JP2000223399A - Exposure apparatus and device manufacturing method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To easily create a shot layout corresponding to an actual shot. SOLUTION: A shot layout is created based on predetermined information, a substrate is positioned at each shot position by a stage based on the shot layout, and an exposure area on a reticle pattern formed by limiting an exposure range. In an exposure apparatus and device manufacturing method for exposing a pattern portion on a substrate, a shot is used as position information of an actual shot determined for each of exposure areas 602 and 603 on a reticle pattern formed by limiting an exposure range. Create a layout. Further, based on the position information of the actual shot, a graphic of a shot layout representing an area to be actually exposed is displayed. The exposure is performed by positioning the stage at each shot position based on the position information of each shot of the created shot layout and the position information of the exposure area on the reticle pattern formed by the means for limiting the exposure area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus and a device manufacturing method for manufacturing a device such as a semiconductor element or a liquid crystal element, and more particularly, to an improvement in a shot layout for exposure and an exposure position. About. The present invention is particularly suitably applied to a semiconductor manufacturing apparatus, particularly a semiconductor exposure apparatus for printing a circuit pattern on a wafer and a device manufacturing method using the same.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor exposure apparatus, a layout of a device to be exposed is made by a size determined by a moving distance (step size) of a stage and a position where a lens center comes at the time of exposure. For example, when the step size X is 20 mm and Y is 15 mm, and four exposures are performed in the X and Y directions, a layout in which four rectangles of 15 mm × 20 mm are arranged in the X and Y directions, respectively, is created. I have. In the case of such a normal layout, a shot layout can be created without any problem, and exposure can be performed along the shot layout.

[0003]

However, according to the above-mentioned prior art, when the TEG is exposed in the layout or the like, the shot is shifted from the normal position and the masking blade is opened at a position away from the center of the lens. Creating a layout is not easy when you need to expose
Also in the layout display, shots of the same size are shifted and displayed in an overlapping manner.

For example, when a layout as shown in FIG. 4 is exposed with a reticle as shown in FIG. 6, a layout to be created is as shown in FIG. Reference numeral 401 in FIG. 5 denotes a normal shot, and the normal pattern 60 of the reticle 601 in FIG.
Exposure is performed in step 3. 402 and 403 in FIG.
This is an EG shot, which is exposed by the TEG pattern 602 of the reticle 601. The conventional shot layout shown in FIG. 5 is made based on the position of the stage and the shot size. To expose the TEG shot 403, the image formed by the TEG pattern
It is necessary to come to the position of the EG shot 403. For that purpose, the TEG shot 403 is placed at the position where the image of the normal pattern 603 (actually, there is no image because it is shielded by the masking blade) with the exposure center 604 at the center The corresponding TEG shot 502 is drawn. Similarly, the TEG shot 402 is drawn like the TEG shot 501. Therefore, since another TEG shot is drawn on top, a part of the picture is hidden.

According to this, exposure can be performed by aligning the shot center with the lens center (exposure center) and moving the masking blade to a designated position, so that the exposure sequence is simple. It is necessary to consider the distance from the exposure center to the pattern to be exposed, which is difficult for an operator to understand. Therefore, the layout display is disclosed in Japanese Patent Application Laid-Open No. 8-167565.
In Japanese Patent Laid-Open Publication No. H10-209, a method of displaying a layout in an area that is actually exposed is proposed, but no proposal is made for creating a layout. For this reason, it has become possible to determine at a glance whether or not the created layout is correct. However, there is a disadvantage that creating such a layout is still difficult.

An object of the present invention is to provide an exposure apparatus and a device manufacturing method that can easily create a shot layout corresponding to an actual shot in view of the problems of the related art.

[0007]

In order to achieve this object, an exposure apparatus according to the present invention comprises: a layout creating means for creating a shot layout based on predetermined information; and a stage using a stage based on the shot layout. In an exposure apparatus having an exposure unit that exposes a reticle pattern on a substrate by positioning it at each shot position and an exposure area limiting unit that limits an exposure area in each shot, the layout creating unit limits the exposure by the exposure area limiting unit A shot layout is created as position information of actual shots determined for each exposure area on a reticle pattern formed thereby.

