JPH0588533B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a method for forming a micro-gap between an X-ray mask on which a circuit pattern is formed and a substrate to be exposed so that the circuit pattern formed on the X-ray mask can be removed. The present invention relates to an X-ray exposure device that transfers images onto the substrate to be exposed.

[Conventional technology]

The conventional exposure equipment for semiconductor manufacturing is mainly photolithography using ultraviolet rays, but as patterns become finer, X-ray lithography is gaining attention for the purpose of forming (submicron) patterns of 1 μm or less. has been done.

FIG. 5 is a basic configuration diagram of an X-ray exposure apparatus for transferring a mask pattern onto a wafer using X-ray lithography.

The illustrated apparatus includes a wafer chuck 13 for sucking the wafer 1, and a wafer stage 2 for moving the wafer 1 to an exposure position.
A mask chuck 4 that holds the mask 3 with a small gap g between the two, an alignment detection optical system 5 that precisely aligns the wafer 1 with respect to the mask 3, and an inert gas such as He (helium) that does not easily attenuate X-rays. chamber 6, and X
It is composed of a line generator 7.

The X-rays 8 are constructed so that characteristic X-rays generated by accelerating and irradiating a target 11 with an electron beam 10 in a vacuum chamber 9 are extracted from an X-ray extraction window 12.

Unlike conventional photomasks for photorinography, the X-ray mask 3 used for X-ray phosphorography is usually made of a silicon substrate (thickness
(approximately 400 microns) 14 has a thin film 15 of SiN ₄ , BN, or polyimide, and a gold circuit pattern 1.
6 is formed, and then silicon is removed from the back surface by etching. Further, the X-ray mask 3 must be precisely aligned with the optical axis of the alignment detection optical system 5 in advance and fixed to the mask chuck 4. Furthermore, in the X-ray exposure apparatus, it is necessary to replace the X-ray mask 3 every time the exposure circuit pattern changes, so it is necessary to make it easy to attach and detach the mask.

In contrast, conventional devices, for example,
As described in Publication No. 74527, Figure 8,
As shown in FIGS. 9 and 10, the X-ray mask 3
The wafer chuck 13 together with the mask holder 50
Then, the mask chuck 4 is lowered uniformly by the mask up/down mechanism 51 and stopped close to the X-ray mask 3. Then, when the vacuum suction of the wafer chuck 13 is turned off, the X-ray mask 3 is It has been proposed that a so-called wafer stage 2, which is attached to the mask chuck 4 by suction, is used to transport and attach the X-ray mask 3 to the mask chuck 4.

[Problem that the invention seeks to solve]

In the prior art (Japanese Unexamined Patent Publication No. 60-74527), as shown in FIGS. 8, 9, and 10, a new X-ray exposure mask is required each time the circuit pattern to be exposed and transferred onto the wafer changes. 3 is adsorbed together with a mask holder 50 onto a wafer chuck 13 provided on the wafer stage 2, and the X-ray mask 3 is transferred and mounted from the wafer chuck 13 to the mask chuck 4 using the wafer stage 2. It is necessary to collect the X-ray mask 3 out of the wafer stage 13 every time the X-ray mask 3 is replaced.
It is difficult to position and fix the X-ray mask 3 at zero position, making handling of the X-ray mask 3 complicated.
When adsorbing the line mask 3 to the mask chuck 4,
The suction force acts directly on the line mask 3, causing problems such as deforming the pattern and causing scratches and dust to adhere to the pattern surface and back surface.

SUMMARY OF THE INVENTION In order to solve the problems of the prior art described above, an object of the present invention is to improve the overall configuration of an apparatus for exchanging and mounting an X-ray exposure mask from a mask set stage to a mask chuck by mounting and fixing an X-ray exposure mask on a mask holder. An object of the present invention is to provide an X-ray exposure device that is simplified and miniaturized, has an X-ray exposure mask that is easy to handle, does not affect the circuit pattern surface of the X-ray exposure mask, and achieves high-precision X-ray exposure. be.

