JPWO2010109647A1 - Mask holding device for multi-column electron beam drawing and multi-column electron beam drawing device - Google Patents

Abstract

To provide a CP mask for multi-column electron beam drawing and a multi-column electron beam drawing apparatus capable of preventing thermal deformation of the entire character projection mask. A mask holding device for multi-column electron beam drawing includes: a holding device main body for holding a mask and cooling the mask; a gas generating unit for generating a gas for cooling the mask; and a temperature and a flow rate of the gas. A control unit for controlling. The mask holding device main body includes a gas supply pipe for supplying the gas generated by the gas generation section to the mask, a gas absorption pipe for absorbing the gas, and a group of character projection patterns (CP patterns) used in each column. A gas absorption groove formed so as to surround the group of CP patterns doubly when the integrated substrate formed in each column region of one substrate is placed, and connected to the gas absorption tube; And a gas supply groove formed between the gas absorption grooves and connected to the gas supply pipe. [Selection] Figure 8

Description

  The present invention relates to a multi-column electron beam drawing mask holding apparatus and a multi-column electron beam drawing apparatus capable of preventing deformation of a character projection pattern due to temperature in the multi-column electron beam drawing apparatus.

  In a conventional electron beam exposure apparatus, a variable rectangular opening or a plurality of mask patterns are prepared in a stencil mask, and these are selected by beam deflection and transferred and exposed on a wafer. In this electron beam exposure apparatus, a plurality of mask patterns are prepared, but only one electron beam is used for exposure, and the pattern transferred at one time is one mask pattern that is selectively transferred by one electron beam. Only.

  As such an exposure apparatus, for example, Patent Document 1 discloses an electron beam exposure apparatus that performs partial batch exposure. Partial batch exposure refers to irradiating a beam to one pattern area selected by beam deflection from a plurality of, for example, 100 mask patterns arranged on a mask, for example, an area of 20 × 20 μm, and the beam cross section is the shape of the mask pattern. Then, the beam that has passed through the mask is deflected back by a later stage deflector, reduced to a constant reduction rate determined by the electron optical system, for example, 1/10, and transferred to the sample surface. The area of the sample surface irradiated at one time is, for example, 2 × 2 μm. If a mask pattern is appropriately prepared according to the device pattern to be exposed, the number of exposure shots required is significantly reduced and the throughput is improved as compared with the case of only a variable rectangular aperture.

  In addition, a multi-column electron beam exposure system that collects a plurality of such exposure apparatuses with smaller columns (hereinafter referred to as column cells) and arranges them on the wafer in parallel is proposed. Has been. Each column cell is equivalent to the column of a single column electron beam exposure apparatus, but the entire multi-column processes in parallel, so that the exposure throughput can be increased by the number of columns.

  In such a multi-column electron beam exposure apparatus, a desired pattern is selected by irradiating a character projection mask (CP mask) with an electron beam in each column cell. In this case, the CP mask is heated by the electron beam irradiation, and the entire temperature of the CP mask is deformed by changing the temperature of the CP mask, so that the position drift of the pattern formed on the CP mask occurs and the drawing accuracy is lowered. There's a problem.

  In the case of a single column electron beam exposure apparatus, this can be dealt with by correcting the selected position of the CP mask pattern by measuring the correspondence between the irradiation time and the positional deviation of the CP mask.

  On the other hand, in the multi-column electron beam exposure apparatus, a CP mask used in each column cell is prepared for each column cell. However, it is possible to reduce the time and labor required for carrying in a mask for each column cell. An integrated mask substrate is used for shortening and the like. For this reason, the positional deviation of one CP mask also affects the position of the CP mask in the other column, so that the positional variation between the CP masks occurs, and the pattern position is corrected for the deformation of the entire CP mask. It is difficult.

  As a technique for suppressing exposure failure caused by deformation due to temperature change of a wafer due to exposure processing, Patent Document 2 discloses a technique for preventing thermal deformation of a wafer by making the temperature of the wafer and the wafer holder substantially the same. Is described.

  Patent Document 3 describes a technique of gas cooling the back surface of a wafer during a dry etching process.

However, there is no report on a technique for preventing thermal deformation of the CP mask in the multi-column electron beam exposure apparatus.
JP 2004-88071 A JP 2006-339303 A JP-A-8-111398

  The present invention has been made in view of the problems of the prior art, and an object of the present invention is to provide a multi-column electron beam drawing CP mask and a multi-column electron capable of preventing thermal deformation of the entire character projection mask (CP mask). A line drawing apparatus is provided.

