JP2005109344A - Charged particle beam projection aligner and method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent resist evaporation spattered particles from adhering to the internal wall of a sample chamber. <P>SOLUTION: In an electron beam projection aligner for irradiating a substrate 6 retained on a stage 9 in the sample chamber 10 with electron beams 3 discharged from an electron gun 2 via lenses 4, 5, a conductive shielding film 12, having a through hole through which the electron beams 3 pass, is removably provided on the inner surface of the sample chamber 10 opposite to the substrate 6. A retention mechanism 13 for retaining the conductive shielding film 12 is provided on the inner surface of the sample chamber 10. An arm 14 is provided in the sample chamber 10, where the arm 14 inserts/extracts and conveys the conductive shielding film 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a charged particle beam exposure apparatus, and more particularly to an electron beam exposure apparatus and a semiconductor device manufacturing method using the same.

FIG. 5 is a schematic diagram for explaining an electron beam exposure apparatus as a conventional charged particle beam exposure apparatus.
As shown in FIG. 5, an electron gun 32 that emits an electron beam 33, an irradiation lens 34 that irradiates the emitted electron beam 33 in a predetermined direction, and an irradiated electron beam 33 are contained in a column 31 that is held in vacuum. A converging lens 35 that converges on the surface of a sample 36 such as a substrate is accommodated. Similar to the column 31, a stage 39 that is movable in the X and Y directions is disposed in a sample chamber 40 that is held in a vacuum, and a sample 36 is held on the stage 39. On the sample 36, a resist 37 as a photosensitive material is applied.
Since the irradiation region of the electron beam 33 on the sample 36 is narrowed down by the converging lens 35, it becomes a minute region.

However, when the resist 37 is irradiated with the electron beam 33 in a minute region, the resist 37 irradiated with the heating energy of the electron beam 33 instantaneously becomes high temperature, and a part of the resist 37 evaporates as particles. It will be scattered around. A part of the resist 37 scattered around is a facing surface and adheres as scattered particles 41 to the inner wall surface of the sample chamber 40 near the lower magnetic pole (not shown) of the converging lens 35.
The amount of scattered particles 41 attached is very small when the number of processing is about one substrate, but becomes an amount that cannot be ignored when the exposure apparatus is continuously operated at a high throughput of about several tens of sheets / hour, for example. Since the adhering scattered particles 41 are electrically insulating, there is a problem that the position control accuracy of the electron beam 33 is lowered due to the position drift of the electron beam 33. For this reason, there has been a problem that if the exposure is continued in a state where a large amount of scattered particles 41 are adhered, the exposure accuracy of the circuit pattern is remarkably lowered.
Part of the scattered particles 41 is removed by the exhaust operation, but empirically, the scattered particles 41 adhere to a region having a radius of several tens of millimeters around the irradiation portion of the electron beam 33. An invisible amount of scattered particles is expected to adhere in a wider range. Therefore, the degree of influence of scattered particles also depends on the maximum shot size, deflection size, and current density of the electron beam.
The inner wall surface of the sample chamber 40 to which the scattered particles 41 adhere is located at the lowermost part of the main body of the column 31 having an overall weight of about several hundred kg. Therefore, in order to clean and remove the adhering scattered particles 41, the inside of the column 31 must be opened to the atmosphere and disassembled, resulting in a problem that the downtime of the exposure apparatus becomes long.

  The present invention has been made to solve the above-described conventional problems, and an object thereof is to prevent adhesion of resist evaporation scattering particles to the wall surface of a sample chamber. Another object of the present invention is to form a high-quality circuit pattern on a substrate.

A charged particle beam exposure apparatus according to the present invention is a charged particle beam exposure apparatus that irradiates a substrate held in a sample chamber with a charged particle beam,
A conductive shielding plate having a through hole through which the charged particle beam passes is detachably provided on an inner wall surface of the sample chamber facing the substrate.

  In the charged particle beam exposure apparatus according to the present invention, it is preferable that an outer dimension of the conductive shielding plate is equal to or larger than a dimension of the substrate.

  In the charged particle beam exposure apparatus according to the present invention, it is preferable that the conductive shielding plate includes a conductive thin film or a conductive film on a surface facing the substrate.

  In the charged particle beam exposure apparatus according to the present invention, it is preferable that the conductive shielding plate further includes a thin film made of a material having a small scattering coefficient of the charged particle beam, below the conductive thin film or the conductive film. is there.

In the charged particle beam exposure apparatus according to the present invention, a preliminary exhaust chamber that is provided adjacent to the sample chamber and temporarily stores the conductive shielding plate;
An arm for attaching and detaching the conductive shielding plate, and transporting the conductive shielding plate between the preliminary exhaust chamber and the sample chamber;
It is preferable to further include

  A method of manufacturing a semiconductor device according to the present invention includes a step of irradiating a resist on a substrate with a charged particle beam to form a circuit pattern using the charged particle beam exposure apparatus.

