JPS6151827A - Semiconductor printing apparatus - Google Patents

Abstract

PURPOSE:To determine an optimum exposure quantity precisely, by doing prints for determining the optimum exposure quantity under the same condition during a single shot. CONSTITUTION:A mask 5 is set and a wafer 8 is set on a wafer srage 9. A CPU40 commands an optimum image face controller 47 to regulate the gap betewen the lens 6 and the wafer 8 to be made a predetermined value. In sequent steps, all the treatments are done under the same image face. The CPU40 commands a masking blade controller 48 to move to a designated position and commands an exposure time controller 49 to open the shutter 2 for a time designated by an exposure time designating section 44 to do exposure operation. The masking blade 3 is drived and the exposure of the number of times designated by an exposure number designating section 43 is finished to complete the treatments.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a semiconductor printing apparatus, and more particularly to a semiconductor printing apparatus in which the optimum exposure aperture is determined under the condition of the same best image surface within a single shot. It is.

[Background of the Invention] Conventionally, in a semiconductor furnace 1q apparatus (stepper) that prints a pattern on a wafer by a step-and-repeat operation, appropriate exposure is determined by the step-and-repeat operation, for example, when determining the exposure time. Accordingly, printing (test printing) is performed by changing the exposure time for each shot, and the appropriate exposure time is determined by observing the vA of the printing results. In this case, image plane (focus) adjustment and the like are performed for each shot in order to deal with warping of the wafer and the like.

However, when determining the appropriate exposure time, such conventional printing equipment performs trial printing by changing shots, and therefore, conditions other than exposure time may occur, such as changes in the image plane due to errors in the above-mentioned image plane adjustment. This has the disadvantage that it is not possible to accurately determine the appropriate exposure time.

OBJECT OF THE INVENTION] The present invention eliminates the drawbacks of the above-mentioned conventional example and performs printing for determining the appropriate exposure m under the same conditions during a single shot, thereby determining the appropriate exposure group with higher accuracy. The purpose of the present invention is to provide a semiconductor printing device that makes it possible to perform the following steps.

[Explanation of Examples] Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 shows a schematic configuration of a semiconductor baking bag according to an embodiment of the present invention. In the figure, 1 is a printing light source that prints the mask pattern onto the wafer, 2 is a shutter that allows the printing light to pass through for a specified time, and 3 is a light shielding plate (hereinafter referred to as masking blade) that limits the range of the printing fj part. ),
4 is an alignment scope for T-cho-L alignment and hh = 1, 5 is a mask, 6 is a lens for printing, 7 is @
An air sensor for detecting the image plane (focus), 8 is a wafer, and the pattern of the 7th screen 5 is projected onto the wafer 8 by a lens 6. 9 is each of X, Y, θ, and Z. This is a wafer stage for holding a wafer that can move in directions.

FIG. 2 is a schematic diagram of the structure of the masking blade 3 seen from the front upper side of the apparatus shown in FIG. In the figure, 20 is a blade that blocks light on the right side (XR) in the X direction,
It can be moved in the X direction by a drive motor 24.

This blade can limit the irradiation range on the right side of the printing light that reaches the wafer 8 (FIG. 1).

Similarly, 21.25 is on the back side in the Y direction (YU), 22.26 is on the left side in the X direction (XL), and 23.27 is on the front side in the Y direction (YD).
) are responsible for the blade and drive motor.

FIG. 3 is a layout diagram of one shot on the wafer 8 when printing (trial printing) is performed using the apparatus shown in FIG. This layout diagram shows an example in which one shot is divided into 16 parts for printing, and 30-1 to 30-16 are the respective printing positions (hereinafter referred to as frames).

First, when printing the frame 30-1, the masking blades 20 to 23 are moved to block the printing light from being applied to areas other than 30-1, and then exposure is performed. Next, when printing onto 30-2, the masking blade (XR) 20 is moved one frame to the left, and the masking blade (XL) 22 is also moved one frame to the left, so that the printing light is 30-2. Expose so that only the part -2 is irradiated. Similarly, 30-3 and 30-
After printing on 4, when printing on 30-5, move the masking blade (YU) 21 and masking blade (YD) 23 one frame toward the front of the device.
Make sure that only the part marked -5 is irradiated with the printing light. Continued<
When printing images 30-8 to 30-8, each time the masking plate (XR) 20 and masking blade (XL) 22 are moved to the right by one frame, the images are printed. Thereafter, the above-mentioned movement and baking are repeated to perform baking up to 30-16.