  In order to solve the above-described problems of the prior art, according to the basic form of the present invention, there is provided a multi-column electron beam drawing mask holding apparatus used in a multi-column electron beam drawing apparatus including a plurality of columns, A holding device main body for holding and cooling the mask; a gas generating unit for generating a gas for cooling the mask; and a control unit for controlling the temperature and flow rate of the gas. The main body includes a gas supply pipe that supplies the gas generated in the gas generation section to the mask, a gas absorption pipe that absorbs the gas, and a group of character projection patterns (CP patterns) used in the columns. Is formed so as to surround the group of CP patterns doubly when the integrated substrate formed in the region for each column of one substrate is placed. A multi-column electron beam drawing comprising: a gas absorption groove connected to a body absorption tube; and a gas supply groove formed between the double gas absorption grooves and connected to the gas supply tube A mask holding device is provided.

  In the mask holding apparatus for multi-column electron beam drawing according to this aspect, the gas absorption groove may double surround the periphery of each group of CP patterns, and the gas absorption groove may be defined by the group of CP patterns. May be surrounded by a single layer, and the entire periphery of each group of CP patterns may be surrounded by a single layer.

  In the multi-column electron beam drawing mask holding apparatus according to this embodiment, the gas may be any one of helium gas, ozone gas, oxygen gas, nitrogen gas, or hydrogen gas, and the mask holding device. The apparatus main body may include a Johnson Rabeck-type electrostatic chuck that attracts the integrated substrate, and the controller supplies the gas at 0.2 to 0.5 [sccm]. May be.

  According to the multi-column electron beam drawing mask holding apparatus of the present invention, the CP mask on which the character projection pattern is formed is adsorbed and fixed by the electrostatic chuck, and a gas such as ozone gas is applied to a portion other than the CP pattern of the CP mask. I try to flow. In particular, the mask holding device main body for holding the CP mask has a gas supply groove for supplying gas around each CP pattern group used in each column and a gas around each CP pattern group so as to sandwich the gas supply groove. Double gas absorption grooves for absorbing are provided. As a result, overheating of the CP mask substrate due to electron beam irradiation can be suppressed, deformation of the entire CP mask due to temperature change can be suppressed, and displacement of the CP pattern can be prevented.

FIG. 1 is a block diagram of a multi-column electron beam exposure apparatus. FIG. 2 is a block diagram of one column cell in the exposure apparatus according to FIG. FIG. 3 is a schematic diagram of a column cell control unit of the exposure apparatus according to FIG. FIG. 4A and FIG. 4B are diagrams illustrating the configuration of the stencil mask. FIG. 5 is a block diagram of a mask holding device having a temperature adjustment function for the CP mask substrate. FIG. 6A is a cross-sectional view of the CP mask attracted to the electrostatic chuck, and FIG. 6B is a diagram illustrating the principle of the electrostatic chuck suction. FIG. 7 is a diagram (part 1) illustrating an example of a power supply pattern for suction of the Johnson Rabeck electrostatic chuck. FIG. 8 is a diagram (part 1) illustrating the arrangement of the gas supply groove and the gas absorption groove. FIG. 9 is a diagram (part 2) illustrating the arrangement of the gas supply groove and the gas absorption groove. FIG. 10 is a schematic configuration diagram of a part of the main body of the mask holding device. FIG. 11 is a second diagram illustrating an example of a power supply pattern for attracting the electrostatic chuck.

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, a multi-column electron beam exposure apparatus will be described as an example of an electron beam drawing apparatus. First, the structure of the multi-column electron beam exposure apparatus will be described with reference to FIGS. Next, with reference to FIGS. 4 to 11, a CP mask and a mask holding device that enables cooling of the CP mask will be described.

  FIG. 1 is a schematic block diagram of a multi-column electron beam exposure apparatus using a multi-column electron beam drawing mask holding apparatus according to the present embodiment.

  The multi-column electron beam exposure apparatus is roughly divided into an electron beam column 10 and a controller 20 that controls the electron beam column 10. Among them, the electron beam column 10 is composed of a plurality of, for example, 16 equivalent column cells 11 to form the entire column. All the column cells 11 are composed of the same unit described later. Note that only one stencil mask is used in the entire column cell. Further, below the column cell 11, for example, a wafer stage 13 on which a 300 mm wafer 12 is mounted is disposed.

