JP2000133578A - Aligner and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly and uniformly attain cleaning of a substrate holding face without deteriorating the level of cleaning in a device, without recouse to an operator, or requiring large occupancy area. SOLUTION: This aligner exposes and transfers the pattern of an original plate to a thin plate-shaped substrate to which a photo-resist is applied which is sucked and held on a substrate holding face 4a provided on a movable table 4. The aligner is provided with a grinder pressurizing means 14 provided in the neighborhood of the movable table for detachably holding a grinder 13 for cleaning the substrate holding face, and for pressurizing the grinder to the substrate holding face with a prescribed force, carrying means 10 and 12 for carrying the grinder in a state that the grinder is housed in a prescribed container for supplying the grinder to the grinder pressurizing means and for collecting the grinder, and movable table controlling means for driving the movable table so that the whole region of the substrate holding face can be cleaned by the grinder pressurized by the grinder pressurizing means. A substrate-carrying means for supplying the substrate on the substrate-holding face and for collecting the substrate is used as the carrying means and a container for holding the grinder, so that the cleaning face of the grinder can be almost sealed is used as the container.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus for holding a substrate such as a semiconductor wafer on a movable table and performing a desired process, and a device manufacturing method using the same.

[0002]

2. Description of the Related Art In a semiconductor exposure apparatus for transferring a reticle pattern by adsorbing and holding a thin plate-like substrate such as a semiconductor wafer coated with a photoresist on a movable table, dirt and dust adhere to the substrate holding surface of the movable table. Then, it is known that the held substrate is contaminated, or the portion sandwiching dust is locally deformed, thereby lowering the yield and processing quality. The holding surface needs to be cleaned.

Conventionally, the cleaning of the substrate holding surface has been performed by
This has been done manually by rubbing a substrate holding surface with a grindstone or wiping it with a clean cloth impregnated with a solvent.

[0004]

However, even cleaning of the substrate holding surface by hand requires skill, and the quality of the work varies depending on the skill and the work of the worker. Spend time and reduce equipment availability. Further, since a maintenance area for cleaning is provided even on the structure of the apparatus, there is a problem that the floor area and occupied area of the apparatus increase. further,
In a mini-environment environment represented by SMIF in recent years, opening the door of the apparatus and working itself is a factor that lowers the cleanliness in the apparatus, and is becoming unacceptable.

Accordingly, a first object of the present invention is to make it possible to uniformly clean the substrate holding surface in a short time without the skill of an operator. A second object of the present invention is to make it possible to clean the substrate holding surface without lowering the cleanliness in the apparatus. This ultimately provides an exposure apparatus with a small occupied area that does not require a maintenance area for cleaning.

[0006]

In order to achieve the above object, an exposure apparatus according to the present invention comprises a thin plate-shaped substrate coated with a photoresist held by suction on a substrate holding surface provided on a movable table. In an exposure apparatus for exposing and transferring a pattern, provided in the vicinity of the movable table, grindstone pressing means for detachably holding a grindstone for cleaning the substrate holding surface and pressing against a predetermined force on the substrate holding surface, The entire surface of the substrate holding surface is cleaned by a conveying unit that conveys the whetstone while being stored in a predetermined container for supplying and collecting the whetstone to the whetstone pressing unit, and a whetstone pressed by the whetstone pressing unit. Movable table control means for driving the movable table as described above. According to this, the substrate holding surface is uniformly cleaned in a short time regardless of the skill of the operator, and the grindstone is transported while being stored in the container. Is prevented.

In the device manufacturing method of the present invention, the exposure apparatus is used to perform exposure while appropriately cleaning the substrate holding surface on the movable table by the grindstone pressing means and the movable table control means. Manufacturing a device. This allows
Device manufacturing is performed while efficiently preventing yield and quality deterioration.