  According to the present invention, as described above, it is possible to prevent the resist evaporation scattered particles from adhering to the wall surface of the sample chamber. Further, according to the present invention, a high-quality circuit pattern can be formed on a substrate.

Embodiment 1 FIG.
FIG. 1 is a schematic diagram for explaining a charged particle beam exposure apparatus according to Embodiment 1 of the present invention. Specifically, FIG. 1 is a schematic diagram for explaining an electron beam exposure apparatus.

As shown in FIG. 1, an electron gun 2 that emits an electron beam 3, an irradiation lens 4 that irradiates the electron beam 3 emitted from the electron gun 2 in a predetermined direction, and an irradiation lens 4 in a column 1 that is held in vacuum. A converging lens 5 for deflecting and converging the electron beam 3 irradiated by the above to the surface of the sample 6 is accommodated.
Similar to the column 1, a stage 9 that is movable in the XY directions is disposed in a sample chamber 10 that is held in vacuum, and a substrate 6 as a sample is held on the stage 9. On the substrate 6, a resist 7 which is a photosensitive material is applied. By driving and controlling the converging lens 5 and the stage 9, the electron beam 3 is irradiated to a desired position on the substrate 6, and the circuit pattern is transferred to the resist 7.

On the inner wall surface of the sample chamber 10 facing the surface of the substrate 6, a conductive shielding plate 12 for attaching evaporated and scattered particles of the resist 7 is detachably provided. It is essential that the conductive shielding plate 12 has conductivity in order to prevent the adhering scattered particles from being charged up. The conductive shielding plate 12 is attached and detached by an arm 14 (described later). On the inner wall surface in the vicinity of the lower magnetic pole (not shown) of the converging lens 5, a holding mechanism 13 including a stopper and a storage guide is provided, and the conductive shielding plate 12 is held by the holding mechanism 13.
On the side surface of the sample chamber 10, a preliminary exhaust chamber 8 for the substrate 6 and a preliminary exhaust chamber 11 for the conductive shielding plate 12 are provided. Each of the preliminary exhaust chambers 8 and 11 is provided with a vent mechanism and an exhaust mechanism (not shown). The replacement of the conductive shielding plate 12 is performed via the preliminary exhaust chamber 11, and the substrate 6 is carried in and out via the preliminary exhaust chamber 8.
In the sample chamber 10, an arm 14 for removing and transporting the conductive shielding plate 12 and an arm 15 for transporting the substrate 6 are provided. These arms 14 and 15 are vertically extendable as shown by arrows in the figure.

FIG. 2 is a view for explaining the conductive shielding plate 12 shown in FIG. Specifically, FIG. 2A is a cross-sectional view for explaining the conductive shielding plate, and FIG. 2B is a top view. FIG. 2A is a diagram showing a cross section taken along the line aa ′ of FIG.
As shown in FIG. 2, the conductive shielding plate 12 is, for example, a disc made of phosphor bronze having a thickness of several millimeters and a diameter of 8 inches (200 mm), and the electron beam 3 passes through the center thereof. It has a through hole 12a. The outer dimension of the conductive shielding plate 12 needs to be at least several tens of millimeters in diameter, and is preferably larger than the dimension of the substrate 6. By making the size of the substrate 6 or larger, scattered particles in an amount that cannot be visually observed can be attached to the conductive shielding plate 12. A positioning groove 12 b is formed on the outer periphery of the conductive shielding plate 12. The conductive shielding plate 12 is positioned by fitting the positioning groove 12b into a protrusion (not shown) provided in the holding mechanism 13.

FIG. 3 is a top view for explaining another example of the conductive shielding plate.
The conductive shielding plate 16 shown in FIG. 3 is used when a backscattered electron detector is provided near the lower magnetic pole of the converging lens 5 shown in FIG. Similar to the conductive shielding plate 12, the conductive shielding plate 16 has a through hole 16 a for passing an electron beam at the center and a positioning groove 16 b on the outer periphery. Furthermore, four detection holes 16c corresponding to the four-divided detectors in the XY directions are formed in the conductive shielding plate 16. The electrons reflected by the substrate 6 are detected by the detector through the detection hole 16c.
Note that the outer shape of the conductive shielding plates 12 and 16 is not limited to the circular shape described above, and may be a rectangular shape. Further, the number of detection holes 16c can be appropriately changed according to the detector.

