooling units 208, 220, 222, 224, and 226.

[Explanation of symbols]

8... Housing, 10... Electron beam generator, 14.
Molded member, 16 first multi-axis electron lens, 18 first
Forming deflector, 20 second deflector, 22 second member, 24 second multi-axis electron lens, 26 blanking electrode array, 28 electron beam shielding member, 34
..Third multi-axis electron lens, 36..4th multi-axis electron lens, 60..deflection unit, 44..wafer, 46..wafer stage, 48..wafer stage drive unit, 62..fifth multi. Axis electron lens, 80 ·· Electron beam control unit, 82 ·
· Multi-axis electron lens control unit, 84 · · Molding deflection control unit, 8
6 blanking electrode array control unit, 92 deflection control unit, 96 wafer stage control unit, 100 electron beam exposure apparatus, 110 electron beam shaping means, 11
2. Irradiation switching means, 114 Projection system for wafer, 12
0 individual control system, 130 general control unit, 140
Control system, 150 exposure unit, 200 magnetic coil unit, 202 magnetic lens unit, 204 lens opening, 206 cooling path, 208 cooling unit, 21
0: heat insulating plate, 212: coil unit, 214: refrigerant supply unit, 216: temperature acquisition unit, 218: cooling control unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/30 541W

Claims (9)

[Claims] 1. An electron beam exposure apparatus for exposing a pattern on a wafer by using a plurality of electron beams, comprising: an electron beam generating unit that generates the plurality of electron beams; and an electron beam generating unit that independently focuses the plurality of electron beams. A first electron lens unit, wherein the first electron lens unit includes a plurality of first electron lenses through which each of the plurality of electron beams passes.
A first magnetic conductor portion provided with a lens opening; and a plurality of first magnetic conductor portions provided around the first magnetic conductor portion.
An electron beam exposure apparatus, comprising: a first coil unit that generates a magnetic field in a lens opening; and a first cooling unit that is provided adjacent to the first coil unit and cools the first coil unit. . 2. The electron beam exposure apparatus according to claim 1, wherein the electron lens unit further includes a heat insulating plate provided between the first magnetic conductor unit and the first coil unit. . 3. A second magnetic conductor portion including a plurality of second lens openings through which each of the plurality of electron beams passes; and a second magnetic conductor portion provided around the second magnetic conductor portion, wherein the second magnetic conductor portion is provided around the second magnetic conductor portion.
A second coil unit that generates a magnetic field in the lens opening; and a second cooling unit that is provided adjacent to the second coil unit and cools the second coil unit. 2. The electron beam exposure apparatus according to claim 1, further comprising a second electron lens unit that converges on the first cooling unit, and a cooling control unit that controls temperatures of the first cooling unit and the second cooling unit. 3. 4. The cooling control unit controls the temperatures of the first cooling unit and the second cooling unit such that the first coil unit and the second coil unit have substantially equal temperatures. 3. An electron beam exposure apparatus according to claim 2, wherein: 5. The cooling control unit controls the temperatures of the first cooling unit and the second cooling unit such that the first magnetic conductor and the second magnetic conductor have a substantially equal temperature distribution. The electron beam exposure apparatus according to claim 3, wherein: 6. The cooling control unit controls the temperature of the first cooling unit and the second cooling unit, thereby controlling the first cooling unit.
4. The relative position between the first lens opening provided in the magnetic conductor and the second lens opening provided in the second magnetic conductor is controlled. 5. Electron beam exposure equipment. 7. The first cooling unit and the second cooling unit,
4. The electron beam exposure apparatus according to claim 3, further comprising: a cooling path through which the cooling medium passes, wherein the cooling control unit controls a flow rate of the cooling medium passing through the cooling path. 5. 8. The cooling unit according to claim 7, wherein the cooling control unit controls the flow rate of the refrigerant based on a current supplied to the first coil unit and the second coil unit. Electron beam exposure equipment. 9. An electron lens that independently focuses a plurality of electron beams, a magnetic conductor portion provided with a plurality of lens openings through which each of the plurality of electron beams passes, and a periphery of the magnetic conductor portion. And a cooling unit provided adjacent to the coil unit and cooling the coil unit, wherein the cooling unit is provided adjacent to the coil unit.