JPH1064791A - Exposure correction and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposure correction apparatus which can perform exposure for proximity effect correction while avoiding reduction of a throughput throughout a lithographic step. SOLUTION: While an electron beam reduction transfer device 2 within a sample chamber 1 performs exposure operation of a predetermined pattern on a wafer 6A, a wafer 6B to be next exposed is waiting on an arm 8 within a supply chamber 7. During the waiting of the wafer 6B, the wafer 6B is subjected to an irradiation of electron beam having such a distribution as to correspond to an inversion of the predetermined pattern from a surface variable electron beam supply source 12 for exposure correction. Usable as the variable electron beam source 12 is, for example, a cathode array of an electric field emission type.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithography process for manufacturing a semiconductor integrated circuit, for example, in which a proximity effect caused by backscattered particles on a photosensitive substrate on which a charged particle beam is drawn or transferred via a charged particle beam is used. The present invention relates to an exposure correction method and apparatus for performing correction.

[0002]

2. Description of the Related Art As a semiconductor integrated circuit is miniaturized, a method of forming a fine pattern on a photosensitive substrate through a charged particle beam such as an electron beam or an ion beam in a lithography process for manufacturing the integrated circuit. Is considered one of the leading exposure methods. When forming a predetermined pattern on a photosensitive substrate using a charged particle beam, a method of directly drawing a predetermined pattern with the charged particle beam, a predetermined mask pattern under the charged particle beam, and a predetermined projection magnification In the present application, such an operation of giving an energy distribution corresponding to a predetermined pattern on a photosensitive substrate by drawing or transfer with a charged particle beam is described as “the predetermined Expose the pattern. "

By the way, when an electron beam is drawn on a photosensitive substrate such as a semiconductor wafer (hereinafter simply referred to as a “wafer”) coated with an electron beam resist using an electron beam drawing apparatus, the pattern is formed by a so-called proximity effect. The line width may deviate from the design value. The main cause of the proximity effect is the backscattering of the electron beam from the electron beam resist, the substrate itself of the wafer, and various underlying patterns having different irregularities and reflection coefficients on the wafer. Therefore, in order to form a desired pattern by correcting the proximity effect, conventionally, (a) changing the design dimensions of the pattern to be formed (resizing), (b) partially modulating the exposure amount, and (c) backward. Correction exposure has been carried out at locations where the amount of scattered particles is small.

In recent years, a pattern to be transferred has been divided into a plurality of small areas on a mask, and a pattern in each of the small areas has been sequentially transferred on a photosensitive substrate while being transferred (hereinafter, referred to as a “divided”). (Transfer system)) has been proposed. The split transfer method can transfer a fine pattern onto a photosensitive substrate with high resolution and high throughput (productivity). On the other hand, as a method for correcting the proximity effect, (a) resizing of a pattern to be formed is performed by creating a mask. It is not very realistic because of the difficulty of the above, and it is also difficult to partially modulate the exposure amount in (b). Therefore, as a method of correcting the proximity effect by the division transfer method,
The method of (c) in which correction exposure is performed at a position where the amount of backscattered particles is small is most suitable. When the correction exposure is performed by the division transfer method in this manner, (d) a method in which a mask in which a transmission part and a shield part of a charged particle beam are inverted is prepared, and the mask is replaced by the same transfer apparatus to perform exposure, or There is a method of performing correction exposure by using another transfer device for correction exposure.

[0005] In addition to the division transfer method, as an exposure method for partially exposing a mask pattern onto a photosensitive substrate sequentially, there is also a method for sequentially exposing a desired pattern onto the photosensitive substrate using a variable shaping beam or a spot beam. Are known. In such an exposure method, similarly to the method (d), correction exposure can be performed by creating exposure pattern data in which a transmission part and a shielding part of a charged particle beam are inverted.

[0006]

As described above, in order to correct the proximity effect by the conventional split transfer method, a method of performing correction exposure on a portion where the amount of backscattered particles is small can be used. However, in order to perform such a correction exposure using the original charged particle beam transfer apparatus for forming a pattern, it is necessary to replace a mask to be used with a mask having an inverted pattern, and thus there is a disadvantage that the throughput is reduced. . On the other hand, if correction exposure is performed using another transfer device similar to the original charged particle beam transfer device, the throughput will not decrease, but the installation floor area of the entire device will increase and the manufacturing equipment as a whole will increase. However, there is an inconvenience that the cost of the system increases considerably.