Further, the device manufacturing method of the present invention includes a layout creating step of creating a shot layout based on predetermined information, a step of positioning a substrate at each shot position by a stage based on the shot layout, and an exposure range. An exposure step of exposing a pattern portion in an exposure area on a reticle pattern formed by restricting the substrate to a substrate, a device manufacturing method comprising:
The layout creation step is characterized in that a shot layout is created as actual shot position information determined for each exposure area on a reticle pattern formed by limiting the exposure range.

According to this, it is easy to set information necessary for creating a shot layout, so that a shot layout corresponding to an actual shot can be easily created. Further, the exposure processing is easily performed by the shot layout.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a preferred embodiment of the present invention, based on position information of each shot of a created shot layout and position information of an exposure area on a reticle pattern formed by limiting an exposure range. Exposure is performed by positioning the stage at each shot position. Also, in the layout creation, based on the actual shot position information,
A figure of a shot layout showing an area to be actually exposed is displayed.

[0011] Further, the layout creation includes the positional information on each exposure area on the reticle pattern formed by limiting the exposure range, and the size or size of each exposure area on the reticle pattern formed by limiting the exposure range. A shot layout is created based on interval information between adjacent shots, the number of rows and columns of shots to be exposed on the substrate, and a reference position of the shot layout on the substrate.

[0012]

FIG. 1 is a perspective view showing the appearance of a semiconductor exposure apparatus according to one embodiment of the present invention. As shown in FIG. 1, the semiconductor exposure apparatus includes a temperature control chamber 101 for controlling an environmental temperature of the apparatus main body, an EWS main body 106 disposed therein and having a CPU for controlling the apparatus main body, and a predetermined Display device 102 for displaying EWS information, monitor TV 105 for displaying image information obtained via the imaging means in the device main body, operation panel 103 for making predetermined input to the device, EW
A console unit including an S keyboard 104 and the like is provided. In the figure, 107 is an ON-OFF switch, 108 is an emergency stop switch, 109 is various switches, a mouse, etc.
10 is a LAN communication cable, 111 is an exhaust duct for generating heat from the console function, and 112 is an exhaust device for the chamber. The semiconductor exposure apparatus main body is installed inside the chamber 101.

The EWS display 102 is of a thin flat type such as EL, plasma, liquid crystal, etc., is housed in the front of the chamber 101, and is connected to the EWS main body 106 by a LAN cable 110. Operation panel 10
3. A keyboard 104, a monitor TV 105, and the like are also installed on the front surface of the chamber 101 so that a console operation similar to the conventional console operation can be performed from the front surface of the chamber 101.

FIG. 2 is a diagram showing the internal structure of the apparatus shown in FIG. FIG. 1 shows a stepper as a semiconductor exposure apparatus. In the drawing, reference numeral 202 denotes a reticle, and 203, a wafer. When a light beam emitted from a light source device 204 illuminates the reticle 202 through an illumination optical system 205, a pattern on the reticle 202 is projected by a projection lens 206 onto the wafer 203. Can be transferred to a layer. The reticle 202 is supported by a reticle stage 207 for holding and moving the reticle 202. Wafer 203
Is exposed while being vacuum-sucked by the wafer chuck 291. The wafer chuck 291 is mounted on the wafer stage 20.
9 allows movement in each axis direction.

Above the reticle 202, a reticle optical system 281 for detecting the amount of displacement of the reticle is arranged. The projection lens 20 is located above the wafer stage 209.
An off-axis microscope 282 is arranged adjacent to the sixth axis. The main role of the off-axis microscope 282 is to detect the relative position between the internal reference mark and the alignment mark on the wafer 203. A reticle library 220 which is a peripheral device adjacent to these stepper bodies is also provided.
Alternatively, a wafer carrier elevator 230 is arranged, and a required reticle or wafer is transferred to the stepper body by the reticle transfer device 221 and the wafer transfer device 231.