[0008]

In a preferred embodiment of the present invention, the transfer means is a substrate transfer means for supplying and collecting the substrate on the substrate holding surface. The container has a thin plate-like shape for receiving the cleaning surface for cleaning by contacting with the substrate holding surface of the grinding wheel so as to substantially seal the cleaning surface. In addition, a magnetic material is attached to a surface of the whetstone opposite to the cleaning surface, and an electromagnet is provided on the whetstone pressing means. The whetstone pressing means is energized or de-energized of the electromagnet. Thus, the grindstone is detachably held.

Further, there is provided a relay means provided on the movable table for supplying and recovering the grinding stone, and the relay means has a relay member. When the grinding stone is supplied, the relay member is relatively moved. Protruding above the substrate holding surface, receiving the container containing the grindstone carried by the carrying means, and burying the relay member below the substrate holding surface when cleaning the substrate holding surface; When collecting, the relay member is projected above the substrate holding surface, and the grindstone pressing means removes and holds the grindstone from the container held on the relay member when the grindstone is supplied, When the grindstone is collected, the grindstone is returned to the container held on the relay member. The transporting unit retracts the empty container on the relay member when cleaning the substrate holding surface, and returns the retracted container to the relay member again when collecting the grindstone.

The relay means is a board relay means for transferring the substrate to the substrate holding surface. The whetstone pressing means is disposed above a movable range of the movable table,
The grindstone is moved along an axis perpendicular to the substrate holding surface and pressed against the substrate holding surface. Further, the apparatus has an insertion port for introducing a storage cassette for supporting and positioning the container storing the grinding stone at a predetermined position for transferring the container to the transfer means into the apparatus. If the outer shape of the container is substantially the same as the substrate, the container can be transported along the same route as the substrate.

According to this, the movable table is moved so as to evenly hit the entire surface of the substrate holding surface while pressing the grindstone held by the grindstone pressing means provided above the movable range of the movable table with a predetermined pressing force. Since all points where the grinding stone comes into contact have the same relative speed with respect to the grinding stone, the entire surface of the substrate holding surface can be uniformly cleaned. Further, since the whetstone is held and transferred by the substrate transfer means and the substrate relay means, a maintenance area for cleaning the substrate holding surface is not required, and the apparatus configuration can be minimized. Furthermore, when the grindstone is transported, the grindstone is housed in a thin dish-shaped container, so that vacuum suction can be performed during transport, and dust can fall off when the grindstone is transported after cleaning, and the transport means and substrate relay means can be used. Does not adhere to In addition, since an introduction port for introducing a grindstone storage cassette for supporting and positioning the grindstone into the exposure apparatus is provided on the outer wall of the exposure apparatus, it is possible to supply and collect the grindstone without opening the exposure apparatus cover. A reduction in cleanliness in the device due to the environment is prevented.

[0012]

1 and 2 are a plan view and a front view of an exposure apparatus according to a first embodiment of the present invention. Thus, the configuration of the apparatus will be described. 1 is a semiconductor wafer, 2 is an anti-vibration mount for supporting an exposure apparatus, 3 is a surface plate on the anti-vibration mount 2,
Reference numeral 4 denotes a movable table provided on the base 3, reference numeral 4a denotes a wafer holding surface on the movable table 4, reference numeral 5 denotes a substrate relay pin provided on the wafer holding surface 4a, reference numeral 6 denotes a projection lens for exposure, and reference numeral 6a.
Is a projection lens support that supports the projection lens 6, 7 is a reticle having an exposure pattern, 7a is a reticle holding table that holds the reticle 7, 8 is an illumination system that illuminates the reticle 7,
9 is a wafer cassette mounting table, 9a is a grindstone cassette positioning pin provided on the wafer cassette mounting table 9, 10 is a first wafer transfer hand, 11 is a wafer pre-alignment unit, 12 is a second wafer transfer hand, 13 Is a whetstone, 1
Reference numeral 4 denotes a grindstone pressing means, and reference numeral 15 denotes a chamber for keeping the entire apparatus clean.

