JPH0141250B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a semiconductor manufacturing method, and more particularly to an automatic mask-wafer alignment and baking method for automatically aligning a mask and a wafer and baking the wafer.

Conventionally, in this type of method, an unexposed wafer is fed along a straight path, and the mask and wafer are aligned at the next location, followed by moving an alignment device, and after the movement. The process of exposing and printing a mask pattern onto a wafer through a mask and then storing the exposed wafer in a wafer carrier was performed semi-automatically.

Problems to be Solved by the Invention In the prior art described above, alignment and printing are performed in the same place, and during that time, unexposed wafers cannot be supplied and exposed wafers cannot be stored, making mass production of semiconductors inefficient. .

Means and Effects for Solving the Problems According to the automatic mask wafer alignment and baking method of the present invention, at least four mask wafer cassettes are arranged around the circumference of the indexing table. Wafer orientation detection and transfer means are provided at one fixed point around the circumference of the indexing table to receive unexposed wafers, orient them, and supply them to an incoming mask wafer cassette. When the mask wafer cassette receives an unexposed wafer from the wafer orientation detection means, a parallel plate with air holes provided in the center of the upper and lower surfaces is inserted between the mask and the wafer in the mask wafer cassette. air is blown against the mask and wafer to adjust and maintain them parallel to each other at a predetermined distance. From this point, the mask and wafer are aligned with respect to the x and y axes and the rotation angle θ at a point where the indexing table is further rotated by a predetermined angle in a predetermined direction. Following this alignment, the wafer is exposed and printed through a mask between the position where the indexing table is rotated further in a prescribed direction by a prescribed angle and the position where the indexing table is further rotated in a prescribed direction by a prescribed angle. be done. After this, the exposed wafer is stored in an exposed wafer carrier.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1, 2, 3, 4, and 5, one implementation of an automatic mask wafer align and bake apparatus 10 according to the present invention is shown. This device is equipped with an indexing table 12 that performs indexing operations, and five mask wafer cassettes 14 are placed on the indexing table 12 at equal intervals along its circumference.
It is provided in 2. As can be seen in FIG. 4, each mask wafer cassette 14 includes a substantially square cover 141 and a bottom plate 14 with variable spacing.
2, the cover 141 is provided with a circular window 143 that receives exposure from the exposure and printing device 30, a peripheral groove 145 that attracts the glass mask 144 by air flow, and a suction nibble 146 that communicates with this. A wafer mounting plate 147 is provided on the bottom plate 142 .
There is a hemispherical matching part 148 below through and below the matching part 148, and further, below the matching part 148, there is a concave spherical pedestal 149 that complementarily receives the matching part 148. In order to keep these parts in an integrated state, air flow grooves 1
49b, 148a, and 147a, and furthermore, air flow grooves are provided at locations 150, 151, and 152 at the joint between the cover 141 and the bottom plate 142. Reference numeral 153 denotes a screw member in the slot 153a, which loosely connects the cover 141 and the bottom plate 142 via a spring 154. A wafer OF detection unit delivery device 16 is provided around the indexing table 12 near the first point P ₁ (unexposed wafer supply and parallel alignment interval measurement unit) in the space, and an unexposed wafer carrier 18 is provided. The OF (notch edge) of the unexposed wafer received from the wafer is detected, the unexposed wafer is given a predetermined orientation, and the air adsorption type parallel plate 20 is attached to the mask wafer cassette 14 with a built-in mask on the indexing table 12. It is designed to adsorb the wafer and hand over the unexposed wafer. This parallel plate 20
is provided at the position of the wafer OF detection unit delivery device 16, and air holes 20a and 20b are provided in the center of the lower surface. By applying a vacuum, unexposed wafers are attracted to the underside of the wafer, and by inserting the wafer into the mask wafer cassette 14 that has arrived, the wafer is inserted between the mask and the unexposed wafer. Apply compressed air to the top so that the mask and unexposed wafer are completely parallel to each other.
Air is blown out toward the mask and unexposed wafer from air holes 20a and 20b provided in the center of the lower surface. At this time, the mask/wafer/cassette 14 receives pressure from above to push each component of the mask/wafer/cassette downward, and adjusts the hemispherical concave/convex alignment section below the wafer mounting plate 147 to adjust the wafer, mask, and other components. The three members of the parallel plate are placed in a parallel state, and gaps are created between these three members to allow air to flow so that these three members do not come into contact with each other. Thereafter, in order to maintain the parallel state between the three members, the spaces between the concave and convex spherical alignment parts, the wafer and its mounting plate, and the flange part of the spherical pedestal and the bottom plate are vacuum clamped. Once parallelism is achieved, the mask-wafer parallel plate 20 is pulled out from the mask-wafer cassette 14 and stands by at a predetermined position. The perfectly parallel mask-to-wafer spacing is read out and stored by a detection device (not shown).