FIG. 4 is a block diagram of a control section that controls the operation of the apparatus shown in FIG.
Only relevant parts are shown.

In the figure, 40 is a central processing unit (CPLI), 41
is a ROM that stores a control program for the CPU 40;
42 is a RAM as a storage device for calculations, flags, etc.
It is. 43 is an exposure number designation section for designating the number of times of printing in one shot, that is, the number of frames in FIG. 3; and 44 is a third
Exposure time designation part 45 designates how to change the fog light time for each frame in the figure, and 45 is a masking blade drive foot designation part that designates the drive R of the masking blades 20 to 23 per frame in Figure 3. , and 46 is a wafer stage control unit that moves the wafer stage 9 to a specified position. Reference numeral 47 denotes an optimum image plane control unit that makes the gap between the lens 6 and the wafer 8 constant by a combination of the wafer detection by the air sensor 7 and the Z-direction drive of the wafer stage 9.

Reference numeral 48 denotes a masking blade control unit that gives commands to the drive motors 24 to 27 to move the masking blades 20 to 23 by an amount specified by the masking blade drive ♀ designation unit 45; and 49, an exposure unit designated by the exposure time designation unit 44; This is an exposure time control section that opens the shutter 2 according to time.

Next, the operations and operations when determining the appropriate exposure time in the apparatus shown in FIG. 1 will be explained with reference to the flowchart shown in FIG.

To determine the appropriate exposure time, the operator first specifies the number of prints in one shot in the exposure number designation section 43 (step 1), and instructs the exposure time designation section 44 to determine the exposure time for each frame as shown in FIG. In step 2), the masking blade drive amount designation section 45
Specify the drive amount per frame in Fig. 3 for (Step 3).
Alternatively, the selection may be performed using a selection switch or a keyboard provided on a console box (not shown) or the like. In addition, these specified data are stored in advance in the RAM of the console box, and when the operator inputs a start command for the appropriate exposure time determination process, each of the above specified data is sent from the main CPU (not shown) of the console box. The data may also be sent out. Furthermore, some or all of the above specified contents may be preset to simplify the operation.

Subsequently, the operator sets the mask 5 (step 4), sets the wafer 8 on the wafer stage 9 (step 5), and then gives a command to the wafer control unit 46 to move it directly below the lens 6. (Step 6). This command is issued from the keyboard provided in the wafer stage control unit 4G, the console box, or the like, or a start switch (not shown) for determining the appropriate exposure time.

Note that these commands and commands may be automatically executed using the main CPU or the like.

Thereby, CI) U3O starts appropriate exposure time determination processing.

In this appropriate exposure time determination process, the CPU,'t.

First, a command is given to the optimum image plane control unit 47 to set the gap between the lens 6 and the wafer 8 to a predetermined value (
Step 7) As a result, all subsequent steps are processed under the same image plane. Next, in step 8, a command is given to the masking blade control section 48 to move to a designated position.

The masking blade is moved, for example, as explained in connection with FIG. 3 above.

Next, the CPU 40 issues a command to the exposure time control section 49 to open the shutter 2 for the time specified by the exposure time specification section 44 to perform exposure (step 9). Then, in step 10, it is determined whether or not the number of exposures specified by the number of exposure designation section 43 has been completed, that is, 30-1 in the example of FIG.
It is judged whether or not exposure has been completed for each frame of 30-16. If the specified number of exposures has not been completed, return to step 8 and drive the masking blade 3 as explained in FIG. 3 to expose the next frame, and proceed to step 9. Perform exposure with . On the other hand, in step 10, Shino and Togi who have completed the exposure for the number of times specified in the exposure number designation section 43 are judged as
At step 1, the wafer is transported to a recovery position (not shown) and the process is completed.