Furthermore, the same as the original charged particle beam transfer apparatus,
Or when performing a correction exposure using another similar transfer device,
Since it is necessary to manufacture a mask having an inverted pattern for each layer having a different type of exposure pattern, the manufacturing cost of the mask for the correction exposure is increased, and the management of the mask for the correction exposure is complicated. is there. Similarly, in an exposure method in which a desired pattern is sequentially exposed on a photosensitive substrate using a variable shaped beam or a spot beam, correction exposure is performed using the same or similar another exposure apparatus as the original exposure apparatus. However, there are inconveniences such as a decrease in throughput or an increase in the floor area on which the exposure apparatus is installed as a whole.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide an exposure correction method which does not reduce the overall throughput of an exposure process when performing correction exposure for proximity effect correction. Still another object of the present invention is to provide an exposure amount correcting apparatus that can be used to carry out such an exposure amount correcting method.

Further, according to the present invention, it is possible to carry out such an exposure amount correcting method, it is not necessary to prepare a mask for correction exposure separately, and it is possible to install an apparatus used for exposing a desired pattern as a whole. It is another object of the present invention to provide an exposure correction device capable of reducing a floor area.

[0010]

According to the exposure amount correcting method of the present invention, when a predetermined pattern is exposed on a photosensitive substrate (6B) using a charged particle beam, the backscattered particles are exposed on the photosensitive substrate (6B). (2) a charged particle beam apparatus for exposing a predetermined pattern on a photosensitive substrate (6B) using a charged particle beam in an exposure amount correcting method for performing a correction exposure on an area having a small amount of energy stored by the apparatus. Substrate (6)
During the loading of B) or the removal of the photosensitive substrate (6B) from the charged particle beam device (2), the photosensitive substrate (6B) is subjected to correction exposure.

In the present invention, generally, a device for exposing a predetermined pattern on a photosensitive substrate via a charged particle beam generally includes a charged particle beam device (2) for actually exposing a predetermined pattern. It is housed in a plurality of rooms (chambers) such as a sample room (exposure room) to be housed and a supply room (preliminary room) for supplying a photosensitive substrate to the charged particle beam (2). In order to improve throughput, during exposure of a pattern on a certain photosensitive substrate, the next photosensitive substrate to be exposed is waiting in the supply chamber, and at the same time as the exposure is completed. The photosensitive substrate is replaced in the sample chamber, carried in, and exposed. Therefore, in the present invention, the correction exposure is performed during the standby time or after the completion of the exposure, for example, in the supply chamber. Thus, the correction exposure may be performed before or after the exposure of the original pattern. As a result, the correction exposure for the proximity effect correction is performed without lowering the throughput of the exposure process, and a pattern whose dimensions are controlled with high precision can be obtained.

Next, the first exposure amount correcting apparatus of the present invention comprises:
An exposure amount correcting apparatus for carrying out the exposure amount correcting method according to the present invention, for loading a photosensitive substrate (6B) into or out of a charged particle beam device (2). Transport system (8, 9), and an energy ray source for performing a correction exposure on the photosensitive substrate (6B) transported by the transport system. The first exposure amount correction apparatus can perform the correction exposure while the photosensitive substrate is on standby or after the exposure is completed.

In this case, it is desirable that the energy ray source is a planar variable energy ray source (12) in which the distribution of the energy ray emitting portions (33) can be controlled in accordance with the predetermined pattern. The planar variable energy radiation source (12) is composed of a large number of micro energy sources having a size of, for example, several μm square to several tens μm square arranged at predetermined pitches in the vertical and horizontal directions. In this case, a desired pattern can be exposed on the photosensitive substrate by controlling the exposure time. That is, since the planar variable energy ray source (12) has a pattern generation function, correction exposure can be performed without creating a mask for correction exposure. As such a planar variable energy radiation source (12), for example, a field emission type cathode array which has been actively developed for use in a wall-mounted display or the like can be used.