FIGS. 3A and 3B are a plan view and a sectional view of the grindstone 13 and its tray. The grindstone 13 comprises a grindstone lower plate 20 made of alumina ceramic having a cleaning surface 20a, and a grindstone upper plate 21 made of a magnetic material having a positioning hole 21a for engaging and positioning the grindstone pressing means 14. Has a recess 22a for fitting the outer diameter of the grinding wheel lower plate 20 to drop the cleaning surface 20a, and a canning hole 22b for positioning the cleaning surface 20a with a grinding wheel cassette described later.

FIG. 4 shows a state in which the grinding wheel 13 is held and the wafer holding surface 4 is held.
FIG. 4 is a structural diagram of a whetstone pressing means 14 that moves along an axis perpendicular to a and presses the whetstone 13 against a wafer holding surface 4a with a predetermined pressing force. At the tip of the piston shaft 30a of the air cylinder 30, there is provided a grindstone engaging portion 31 having a mating pin 31a for engaging with the grindstone 13 and an electromagnet 32 for holding the grindstone 13 by suction. A positive pressure air inlet 30b for urging the piston shaft 30a downward with a predetermined force is provided.
A spring 30c for urging the piston shaft 30a upward is formed inside the inside. A predetermined pressure is applied to the grindstone 13 by introducing air of a predetermined pressure into the positive-pressure air inlet 30b to move the piston shaft 30a downward, and the inlet 30b is opened to the atmosphere, whereby the spring 30c is released.
Causes the piston shaft 30a to move upward. Further, the grindstone 13 is held by energizing the electromagnet 32, and is released by deenergizing the electromagnet 32.

FIGS. 5A and 5B are a front view and a rear view of a grindstone cassette 40 for placing a tray 22 containing a grindstone 13 on a placing table 9 for placing a wafer cassette. is there. The cassette 40 is provided with two-stage shelves 40a and 40b for accommodating the tray 22.
0a is provided with a pin 40c which engages with a mating hole 22b provided on the tray 22 to determine the position of the tray 22, and a positioning pin 9a provided on the wafer cassette mounting table 9 is provided on the lower surface of the cassette 40. And a can mating hole 40d for determining the position.

First, the operation of transferring a reticle pattern onto a wafer will be described. A wafer 1 in the wafer cassette (not shown) on the wafer cassette mounting table 9 is detected by a wafer presence / absence detection sensor (not shown), and the wafer cassette mounting table 9 is moved up and down by an unshown elevating means based on the detected information.
The wafer 1 is taken out of the wafer cassette by the first transfer hand 10 and transferred to the pre-alignment unit 11. The pre-alignment unit 11 detects the amount of displacement of the wafer 1 by a sensor (not shown), and positions the wafer 1 by a positioning unit (not shown). The wafer 1 positioned by the pre-alignment unit 11 is transferred by the second transfer hand 12 onto the substrate relay pins 5 fixed on the movable table 4 at the wafer supply position and protruding above the wafer holding surface 4a. The wafer 1 held on the substrate relay pins 5 is moved up and down by a not-shown substrate holding surface 4a.
Is lifted so as to be slightly higher than the board relay pin 5 and is held on the board holding surface 4a.

Next, the movable table 4 moves from the wafer supply position to the first shot exposure position, and aligns the wafer 1 with the image plane of the projection lens. Here, the reticle 7 held on the reticle holding table 7 a is illuminated by the illumination system 8, and the reticle pattern is transferred onto the wafer 1 by the projection lens 6.
Thereafter, exposure is performed while moving the movable table 4 according to a predetermined shot layout, and after all the exposures are completed, the movable table 4 is moved to the wafer collecting position, and the wafer holding surface 4a is lowered. The wafer 1 supported on the wafer relay pins 5 is collected by the first transfer hand 10 and stored in the wafer cassette. At this time, the grindstone pressing means 14 is at the upper position, and does not hinder the above operation.