  On the other hand, the control unit 20 includes an electron gun high-voltage power supply 21, a lens power supply 22, a digital control unit 23, a stage drive controller 24, a stage position sensor 25, a mask position sensor 27, a mask mounting controller 28, and a mask stage drive controller 29. . Among these, the electron gun high-voltage power supply 21 supplies power for driving the electron gun of each column cell 11 in the electron beam column 10. The lens power supply 22 supplies power for driving the electromagnetic lens of each column cell 11 in the electron beam column 10. The digital control unit 23 is an electric circuit that controls each part of the column cell 11 and outputs a high-speed deflection output or the like. The number of digital control units 23 corresponding to the number of column cells 11 is prepared.

  The stage drive controller 24 moves the wafer stage 13 based on the position information from the stage position sensor 25 so that the electron beam is irradiated to a desired position on the wafer 12.

  The mask position sensor 27 captures the reference positioning mark on the mask stage and the corresponding positioning mark on the mask substrate in the same field of view, and the relative displacement between the mask stage and the mask substrate based on the microscope image. It consists of an image analysis unit to measure.

  The mask mounting controller 28 includes a mechanism unit for finely adjusting the mounting position and mounting angle of the mask substrate with respect to the mask stage, and a circuit unit for controlling the mechanism unit. The mask mounting controller 28 adjusts the mask position based on the mask position information from the mask position sensor 27. The mask mounting controller 28 functions as a control unit of a mask holding device to be described later, and controls the generation of gas used for cooling the CP mask substrate, and the flow rate and temperature of the generated gas.

  The mask stage drive controller 29 moves the mask stage 123 according to an instruction from the integrated control system 26.

  The above-described units 21 to 29 are controlled in an integrated manner by an integrated control system 26 such as a workstation.

  In the above-described multi-column electron beam exposure apparatus, all the column cells 11 are composed of the same column unit. FIG. 2 is a schematic configuration diagram of each column cell 11 of FIG. 1 used in the multi-column electron beam exposure apparatus.

  Each column cell 11 is roughly divided into an exposure unit 100 and a digital control unit 23 that controls the exposure unit 100. Among these, the exposure unit 100 includes an electron beam generation unit 130, a mask deflection unit 140, and a substrate deflection unit 150.

  In the electron beam generator 130, the electron beam EB generated from the electron gun 101 is converged by the first electromagnetic lens 102, then passes through the rectangular aperture 103 a (first opening) of the beam shaping mask 103, and the electron The cross section of the beam EB is shaped into a rectangle.

  The electron beam EB shaped into a rectangle is imaged on the second mask 106 for beam shaping by the second electromagnetic lens 105a and the third electromagnetic lens 105b. Then, the electron beam EB is deflected by the first electrostatic deflector 104a and the second electrostatic deflector 104b for variable rectangular shaping, and the rectangular aperture 106a (second opening) of the second mask 106 for beam shaping. Transparent. The electron beam EB is shaped by the first opening and the second opening.

  Thereafter, the electron beam EB is imaged on the stencil mask 111 by the fourth electromagnetic lens 107 a and the fifth electromagnetic lens 107 b of the mask deflection unit 140. The electron beam EB is identified by the third electrostatic deflector 108a (also referred to as a first selective deflector) and the fourth electrostatic deflector 108b (also referred to as a second selective deflector) formed on the stencil mask 111. The pattern P is deflected and its cross-sectional shape is formed into the pattern P shape. This pattern is also called a character projection (CP) pattern. The deflector 108b disposed in the vicinity of the fifth electromagnetic lens 107b is bent so that the electron beam EB enters the stencil mask 111 in parallel with the optical axis.

  The stencil mask 111 is fixed to the mask stage 123 in the electron beam column 10, but the mask stage 123 is movable in a horizontal plane, and the third electrostatic deflector 108a and the fourth electrostatic deflector 108b. When the pattern P in the part exceeding the deflection range (beam deflection region) is used, the pattern P is moved into the beam deflection region by moving the mask stage 123.

  The sixth electromagnetic lens 113 disposed under the stencil mask 111 plays a role of making the electron beam EB parallel in the vicinity of the shielding plate 115 by adjusting the amount of current.