The planar variable energy radiation source (12)
By disposing the and the photosensitive substrate (6B) close to each other, the apparatus for the correction exposure can be easily incorporated in a photosensitive substrate transport device in a photosensitive substrate supply chamber, for example.
Therefore, the installation floor area of the entire exposure apparatus can be reduced. Further, the planar variable energy ray source can expose the entire surface of the photosensitive substrate at one time, and the correction exposure amount is
Since the exposure amount may be several percent to several tens percent of the original proper exposure amount, the correction exposure can be sufficiently completed within the waiting time (including after the completion of the exposure) in the supply chamber.

Further, as the energy ray source for correction exposure of the present invention, a light source of ultraviolet light or the like can be used. In this case, the ultraviolet light is applied to a mask for correction exposure which has been prepared in advance and transferred at, for example, the same magnification. However, such an exposure apparatus can also be downsized. Next, the second embodiment of the present invention
The exposure amount correcting apparatus is used to perform a correction exposure on a region where the amount of energy accumulated by the backscattered particles on the photosensitive substrate is small when a predetermined pattern is transferred onto the photosensitive substrate using a charged particle beam. In the exposure amount correcting apparatus, the correction exposure is performed on the photosensitive substrate by using a planar variable energy ray source (12) in which the distribution of the energy ray emitting portions (33) can be controlled in accordance with the predetermined pattern. Things.

Since the second exposure amount correcting device uses the planar variable energy radiation source (12), it can be miniaturized, and can be incorporated in, for example, a photosensitive substrate transfer device, or can be provided in a supply chamber. The exposure amount correcting method of the present invention can be carried out. Further, there is no need to manufacture a mask for correction exposure, and the installation floor area of the entire apparatus can be reduced.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Hereinafter, the whole of the apparatus from the wafer carrier to the apparatus that exposes the original pattern via the transfer device is referred to as an exposure device. FIG.
In this example, a sample chamber (exposure chamber) 1 where exposure is performed, and a supply chamber (preliminary chamber) 7 where a photosensitive substrate supplied to the sample chamber 1 is on standby.
In FIG. 1, the sample chamber 1 and the supply chamber 7 are directly connected and are always kept in a vacuum state. In the sample chamber 1, an electron gun 3, an electron optical system 4,
The electron beam reduction transfer device 2 including the sample table 5 is stored, and the sample table 5 holds a wafer 6A coated with an electron beam resist to be exposed. The electron beam reduction transfer device 2 of this example uses a mask in which a pattern to be transferred is divided into a plurality of small areas, and sequentially connects reduced images of the patterns in the respective small areas on the wafer 6A. This is a transfer device of a division transfer system for transferring images together. However, instead of the electron beam reduction transfer device 2, a charged particle beam device or the like that sequentially exposes a desired pattern on a photosensitive substrate using a variable shaped beam, a spot beam, or the like may be housed.

On the other hand, in the supply chamber 7, a loading arm 8, a driving unit 9 for reciprocating the distal end of the arm 8 between the supply chamber 7 and the sample chamber 1, and an unloading arm 1
A wafer transfer system is provided which has a drive unit 11 which reciprocates the tip of the arm 10 between the supply chamber 7 and the sample chamber 1. The operations of the driving units 9 and 11 are controlled by a control device 14 that controls the operation of the entire apparatus.
The wafer to be exposed is loaded onto the sample table 5 of the electron beam reduction transfer device 2 in the sample chamber 1 via the loading arm 8, and the sample table 5 is loaded via the unload arm 10. Is carried out of the exposed wafer. In FIG.
A state is shown in which the wafer 6B to be next exposed is held at the tip of the arm 8, and the wafer 6B is on standby for the next exposure.

Further, in the supply chamber 7 of the present embodiment, a planar exposure variable electron beam source 12 for correction exposure having a bottom surface having substantially the same size as the wafer 6B is arranged near the wafer 6B in standby. Have been. The planar variable electron beam source 12 is a field emission type cathode array (details will be described later) in which a large number of micro electron beams of several μm square to several tens μm square are arranged at predetermined pitches on the bottom surface of a predetermined substrate. A desired pattern can be exposed on the entire surface of the wafer 6B by independently flashing each micro electron beam source capable of emitting the electron beam EB.