Hereinafter, the operation of the charged particle beam exposure apparatus will be described.
First, a pattern exposure operation on a substrate that is normally performed will be described.
The substrate 6 is transferred to the preliminary exhaust chamber 8 by a transfer mechanism (not shown), and the inside of the preliminary exhaust chamber 8 is exhausted. After the inside of the preliminary exhaust chamber 8 reaches a predetermined degree of vacuum, the gate on the sample chamber 10 side is opened, and the substrate 6 is transferred onto the stage 9 by the arm 15. Then close the gate.
After transporting the substrate 6, an electron beam 3 is emitted from the electron gun 2 in the column 1, and the emitted electron beam 3 is irradiated in a predetermined direction by the irradiation lens 4, and then the electron beam 3 is further resisted by the converging lens 5. Pattern exposure is performed by irradiating the desired position.
After the exposure, the gate is opened and the substrate 6 is transferred to the preliminary exhaust chamber 8 by the arm 15. Then, after the gate is closed, the inside of the preliminary exhaust chamber 8 is vented to the atmospheric pressure, and the substrate 6 is transferred from the preliminary exhaust chamber 8.

  As the pattern exposure operation continues, the amount of scattered particles attached to the conductive shielding plate 12 increases. Therefore, before the position control accuracy of the electron beam 3 is lowered, the conductive shielding plate 12 described later is exchanged. The conductive shielding plate 12 may be replaced periodically. Further, a monitor device for monitoring the amount of scattered particles attached may be provided in the sample chamber 10, and the conductive shielding plate 12 may be replaced according to the monitoring result obtained from the monitor device.

Next, replacement work of the conductive shielding plate 12 will be described.
As described above, after the substrate 6 is unloaded from the sample chamber 10, the conductive shielding plate 12 is removed from the holding mechanism 13 by the arm 14. After the gate on the sample chamber 10 side of the preliminary exhaust chamber 11 is opened, the removed conductive shielding plate 12 is transferred to the preliminary exhaust chamber 11 by the arm 14. Then, after closing the gate, the inside of the preliminary exhaust chamber 11 is vented to atmospheric pressure, and the conductive shielding plate 12 is taken out from the preliminary exhaust chamber 11. The conductive shielding plate 12 to which the scattered particles adhere can be dried and reused after being cleaned by a cleaning device (not shown).
Next, after cleaning or a new conductive shielding plate 12 is placed in the preliminary exhaust chamber 11, and the preliminary exhaust chamber 11 is exhausted. After the inside of the preliminary exhaust chamber 11 reaches a predetermined degree of vacuum, the gate on the sample chamber 10 side is opened, and the conductive shielding plate 12 is carried into the sample chamber 10 by the arm 14, and the conductive shielding plate is further moved by the arm 14. 12 is attached to the holding mechanism 13. At this time, the conductive shielding plate 12 is accurately positioned by fitting the positioning groove 12b (see FIG. 2) of the conductive shielding plate 12 into the protrusion of the holding mechanism 13. In addition, the operation | work which attaches the electroconductive shielding board 12 first before exposure is the same as the attachment operation | work mentioned above.
After replacing the conductive shielding plate 12 in this way, the normal pattern exposure operation described above is performed.

As described above, in the first embodiment, the conductive shielding plate 12 is detachably disposed on the inner wall of the sample chamber 10 facing the substrate 6, and scattered particles are attached to the conductive shielding plate 12. . Then, the conductive shielding plate 12 with the scattered particles attached was replaced with a new or washed conductive shielding plate 12.
Therefore, adhesion of resist scattering particles to the inner wall of the sample chamber 10 facing the substrate 6 can be prevented. For this reason, since it is not necessary to clean the inner wall of the sample chamber 10, it is not necessary to disassemble the column 1 by opening it to the atmosphere, and the downtime of the exposure apparatus can be greatly reduced.
Moreover, since the position control of the electron beam 3 can be performed with high accuracy by periodically exchanging the conductive shielding plate 12, a high-quality circuit pattern can be formed on the substrate.

  Although the electron beam exposure apparatus has been described in the first embodiment, the present invention can also be applied to an exposure apparatus using other charged particle beams such as an ion beam (the same applies to the second embodiment described later). ).

Embodiment 2. FIG.
The difference between the second embodiment and the first embodiment described above is that a different conductive shielding plate is used. Except for this difference, the second embodiment is the same as the first embodiment, and a description thereof will be omitted.