  The electron beam EB that has passed through the stencil mask 111 is deflected by a fifth electrostatic deflector 112a (also referred to as a first back deflector) and a sixth electrostatic deflector 112b (also referred to as a second back deflector). It is turned back to the optical axis. By the deflector 112b disposed in the vicinity of the sixth electromagnetic lens 113, the electron beam EB is bent on the axis and then travels along the axis.

  The mask deflection unit 140 is provided with first and second correction coils 109 and 110, which generate the first to sixth electrostatic deflectors 104a, 104b, 108a, 108b, 112a, and 112b. Beam deflection aberration is corrected.

  Thereafter, the electron beam EB passes through the aperture 115a (round aperture) of the shielding plate 115 constituting the substrate deflecting unit 150, and is projected onto the substrate by the projection electromagnetic lens 121. As a result, the pattern image of the stencil mask 111 is transferred to the substrate at a predetermined reduction rate, for example, a reduction rate of 1/10.

  The substrate deflecting unit 150 is provided with a seventh electrostatic deflector 119 and an eighth electrostatic deflector 120, and the electron beam EB is deflected by these deflectors 119 and 120 to be placed at a predetermined position on the substrate. An image of the stencil mask pattern is projected.

  Further, the substrate deflection unit 150 is provided with third and fourth correction coils 117 and 118 for correcting the deflection aberration of the electron beam EB on the substrate.

  On the other hand, the digital control unit 23 includes an electron gun control unit 202, an electron optical system control unit 203, a mask deflection control unit 204, a blanking control unit 206, and a substrate deflection control unit 207. Among these, the electron gun control unit 202 controls the electron gun 101 to control the acceleration voltage of the electron beam EB, beam emission conditions, and the like. Further, the electron optical system control unit 203 controls the amount of current to the electromagnetic lenses 102, 105a, 105b, 107a, 107b, 113, and 121, and the magnification of the electron optical system in which these electromagnetic lenses are configured. Adjust the focus position. The blanking control unit 206 controls the voltage applied to the blanking deflector to deflect the electron beam EB generated before the start of exposure onto the shielding plate 115, and before the exposure, the electron beam EB is applied onto the substrate. Is prevented from being irradiated.

  The substrate deflection control unit 207 controls the voltage applied to the seventh electrostatic deflector 119 and the eighth electrostatic deflector 120 so that the electron beam EB is deflected to a predetermined position on the substrate. The above-described units 202 to 207 are controlled in an integrated manner by an integrated control system 26 such as a workstation.

  FIG. 3 is a schematic diagram of a column cell control unit 31 that controls processing related to deflection data in the multi-column electron beam exposure apparatus. Each column cell 11 has a column cell control unit 31. Each column cell control unit 31 is connected by a bus 34 to an integrated control system 26 that controls the entire multi-column electron beam exposure apparatus. Further, the integrated storage unit 33 is composed of, for example, a hard disk, and stores data necessary for all column cells such as exposure data. The integrated storage unit 33 is also connected to the integrated control system 26 via the bus 34.

  The exposure data of the pattern exposed on the wafer 12 placed on the wafer stage 13 is transferred from the integrated storage unit 33 to the column cell storage unit 35 of each column cell control unit 31. The transferred exposure data is corrected by the correction unit 36, converted into data necessary for actual exposure processing by the exposure data conversion unit 37, and pattern exposure processing in the exposure area on the wafer assigned to each column cell 11. I do.

  Next, the configuration of a stencil mask (character projection (CP) mask) formed on an integrated substrate will be described with reference to FIG.

  FIG. 4A shows a CP pattern group 42 formed in a range in which an electron beam can be deflected by a deflector in one column cell. The CP pattern group 42 is a set of a plurality of small sections 43 of 20 × 20 μm, and a CP pattern that is frequently used is formed in each small section 43. By selecting this small section 43, the electron beam cross-section is formed, and a desired pattern is irradiated onto the wafer 12 for exposure.

  FIG. 4B is a diagram showing an example of the arrangement of the CP pattern formed on the CP mask substrate 51 in the case of being composed of 2 × 2 four column cells. As shown in FIG. 4B, the CP pattern used in each column is formed at a position where the electron beam of each column of the integral CP mask substrate 51 passes.