An alignment microscope 13 is arranged near the side surface of the planar variable electron beam source 12. This alignment microscope 13 is a part of the contour of the wafer 6B or the wafer 6B.
An image of the alignment mark formed on the surface of B is taken, and this image signal is supplied to the control device 14. The control device 14 determines the contour of the wafer 6B based on the supplied image signal,
Alternatively, the position of the alignment mark is obtained, and from this result, the positional relationship between the planar variable electron beam source 12 and the wafer 6B is obtained. Further, the control device 14 positions the wafer 6 </ b> B with respect to the planar variable electron beam source 12 via the driving device 9.

Further, the wafer 6A is
CAD (Computer Aid) of the mask pattern transferred onto
ed Design) data is stored in a storage device 15 such as a hard disk device. Then, the data conversion unit 16
Then, based on the CAD data read from the storage device 15, the data of the correction exposure pattern is generated such that the transmission portion and the shielding portion of the electron beam in the mask pattern exposed by the electron beam reduction transfer device 2 are inverted. Then, this data is supplied to the driving unit 17 of the planar variable electron beam source 12. The drive unit 17 is also supplied with data on the amount of displacement between the planar variable electron beam source 12 and the wafer 6B from the control unit 14, and is also supplied with a predetermined high voltage drive power from the high voltage power supply 18. . Then, the driving unit 17 selects the arrangement of the minute electron beam sources to be turned on in the planar variable electron beam source 12 based on the supplied data, and selects the selected minute electron beam sources using the supplied driving power. The correction exposure is performed by turning on the light for a time corresponding to the necessary correction exposure amount. The exposure correction apparatus of this embodiment includes a loading arm 8, a driving unit 9, a planar variable electron beam source 12, a microscope 13 for alignment, and a control device 14 to a high voltage power supply 18.

Further, the supply chamber 7 in FIG. 1 is further connected to a chamber for further reducing the pressure and loading and unloading the wafer. FIG. 2 shows a cross-sectional view of all the rooms in which the exposure apparatus of the present example is stored. In FIG. 2, an intermediate chamber 20 is connected to a side surface of the supply chamber 7 via a valve 19 which can be opened and closed. An atmosphere chamber 22 is connected to a side surface of the intermediate chamber 20 via a valve 21 which can be freely opened and closed. The air pressure inside the atmosphere chamber 22 is the same as the atmosphere. The inside of the atmosphere chamber 22 includes a wafer carrier 23 in which a plurality of wafers before exposure and a plurality of exposed wafers are stored, A wafer transfer system (not shown) for loading a wafer into the wafer carrier 23 is provided. A wafer transfer system (not shown) for transferring a wafer is installed inside the intermediate chamber 20.
Before the transfer of the wafer to / from the supply chamber 7, the gas is evacuated from the atmospheric pressure to a vacuum state. Before the transfer of the wafer to / from the atmospheric chamber 22, the gas is leaked from the vacuum to the atmospheric pressure. become.

Next, an example of the entire operation in the case of sequentially exposing a plurality of wafers will be described. In FIG. 2, first, the valves 19 and 21 are closed, and the sample chamber 1 is closed.
In the state where the exposure of the wafer 6A is being performed, the next wafer 6B to be exposed is waiting in the supply chamber 7. At this time, the wafer 6C exposed immediately before is located in the intermediate chamber 20, and the wafer 6D to be exposed next to the wafer 6B is taken out of the wafer carrier 23 in the atmosphere chamber 22 and is on standby. Next, when the exposure of the wafer 6A is completed, the wafer 6A is carried out of the sample chamber 1 to the position A in the supply chamber 7 via the arm 10 of FIG. 1, and the wafer 6B is moved to the arm 8 of FIG.
Is carried into the electron beam reduction and transfer device 2 in the sample chamber 1 via.