[Means for solving problems]

In order to achieve the above object, the present invention forms a minute gap between an X-ray mask on which a circuit pattern is formed and a substrate to be exposed, and irradiates the X-ray mask with the circuit pattern formed on the X-ray mask. An X-ray exposure apparatus for transferring images onto a substrate to be exposed, comprising a mask holder having the X-ray mask mounted and fixed in a groove formed on the lower side, and a substrate chuck to be exposed on which the substrate to be exposed is placed by suction. , a stage for the exposed substrate chuck to move the exposed substrate chuck two-dimensionally at least in a horizontal plane, a conveyance means for holding the mask holder from above and conveying it between the mask set stage; A protrusion formed around the lower groove of the mask holder is recessed on the inside for suction and holding, so that the mask holder carrying the X-ray mask carried from the mask set stage is transferred at the pre-alignment position. The substrate is provided with a ring-shaped suction protrusion, and is configured to bring the mask holder suction-held by the ring-shaped suction protrusion from the pre-alignment position to the exposure position by moving the stage of the exposed substrate in at least a horizontal plane. A mask carrier fixed to the side of the exposed substrate chuck on the stage of the exposed substrate, and a mask carrier installed at the clear alignment position for transferring the mask holder from the transport means to the mask carrier, and held by suction on the mask carrier. It has a pre-alignment position detecting means for detecting the pre-alignment position of the X-ray mask fixedly attached to the mask holder and calculating the amount of positional deviation from the reference position, and a driving means for slightly raising and lowering the X-ray mask with respect to the base. correcting the positional deviation amount calculated by the alignment position detection means, and driving the driving means to lower the mask holder brought to the exposure position by the mask carrier by moving the stage of the substrate to be exposed; The mask carrier is brought into contact with the upper surface of the mask holder to release the suction hold by the ring-shaped suction protrusion of the mask carrier to suction hold the mask holder, and the driving means is driven to raise the mask holder to a desired position and attach it to the mask holder. The mask chuck is configured to form the minute gap between the fixed X-ray mask and the substrate to be exposed which is suctioned and placed on the chuck of the substrate to be exposed on the stage of the substrate to be exposed. This is a characteristic X-ray exposure device. Further, in the X-ray exposure apparatus of the present invention, the mask carrier has a rotation drive means for rotating the mask holder held by suction in a horizontal plane with respect to the stage of the substrate to be exposed, and the rotation drive means is arranged in the X-ray exposure apparatus. It is characterized in that it is configured to be driven to correct the amount of positional deviation in the rotational direction among the amount of positional deviation calculated by the pre-alignment position detecting means.

[Effect]

In the present invention, a mask holder with an X-ray mask mounted in a groove formed on the lower side is transported by a transport means from a mask set stage to a mask carrier fixed to a stage of a substrate to be exposed, and the X-ray mask is Since the mask holder with the X-ray exposure mask mounted thereon is passed from the mask carrier to the mask chuck, the overall structure of the apparatus for exchanging and mounting the X-ray exposure mask from the mask set stage to the mask chuck can be simplified and miniaturized, and the X-ray mask can be transferred from the mask carrier to the mask chuck. In addition, high-precision X-ray exposure can be achieved by eliminating the influence on the circuit pattern surface of the X-ray exposure mask without applying direct force to the X-ray mask.

〔Example〕

1 to 4 showing embodiments of the present invention will be described below. FIG. 1 is an explanatory diagram of the overall operation of the mask fitting device according to the present invention, and FIG. 2 is a flowchart showing the operation sequence of the mask fitting device of FIG. 1.
FIG. 3 is a sectional view showing the state in which the mask is attached to the mask chuck at the exposure position, and FIGS. 4a to 4f are explanatory diagrams showing the operation of the mask in the C, D, T, and R positions of FIG. 1.

In FIG. 1, the mask 3 has a V-groove 17 formed on its outer peripheral surface as shown in FIG.
and the pin 1 fastened to the mask holder 18.
9 is engaged with the slope of the head 19a and is fixed to the mask holder 18. This mask holder 18 has a recess 18a large enough to insert the mask 3 and the pin 19, and a ring-shaped projection 18b on the outer periphery of the recess 18a.
From the lower end surface 18c of 8b to the mounting surface 18 of the mask 3
Air passage 18e leading to d and mounting surface 1 of mask 3
Air passage 18g leading from 8d to upper end surface 18f
A through hole 18h for light beams and X-rays is formed in the center.