Next, the operation for cleaning the wafer holding surface will be described with reference to the flowchart of FIG. When the cleaning process is started by placing the grindstone cassette 40 in which the tray 22 on which the grindstone 13 is placed in the shelf 40a on the wafer cassette mounting table 9 and instructing the start of cleaning from an operation panel (not shown), the cleaning process is started. The presence / absence of the grindstone 13 and the tray 22 and the mounting position are detected by the wafer presence / absence detection sensor (step S1), and it is determined whether or not the wafer is at a normal position (that is, on the shelf 40a) (step S2). Here, when an abnormality is detected, a warning is issued to the operator so that the grindstone 13 and the tray 22 are repositioned at the proper positions (step S3).

If the result of the determination in step S2 is normal, the wafer cassette mounting table 9 is raised and lowered by a lifting means (not shown) (step S4). The wafer is taken out and placed on the substrate relay pins 5 on the movable table 4 at the wafer collection position (Step S5). Next, after the tray 22 is vacuum-sucked by the substrate relay pins 5, the movable table 4 is moved below the grindstone pressing means 14 (Step S).
6). Here, positive pressure air is introduced into the cylinder 30 of the grinding wheel pressing means 14 to push down the piston shaft 30a,
The grinding wheel 13 is engaged with the grinding wheel 13, and the electromagnet 32 is energized to attract and hold the grinding wheel 13 by its magnetic force (step S7). Here, in order to collect the empty tray 22, the cylinder 30 is opened to the atmosphere and the grinding wheel engaging portion 31 is opened.
Is moved upward (step S7), the movable table 4
Is moved to the wafer collection position (step S8), and the tray 22 is collected by the first transfer hand 10 (step S8).
9).

The movable table 4 is again moved to the grindstone pressing means 1.
4 (step S10), the substrate holding surface 4a is lifted by a substrate holding surface elevating means (not shown) so as to be slightly above the substrate relay pins 5 (step S11), and positive pressure air is introduced into the cylinder 30. And grinding wheel 13 and substrate holding surface 4
a is brought into contact (step S12). In this state, the movable table 4 is moved two-dimensionally, and the grinding wheel 13 is evenly applied to the entire surface of the substrate holding surface 4a to clean the substrate holding surface 4a (step S13).

After the cleaning is completed, the cylinder 30 is opened to the atmosphere to lift the grindstone 13 (step S1).
5) The substrate holding surface 4a is lowered (Step S16), and the movable table 4 is moved to the wafer collection position (Step S1).
7) The empty tray 22 is placed on the board relay pins 5 from the first transport hand 10 (Step S18). After moving the movable table 4 to the grinding wheel engagement position (Step S19), positive pressure air is introduced into the cylinder 30 to
Is placed on the tray 22, the electromagnet 32 is de-energized and the holding force of the grindstone engaging means 31 is lost, and then the cylinder 30 is released to the atmosphere to move the grindstone engaging means 31 upward (step S20). . Finally, the movable table 4 is moved to the wafer collection position (step S21), and the first transfer hand 1
0, the tray 22 is moved to the shelf 40b on the grindstone cassette 40.
And the cleaning process is completed (steps S22 to S24).

Here, it seems that the electromagnet 32 serving as the holding means of the grinding wheel 13 provided on the grinding wheel pressing means 14 may be omitted, but the positive pressure air serving as the driving source of the grinding wheel pressing means 14 is used during cleaning. The purpose of preventing the grinding wheel 13 and the grinding wheel engaging means 31 from being disengaged when it is down,
The electromagnet 32 is necessary in order to keep a clean grindstone at all times so that it can be cleaned at any time.