  The CP mask substrate 51 thus formed is held by a mask holding device, and the temperature of the CP mask substrate 51 is controlled to be constant. FIG. 5 is a block diagram showing an outline of the mask holding device. The mask holding device includes a gas generation unit 50, a gas temperature adjustment unit 52, a gas recovery unit 53, a mask holding device body 54 on which the CP mask substrate 51 is directly placed, a gas generation unit 50, and a gas temperature adjustment unit 52. And the control part 28 which controls the gas collection | recovery part 53 is comprised fundamentally.

  The gas generation unit 50 generates a gas for cooling the CP mask substrate 51. The generated gas is, for example, helium gas, ozone gas, nitrogen gas, oxygen gas, or hydrogen gas.

  The gas temperature adjustment unit 52 adjusts the temperature of the gas generated by the gas generation unit 50 or the gas recovered by the gas recovery unit 53 to a predetermined constant temperature under the control of the control unit 28. For example, the gas is cooled using a pipe having a predetermined length cooled to a constant temperature.

  The gas recovery unit 53 recovers the gas supplied into the mask holding device main body 54 with a pump.

  The gas generated in the gas generating unit 50 is supplied to the gas supply groove through a gas supply pipe formed in the mask holding device main body 54 after adjusting to a desired temperature, flow rate, and pressure. These conditions such as temperature, flow rate, pressure, and the like are appropriately determined in terms of the area where the gas directly contacts the CP mask substrate 51 and the drawing accuracy of the CP mask pattern. For example, ozone gas is used and supplied at a pressure of several [Pa] at 0.2 to 0.5 [sccm].

  The gas generated in the gas generation unit 50 may be discharged after flowing through the gas supply groove and the gas absorption groove formed in the mask holding device main body 54, or the gas may be circulated.

  FIG. 6 shows a state in which the CP mask substrate 51 is attracted to the mask holding device main body 54. The CP mask substrate 51 is formed using an SOI (Silicon On Insulator) substrate. The SOI substrate is composed of a 2 μm silicon membrane 51a bonded to a silicon wafer 51c of about 700 μm via a 0.5 μm silicon oxide film 51b, and a CP pattern is formed on the silicon membrane 51a. In FIG. 6, the CP pattern is formed in the regions 55a and 55b of the CP mask substrate 51, and the silicon oxide film 51b and the silicon wafer 51c below the regions 55a and 55b are opened so that an electron beam can pass through.

  The CP mask substrate 51 is placed on the mask holding device main body 54 and is adsorbed by an electrostatic chuck 56. In this embodiment, the mask holding device main body 54 is made of alumina, for example. Further, as the electrostatic chuck 56, a Johnson Rabeck type of a type in which a contact type current flows constantly is used. For example, the electrode 56c embedded in the mask holding device main body 54 in FIG. 6A is a positive electrode, and the electrode 56d is a negative electrode.

FIG. 6B is a partial cross-sectional view illustrating the principle of adsorption of the Johnson Rabeck type electrostatic chuck. As shown in FIG. 6 (b), the Johnson Rahbeck-type attracting force is applied to the surface 58 on the CP mask substrate 51 side by moving the charge generated in the electrode 56d through the mask holding device main body 54 having a relatively low resistance. Caused by a charge of the same polarity that has reached and stayed. The Johnson Rabeck-type adsorption force is said to occur when the specific resistance is 10 ¹³ Ωcm or less. Since the specific resistance of the alumina constituting the mask holding device main body 54 is about 10 ¹² Ωcm, the Johnson Rahbek-type adsorption force works and the CP mask substrate 51 can be strongly adsorbed.

  In addition to the Johnson Rabeck type electrostatic chuck, there is a Coulomb type, but since the Johnson Rabeck type attracting force is stronger, a Johnson Rabeck type electrostatic chuck is used in this embodiment.

  FIG. 7 is a diagram showing an example of the arrangement of the electrodes of the electrostatic chuck. FIG. 7 is a plan view of the mask holding device main body 54, and shows an example of electrode patterns 63 and 64 embedded in the mask holding device main body 54. When the CP mask substrate 51 is placed on the mask holding device main body 54, the positive electrodes 63 and the negative electrodes 64 are alternately arranged in portions other than the opening portions 62a to 62d corresponding to the region where the CP pattern is formed. Is arranged.