The chamber 101 is mainly composed of an air conditioner room 210 for controlling the temperature of air, a filter box 213 for filtering fine foreign matters to form a uniform flow of clean air, and a booth 214 for shutting off the environment of the apparatus from the outside. Have been. In the chamber 101, air whose temperature has been adjusted by the cooler 215 and the reheat heater 216 in the air conditioner room 210 is supplied into the booth 214 via the air filter g by the blower 217. The air supplied to the booth 214 is taken into the air conditioner room 210 again from the return port ra and circulates in the chamber 101. Normally, the chamber 101 is not strictly a complete circulation system. To maintain the inside of the booth 214 at a positive pressure at all times, about 10% of the amount of circulating air outside the booth 214 is supplied to the outside air provided in the air conditioner room 210. It is introduced from the inlet oa via a blower. In this way, the chamber 101 enables the environment temperature where the apparatus is placed to be kept constant and the air to be kept clean. The light source device 204 is provided with an intake port sa and an exhaust port ea in preparation for cooling of the ultra-high pressure mercury lamp and generation of toxic gas at the time of laser abnormality, and a part of the air in the booth 214 passes through the light source device 204 to be air-conditioned. The air is forcibly exhausted to factory equipment via a dedicated exhaust fan provided in the machine room 210. Further, a chemical adsorption filter cf for removing chemical substances in the air is provided so as to be connected to the outside air introduction port oa and the return port ra of the air conditioner room 210, respectively.

FIG. 3 is a block diagram showing an electric circuit configuration of the apparatus shown in FIG. In the figure, reference numeral 321 denotes a main unit C built in the EWS main unit 106, which controls the entire apparatus.
It is a PU and comprises a central processing unit such as a microcomputer or a minicomputer. 322 is a wafer stage driving device, and 323 is the off-axis microscope 28.
2 is an alignment detection system, 324 is a reticle stage driving device, 325 is an illumination system such as the light source device 204, 3
26 is a shutter driving device, 327 is a focus detection system,
Reference numeral 328 denotes a Z drive, which is a main body CPU 32
1 is controlled. 329 is the reticle transport device 2
21, a transfer system such as a wafer transfer device 231. 330
Is a console unit having the display 102, the keyboard 104, etc., for giving various commands and parameters relating to the operation of the exposure apparatus to the main body CPU 321. That is, it is for exchanging information with the operator. Reference numeral 331 denotes a console CPU, and 332 denotes an external memory for storing various job parameters and the like. The job parameters include a mask to be used, an opening of a masking blade, an exposure amount, layout data, and the like.

In this embodiment, the masking blade position is converted on the wafer. Also, when exposing a shot, the step size and the opening width of the masking blade are specified by the same amount, and the amount specified by the parameter,
For example, an opening between 0 and 1 mm in both the X and Y directions is additionally opened on both sides, and the opening is opened to about 1/2 of the width of the reticle light shielding band. This is to prevent the influence of the shadow of the masking blade from occurring. The lens center (exposure center) is at the position (0, 0) of the stage.
For simplicity and simplicity, the process of validating / invalidating shots according to the shape of the wafer and the like is omitted. This embodiment is an example of a case where there is a normal shot and a TEG shot. All the processing described below is processed by the console CPU 331 using another console unit, and is sent to the main body CPU 321 when operating the apparatus. . In the following drawings, the right direction and the upward direction are plus directions.

FIG. 9 is a flowchart of a layout creation process. The shot layout creation process will be described with reference to this flowchart. When the process is started, first, in step S901, position information of a masking blade at the time of exposure is set. Usually, this setting is performed by the operator inputting from the console unit. The data to be set is an array of structures mpinfo so that a plurality of sets of information can be set in order to correspond to the exposure of a plurality of areas of the reticle. Position 605
And 607, x-position rux and y-position ruy, and lower left positions 606 and 608 of x-position Ldx and y-position Ldy. The position information of the masking blade is also used in the exposure processing described later with reference to FIG.