Although not shown, the wafer stage 2 includes a vacuum chuck that suctions and fixes the wafer 1, and an XY stage and a θ stage that move the wafer 1 in two orthogonal directions (XY direction) and rotational direction (θ direction) on a horizontal plane. and the mask carrier 22 is fixedly installed on the side so that the mask carrier 22 can be positioned at the pre-alignment position. A mask carrier 22 fixed to the side of the wafer stage 2 is composed of a vacuum chuck 22a having a ring-shaped protrusion 22b. That is, this mask carrier 22, together with the wafer stage 2, a vacuum chuck 22a which is movable in the direction and which fixes the mask holder 18 by suction;
An optical microscope 23 is provided with a rotary drive mechanism (not shown) for rotating the vacuum chuck 22a, and detects the pre-alignment position of the mask 3 at a position above the mask 3 which is suctioned and fixed to the vacuum chuck 22a. has been established. The vacuum chuck 22a is connected to the mask holder 1 as shown in FIG.
A ring-shaped protrusion 22b that is in contact with the tip surface 18c of the protrusion 18b of No. 8 is formed, and this protrusion 22b
The air passage 18 of the mask holder 18 on the distal end surface of
An air passage 22c is formed to connect the air passage 22c and the vacuum supply source (not shown).

The reason for providing the rotation drive mechanism is that the rotation center of the mask 3 and the rotation center of the wafer 1 are at different positions, so in order to correct the rotation error of the mask 3 using the θ stage of the wafer stage 2, This is to prevent the need to increase the amount of rotational displacement of the θ stage more than necessary, which would complicate the configuration.

The set stage 20 automatically or manually places the mask 3 fixed to the mask holder 18 in advance at the center of its upper surface, and the apparatus of the present invention starts transporting the mask 3 from this state.

The mask transfer arm 21 has a central axis O ₁ in the vertical direction.
The distal end portion 21a rotates around the center line O ₁ between the upper position of the set stage 20 and the upper position of the mask carrier 22, and is aligned with the vertical center line O ₁ -O ₁ . As shown in FIGS. 4a to 4c, a leaf spring 33 is connected to a drive source (not shown) and is movable in the vertical direction between the and B positions. , a floating chuck 3 fixed to the center of the leaf spring 33 and moving toward and away from the receiver 21b of the tip end 21a.
2 are provided. The floating chuck 32 faces the upper end surface 18f of the mask holder 18 so that its lower end surface approaches and separates from the upper end surface 18f of the mask holder 18, and has an air passage 32a inside that connects the air passage 18g of the mask holder 18 and the vacuum supply source. is forming.

Next, the tilt mechanism 40 shown in FIGS. 4 d to 4 f,
A base 41 is installed at an exposure position, is fixed to an indicating member (not shown), and has a position adjustment mechanism (not shown) in the X, Y, and θ directions, and at least three pieces are fixed in the circumferential direction on the lower end surface of the base 41. When the supports 42 and the ⊥-shaped links 43 swingably supported by the supports 42 are fixed to the base 41 and energized, the tip presses one end of each link 43 downward. a linear motion actuator 44, and a spring 46 whose lower end surface peripheral end is held by the other end of the plurality of links 43 via a ball 45, and which is inserted between the upper end surface and the base 41.
The mask chuck 4 is always pressed downward by the elastic force of
It is composed of two electric micrometers 48. The mask chuck 4 has a through hole 4 in the center.
9, and an air passage 47 connected to the air passage 18g of the mask holder 18 and a vacuum supply source is formed around the air passage 9.

Since the mask mounting device according to the present invention is constructed as described above, its operation will be explained next.

First, the mask 3 fixed to the mask holder 18 is supplied so that its center is located at the A position. The mask transfer arm 21 that is waiting at the upper position lowers and the lower end surface of the floating chuck 32 in its tip 21a is transferred to the mask holder 18.
When it comes into contact with the upper end surface 18f, the inside of the air passage 32a becomes a vacuum, and the suction force causes the mask holder 1 to
The mask 3 is suctioned and fixed together with the mask 8.

After that, the mask transfer arm 21 rises,
When the mask carrier 22 reaches the B position, it rotates in the direction of the arrow C, and the mask carrier 22 moves to the D position, that is, as shown in FIG. 4a.
When the rotation of the mask transfer arm 21 reaches a position where there is a distance h between the lower end surface 18c of the mask holder 18 and the upper end surface of the protrusion 22b formed on the air chuck 22a of the mask carrier 22, Stop.