An alignment microscope 22 and a manipulator 2 are placed at a second point P ₂ (alignment part) in the indexing table 12 rotated 1/5 clockwise from the first point P _{1 .}
4 is provided, which cooperates with the left and right fine adjustment handles 26 for mask/wafer alignment (fine adjustment possible within XY ± 5 mm) and coarse adjustment handles 28 (XY ± 20 mm) for mask/wafer alignment. It is possible to accurately align the x and y axes and rotation angle θ (by controlling the operation of the motor using a switch).

At the center of the indexing table 12, a rotatable exposure section printing device 30 with a built-in mercury lamp is provided, and a cassette arriving from a second point _P2 is exposed through an exposure guide section 30a extending radially outward and downward. For the unexposed wafer, start exposure printing from the third point _P3 in the space rotated 1/5 turn clockwise from the second point _P2 , and further clockwise from the third point. The fourth point P ₄ in the space rotated by 1/5 (exposure end part)
The exposure and printing device 30 continues to perform exposure and printing by rotating together with the wafer until the end of the exposure and printing process, and when the printing is completed at the fourth point _P4 , the exposure and printing device ₃₀ returns to the third point P3.

The wafer after baking is stored in the cassette 14 and moved by the indexing table 12 from the fourth point P ₄ to the fifth point P ₅ (exposed wafer take-out section) in a space 1/5 turn clockwise. rotated to the fifth point
At _P5 , the exposed wafer is transferred to the exposed and printed wafer carrier 32 and stored therein.

Operation First, for the operation of this device, the main power switch, each mechanism function switch, the mask alignment microscope light source power switch, and the mercury lamp light source power switch for exposure and printing are turned on.

(a) Next, turn on each mechanism and function start switch (not shown). Then, the exposed wafer carrier 32 is set at the lowest position and is ready to receive the exposed wafer from above. Further, the unexposed wafer carrier 18 is set at the uppermost position, and the OF detection delivery unit 16 is moved from the lowermost position.
After supplying unexposed wafers, the process goes down one step.
The OF detection/delivery section 16 detects the OF of the supplied unexposed wafer, gives the wafer a proper orientation, and when the mask/wafer cassette 14 of the indexing table 12 comes to the first point _P1 , the wafer is transferred. Prepare to supply.

Mask wafer cassette 14 is the first point
At P ₁ , the OF detection and delivery device 16 attracts the unexposed wafer in the proper orientation to the parallel plate 20 and inserts it into the cassette 14 . Then cassette 1
Pressure is applied to 4 from above to make the mask and wafer parallel to each other with the parallel plate 20 in between.
48 and a concave hemispherical spherical pedestal 149 that receives it.
The angle is adjusted between the spherical surface portion 149b and the spherical surface portion 149b.
A gap is created between the wafer, the mask, and the parallel plate 20 to allow air flow to prevent these three members from coming into contact and being damaged. Next, in order to maintain these three members clamped in a parallel state, between the convex alignment part 148 and the spherical pedestal 149,
Between the wafer and its mounting plate 147, the spherical pedestal 1
Air flow grooves 148a and 149 respectively exist between the flange portion 149d of 49 and the bottom plate 142.
b, 147a, 149e are vacuum-suctioned, and the joint portion 150 of the cover 141 and the bottom plate 142 is
Air flow grooves 151 and 152 (not shown) are also vacuumed. After this, the distance between the mask and the wafer is measured and the value is stored, and the parallel plate 20 is withdrawn from between the mask and the wafer and stopped in position. At this time, the mercury lamp light source lamp house of the exposure and printing device 30 is still at the third point P ₃
The shutter is off. After this, each mechanism, function, coarse movement, and fine movement handle are set to the zero position.