Next, a second embodiment will be described. FIG.
FIG. 4 is a plan view of a semiconductor exposure apparatus according to a second embodiment.
The difference from the first embodiment is that there is no wafer cassette mounting table 9 and instead a front open type SMIF
Opening / closing means 50 is provided. The wafer is supplied by the SMIF box 51. Therefore, the whetstone cassette 4
SM with built-in grindstone support shelf 52 having the same function as
The grindstone 13 is supplied to the semiconductor exposure apparatus by the IF box 51.

<Embodiment of Device Manufacturing Method> Next, an embodiment of a device manufacturing method using the above-described exposure apparatus will be described. FIG. 8 shows a flow of manufacturing micro devices (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, thin-film magnetic heads, micromachines, etc.). In step 1 (circuit design), a device pattern is designed. Step 2 is a process for making a mask on the basis of the designed pattern. On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon or glass.
Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer. The next step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer produced in step 4, and includes an assembly process (dicing and bonding).
It includes steps such as a packaging step (chip encapsulation). In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device manufactured in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7).

FIG. 9 shows the wafer process (step 4).
The detailed flow of is shown. Step 11 (oxidation) oxidizes the wafer's surface. Step 12 (CVD) forms an insulating film on the wafer surface. Step 13 (electrode formation) forms electrodes on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. In step 15 (resist processing), a resist is applied to the wafer. Step 16 (exposure) uses the above-described exposure apparatus or exposure method to align and print the circuit pattern of the mask on a plurality of shot areas of the wafer.
Step 17 (development) develops the exposed wafer.
In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), unnecessary resist after etching is removed. By repeating these steps,
Multiple circuit patterns are formed on the wafer.

By using the production method of this embodiment, it is possible to produce a large-sized device, which was conventionally difficult to produce, at low cost.

[0027]

As described above, according to the present invention, the movable table can be moved so that the whetstone held by the whetstone pressing means is evenly hit on the entire substrate holding surface while being pressed with a predetermined pressing force. Therefore, every point where the grinding wheel contacts has the same relative speed to the grinding wheel,
It is possible to evenly clean the entire surface of the substrate holding surface. Therefore, the substrate holding surface can be uniformly cleaned in a short time without depending on the skill of the operator. Also,
Since the whetstone is held and transferred by the substrate transfer means and the substrate relay means, a maintenance area for cleaning the substrate holding surface is not required, and the apparatus configuration can be minimized. Furthermore, when the grinding wheel is transported, it is placed on a container such as a tray-shaped tray that supports the cleaning surface in a substantially hermetically sealed manner and transported, thereby enabling vacuum suction at the time of transporting, and after cleaning is completed. No dust adheres to the cleaning surface when the grindstone is transported, and does not adhere to the transport means and the substrate relay means. Further, by providing an introduction port for introducing a grindstone storage cassette for supporting and positioning the grindstone into the exposure apparatus on the outer wall of the exposure apparatus, it becomes possible to supply and collect the grindstone without opening the exposure apparatus cover, It is possible to prevent a decrease in cleanliness in the apparatus due to an external environment.

[Brief description of the drawings]

FIG. 1 is a plan view of a semiconductor exposure apparatus according to a first embodiment of the present invention.

FIG. 2 is a front view of the apparatus of FIG.

FIG. 3 is a plan view and a sectional view of a grindstone and a tray of the apparatus of FIG. 1;

FIG. 4 is a structural view of a grindstone pressing means of the apparatus of FIG. 1;

FIG. 5 is a plan view and a sectional view of a grindstone cassette of the apparatus of FIG. 1;

FIG. 6 is a flowchart of a cleaning procedure by the apparatus of FIG. 1;

FIG. 7 is a plan view of a semiconductor exposure apparatus according to a second embodiment of the present invention.

FIG. 8 is a flowchart illustrating a device manufacturing method that can use the exposure apparatus of the present invention.