Almost in parallel with this operation, after the inside of the intermediate chamber 20 becomes atmospheric pressure due to the gas leak, the valve 21 is opened and the already exposed wafer 6C is removed from the inside of the intermediate chamber 20 into the atmosphere chamber 22. The wafer is returned to the wafer carrier 23. The wafer 6D waiting in the atmosphere chamber 22 is transferred to a position B in the intermediate chamber 20 along a path 25 indicated by an arrow. Thereafter, when the valve 21 is closed and the pressure in the intermediate chamber 20 is reduced to a vacuum state, the valve 19 is opened, and the wafer 6A reaching the position A in the supply chamber 7 is moved along the path indicated by the arrow 24. The wafer 6D which has been transferred into the intermediate chamber 20 and has reached the position B in the intermediate chamber 20 is
And the valve 19 is closed. Thereafter, exposure is performed on the wafer 6B carried into the sample chamber 1, and the above-described operation is repeated until the exposure on all the wafers is completed.

During this operation, in this embodiment, a correction exposure for correcting the proximity effect is performed on the wafer 6B waiting in the supply chamber 7 by using the planar variable electron beam source 12 of FIG. Done. The surface variable electron beam source 12 can expose the entire surface of the wafer 6B at one time, and the correction exposure amount may be several% to several tens% of the proper exposure amount for exposing the original pattern. Further, since the inside of the supply chamber 7 is in a vacuum state, the electron beam emitted from the planar variable electron beam source 12 irradiates the wafer 6B without much attenuation. Therefore, the correction exposure can be completed within the time when the wafer 6B is waiting in the supply chamber 7.

As described above, in the present embodiment, since the correction exposure for correcting the proximity effect is performed on the wafer waiting in the supply chamber 7, the electron beam reduction transfer device 2 in the sample chamber 1 is used. The throughput is higher than the method of performing the correction exposure by using the method. Further, the planar variable electron beam source 12 is small, and the installation area of the supply chamber 7 is almost the same as that without the planar variable electron beam source 12. In addition, the planar variable electron beam source 12 can change the distribution of the blinking minute electron beam sources corresponding to a desired pattern, so that it is not particularly necessary to use a mask for correction exposure. That is, compared with the method of performing correction exposure using another exposure apparatus similar to the electron beam reduction transfer apparatus 2, there is no need to use a mask for correction exposure,
And the installation area as a whole is also small.

In the above-described embodiment, the correction exposure for the proximity effect is performed on the wafer waiting in the supply chamber 7, but the correction exposure on the wafer carried out to the supply chamber 7 after the exposure is completed. May be performed. Next, the configuration of the planar variable electron beam source 12 of FIG. 1 will be described in detail with reference to FIGS.

FIG. 3 shows a state in which the planar variable electron beam source 12 of the present embodiment is opposed to the wafer 6B. In FIG. Pitches PX and PY in two directions (X and Y directions) orthogonal to each other on the (electron beam emitting surface)
And a large number of micro electron beam sources 33 are formed. Each of the micro electron beam sources 33 has a size of about several μm square to several tens μm square, and the pitches PX and PY are each equal to the width of the micro electron beam source 1.
It is about 5 to 2 times.

A plurality of shot areas 31 are arranged at a predetermined pitch in the X and Y directions on the surface of the wafer 6B of this embodiment, and each shot area 31 has the same circuit pattern in the previous exposure process. Are formed, and then the same pattern is exposed in the sample chamber 1 of FIG. Therefore, the correction exposure is performed in each shot area 31.
Therefore, the distribution of the fine electron beam sources 33 that are turned on when performing the correction exposure is periodic in accordance with the arrangement pitch of the shot regions 31.

FIG. 4 is an enlarged perspective view of a part of the planar variable electron beam source 12 of FIG. 3 viewed from the bottom (electron beam emitting surface) side. In FIG. A cathode electrode 34 made of a conductor film such as niobium (Nb) is formed in a strip shape parallel to the pitch PY, and an insulating layer 35 made of, for example, silicon dioxide (SiO ₂ ) is formed on each of the cathode electrodes 34. I have. Further, the glass substrate 32
A gate electrode 36 made of a conductor film such as niobium is formed on the insulating layer 35 in a strip shape parallel to the X direction at a pitch PX so as to cross over the insulating layer 35. The rectangular areas that intersect through 35 each serve as a micro electron beam source 33.