(b) Next, turn on the start switch for each mechanism function. Then, the indexing table 12 rotates 1/5 turn clockwise and stops at the second point _P2 . The clamped cassette of the indexing table 12 is attached to the manipulator section 24 by air suction. Also, at this time, the unexposed wafer is supplied to the OF detection delivery device 16.
Carrier 18 goes down one step. The OF detection delivery device 16 performs OF detection of the supplied unexposed wafer.

After this, as in the case of step (a) above, the wafer for OF detection is inserted into the cassette that has arrived at the first point _P1 by the parallel plate 20, and the parallelism of the mask, the parallel plate 20, and the wafer is established. , the distance between the mask and the wafer is measured and the value is memorized, the mask and wafer positions are held and clamped, and the parallel plate 20 is retreated to its home position.

The Z-axis 24 of the manipulator section 24 is
a increases in accordance with the stored value of the distance between the mask and the wafer obtained in step (a) above, and is stopped at a distance between the mask and the wafer that allows alignment. Then, using the alignment microscope 22, the fine movement stage movement handle 26, coarse movement stage movement handle 28, and θ
The mask and wafer are aligned using an angle adjustment switch (not shown) {Figure 4G}. At this time, each cassette is set at a fixed position between the first point _P1 and the second point _P2 .

Next, the suction of the cassette 14 attached to the manipulator section 24 at the second point _P2 is released, and the cassette 14 becomes ready to be attached to the indexing table 12. Next, the Z-axis 24a of the manipulator section 24 is lowered and the cassette 14 is mounted on the indexing table 12. After the cassette 14 is ejected from the manipulator section 24, the various mechanisms, functions, and stage coarse and fine movement handles are set to the zero position.

(c) Next, turn on the start switch for each mechanism/function. Then, the index table 12 rotates 1/5 turn clockwise and stops. As a result, the manipulator section 24 has the first position of the index table 12.
The cassette 14 at point _P1 is loaded.
On the other hand, a wafer is supplied to the OF detection delivery device 16 from the unexposed wafer carrier 18, and the unexposed wafer carrier 18 is lowered one step.
The OF detection and delivery device 16 detects the OF of the supplied unexposed wafer, and as described above, the unexposed wafer is oriented and attracted to the parallel plate 20 and reaches the mask point _P1 . the wafers are inserted into the wafer cassette 14 and made parallel;
The distance between the mask and the wafer is measured, the value is memorized, the mask is vacuum clamped, and the parallel plate 2
0 retreats to its home position.

A cassette 14 of aligned masks and wafers has arrived at the third position _P3 , and the mercury lamp shutter of the exposure and printing device 30 is opened to begin irradiation.

At the second point _P2 , the Z-axis 24a of the manipulator 24 is raised relative to the cassette 14 mounted on the manipulator 24 by an amount corresponding to the stored value of the distance between the mask and the wafer of the corresponding cassette 14, and the mask and wafer can be aligned. Stops at wafer intervals. Then, using the alignment microscope 22, the mask and wafer are aligned using the fine and coarse movement stage movement handles 26, 28 and the θ angle adjustment switch, and the mask and wafer in the cassette 14 are fixed in a proper positional relationship by pneumatic action. be done. The suction of the cassette 14 mounted on the manipulator section 24 is released, and the cassette 14 becomes ready to be mounted on the indexing table 12. Then, manipulator part 2
The cassette 14 is mounted on the indexing table 12 with the Z-axis 24a of the cassette 14 descending. After the cassette 14 is ejected from the manipulator section 24, the various mechanisms, functions, stage coarse and fine movement handles, etc. are set to the zero position. In this state, the first, second, and third points P1,
At P2 and P3, the cassettes 14 are set in their respective positions.