Next, in step S902, the shot counter s is set to 0, and in step S903, it is determined whether layout creation is completed. This determination is also usually made according to the instruction of the operator. If the process is continued, the process proceeds to step S904, and if completed, the process proceeds to step S916.

In step S904, step S901
The order of the information of the masking blade position information array set in the above is entered in n. In addition, Row (column) and Column (column) of the layout created this time
Is input to row and coL. This n, row, c
oL is also usually set by the operator.

Next, in step S905, from the selected masking blade position information, the masking blade opening width m at the masking blade position is calculated by the following equation.
bw_x, mbw_y are calculated.

[0023]

(Equation 1) Next, in step S906, step sizes stepx and stepy, which are movement distances of the stage from the center of the shot at the time of exposure to the center of the next shot, are input. Here, for the sake of simplicity, the opening width is the same as the masking blade opening width.

Next, in step S907, the center positions sbase_x and sbase_y of the shots, which are the reference of the shots arranged in the row and column directions, are input. When arranging an odd number, the center position of the center shot is input. When arranging an even number, the center position of the shot in the plus direction of the two center shots is input.
For example, in the case of a layout 701 including a normal shot and a TEG shot as shown in FIG. 7, the center position 704 of the shot 702 (the wafer center 70
3). After a series of processing for creating a layout of a normal shot, processing of a TEG shot is performed. In this case, the center position 706 of the TEG shot 705 is input. This setting is also usually performed by the operator.

Next, in step S908, the counter c for the number of columns coL is initialized to 0, and in step S909, the counter r for the row number row is initialized to 0. Next, in step S910, the center position of each shot is calculated by the following equation.

[0026]

(Equation 2) Here, in the calculation of row / 2 and coL / 2, the remainder is rounded down to an integer and the following calculations are performed. shot is an array of shot information structures, and here, x,
The y coordinate is set to members x and y, and the number n indicating at which masking blade position this shot is exposed is set to member mpn. This shot arrangement shot is shown in FIG.
0 is also used in the exposure processing.

Next, in step S911, a picture of the shot having the size of the opening of the masking blade is drawn with reference to the center position of the shot. Then, Step S91
At 2, the counter r of the row number row and the shot number s are counted up by one.

Next, in step S913, the counter r is compared with the number row of shots arranged in the row direction. If r is smaller, the process returns to step S910. Otherwise, the process proceeds to step S914, and the counter c for the column number coL is counted up by one.

Next, in step S915, if c is smaller than this counter c and the number of shots coL arranged in the column direction, the process returns to step S909. If not, the process advances to step S903 to determine whether to add a shot layout to the layout created so far or to finish creating the layout.

In step S916, the shot counter s is stored in the shot total number shot_n. shot_
n is also used in the exposure processing of FIG.

By the above-described processing, the layout conventionally formed as shown in FIG. 5 can be formed as shown in FIG. 4, so that the layout can be easily prepared for the operator, and the completed layout can be understood. It will be easier. In this example, the parameter is set by the operator each time, but it is also possible to use preset data, or the parameter itself may be created automatically.

Next, the process of performing exposure in accordance with the layout thus created will be described with reference to the flowchart of FIG. When the exposure processing is started, first, in step S1001, the shot counter s
Is set to 0. Next, in step S1002,
The masking blade position information number shot [s]. mpn is set to m, and in step S1003, using the masking blade position information mpinfo [m] of the shot, the center position of the opening of the masking blade for exposing the shot is calculated by the following equation, and mbc_x, mb
Set to c_y.

[0033]

(Equation 3) This position is a position based on the lens center. This reference position is the exposure center position, and is also the position of (0, 0) on the stage.