In this way, the mask holding device main body 54 and the CP mask substrate 51 are brought into close contact with each other, and a gas at a constant temperature is caused to flow through the lower surface portion of the CP mask substrate 51.
FIG. 8 is a plan view showing an example of a gas supply groove and a gas absorption groove formed on the surface of the mask holding device main body 54.

  As shown in FIG. 8, the mask holding device main body 54 has four openings (62a, 62b, 62c, 62d) corresponding to the CP mask region. A groove is formed around each opening, and when the CP mask substrate 51 is placed and sucked, a gas is allowed to flow through the groove.

  For example, a gas supply groove 72 is formed around the opening 62a, and gas absorption grooves 71a and 71b are formed so as to sandwich the gas supply groove 72.

  FIG. 9 shows a cross-sectional view taken along the line II of FIG. As shown in FIG. 9, when the CP mask substrate 51 is placed on the mask holding device main body 54, a space is formed in the gas supply groove 72 and the gas absorption grooves 71a and 71b. The depth of the gas supply groove 72 is formed shallower than the depth of the gas absorption grooves 71a and 71b. The gas generated in the gas generator 50 is supplied to the gas supply groove 72 from a gas supply port 72 a through a gas supply pipe 81 disposed in the mask holding device main body 54. The supplied gas diffuses from the gas supply groove 72 to the gas absorption grooves 71a and 71b, and is exhausted through the gas absorption pipes 82 from the gas absorption ports 71c and 71d. The configuration of the gas supply and gas absorption around the other openings 62b, 62c, and 62d in FIG. 8 is the same.

  Except for the gas supply grooves 72, 74, 76, 78 and the gas absorption grooves 71 a, 71 b, 73 a, 73 b, 75 a, 75 b, 77 a, 77 b, the CP mask substrate 51 and the electrostatic chuck 56 are in close contact.

  As shown in FIG. 8 and FIG. 9, the gas hits the lower surface of the CP mask substrate 51 due to the diffusion of the gas at a constant temperature in the gas supply groove and the gas absorption groove, and the CP mask substrate 51 heated by the electron beam irradiation is heated. Heat is transferred to the gas to exchange heat. Thereby, the CP mask substrate 51 can be kept at a constant temperature, and deformation of the entire CP mask due to overheating can be prevented.

  By providing the double gas absorption groove around the gas supply groove in this way, the gas is prevented from flowing out from the opening of the CP mask and the flow of the diffusing gas is opposed to the gas supply groove and the gas absorption groove. It spreads widely to the surface to be.

  In addition, as shown in FIG. 8, you may make it provide the groove | channels 79a-79d which connect the gas absorption groove | channel of the outer circumference | surroundings of each four opening part, and this groove | channel 79a-79d is not provided, but each opening part is provided. Gas may be absorbed and exhausted from the gas absorption grooves (71a, 73a, 75a, 77a) outside 62a to 62d.

  FIG. 10 is a diagram illustrating another example of the configuration of the gas supply groove and the gas absorption groove. Gas absorption grooves 83 to 86 are formed around the openings 62a to 62d, and a gas absorption groove 87 is formed so as to surround the gas absorption grooves 83 to 86. A gas supply groove 88 is formed between the gas absorption groove 87 and the gas absorption grooves 83 to 86. In this case, an electrostatic chuck is provided outside the gas absorption groove 87 and between each of the openings 62 a to 62 d and the inner gas absorption grooves 83 to 86, and adsorbs the CP mask substrate 51.

Although the gas absorption ports 87a to 87d for discharging gas are provided in the outer gas absorption groove 87, the number of gas absorption ports may be one. Moreover, although the gas supply port 88a-88d which supplies gas in the gas supply groove 88 is provided, the gas supply port may be one place. Moreover, the shape of the gas absorption grooves 83 to 86 and 88 is not limited to a circle but may be a rectangle.
Further, the area of the gas supply groove 88 is appropriately reduced, and an electrostatic chuck is used in order to further enhance the adsorption state of the CP mask substrate 51 between the inner gas absorption grooves 83 to 86 and the outer gas absorption groove 87. You may make it provide.

  The shape of the electrostatic chuck electrode may be changed as appropriate. FIG. 11 is a view showing an example of the shape of the electrode of the electrostatic chuck provided between the opening and the inner gas absorption groove in the case of the gas supply groove and the gas absorption groove shown in FIG. As shown in FIG. 11, for example, the space between the opening 62a and the inner gas absorption groove 71b is equally divided into two regions (91a, 91b), with one serving as a positive electrode and the other serving as a negative electrode. Also good.

