JP2007286411A - Gap control device and gap control method for proximity exposure device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a contact between a mask and a substrate due to operation failure of a gap control device. <P>SOLUTION: A gap sensor 30 detects a gap between a mask 2 and a substrate 1. A judging section 52 judges whether the detected value of the gap is in an allowable range (target range) or not with respected to a target value input from an input device 40. If the detected value of the gap is out of the target range, a movement amount determining section 53 determines an elevation amount of the substrate 1 based on the target value and the detected value of the gap. A cumulative value checking section 54 checks that the cumulative value of movement amounts determined by the movement amount determining section 53 is not more than an upper limit determined by an upper limit determining section 51. As the cumulative value of the movement amount is checked to be not more than the upper limit prior to elevating the substrate 1, elevation of the substrate 1 causing a contact between the mask 2 and the substrate 1 can be avoided in advance even when error detection occurs upon detecting the gap between the mask 2 and the substrate 1 or malfunction occurs in a Z-tilt mechanism 9 upon elevating the substrate 1, and therefore, a contact between the mask 2 and the substrate 1 can be prevented. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gap control apparatus and a gap control method for a proximity exposure apparatus that controls a gap between a photomask (hereinafter referred to as “mask”) and a substrate in the proximity exposure apparatus.

  Manufacturing of TFT (Thin Film Transistor) substrates, color filter substrates, plasma display panel substrates, organic EL (Electroluminescence) display panel substrates, and the like of liquid crystal display devices used as display panels is performed using photolithography using an exposure apparatus. This is performed by forming a pattern on the substrate by a technique. As an exposure apparatus, a projection method in which a mask pattern is projected onto a substrate using a lens or a mirror, and a minute gap (proximity gap) is provided between the mask and the substrate to transfer the mask pattern to the substrate. There is a proximity method. The proximity method is inferior in pattern resolution performance to the projection method, but the configuration of the irradiation optical system is simple, the processing capability is high, and it is suitable for mass production.

  The proximity exposure apparatus includes a gap control device that controls the gap between the mask and the substrate. The gap control device detects a gap between the mask and the substrate using a gap sensor, and drives a Z-tilt mechanism equipped with a chuck for holding the substrate so that the detected gap is within a target range. The mask is usually provided with four gap detection windows.

  FIG. 3 is a flowchart showing the operation of the gap control device of the conventional proximity exposure apparatus. First, the target value of the gap is input to the gap control device (step 201). The gap control device drives the Z-tilt mechanism to move the chuck so that the surface of the chuck has a predetermined height (step 202). Next, the gap control device detects a gap between the mask and the substrate using a gap sensor (step 203). Subsequently, the gap control device determines whether or not the detected value of the gap is within an allowable range (target range) for the target value (step 204). If the detected value of the gap is not within the target range, the gap control device determines the amount of substrate lift based on the target value and detected value of the gap (step 205). Then, the gap control device drives the Z-tilt mechanism in accordance with the determined amount of increase to raise the substrate (step 206). The gap control device repeats the operations from step 203 to step 206 until the detected value of the gap falls within the target range.

As for the gap control of the proximity exposure apparatus, for example, there is one described in Patent Document 1.
Japanese Unexamined Patent Publication No. Hei 6-291010

  The gap controlled by the gap control device of the proximity exposure apparatus is as small as about several hundred μm. In the conventional proximity exposure apparatus, the mask and the substrate may come into contact with each other due to malfunction of the gap control device, and the mask may be damaged. was there.

The malfunction of the gap control device includes the following.
(1) Misdetection of gap in step 203 of FIG. This is caused by a failure of the gap sensor, an abnormality in the gap detection position (gap sensor installation position), scattered light due to scratches on the gap detection window provided on the mask, and the like.
(2) Malfunction of the Z-tilt mechanism in step 206 in FIG.

  An object of the present invention is to prevent a mask and a substrate from coming into contact with each other due to a malfunction of a gap control device.