FIG. 5 shows one micro electron beam source 33 in FIG.
FIG. 5 shows an enlarged cross-sectional view.
A hole 35a having a diameter of about 1 μm is formed at a predetermined pitch, and a hole 36a having a slightly smaller diameter than the hole 35a is also formed in the gate electrode 36 at the same position as the hole 35a. A conical field emission cathode 37 made of, for example, molybdenum (Mo) is formed inside each of the holes 35a on the cathode electrode 34. in this case,
When a voltage higher than a predetermined value is applied between the cathode electrode 34 and the gate electrode 36, an electron beam 38 is emitted from the field emission cathode 37. Since the planar variable electron beam source 12 in this example is installed in a vacuum, the electron beam 38 efficiently travels to a wafer as a target. Such a structure in which a large number of field emission cathodes 37 are two-dimensionally arranged is called a field emission cathode array.

The field emission type cathode array as shown in FIGS. 4 and 5 is an electron beam source which is being actively developed, for example, for a wall-mounted thin display. Can be manufactured by An example of the manufacturing method is disclosed in, for example, JP-A-8-1068.
No. 69 and JP-A-8-111167.

In FIG. 4, a cathode selection circuit 1 for applying a predetermined high voltage to a desired electrode in the cathode electrode 34 in order to control the blinking distribution of the minute electron beam source 33.
7a, a gate selection circuit 17b for applying a predetermined voltage to a desired electrode in the gate electrode 36, and a control circuit (not shown) for controlling the operation of these selection circuits are provided. The driving unit 17 of FIG. 1 is constituted by the control circuit, the cathode selection circuit 17a, and the gate selection circuit 17b, and the cathode electrode 34 selected by the cathode selection circuit 17a
And the gate electrode 36 selected by the gate selection circuit 17b
Is turned on.

For example, as shown in FIG. 6, the minute electron beam sources 33 at the positions 39A, 39B, and 39C in the planar variable electron beam source 12 are turned on in a time-division manner or at the same time, so that the wafer is turned on. On the upper side, the electron beams from the three small electron beam sources 33 are irradiated so as to overlap to a certain extent at the boundaries as shown by irradiation regions 40A, 40B and 40C. As a result, it is almost equivalent to the correction exposure performed by the pattern 41 almost circumscribing the irradiation areas 40A, 40B, and 40C as a whole. Therefore, only the minute electron beam source 33 corresponding to the pattern to be corrected and exposed Is lighted in a time-sharing manner, for example, so that correction exposure of a substantially desired pattern can be performed.

For example, in FIG. 3, the minimum line width of the pattern transferred to each shot area 31 on the wafer 6B may be 1 μm or less, whereas the minute electron beam of the planar variable electron beam source 12 At present, the pitch of the array of the sources 33 is several μm to several tens of μm, and when the planar variable electron beam source 12 is used, the transmission part and the shielding part of the electron beam of the pattern transferred onto the wafer 6B are not necessarily required. In some cases, corrective exposure cannot be performed using a pattern obtained by accurately inverting the pattern. However, as shown in FIG. 7, the pattern for correction exposure may be generally coarser than a pattern obtained by inverting the pattern used in the original exposure.
By using 2, the correction exposure can be performed with necessary accuracy.

FIG. 7 shows an example of the distribution of the stored energy on the wafer due to the original exposure and the correction exposure. The horizontal axis in FIGS. 7A to 7C indicates the position in the X direction on the wafer. The vertical axis represents the stored energy at the position X.
First, FIG. 7A shows the stored energy E1 (X) at the position X when a line and space pattern having a predetermined pitch is exposed on the wafer. In FIG. The dotted line distribution 43 that gradually changes in the background of the peak 42 corresponds to the stored energy due to backscattered particles from the wafer itself and the underlying pattern on the wafer. In this case, in order to equalize the energy stored by the backscattered particles, a distribution 43 that changes slowly in the background.
Is corrected, exposure is performed based on the distribution 44 substantially inverted from the above, that is, the distribution 44 indicated by the dotted line in FIG.
(X) may be given. As a result, the stored energy E3 after the original exposure and the correction exposure are performed on the wafer.
7 (C), as shown in FIG. 7 (c), a substantially constant level of energy indicated by a dotted straight line 45 is superimposed on the background of the sharp peak 42 in FIG. 7 (a). By developing, a pattern with high accuracy and no variation can be obtained. Therefore, since the pattern of the correction exposure may be coarser than the original design pattern, high-precision correction exposure can be performed by using the planar variable electron beam source 12 of this example.