  Further, a temperature measuring element for measuring the temperature of the CP mask substrate 51 may be provided in the mask holding device main body 54. A temperature measuring element is disposed near the surface of the mask holding device main body 54 and connected to the control unit 28. The control unit 28 controls the temperature of the gas generated from the gas generation unit 50 based on temperature information from the temperature measuring element.

  The temperature measuring element is disposed on the contact surface side of the mask holding device main body 54 with the CP mask substrate 51 so that the temperature of the CP mask substrate 51 can be detected when the CP mask substrate 51 is adsorbed. A groove may be formed on the surface of the mask holding device main body 54, and a temperature measuring element may be installed in the groove, or a platinum resistance thermometer or the like may be directly formed on the surface of the mask holding device main body 54. Also good.

  When the electron beam is irradiated and the temperature of the CP mask substrate 51 rises, the temperature rise is transmitted to the control unit 28 as an electrical signal by the temperature measuring element, and the control unit 28 monitors the temperature change of the CP mask substrate 51. The allowable temperature of the CP mask substrate 51 is determined in advance from the viewpoint of the material of the CP mask substrate 51 and the drawing accuracy, and the gas temperature and flow rate are controlled so that the temperature of the CP mask substrate 51 does not exceed the allowable temperature. As a result, the temperature of the CP mask substrate 51 can be kept constant, and overheating of the CP mask substrate 51 due to electron beam irradiation can be prevented.

  As described above, in the present embodiment, the CP mask on which the character projection pattern is formed is attracted and fixed by the electrostatic chuck, and a gas such as ozone gas is allowed to flow in a portion other than the CP pattern of the CP mask. Yes. In particular, the mask holding device main body for holding the CP mask has a gas supply groove for supplying gas around each CP pattern group used in each column and a gas around each CP pattern group so as to sandwich the gas supply groove. Double gas absorption grooves for absorbing are provided. As a result, overheating of the CP mask substrate due to electron beam irradiation can be suppressed, deformation of the entire CP mask due to temperature change can be suppressed, and displacement of the CP pattern can be prevented.

In addition, the present invention is a patent application related to the results of the commissioned research of the national government (2008 New Energy and Industrial Technology Development Organization “Mask Design / Drawing / Inspection Optimization Technology Development” commissioned research, industrial technology Patent application subject to the application of Article 19 of the Strengthening Law).

Claims (7)

A multi-column electron beam drawing mask holding device used in a multi-column electron beam drawing apparatus comprising a plurality of columns,
A holding device body for holding the mask and cooling the mask;
A gas generating section for generating a gas for cooling the mask;
A controller for controlling the temperature and flow rate of the gas;
Have
The mask holding device main body is
A gas supply pipe for supplying the gas generated in the gas generating section to the mask;
A gas absorption tube for absorbing the gas;
When an integrated substrate in which a group of character projection patterns (CP patterns) used in each column is formed in an area of each column of one substrate is placed, the periphery of each group of CP patterns is doubled. A gas absorption groove formed to surround the gas absorption pipe and connected to the gas absorption tube;
A gas supply groove formed between the double gas absorption grooves and connected to the gas supply pipe;
A mask holding device for multi-column electron beam drawing, comprising:   The multi-column electron beam drawing mask holding apparatus according to claim 1, wherein the gas absorption groove doublely surrounds each group of CP patterns.   2. The multi-column electron beam according to claim 1, wherein the gas absorption groove surrounds each group of CP patterns in a single layer and also surrounds the entire group of CP patterns in a single layer. Mask holding device for drawing.   2. The mask holding apparatus for multi-column electron beam drawing according to claim 1, wherein the gas is helium gas, ozone gas, oxygen gas, nitrogen gas or hydrogen gas.   The mask holding apparatus for multi-column electron beam drawing according to claim 1, wherein the mask holding apparatus main body includes a Johnson Rabeck type electrostatic chuck for attracting the integrated substrate.   The said control part supplies the said gas by 0.2-0.5 [sccm], The mask holding | maintenance apparatus for multi-column electron beam drawing of Claim 1 characterized by the above-mentioned. A multi-column electron beam drawing apparatus comprising the mask holding device for multi-column electron beam drawing according to any one of claims 1 to 6.

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