  The gap control device of a proximity exposure apparatus according to the present invention includes a moving means for relatively moving a mask and a substrate, a detecting means for detecting a gap between the mask and the substrate, and a detection value of the detecting means within a target range. Determination means for determining whether there is a movement amount determination means for determining the movement amount of the movement means according to the target value and the detection value of the detection means until the detection value of the detection means falls within the target range; A gap control apparatus for a proximity exposure apparatus comprising a driving means for driving the moving means according to the moving amount determined by the means, wherein the movement determined by the moving amount determining means before the driving means drives the moving means A confirmation means for confirming whether or not the cumulative value of the quantity is equal to or less than the upper limit value is provided.

  The gap control method for a proximity exposure apparatus according to the present invention includes a step of detecting a gap between a mask and a substrate, a step of determining whether a detected value of the gap is within a target range, and a detected value of the gap being a target range. If not, a step of determining a relative movement amount of the mask and the substrate according to the target value and detection value of the gap, and a step of relatively moving the mask and the substrate according to the determined movement amount. A method for repeatedly controlling a gap in a proximity exposure apparatus includes a step of confirming whether the cumulative value of the determined movement amount is equal to or less than an upper limit value before the step of relatively moving the mask and the substrate.

  Before moving the mask and the substrate relative to each other, it is checked whether the cumulative value of the determined movement amount is less than or equal to the upper limit value, so that an erroneous detection occurs when detecting the gap between the mask and the substrate, or the mask Even if a malfunction occurs during relative movement between the substrate and the substrate, the relative movement between the mask and the substrate that causes contact between the mask and the substrate is avoided in advance, and contact between the mask and the substrate is prevented. The

  Further, the gap control device of the proximity exposure apparatus according to the present invention includes an input unit for inputting a substrate thickness and a target value of the gap, and a cumulative value based on the substrate thickness and the target value of the gap input by the input unit. And an upper limit determining means for determining the upper limit of the value.

  The gap control method of a proximity exposure apparatus according to the present invention includes a step of inputting a substrate thickness and a target value of a gap, and an upper limit value of a cumulative value based on the input substrate thickness and the target value of a gap. Is included.

  The target value of the substrate thickness and gap is input, and the upper limit value of the cumulative value is determined based on the input target value of the substrate thickness and gap, so the upper limit value is the target value of the substrate thickness and gap. Accordingly, the contact between the mask and the substrate is more reliably prevented.

  According to the present invention, before the relative movement between the mask and the substrate, the mask and the substrate are brought into contact with each other due to a malfunction of the gap control device by checking whether the accumulated value of the determined movement amount is equal to or lower than the upper limit value. Can be prevented.

  Further, the target value of the substrate thickness and the gap is input, and the upper limit value of the cumulative value is determined based on the input target value of the substrate thickness and the gap. It can prevent more reliably that a board | substrate contacts.

  FIG. 1 is a diagram showing a schematic configuration of a gap control device of a proximity exposure apparatus according to an embodiment of the present invention. The proximity exposure apparatus includes a base 3, an X guide 4, an X stage 5, a Y guide 6, a Y stage 7, a θ stage 8, a Z-tilt mechanism 9, a chuck 10, a mask holder 20, a gap sensor 30, an input device 40, A processing device 50 and a Z-tilt mechanism driving circuit 60 are included. Among these, the gap control device includes a Z-tilt mechanism 9, a gap sensor 30, an input device 40, a processing device 50, and a Z-tilt mechanism drive circuit 60. In addition to these, the exposure apparatus includes a carry-in unit for carrying in the substrate 1, a carry-out unit for carrying out the substrate 1, a temperature control unit for managing the temperature in the apparatus, and the like.

  In FIG. 1, the chuck 10 is at an exposure position where the substrate 1 is exposed. The mask 2 is held by the mask holder 20 above the exposure position. The substrate 1 is mounted on the chuck 10 by a carry-in unit (not shown) at a delivery position away from the exposure position, and is recovered from the chuck 10 by a carry-out unit (not shown).