At this time, the floating chuck 32 holding the mask holder 18 is held horizontally, fixed to the leaf spring 33, and mounted on the receiver 21b, so it can be moved in the horizontal direction, vertical direction, and rotational direction. has been fixed.

Therefore, the mask holder 18 and the mask 3 are prevented from swinging while being transported from the A position to the D position by the mask transport arm 21.

Next, the mask carrier 22 rises together with the wafer stage 2, and as shown in FIG. When the mask carrier 22 rises by an amount H, the leaf spring 33 is bent by an amount H-h, creating a gap between the floating chuck 32 and the receiver 21b of the mask transfer arm 21. Also, the vacuum chuck 22 of the mask carrier 22
The inside of the air passage 22b formed in the air passage 22b becomes a vacuum, and the lower end surface 18c of the mask holder 18 is caused by the suction force and the downward elastic force caused by the bending of the leaf spring 33.
is firmly fixed to the upper end surface of the protrusion 22b of the vacuum chuck 22a. In addition, in this case, mask 3
The circuit pattern surface is located in the space formed by the protrusion 22b of the vacuum chuck 22a to prevent contact.

In this state, as shown in FIG. 4c, when the mask carrier 22 is lowered to its original position together with the wafer stage 2, the leaf spring 33 returns to its original horizontal state and the floating chuck 32 is attached to the receiver 21b of the mask transfer arm 21. The lower end surface is between the upper end surface 18f of the mask holder 18〓h
Separate with.

Note that the vertical movement amount H of the mask carrier 22 is approximately 1 mm, but if the deflection amount H-h of the leaf spring 33 is approximately 0.2 mm, the vertical movement amount H of the mask carrier 22 is sufficient to be 0.5 mm or less. It is.

Thereafter, the optical microscope 23 detects whether the center position of the mask 3 is pre-aligned to the E position. If the center position is misaligned, the It is adjusted and positioned by a rotational drive mechanism.

Next, when the mask carrier 22 moves together with the wafer stage 2 in the directions of the arrows H and D, and the center position of the mask 3 reaches the lower position of the tilt mechanism 40 provided at the H position, that is, the exposure position, the mask carrier 22 moves together with the wafer stage 2. 2
2 rises.

Note that when the mask 3 reaches the hit position, the upper mask chuck 4 has already been positioned in the X, Y, and θ directions, and is tilted in the tilt direction by the linear actuator 44, link 43, and electric micrometer 48 of the tilt mechanism 40. The positioning of the lower end surface and the upper end surface 18 of the mask holder 18 is completed.
There is a distance 〓H + Δh between it and f.

Thereafter, as shown in FIG. 4e, the mask carrier 22 rises by an amount H and comes into contact with the upper end surface 18f of the mask holder 18 and the lower end surface of the chuck 4, changing the output of the linear actuator 44 of the tilt mechanism 40. Pull the tip inward and lower the mask chuck 4 using the elastic force of the spring 46 to remove the mask chuck 4.
The lower end surface of the mask holder 18 and the upper end surface 18f of the mask holder 18 are brought into contact with each other, and the position of the chuck 4 at this time is detected by an electric micrometer 48.

Also, air passages 4 formed in the mask chuck 4
7 is evacuated and the upper end surface 18f of the mask holder 18 is attracted to the lower end surface of the mask chuck 4.

Then, as shown in FIG. 4F, when the mask carrier 22 is lowered together with the wafer stage 2 to its original position, the lower end surface 18c of the mask holder 18 is separated from the upper end surface of the protrusion 22b of the vacuum chuck 22a, resulting in the state shown in FIG. 3. Delivery of mask 3 is completed.

Thereafter, when unloading (recovering) the mask 3, the operation is basically the reverse of the above, so the explanation thereof will be omitted.

As for the mask holder 18, the structure shown in the embodiment described above is only one example, and it goes without saying that any structure that can hold the outer circumference of the mask 3 can be applied.

