JPH0693539B2 - Exposure equipment - Google Patents

Description

The present invention relates to an exposure apparatus suitable for proximity exposure in which the gap between a mask and a substrate can be set to a predetermined value.

[Conventional technology]

As a conventional technique of a proximity exposure apparatus with this type of gap setting, there is a technique disclosed in Japanese Patent Application Laid-Open No. 57-204547, the outline of which is shown in FIG.

The exposure apparatus shown in FIG. 8 includes an exposure X-ray source 50, a mask and a stage.
Mask flatness measuring device 53 on wafer 52, wafer flatness measuring device 53, wafer deformation chuck 13 on stage 52, and controller 17
It consists of

First, the mask flatness measuring device 53 is placed under the mask 51, and the flatness of the mask 51 is measured. Next, while measuring the flatness of the wafer 54 by the wafer flatness measuring device 53, the surface flatness of the wafer 54 is made to match the flatness of the mask 51 by using the wafer deformation chuck 13. After that, if the wafer 54 is moved under the mask 51, the gap between the mask and the wafer becomes uniform, and the proximity exposure can be realized.

[Problems to be solved by the invention]

In the above-mentioned conventional technique, the flatness of the mask and the substrate is measured and the gap is set, so that the flatness measurement accuracy is important.
For this reason, high precision (expensive / complex) of the flatness measuring instrument is indispensable, and the flatness measuring instrument is inevitably expensive.

An object of the present invention is to provide an exposure apparatus capable of realizing inexpensive and highly accurate proximity exposure by directly setting a gap without measuring flatness.

[Means for solving problems]

The purpose of the above is to put a gap measuring device between the mask and the substrate, set the gap uniformly according to this value, and after the setting is completed, take out the measuring device and move the mask or substrate in parallel up and down to set the desired gap amount. It is achieved by

[Action]

The gap measuring device is set between the mask and the substrate and measures the gap between the mask and the substrate. The substrate deformation chuck deforms the substrate on the basis of the previously obtained gap value, and operates so that the mask-substrate gap becomes uniform or has a desired amount.

After the gap becomes uniform (or a desired value), the substrate and the chuck can be sufficiently brought close to each other by moving the substrate deforming chuck / mask in parallel or in parallel.

〔Example〕

 The printed circuit board for a computer is manufactured as follows.

A glass epoxy thin plate is sandwiched with copper foil, a through hole is provided in this, a resist is coated on the copper foil or a dry film resist is pressure-bonded, and the pattern on the mask is transferred to the resist by parallel ultraviolet light exposure and developed. Then, copper is etched to form a circuit pattern. A plurality of these inner layer boards are prepared, adhered and laminated to form a multilayer printed board. For more details, see Material Science Showa
As stated in the October 61 issue, P65-P128, etc.

However, increasing the area of printed circuit boards for computers (600
X 600 mm or more), miniaturization of pattern line width (100 μm or less)
As a result, many defects occur in the exposure of the pattern. This is caused by foreign matter between the mask and the substrate and pattern damage due to contact between the two. To address this, it is necessary to realize a proximity exposure method in which the mask and the substrate are separated and exposed.

In the proximity exposure method, the distance between the mask and the substrate needs to be close to 100 μm or less, but a large-area glass mask has a deflection of several hundred μm.
It is not possible to obtain a gap of 0 μm inside and outside over the entire exposed surface.

An embodiment of the present invention for realizing the proximity exposure method will be described below with reference to the drawings. FIG. 1 is a front view showing an embodiment of the present invention, and FIG. 2 is a view showing an exposure in this embodiment. The exposure apparatus of the embodiment shown in FIG.
An alignment optical system 2, a mask chuck 3, a mask 5 having a pattern 4 on its lower surface, a mask side sensor 6,
Gap measuring device 8 including substrate side sensor 7 and gap measuring device 8
Drive system 9, calibration gap 10 for gap measuring device 8, and substrate 11 on which dry resist (not shown) is pressure-bonded to vacuum suction means (pipes connected to a vacuum source and grooves formed on the chuck surface) 12. Thus, the substrate deformation chuck 13 that is vacuum-adsorbed, and the vertical drive system that tilts and vertically moves the substrate deformation chuck 13
14, vertical amount sensor 15, θ (rotation in horizontal plane), X,
The Y stage 16 and the controller 17 are provided.

Next, the operation will be described.

Mask 5 for mask chuck 3, substrate 11 for substrate deformation chuck
13 is loaded, the stage 16 is moved, and the substrate 11 is masked 5
Set below. Next, the calibrated gap measuring device 8 located between the calibrated gaps 10 is moved, and the substrate deformation chuck 13 is driven so that the gap 20 has a constant value. Deformation chuck 13
Is a chuck surface 25 divided by a groove and a tension spring 26,
It consists of a vertical movement table 27 and a chuck surface left and right stopper (not shown).
Drive 27. When the gap measuring device 8 passes between the mask 5 and the substrate 11, the gap 20 becomes constant (or a desired value). When the gap measuring device 8 is returned to the calibration gap 10, the gap 20 is checked, and if it is within the allowable value, the substrate deformation chuck 13 is raised by the vertical drive system 14 while monitoring the value of the vertical movement sensor 15,
Pause at a gap of μm. Here, the substrate 11 and the mask 8 are aligned by the alignment optical system 2, the substrate deformation chuck 13 is further raised after the alignment is completed, and the predetermined gap value S is set as shown in FIG. 2, and the alignment optical system 2 is retracted. , Expose with parallel ultraviolet light 30.