  The chuck 10 is mounted on the θ stage 8 via a Z-tilt mechanism 9, and a Y stage 7 and an X stage 5 are provided below the θ stage 8. The X stage 5 moves in the X direction (the horizontal direction in the drawing) along the X guide 4 provided on the base 3. As the X stage 5 moves in the X direction, the chuck 10 moves between the delivery position and the exposure position. The Y stage 7 moves in the Y direction (the drawing depth direction) along the Y guide 6 provided on the X stage 5. The θ stage 8 rotates in the θ direction, and the Z-tilt mechanism 9 moves and tilts in the Z direction (vertical direction in the drawing).

  At the exposure position, the substrate 1 is positioned by moving the X stage 5 in the X direction, moving the Y stage 7 in the Y direction, and rotating the θ stage 8 in the θ direction. Further, the gap control between the mask 2 and the substrate 1 is performed by the movement and tilt of the Z-tilt mechanism 9 in the Z direction.

  The mask 2 is provided with four gap detection windows. Inside the mask holder 20, a gap sensor 30 indicated by a broken line is installed above the gap detection window of the mask 2. The gap sensor 30 detects a gap between the mask 2 and the substrate 1 and outputs a detected value of the gap to the processing device 50.

  The input device 40 inputs the target value of the thickness of the substrate 1 and the gap between the mask 2 and the substrate 1 to the processing device 50. The processing device 50 is configured to include an upper limit determination unit 51, a determination unit 52, a movement amount determination unit 53, and a cumulative value confirmation unit 54. As will be described later, the processing device 50 transmits the substrate 1 to the Z-tilt mechanism drive circuit 60. Command the ascent. The Z-tilt mechanism drive circuit 60 drives the Z-tilt mechanism 9 in accordance with a command from the processing device 50.

  FIG. 2 is a flowchart showing the operation of the gap control device of the proximity exposure apparatus according to the embodiment of the present invention. First, the target value of the thickness of the substrate 1 and the gap between the mask 2 and the substrate 1 is input from the input device 40 to the processing device 50 (step 101). The upper limit determination unit 51 determines an upper limit for the accumulated value of the amount of increase of the substrate 1 based on the target thickness and gap target values of the substrate 1 (step 102).

  The target value of the substrate 1 and the gap are input, and the upper limit value of the cumulative value is determined based on the input target value of the substrate 1 and the gap. Therefore, the upper limit value is the thickness and the gap of the substrate 1. Is appropriately determined according to the target value.

The movement amount determination unit 53 determines the movement amount of the chuck 10 so that the surface of the chuck 10 has a predetermined height, and the Z-tilt mechanism drive circuit 60 follows the increase amount determined by the movement amount determination unit 53. Then, the Z-tilt mechanism 9 is driven to move the chuck 10 (step 103).

  The gap sensor 30 detects the gap between the mask 2 and the substrate 1 (step 104). The determination unit 52 determines whether the detected value of the gap from the gap sensor 30 is within an allowable range (target range) for the target value input from the input device 40 (step 105). If the detected value of the gap is not within the target range, the movement amount determination unit 53 determines the amount of rise of the substrate 1 based on the target value and detected value of the gap (step 106).

  The cumulative value confirmation unit 54 confirms whether the cumulative value of the movement amount determined by the movement amount determination unit 53 is equal to or less than the upper limit value determined by the upper limit value determination unit 51 (step 107). When the cumulative value of the movement amount is less than or equal to the upper limit value, the cumulative value confirmation unit 54 outputs the movement amount determined by the movement amount determination unit 53 to the Z-tilt mechanism drive circuit 60, and the Z-tilt mechanism drive circuit 60 Then, the Z-tilt mechanism 9 is driven in accordance with the rising amount determined by the movement amount determining unit 53 to raise the substrate 1 (step 108).