As described above, since the exposure apparatus for correction exposure of this embodiment uses the planar variable electron beam source 12, almost any blinking control of the minute electron beam source 33 can be controlled. Correction exposure according to the pattern for correction exposure can be performed. Further, since the planar variable electron beam source 12 can be brought close to the wafer 6B, the size of the exposure apparatus can be reduced, and the planar variable electron beam source 12 can be manufactured using semiconductor manufacturing technology. It is expected that costs can be reduced.

Next, another embodiment of the present invention will be described with reference to FIG. This example is an example in which ultraviolet light is used as an energy beam for correction exposure.
The same reference numerals are given to the portions corresponding to and the detailed description thereof will be omitted. FIG. 8 shows the sample chamber 1 and the supply chamber 7 in which the exposure apparatus of this embodiment is housed. In FIG. 8, the supply chamber 7 has a loading arm 8 and a driving unit 9 for the arm 8. A wafer transfer system having an arm 10 for unloading and a drive unit 11 for the arm 10 is provided, and a tip of the arm 8 holds a wafer 6B to be exposed next. The mask holder 5 is placed above the wafer 6B in the supply chamber 7.
2, a mask 51 for correction exposure is held on a mask holder 52. The mask holder 52 is also provided with a mechanism for finely adjusting the position and the rotation angle of the mask 51. The mask 51 for correction exposure is replaced with another mask according to the exposure layer of the wafer 6B.

An alignment microscope 53 for detecting the amount of displacement between the mask 51 and the wafer 6B is disposed above the end of the mask 51. The alignment microscope 53 detects, for example, the amount of misalignment between the alignment mark on the mask 51 and the alignment mark on the wafer 6B, and fine-adjusts the position of the mask 51 or the wafer 6B according to the detection result. Alignment of 51 and wafer 6B is performed.

A rectangular hole 7a is formed above the mask 51 in the upper plate of the supply chamber 7, and a hole 7a is formed in the upper surface of the supply chamber 7.
A light source system 54 for generating ultraviolet illumination light is provided so as to cover the light source. The light source system 54 is, for example, a mercury lamp,
An optical filter plate for extracting the i-line (wavelength 365 nm) of the mercury lamp, an optical integrator for equalizing the illuminance distribution of the ultraviolet light extracted by the optical filter plate, and a parallel light beam for the ultraviolet light from the optical integrator. And a condenser lens for illuminating the mask 51. In addition, as the ultraviolet light source,
An excimer laser light source, a harmonic generator of a YAG laser, or the like may be used. In this example, the mask 51 and the wafer 6B are in a standby period in which the wafer 6B is ready for the next exposure.
Is aligned, the mask 51 is illuminated by the parallel light beam 55 of ultraviolet light emitted from the light source system 54, and the parallel light beam 55 transmitted through the mask 55 performs correction exposure of the wafer 6B.

According to the present embodiment, the light source system 54 is not housed in the supply chamber 7, but can be mounted above the supply chamber 7 because it is small. Accordingly, the correction exposure can be performed without increasing the floor area of the entire apparatus and without reducing the throughput of the exposure process. In addition,
It goes without saying that the correction exposure may be performed on the wafer on which the original exposure in the sample chamber 1 has been completed.

Note that the present invention is not limited to the above-described embodiment, and may take various configurations without departing from the gist of the present invention, for example, when the present invention is applied to the case where correction exposure for ion beam exposure is performed. Of course.

[0043]

According to the exposure amount correcting method of the present invention, the photosensitive substrate is moved during the loading of the photosensitive substrate into the charged particle beam apparatus or during the unloading of the photosensitive substrate from the charged particle beam apparatus. Therefore, there is an advantage that the overall throughput of the exposure process is not reduced.