Next, in step S1004, the positions sx and sy of the stage at the time of exposure are calculated. FIG. 8 shows the positional relationship at this time. Reference numeral 801 denotes a shot layout pattern to be exposed on the wafer, and reference numeral 803 denotes a reticle having a pattern to be exposed. Reference numeral 802 denotes a shot that has just come to the exposure position, and the shot and light from the light source are transmitted through the masking blade opening and the reticle 80.
3 shows that the pattern above, and the image made through the lens, fit snugly. The position of the reticle here is not the actual position because it passes through the lens, but for the sake of simplicity, it is assumed that the position of the image is the position of the reticle for convenience. Reference numeral 804 denotes the center of the wafer, which is the same as the center position of the stage here. The position of the stage is indicated by a positional relationship from the lens center to the stage center position. 805 is the center position of the opening of the masking blade, 806 is the lens center, 807
Is a vector (shot [s] .x, sho from the wafer center 804 indicating the center position 805 of the exposure shot 802.
t [s]. y) and 808 are vectors (mbc_x, mbc_y) from the lens center 806 indicating the opening center position 805 of the masking blade. Reference numeral 809 denotes a vector from the stage origin (lens center 806 position) for the stage to come to such a position. The position indicated by this vector is the stage movement position sx, sy calculated in step S1004.

Next, in step S1005, the stage is moved to the position calculated in step S1004, and in step S1006, the masking blade is opened to the position set by the masking blade position information mpinfo [m] to perform exposure.

Next, in step S1007, the shot counter s is incremented by one, and
In step 1008, the shot counter s is compared with the shot total number shot_n. If the shot counter s is smaller, the process returns to step S1002 to continue the exposure sequence. If not, the exposure sequence ends. By such processing, exposure processing can be performed using a shot layout of an area to be actually exposed.

According to this embodiment, a layout to be exposed can be easily created as it is in a shot layout, and a target area can be exposed by the shot layout. There is an effect that the operation of creating parameters can be simplified.

<Embodiment of Device Manufacturing Method> Next, an embodiment of a device manufacturing method using the above-described exposure apparatus will be described. FIG. 11 shows a flow of manufacturing micro devices (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, thin-film magnetic heads, micromachines, etc.). Step 1
In (Circuit Design), a device pattern is designed. Step 2 is a process for making a mask on the basis of the designed pattern. Step 3 (wafer manufacturing)
Then, a wafer is manufactured using a material such as silicon or glass. Step 4 (wafer process) is called a pre-process,
An actual circuit is formed on the wafer by lithography using the prepared mask and wafer. The next step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer produced in step 4, and includes processes such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation). including. In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device manufactured in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7).

FIG. 12 shows a detailed flow of the wafer process (step 4). Step 11 (oxidation) oxidizes the wafer's surface. Step 12 (CVD) forms an insulating film on the wafer surface. Step 13 (electrode formation) forms electrodes on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. In step 15 (resist processing), a resist is applied to the wafer. Step 16 (exposure) uses the above-described exposure apparatus or exposure method to align and print the circuit pattern of the mask on a plurality of shot areas of the wafer. Step 17 (development) develops the exposed wafer. In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), unnecessary resist after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.

By using the production method of this embodiment, it is possible to produce a large-sized device, which was conventionally difficult to produce, at low cost.

[0041]

As described above, according to the present invention,
A shot layout corresponding to an actual shot can be easily created and displayed. Further, the exposure processing can be easily performed by the shot layout. Therefore, even when the center of the exposure and the center of the pattern to be printed are apart from each other, a shot layout can be easily created.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an appearance of a semiconductor exposure apparatus according to one embodiment of the present invention.

FIG. 2 is a diagram showing the internal structure of the device of FIG.

FIG. 3 is a block diagram showing an electric circuit configuration of the device shown in FIG.

FIG. 4 is a diagram showing an example of a shot layout to be exposed by the apparatus of FIG. 1, which is created by the apparatus of FIG. 1;

FIG. 5 is a diagram showing a conventional shot layout corresponding to the shot layout of FIG. 4;

FIG. 6 is a view showing a relationship between a reticle used in the apparatus of FIG. 1 and shots to be exposed;

FIG. 7 is an example of a shot layout created by the apparatus of FIG. 1, showing a reference shot at the time of creation;

FIG. 8 is a diagram showing a positional relationship between an exposure shot and a reticle when performing exposure processing with the apparatus of FIG. 1;

FIG. 9 is a flowchart showing a layout creation process in the apparatus of FIG. 1;

FIG. 10 is a flowchart showing an exposure process in the apparatus of FIG. 1;

FIG. 11 is a flowchart illustrating a device manufacturing method that can use the exposure apparatus of the present invention.