  The operations from step 104 to step 108 are repeated until the detected value of the gap falls within the target range. On the way, if the accumulated amount of movement is not less than or equal to the upper limit value in step 107, the gap control operation is stopped. Before raising the substrate 1 in step 108, it is checked in step 107 whether the accumulated value of the movement amount is equal to or less than the upper limit value, so that an erroneous detection occurs when detecting the gap between the mask 2 and the substrate 1 in step 104. Even if the Z-tilt mechanism 9 malfunctions when the substrate 1 is raised in step 108, the elevation of the substrate 1 that causes contact between the mask 2 and the substrate 1 is avoided in advance. Contact with 1 is prevented.

  According to the embodiment described above, before the substrate 1 is lifted, the mask 2 and the substrate 1 are caused to malfunction due to a malfunction of the gap control device by confirming whether or not the accumulated value of the determined movement amount is equal to or lower than the upper limit value. Contact can be prevented.

  Further, the target value of the thickness of the substrate 1 and the target value of the gap are input, and the upper limit value of the cumulative value is determined based on the input target value of the thickness of the substrate 1 and the gap. Since the thickness is appropriately determined according to the target value of the gap and the gap, it is possible to more reliably prevent the mask 2 and the substrate 1 from coming into contact with each other due to the malfunction of the gap control device.

  In the embodiment described above, the chuck 10 on which the substrate 1 is mounted is moved up and down to control the gap between the mask 2 and the substrate 1, but instead of moving the chuck 10 up and down, the mask 2 You may move the mask holder 20 which hold | maintains up and down.

It is a figure which shows schematic structure of the gap control apparatus of the proximity exposure apparatus by one Embodiment of this invention. It is a flowchart which shows operation | movement of the gap control apparatus of the proximity exposure apparatus by one Embodiment of this invention. It is a flowchart which shows operation | movement of the gap control apparatus of the conventional proximity exposure apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Mask 3 Base 4 X guide 5 X stage 6 Y guide 7 Y stage 8 θ stage 9 Z-tilt mechanism 10 Chuck 20 Mask holder 30 Gap sensor 40 Input device 50 Processing device 60 Z-tilt mechanism drive circuit

Claims (4)

Moving means for relatively moving the mask and the substrate;
Detecting means for detecting a gap between the mask and the substrate;
Determination means for determining whether the detection value of the detection means is within a target range;
A moving amount determining means for determining a moving amount of the moving means according to the target value and the detected value of the detecting means until the detected value of the detecting means falls within a target range;
A gap control device for a proximity exposure apparatus, comprising: a driving unit that drives the moving unit according to the moving amount determined by the moving amount determining unit;
A proximity exposure apparatus comprising: a confirmation unit configured to confirm whether an accumulated value of the movement amount determined by the movement amount determination unit is equal to or less than an upper limit value before the driving unit drives the movement unit. Gap control device. Input means for inputting the target values of the thickness and gap of the substrate;
2. The proximity exposure apparatus according to claim 1, further comprising an upper limit value determining unit that determines an upper limit value of the cumulative value based on the substrate thickness and the target value of the gap input by the input unit. Gap control device. Detecting a gap between the mask and the substrate;
Determining whether the detected value of the gap is within a target range;
If the detected value of the gap is not within the target range, determining a relative movement amount of the mask and the substrate according to the target value and the detected value of the gap;
A proximity exposure apparatus gap control method that repeats a step of relatively moving a mask and a substrate in accordance with a determined movement amount,
A gap control method for a proximity exposure apparatus, comprising a step of confirming whether a cumulative value of a determined movement amount is equal to or less than an upper limit value before a step of relatively moving a mask and a substrate. Inputting target values for substrate thickness and gap;
The gap control method for a proximity exposure apparatus according to claim 3, further comprising: determining an upper limit value of the cumulative value based on the input substrate thickness and gap target value.

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