[Effects of the Invention] According to the present invention, in an X-ray exposure apparatus, a mask holder with an X-ray mask mounted and fixed in a groove formed on the lower side is fixed from a mask set stage to a stage of a substrate to be exposed. The structure is such that the mask holder with the X-ray mask mounted and fixed thereon is transferred to the mask carrier by a conveying means and passed from the mask carrier to the mask chuck, so that the X-ray mask can be transferred from the mask set stage to the mask chuck independently This eliminates the need for a mask loader mechanism, simplifies and downsizes the overall configuration of the device for replacing and mounting X-ray exposure masks, and facilitates handling of the X-ray mask, while allowing direct force to act on the X-ray mask. This has the effect of eliminating the effect on the circuit pattern surface of the X-ray exposure mask and realizing highly accurate X-ray exposure.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the overall operation of the mask mounting device according to the present invention, FIG. 2 is a flowchart showing the operation sequence of the mask mounting device of FIG. 1, and FIG. 3 shows the state in which the mask is mounted on the mask chuck at the exposure position. The cross-sectional views shown in FIGS. 4a to 4f show the masks shown in FIG.
FIG. Fifth
The figure is a sectional view of the basic configuration of the X-ray exposure device, and Figure 6 is the X-ray exposure device.
7 is a sectional view of FIG. 6, and FIGS. 8 to 10 are diagrams showing the operation of transporting and mounting the X-ray mask from the wafer chuck to the mask chuck in a conventional X-ray exposure apparatus. It is. 1...Wafer, 2...Wafer stage, 3...
Mask, 4... Mask chuck, 18... Mask holder, 19... Pin, 20... Set stage, 21... Mask transport arm, 22... Mask carrier, 23... Optical microscope, 32... Floating chuck, 33...Plate spring, 40...Tilt mechanism, 41...Base, 42...Support, 4
3...Link, 44...Linear actuator, 4
5...ball, 46...spring, 48...electric micrometer.

Claims (1)

[Scope of Claims] 1. A micro gap is formed between an X-ray mask on which a circuit pattern is formed and a substrate to be exposed, and the circuit pattern formed on the X-ray mask is transferred to the exposed substrate by irradiation with X-rays. An X-ray exposure apparatus comprising: a mask holder with the X-ray mask mounted and fixed in a groove formed on the lower side; and an exposed substrate chuck on which the exposed substrate is placed by suction; a stage for the substrate to be exposed that moves the chuck two-dimensionally at least in a horizontal plane; a transport means for holding the chuck from above the mask holder and transporting it between the mask set stage; and a transport means for transporting the chuck from the mask set stage to the A ring-shaped suction protrusion with a concave inner side that suctions and holds a protrusion formed around the lower groove of the mask holder so that the mask holder with the transported X-ray mask attached and fixed thereon is delivered at the pre-alignment position. on the stage of the substrate to be exposed so as to bring the mask holder sucked and held by the ring-shaped suction protrusion from the pre-alignment position to the exposure position by moving the stage of the substrate to be exposed at least in a horizontal plane. a mask carrier fixed to the side of the exposed substrate chuck; and a mask carrier installed at the pre-alignment position for transferring the mask holder from the transport means to the mask carrier, and attached and fixed to the mask holder held by suction to the mask carrier. The pre-alignment position detecting means has a pre-alignment position detecting means for detecting the pre-alignment position of the X-ray mask and calculating the amount of positional deviation from the reference position, and a driving means for slightly raising and lowering the base. The driving means is driven to lower the mask holder, which has been brought to the exposure position by the mask carrier by moving the stage of the substrate to be exposed, by correcting the amount of positional deviation calculated in . The mask carrier is brought into contact with the ring-shaped suction protrusion to release the suction holding by the ring-shaped suction protrusion, and the mask holder is suction-held. X characterized in that it is equipped with a mask chuck configured to form the minute gap between a line mask and the substrate to be exposed which is adsorbed and placed on the chuck of the substrate to be exposed on the stage of the substrate to be exposed. Line exposure equipment. 2. The mask carrier has a rotation drive means for rotating the suction-held mask holder in a horizontal plane with respect to the stage of the exposed substrate, and drives the rotation drive means to calculate the pre-alignment position by the pre-alignment position detection means. 2. The X-ray exposure apparatus according to claim 1, wherein the X-ray exposure apparatus is configured to correct the rotational direction positional deviation amount among the positional deviation amounts determined.