FIG. 12 is a detailed flowchart of a wafer process in FIG. 11;

[Explanation of symbols]

101: temperature control chamber, 102: display device for EWS, 103: operation panel, 104: keyboard for EWS, 105: monitor TV, 106: EWS body, 10
7: ON-OFF switch, 108: emergency stop switch, 109: various switches, mouse, etc. 110: LAN
Communication cable, 111: exhaust duct, 112: exhaust device, 202: reticle, 203: wafer, 204: light source device, 205: illumination optical system, 206: projection lens, 20
7: reticle stage, 209: wafer stage, 28
1: reticle microscope, 282: off-axis microscope, 2
10: air conditioner room, 213: filter box, 214:
Booth, 217: blower, g: air filter, cf: chemical adsorption filter, oa: outside air introduction port, ra: return port, 321: main body CPU, 330: console, 33
1: console CPU, 332: external memory, 401:
Normal shot, 402, 403, 501, 502: TE
G shot, 601: reticle, 602: TEG pattern, 603: normal shot pattern, 604: lens center position, 605, 607: upper right position of masking blade opening at the time of exposure, 606, 608: masking blade opening at the time of exposure Lower left position, 701: shot layout, 702, 705: reference shot, 703:
Wafer center position, 704, 706; reference shot center position, 801: shot layout, 802: exposure shot, 803: reticle, 804: wafer center position, 805: exposure shot center position, 806: lens center position, 807: Vector indicating the exposure shot position, 8
08: vector indicating the masking blade opening center position, 809: vector indicating the stage position.

Claims (7)

[Claims] 1. A layout creating means for creating a shot layout based on predetermined information, and an exposure means for exposing a reticle pattern on the substrate by positioning a substrate at each shot position by a stage based on the shot layout. And an exposure apparatus having an exposure area limiting means for limiting an exposure area in each shot,
The layout creating means creates the shot layout as position information of an actual shot determined for each exposure area on the reticle pattern formed by limiting by the exposure area limiting means. Exposure equipment characterized. 2. The apparatus according to claim 1, wherein the exposure unit is configured to determine a position of each shot based on position information of each shot of the shot layout created and position information of an exposure area on a reticle pattern formed by a unit that limits the exposure area. 2. The exposure apparatus according to claim 1, wherein the stage is positioned to perform exposure. 3. The layout creating means has a function of displaying a shot layout graphic representing an area to be actually exposed, based on the position information of the actual shot. 3. The exposure apparatus according to claim 1. 4. The apparatus according to claim 1, wherein the layout creating unit is configured to store position information on each exposure area on the reticle pattern formed by the exposure area limiting unit, Or the distance between adjacent shots, the number of rows and columns of shots to be exposed on the substrate, and the reference position of the shot layout on the substrate to create the shot layout. The exposure apparatus according to claim 1, wherein: 5. A layout creating step for creating a shot layout based on predetermined information, a step of positioning a substrate at each shot position by a stage based on the shot layout, and a step of limiting an exposure range. An exposure step of exposing a pattern portion in an exposure area on a reticle pattern onto the substrate, wherein in the layout creating step,
A device manufacturing method, wherein the shot layout is created as actual shot position information determined for each exposure area on a reticle pattern formed by limiting the exposure range. 6. In the exposing step, each shot position is determined based on position information of each shot of the created shot layout and position information of an exposure area on a reticle pattern formed by limiting the exposure range. 2. The method according to claim 1, wherein the exposure is performed by positioning the stage.
3. The device manufacturing method according to claim 1. 7. The layout creating step according to claim 5, wherein a graphic of a shot layout representing an area to be actually exposed is displayed based on the position information of the actual shot. Device manufacturing method.