(d) Next, turn on the start switch for each mechanism function. Then, the index table 12 is rotated 1/5 turn clockwise and then stopped. At this time, the mask wafer cassette 14 that has just arrived from the first point P1 from the indexing table 12 is mounted on the manipulator section 24.

On the other hand, unexposed wafer carrier 18 is OF
The unexposed wafer is supplied to the detection and delivery device 16 and goes down one stage. The OF detection transfer device 16 detects the OF of a received unexposed wafer and provides proper orientation to the wafer. The parallel plate 20 attracts this wafer and supplies the wafer to the cassette 14 at the first point P1, and as in the case described above, the mask and the wafer are made parallel, the distance between them is memorized, and the mask and the wafer are placed in that position. Clamped in a parallel state, the parallel plate 20 moves to the retracted position and stops.

The cassette 14 that has reached the third point P3 is ready for exposure and printing. At this time, the wafers in the cassette 14 rotating from the third point P3 to the fourth point P4, which is shifted clockwise by 1/5 turn from the third point P3, are irradiated by the mercury lamp light source. The shutter is turned off when the set amount of the reset light meter is reached, and the exposure/printing device 30 rotates back to the second point P2 and starts exposing and printing the wafers in the cassette 12 that have arrived there through the mask.

The manipulator unit 2
The Z-axis 24a of No. 4 rises and stops at a distance between the mask and wafer that allows alignment. Alignment microscope 2
2, the mask and wafer are aligned using the coarse movement stage movement handle 28, the fine movement stage movement handle 26, and the θ angle adjustment switch.
As a result, the positions of the masks and wafers in the cassette 14 are fixed by the retained air action. The cassette 14 attached to the manipulator section 24
The suction of the cassette is released, and this cassette is placed on the index table 1.
2 can be installed. Then, the Z-axis 24a of the manipulator section 24 descends to remove the cassette 1.
4 is attached to the indexing table 12. After the cassette 14 is ejected from the manipulator section 24, the various mechanisms, functions, stage coarse and fine movement stage movement handles, etc. are set to the 0 position.

(e) Next, each mechanism/function start switch is turned on. Then index table 1
2 is rotated 1/5 turn clockwise and then stopped.

The cassette 14 of the indexing table 12 is attached to the manipulator section 24.

The unexposed wafer carrier 18 supplies unexposed wafers to the OF detection delivery section 16 and moves down one stage. The OF detection transfer device 16 detects the OF of the supplied unexposed wafer and provides proper orientation to the wafer. The parallel plate 20 attracts the oriented wafer and inserts the wafer into the cassette 14 which has arrived at the first point P1. As before, the mask, wafer and parallel plate 20 are aligned and the spacing between the mask and wafer is measured and stored. The mask and wafer interaction is vacuum clamped and the parallel plates 20 are retracted into position.

At the third point P3, the cassette 14 of the indexing table 12 becomes ready for exposure and printing. The cassette 12, which had previously been at the third point P3, moves to the fourth point P4 while being irradiated with the mercury lamp, and when the set amount of the reset light meter is reached, the shutter is turned off. The light source of the exposure and printing device 30 is a second light source.
The camera rotates back to point 3, and begins exposure printing on the cassette that reaches that point. Also, the fourth point P
The exposed and baked wafers in the cassette 14 rotated from the fourth point P4 to the fifth point P5, which is 1/5 rotation clockwise from 4, are exposed and baked as the cassette 14 rotates on the indexing table 12. Wafer
The discharge port is directed toward the carrier 32, and the exposed and baked wafer is transferred to and stored in the exposed and baked wafer carrier 32.