Here, the gap 20 is the sum of the width 21 of the gap measuring device 8, the value 22 of the mask side sensor 6 and the value 23 of the substrate side sensor 7, and since the values of these sensors are constantly calibrated by the calibration gap 10,
There is no offset error, which is the most error in this method. Further, because the sum of the sensors 6 and 7, the value of the gap 20 does not change even if the gap measuring device 8 moves up and down during movement, the accuracy of the drive system 9 is good, and the device is inexpensive. The gap 20 is 10μ by the above method.
It can be set in the order of m, and can be applied to liquid crystal pattern printing and LSI printing.

FIG. 3 is a plan view of the mask chuck 3 and the gap measuring device 8, and FIG. 4 is a side view thereof. In the case of a large area of the mask 5, when it is supported on two sides, its own weight causes a deflection of several hundred μm or more, which becomes a factor of increasing the stroke of the component.

On the other hand, the mask 5 is ideal because the lower surface support can be prevented from being affected by the thickness of the mask 5 and can be prevented from falling. But,
When the gap between the mask side sensor 6 of the gap measuring device 8 and the lower surface of the mask is narrow, the gap measuring device 8 interferes with the mask chuck 3. Therefore, the adjacent mask-side sensor 6 is recessed, and the lower surface chuck 31 is partially formed in accordance with this.

FIG. 5 is a sectional view of the air gap type gap measuring device 8. The supply air 34 enters the mask side sensor 6 and the substrate side sensor 7, respectively. Value between sensor top and measured surface 22,23
The back pressure values 35 and 36 due to are converted into gaps by pre-calibrated data by an amplifier (not shown) or the like.

FIG. 6 shows a gap sensor 40 that directly measures the gap 20. The gap value 20 is output directly as one back pressure value 37.

FIG. 7 is a front view of the sensor-following type gap measuring device 8.
The vertical movement driving means 41 such as a voice coil is driven so that the value 22 of the mask side sensor 6 becomes the reference value, and the value 23 of the substrate side sensor 7 is set to another reference value. In this way, all the gaps can be set by the zero method, and the accuracy is improved.

The above device is horizontal, but may be vertical.

〔The invention's effect〕

According to the present invention, the gap between the mask and the substrate is directly measured,
Make the gap uniform by the substrate deformation chuck (or
Since a desired gap is provided, high-accuracy, inexpensive, high-throughput proximity exposure can be realized with a simple configuration, and a printed circuit board circuit pattern of 100 μm or less (or a liquid crystal pattern of 10 μm or less, or a sub-μm LSI pattern, etc.) ) Can be obtained.

Further, according to another embodiment of the present invention, since the gap measuring device can be easily calibrated, an error such as an offset of the measuring device is eliminated and a highly accurate mask-substrate gap can be obtained.

Furthermore, according to another embodiment of the present invention, since the lower portions of the four sides of the glass mask can be supported without interfering with the gap measuring device,
Deflection of the mask is reduced (1/3 or less), and control of the gap becomes significantly easier.

Further, according to another embodiment of the present invention, the gap measuring device can be simplified and the measurement range can be reduced to achieve high precision, which is an inexpensive and high precision device.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of the present invention, FIG. 2 is a view showing an exposure of the embodiment of FIG. 1, FIG. 3 is a plan view showing another embodiment of the present invention, and FIG. Is a side view of FIG. 3, FIG. 5 is a sectional view of a gap measuring device according to one embodiment of the present invention, FIG. 6 is a sectional view of a gap measuring device according to another embodiment of the present invention, and FIG. FIG. 8 is a front view of a gap measuring device according to still another embodiment of the invention, and FIG. 8 is a front view showing a conventional example. 5 ... Mask, 8 ... Gap measuring device, 10 ... Gap, 11 ... Substrate, 13 ... Substrate deformation chuck, 14 ... Vertical drive unit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number for FI Technical indication H01L 21/027 (56) Reference JP-A-60-250689 (JP, A) JP-A-49- 105468 (JP, A) Japanese Patent Sho 63-49892 (JP, B2)

Claims (2)

[Claims] 1. An exposure apparatus for exposing and transferring a pattern on a mask onto a substrate, mask holding means for holding the mask, substrate deforming chuck for adsorbing the substrate to partially deform the substrate, and the mask holding device. A mask and a substrate deforming chuck, the mask and the substrate being movably supported so as to be inserted between them in a state of being opposed to each other, and a measuring unit for measuring a gap between the substrate and the mask; and the mask holding unit and the substrate deforming chuck. An exposure apparatus comprising: an up-and-down moving unit that relatively translates vertically. 2. The exposure apparatus according to claim 1, wherein the measuring means is configured to be calibrated when retracted from the gap between the substrate and the mask.