FIG. 9 is a detailed flowchart of a wafer process in FIG. 8;

[Explanation of symbols]

1: semiconductor wafer, 2: anti-vibration mount, 3: surface plate, 4:
Movable table, 4a: wafer holding surface, 5: substrate relay pin, 6: projection lens, 6a: projection lens support, 7: reticle, 7a: reticle holding, 8: illumination system, 9: wafer cassette mounting, 9a ： Positioning pin for whetstone cassette,
10: first wafer transfer hand, 11: pre-alignment unit, 12: second wafer transfer hand, 13: whetstone, 1
4: grinding wheel pressing means, 15: chamber, 20: grinding wheel lower plate, 20a: cleaning surface, 21: grinding wheel upper plate, 21
a: positioning hole, 22: tray, 22a: depression, 22
b: perforated hole, 30: air cylinder, 30a: piston shaft, 30b: positive pressure air inlet, 30c: spring, 3
1: grinding wheel engaging portion, 31a: canning pin, 32: electromagnet,
40: whetstone cassette, 40a, 40b: shelf, 40c:
Pin, 40d: perforated hole.

Claims (10)

[Claims] An exposure apparatus for exposing and transferring a pattern of an original plate onto a thin substrate coated with a photoresist that is suction-held on a substrate holding surface provided on a movable table is provided near the movable table. A grindstone pressing means for detachably holding a grindstone for cleaning the substrate holding surface and pressing the grindstone against the substrate holding surface with a predetermined force, and a predetermined grindstone for supplying and collecting the grindstone to the grindstone pressing means. A transporting unit for transporting the whetstone in a state housed in a container; and a movable table control unit for driving the movable table so that the entire substrate holding surface is cleaned by the whetstone pressed by the whetstone pressing unit. An exposure apparatus comprising: 2. The exposure apparatus according to claim 1, wherein the transfer unit is a substrate transfer unit for supplying and collecting the substrate on the substrate holding surface. 3. The grinding wheel according to claim 1, wherein the container houses the grinding stone so as to substantially seal a cleaning surface for cleaning by contacting the substrate holding surface of the grinding stone. Exposure apparatus according to the above. 4. A magnetic material is attached to a surface of the whetstone opposite to the cleaning surface, and an electromagnet is provided on the whetstone pressing means. The exposure apparatus according to any one of claims 1 to 3, wherein the whetstone is detachably held by non-energization. 5. A relay device provided on the movable table for supplying and collecting the grinding wheel, the relay device having a relay member, and the relay member is relatively moved when the grinding stone is supplied. Protruding above the substrate holding surface, receiving the container containing the grindstone carried by the carrying means, and burying the relay member below the substrate holding surface when cleaning the substrate holding surface; When collecting, the relay member is projected above the substrate holding surface, and the grindstone pressing means removes and holds the grindstone from the container held on the relay member when the grindstone is supplied, The exposure apparatus according to any one of claims 1 to 4, wherein the whetstone is returned into the container held on the relay member when the whetstone is collected. 6. The cleaning device according to claim 1, wherein the transport unit retracts the empty container on the relay member when cleaning the substrate holding surface, and returns the retracted container to the relay member when recovering the grindstone. 6. The exposure apparatus according to claim 5, wherein the exposure apparatus is an apparatus. 7. The exposure apparatus according to claim 5, wherein the relay unit is a substrate relay unit for transferring the substrate to the substrate holding surface. 8. The whetstone pressing means is disposed above a movable range of the movable table, and moves the whetstone along an axis perpendicular to the substrate holding surface and presses the whetstone against the substrate holding surface. The exposure apparatus according to claim 1, wherein: 9. An apparatus according to claim 1, further comprising an insertion opening for introducing a storage cassette for supporting and positioning the container storing the grinding stone at a predetermined position for transferring the container to the transfer means into the apparatus. The exposure apparatus according to any one of claims 1 to 8. 10. A device is obtained by performing exposure while appropriately cleaning the substrate holding surface on the movable table by the whetstone pressing means and the movable table control means using the exposure apparatus according to claim 1. A device manufacturing method characterized by manufacturing.