FIG. 4 is a diagram for explaining the conductive shielding plate in the second embodiment of the present invention. Specifically, FIG. 4A is a cross-sectional view for explaining the conductive shielding plate, and FIG. 4B is a top view. FIG. 4A is a view showing a bb ′ cross section of FIG.
As shown in FIG. 4, the conductive shielding plate 17 used in Embodiment 2 is formed by forming a conductive film 19 on the surface of the conductive substrate 18, that is, the scattered particle adhesion surface. Specifically, the conductive film 19 is fixed to the surface of the conductive substrate 18 with a conductive tape, a screw, or the like. Thereby, the evaporated particles of the resist adhere to the conductive film 19. In place of the conductive film 19, a conductive thin film can be used. Moreover, the electroconductive base material 18 is not used, but you may be comprised only with the electroconductive film 19. FIG.
As with the conductive shielding plates 12 and 16 of the first embodiment, the conductive shielding plate 17 has a through hole 17a for passing an electron beam at the center and a positioning groove 17b on the outer periphery. Similar to the conductive shielding plate 16, a plurality of detection holes may be provided in the conductive shielding plate 17.

  In addition, you may interpose the thin film which consists of material with a small scattering coefficient of an electron beam like a carbon film between the electroconductive base material 18 and the electroconductive film 19, for example. Thereby, scattering of electrons can be prevented, and so-called “fogging” phenomenon to a wide area can be prevented.

  In the first embodiment, the conductive shielding plate 12 to which the scattered particles adhere is washed and dried for reuse. On the other hand, in the second embodiment, the conductive shielding plate 17 is detached from the holding mechanism 13 by the same method as in the first embodiment, and the conductive film to which the scattered particles constituting the conductive shielding plate 17 are attached. 19 may be replaced with a new conductive film 19.

As described above, in the second embodiment, the conductive shielding plate 17 is detachably disposed on the inner wall of the sample chamber 10 facing the substrate 6, and scattered particles are attached to the conductive shielding plate 17. . Therefore, the same effect as in the first embodiment can be obtained.
In the second embodiment, the conductive shielding plate 17 has a laminated structure of the conductive base material 18 and the conductive film 19, and the conductive film 19 with scattered particles attached is replaced with a new conductive film 19. I made it. The conductive film 19 is inexpensive and easy to handle. Therefore, compared with the case where the conductive shielding plate 12 is washed as in the first embodiment, the operation cost can be reduced and the working time (film exchange time) can be greatly shortened.

It is the schematic for demonstrating the charged particle beam exposure apparatus by Embodiment 1 of this invention. It is a figure for demonstrating the electroconductive shielding board shown in FIG. In Embodiment 1 of this invention, it is a top view for demonstrating the other example of an electroconductive shielding board. In Embodiment 2 of this invention, it is a figure for demonstrating a conductive shielding board. It is the schematic for demonstrating the conventional charged particle beam exposure apparatus.

Explanation of symbols

1 Column 2 Electron Gun 3 Electron Beam 4 Irradiation Lens 5 Converging Lens 6 Sample (Substrate)
7 Resist 8 Pre-exhaust chamber (for sample)
9 Stage 10 Sample chamber 11 Pre-exhaust chamber (for conductive shield)
12 Conductive shielding plate 12a Through hole 12b Positioning groove 13 Holding mechanism 14, 15 Arm 16 Conductive shielding plate 16a Through hole 16b Positioning groove 16c Detection hole 17 Conductive shielding plate 17a Through hole 17b Positioning groove 18 Conductive base Material 19 Conductive Film, Conductive Thin Film

Claims (6)

A charged particle beam exposure apparatus for irradiating a charged particle beam onto a substrate held in a sample chamber,
A charged particle beam exposure apparatus, wherein a conductive shielding plate having a through hole through which the charged particle beam passes is detachably provided on an inner wall surface of the sample chamber facing the substrate. The charged particle beam exposure apparatus according to claim 1,
The charged particle beam exposure apparatus, wherein an outer dimension of the conductive shielding plate is equal to or larger than a dimension of the substrate. In the charged particle beam exposure apparatus according to claim 1 or 2,
The charged particle beam exposure apparatus, wherein the conductive shielding plate includes a conductive thin film or a conductive film on a surface facing the substrate. In the charged particle beam exposure apparatus according to claim 3,
The charged particle beam exposure apparatus, wherein the conductive shielding plate further includes a thin film made of a material having a small scattering coefficient of a charged particle beam, below the conductive thin film or the conductive film. In the charged particle beam exposure apparatus according to any one of claims 1 to 4,
A preliminary exhaust chamber provided adjacent to the sample chamber and temporarily storing the conductive shielding plate;
An arm for attaching and detaching the conductive shielding plate, and transporting the conductive shielding plate between the preliminary exhaust chamber and the sample chamber;
A charged particle exposure apparatus, further comprising:   6. A method for manufacturing a semiconductor device, comprising: using the charged particle beam exposure apparatus according to claim 1 to form a circuit pattern by irradiating a resist on a substrate with a charged particle beam.

Images