Here, regarding the exposure time in step 9, for example, if the fog light time designation section 44 designates 200 m 3 ec as a base and increases it by 10 m 3 ec per frame, in the example of FIG. 200m 3 cc
, 30-1 has an exposure time of 210rn 3 cc, and 30-3 has an exposure time of 220m 3 cc.

[Modified example of the embodiment] In the above-mentioned embodiment, there are four masking blades.
&, but the number of sheets is not limited and may be any number.

In addition, in the case of d3 in the upper j box, the exposure for one frame in Figure 3 was made only once, and the exposure time was changed for each frame, but the exposure time for one time was constant. Toshi 1 frame 1
However, the exposure time may be changed for each frame by performing multiple exposures. For example, in FIG. 3, first, 20 m 3 cc; (XL> By moving only 22 one frame to the left, both 30-1 and 30-2 will be irradiated with the printing light, and the image will be printed again for 20m Sec.
If you expose it to light, at this point it will be 4 compared to 30-1.
This means that the exposure was 0 m 3 ec. By roughly repeating the above steps, even if the exposure time for one exposure is constant, it is possible to change the exposure time for each frame depending on how the masking blade is moved.

Roughly speaking, in the above, the range of a single shot is divided into multiple frames by a masking blade, but instead, multiple frames are divided using a filter with different transmittance within the range of a single shot. If the exposure is divided into two, it is possible to perform exposure using a plurality of types of exposure amounts in one exposure.

In this case, the lamp brightness may be adjusted based on the appropriate exposure amount determined by the result of this printing, or the transmittance of the filter may be adjusted to the above exposure time. Moreover, as the above-mentioned filter, a filter whose transmittance changes continuously can also be used.

[Effects of the Invention] As explained above, according to the present invention, when determining the appropriate exposure time, the exposure time is changed under the condition of a single shot, especially under the condition that the image plane (focus) is kept constant. This has the effect of making it possible to accurately determine the appropriate exposure time.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a semiconductor printing apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of a masking blade 11 in FIG.
11 schematic diagram, Figure 3 is a shot layout diagram, Figure 4 is a shot layout diagram.
1 is a block diagram of a control section for controlling the three operations for determining the appropriate exposure time in the apparatus of FIG. 1, and FIG. 5 is a schematic flowchart for explaining the operation of the apparatus of FIG. 1. 1...Light source for printing, 2...Shutter, 3.20-2
3... Light shielding plate (masking blade), 4... Alignment scope, 5... Mask, 6... Lens for printing, 7... Air sensor, 8... Wafer, 9...
・Wafer stage, 24 to 27... Masking blade drive motor, 30-1 to 30-16... Frame, 40
...Central processing unit (CPU), 41...ROM, 4
2...RAM, 43...Exposure number designation section, 44...
・Exposure time specification section, 45...Masking blade drive!
! ! IJ m designation section, 46... Wafer stage control section, 47... Optimal image plane control section, 48... Masking blade control section, 49... Exposure time control section.

Claims (1)

[Claims] 1. A semiconductor printing apparatus that prints a pattern formed on a mask onto a wafer, which comprises a plurality of parts within a range to be exposed in a single shot when printing the mask pattern on the wafer. The image forming apparatus is provided with a divided exposure means for exposing each of the images with a desired exposure amount, so that during printing to determine the appropriate exposure amount, exposure with multiple exposure amounts is performed under the same best image plane condition within the single shot. A semiconductor printing device characterized by: 2. The divided exposure means includes a light shielding means for irradiating the printing light only on an arbitrary part of the pattern on the mask, and a light shielding means for dividing the range to be exposed in the single shot into a plurality of parts. 2. A semiconductor printing apparatus according to claim 1, further comprising means for exposing one or more portions to light for a desired time while successively limiting one or more portions by said light shielding means. 3. Semiconductor printing according to claim 1, wherein the divided exposure means includes a filter means having a plurality of portions having different transmittances for exposure light within the range to be exposed in the single shot. Device. 4. The semiconductor printing apparatus according to claim 1, 2 or 3, wherein the mask pattern printing is performed by a step-and-repeat operation.