Further, according to the first exposure amount correcting apparatus of the present invention, a transport system for carrying the photosensitive substrate into or out of the charged particle beam apparatus, and the transport system for transporting the photosensitive substrate out of the charged particle beam apparatus. And an energy ray source for performing the correction exposure on the photosensitive substrate conveyed by the system. Therefore, there is an advantage that the exposure amount correction method of the present invention can be implemented. At this time, if the energy ray source is a planar variable energy ray source in which the distribution of the energy ray emitting portions can be controlled according to a predetermined pattern, it is not necessary to separately provide a correction exposure mask. . Furthermore, since the planar variable energy ray source can be easily arranged on the photosensitive substrate transport system, the installation floor area of the entire exposure apparatus can be reduced, and the manufacturing cost of the exposure correction apparatus can be reduced.

Further, according to the second exposure amount correcting apparatus of the present invention, the distribution of the energy beam emitting portion can be controlled on the photosensitive substrate by using a planar variable energy ray source whose distribution is controllable in accordance with a predetermined pattern. Since the exposure is performed, the correction exposure can be easily performed while the photosensitive substrate is being conveyed. Therefore, the exposure amount correcting method of the present invention can be implemented, and there is also an advantage that it is not necessary to separately prepare a mask for correction exposure, and the exposure amount correcting apparatus can be downsized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the internal configuration of a sample chamber 1 and a supply chamber 7 used in an example of an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing all rooms (chambers) used in an example of the embodiment.

FIG. 3 is a planar variable electron beam source 12 and a wafer 6B in FIG.
FIG.

FIG. 4 is an enlarged perspective view, partially cut away, showing a configuration of an electron beam emitting surface of the planar variable electron beam source 12.

FIG. 5 is an enlarged cross-sectional view showing a configuration of a micro electron beam source 33 in FIG.

FIG. 6 is an explanatory diagram in the case where correction exposure is performed using the planar variable electron beam source 12.

7A is a diagram showing an energy distribution accumulated on the wafer after the original exposure, FIG. 7B is a diagram showing an energy distribution accumulated on the wafer by the correction exposure, and FIG. FIG. 7 is a diagram showing a distribution of energy stored on a wafer after correction exposure.

FIG. 8 is a longitudinal sectional view showing the internal configuration of a sample chamber 1 and a supply chamber 7 used in another example of the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sample chamber 2 Electron beam reduction transfer apparatus 6A, 6B, 6C, 6D Wafer 7 Supply chamber 8 Arm for loading 9, 11 Arm driving part 10 Arm for unloading 12 Planar variable electron beam source 13, 53 Alignment Microscope 14 Controller 17 Driving unit for planar variable electron beam source 12 20 Intermediate chamber 22 Atmospheric chamber 23 Wafer carrier 33 Microelectron beam source 34 Cathode electrode 35 Insulating layer 36 Gate electrode 37 Field emission cathode 54 Ultraviolet light source system

Claims (4)

[Claims] 1. An exposure for performing a correction exposure on an area of a small amount of energy accumulated by backscattered particles on the photosensitive substrate when exposing a predetermined pattern on the photosensitive substrate using a charged particle beam. In the amount correction method, during the loading of the photosensitive substrate to a charged particle beam device that exposes the predetermined pattern using a charged particle beam on the photosensitive substrate, or during the unloading of the photosensitive substrate from the charged particle beam device The exposure correction method, wherein the correction exposure is performed on the photosensitive substrate in the middle. 2. An exposure amount correcting apparatus for performing the exposure amount correcting method according to claim 1, wherein the photosensitive substrate is loaded into the charged particle beam device or unloaded from the charged particle beam device. And an energy beam source for performing the correction exposure on the photosensitive substrate transported by the transport system. 3. The exposure amount correcting apparatus according to claim 2, wherein the energy ray source is a planar variable energy ray source capable of controlling the distribution of energy beam emitting portions according to the predetermined pattern. An exposure correction apparatus characterized in that: 4. An exposure for performing a correction exposure on an area of a small amount of energy accumulated by backscattered particles on the photosensitive substrate when a predetermined pattern is transferred onto the photosensitive substrate using a charged particle beam. In the dose correcting apparatus, the correction exposure is performed on the photosensitive substrate using a planar variable energy ray source in which the distribution of energy beam emitting portions can be controlled according to the predetermined pattern. apparatus.