The Z-axis 24 of the manipulator section 24 is
a rises by an amount corresponding to the measured and stored value of the distance between the corresponding mask and wafer, and stops at the mask-to-wafer distance that allows alignment. Alignment microscope 2
2. Fine movement, coarse movement stage movement handle 26, 2
8. The mask and wafer can be aligned using the θ angle adjustment switch. After this, the second point P2
The positions of the masks and wafers in the cassette 14 are maintained and fixed by air action. The suction of the cassette 14 attached to the manipulator section 24 is released, and the cassette 14 is attached to the indexing table 12.
It is now ready to be installed. Next, the Z-axis 24a of the manipulator section 24 descends to the indexing table 12.
The cassette 14 is then loaded. After the cassette is ejected from the manipulator section 24, the various mechanisms, functions, coarse and fine movement stage movement handles, etc. are set to the zero position.

In this state, the first, second,
3, 4, 5 points P1, P2, P3, P4, P
The cassettes are set at five fixed points.

Although the alignment device described above is shown as being manually performed using a microscope, full automation of the device can be achieved by incorporating a known automatic alignment device. In addition, a single television screen is provided in place of the alignment microscope 22, and a plurality of these devices can be controlled by a computer, allowing an operator to remotely control the alignment of masks and wafers in a time-division centralized control mode. .

Effects of the invention As is clear from the above, according to this invention,
Supply of unexposed wafers, OF detection, insertion of parallel plates,
Positioning of x, y, θ, etc., printing, etc. are all performed sequentially, and there is no idle work during each process, so operations are performed automatically and efficiently, and cassettes are placed sequentially around the table. This made the entire device more compact.

[Brief explanation of drawings]

Fig. 1 is a simplified plan view of the apparatus used in the automatic mask/wafer aligning and baking method of the present invention, Fig. 2 is a front view, Fig. 3 is a side view, Fig. 4 is A, B, C,
D is a plan view of the mask, wafer, and cassette, respectively.
4G is a compressed view of the elements in B; FIG. 4E is a bottom view of the mask/wafer cassette; FIG. 4F is a view in the direction of arrow F in FIG. 4E. 5A is a plan view of the parallel plate, FIG. 5B is a side view taken in the direction of arrow B in FIG. 5A, and FIG. 5C is a side view of the parallel plate in use. 10... Automatic alignment and printing device, 12... Indexing table, 14... Mask/wafer/cassette, 16... OF detection unit delivery device, 18... Unexposed wafer/cassette, 20... Mask/wafer parallel Plate, 22... Alignment microscope, 24...
Manipulator unit, 26... Fine movement stage movement handle for mask/wafer alignment, 28... Coarse movement stage movement handle for mask/wafer alignment, 30... Exposure and printing device, 30a... Exposure guide section, 32... Exposure Baked wafer carrier, 3
4...Equipment power supply pneumatic control box, 3
6...Device control switch section, 38...
Light source lamp for alignment microscope, 147b... Air flow groove.

Claims (1)

[Scope of Claims] 1. On the outer periphery of an indexing table that rotates intermittently at predetermined angles, the first to nth
At least four mask wafer cassettes are arranged, and at the positions corresponding to each of the mask wafer cassettes when the rotation of the indexing table is stopped, unexposed wafer supply and parallelization interval measuring units, Alignment section, exposure section,
Exposed wafer take-out sections are provided in sequence along the rotational direction of the indexing table, and in the unexposed wafer supply and parallelization interval measurement section, the unexposed wafer is removed from the unexposed wafer carrier by the wafer orientation detection and delivery means. After receiving the wafer and determining its orientation, it is inserted into the rotating mask/wafer cassette into the unexposed wafer supply parallel alignment interval measuring unit, and the mask in the mask wafer cassette is connected to the unexposed wafer. Blowing out compressed air from an air hole provided in a parallel plate inserted between them, and positioning and maintaining the mask and the unexposed wafer parallel to each other at a predetermined interval using the compressed air, and in the alignment section. , aligning the X and Y axes and the rotation angle θ with the mask and the unexposed wafer kept parallel and at a predetermined distance in the mask wafer cassette; The exposed mask and the unexposed wafer are baked and exposed in a predetermined pattern in a mask wafer cassette, and the exposed wafer that has been subjected to the baking is taken out from the mask wafer cassette in the exposed wafer take-out section. , exposed wafer
An automatic mask/wafer aligning and baking method characterized in that the mask/wafer is stored in a carrier.