JPH07130638A - Semiconductor manufacturing equipment - Google Patents

Abstract

PURPOSE:To eliminate the detaching or a substrate retainer from equipment, avoid the possibility that foreign matter is taken in the part between the substrate retainer and the fixing part member thereof, and reduce the pause period of an equipment caused by the cleaning work. CONSTITUTION:In a semiconductor manufacturing equipment provided with a semiconductor transfer means 7, a substrate retainer 9, and an X-Y stage 8, the semiconductor transfer means transfers a substrate 15 for cleaning of the substrate retainer wherein cleaning function is constituted on the lower surface, to a specified position, and fixes the substrate almost in the horizontal plane. The X-Y stage moves the substrate retainer to a part below the substrate for cleaning, and moves the substrate retainer up and down in a manner in which the surface of the substrate retainer comes into contact with the lower surface of the substrate for cleaning under a specified pressure. In order that the surface of the substrate retainer may be cleaned by the substrate for cleaning the substrate retainer is moved in the horizontal plane for specified movement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus such as an exposure apparatus and an inspection apparatus for processing a semiconductor substrate in a semiconductor manufacturing process.

[0002]

2. Description of the Related Art As the miniaturization of semiconductor elements progresses, defects are generated in semiconductors due to foreign matter adhering to the back surface of a semiconductor substrate such as a wafer or contamination of a wafer chuck, and productivity is remarkably reduced. . Therefore, in the semiconductor manufacturing process, in order to prevent foreign matter from adhering to the back surface of the semiconductor substrate, measures such as cleaning called back rinse are taken, and on the manufacturing apparatus side, the shape and material of the chuck are improved, We have taken measures to prevent foreign matter from adhering,
Since the back side of the semiconductor substrate is handled during transportation,
At present, no complete preventive measures have been found.

In the processing of a semiconductor substrate, most of the foreign substances attached to the wafer chuck of the exposure apparatus are a part of the photosensitizer (photoresist) which is attached and carried to the back surface of the semiconductor substrate and remains on the chuck. , Thought to be a solid one. In addition to this, the volume of floating dust in the atmosphere in which the device is placed can be considered, but in the case of floating dust,
It can be easily wiped off with a cleaning agent or solvent dipped in dust-free paper. Therefore, a particular problem in the semiconductor manufacturing process is that the solidified photosensitizer described above adheres to the chuck,
This is something that cannot be removed by normal cleaning work.
In order to remove the solid foreign matter adhering to the chuck, it has to be scraped off with a tool having a sharp edge. However, the use of a knife having a knife edge, a file, or the like may cause damage to the surface of the wafer chuck that requires a plane accuracy of the order of 0.1 μm or deteriorate the surface accuracy. For this reason, when cleaning a wafer chuck, a special tool with a lot of sharp edges is formed on a flat plate having a surface accuracy similar to that of the wafer chuck. Is used to scrape off foreign matter adhering to the surface of the chuck by rubbing them together.

[0004]

At present, in the semiconductor manufacturing process, the substrate holding means (chuck) is regularly (or irregularly) detached from the apparatus, and the cleaning work is performed by this method. However, in this method, when the chuck is attached or detached, there is a risk that a secondary obstacle such as a foreign substance being caught between the chuck and the substrate holding means fixing member (chuck fixing member) is generated. There was a problem that the device had to be stopped for a certain period of time due to problems such as temperature stabilization of the device.

In view of the problems of the prior art, an object of the present invention is to provide a mechanism for automatically cleaning a substrate holding means such as a chuck in a semiconductor manufacturing apparatus by the semiconductor manufacturing apparatus itself. And the control device to automatically perform the determination so that the device quantitatively determines whether or not the cleaning that was conventionally performed by the operator is performed, and the substrate holding means is detached from the device. The object is to eliminate the risk of foreign matter being caught between the substrate holding means and the substrate holding means fixing member, and to minimize the downtime of the apparatus due to the cleaning work.

[0006]

In order to achieve this object, according to the present invention, a semiconductor substrate carrying means for carrying a semiconductor substrate and placing it at a predetermined position, and a semiconductor substrate carried and placed by the semiconductor substrate carrying means. In a semiconductor manufacturing apparatus provided with a substrate holding means for adsorbing and fixing, and an XY stage for moving the substrate holding means to a predetermined position, the semiconductor substrate carrying means is a substrate holding means for cleaning the lower surface of the substrate holding means. A function of transporting the cleaning substrate to a predetermined position and fixing it in a horizontal plane or fixing it in parallel with the surface of the substrate holding means, and detecting a horizontal force acting on the cleaning substrate. The XY stage moves the substrate holding means below the cleaning substrate fixed by the semiconductor substrate carrying means. Moving the substrate holding means up and down so that the surface of the substrate holding means and the lower surface of the cleaning substrate come into contact with each other at a constant pressure, and the surface of the substrate holding means is cleaned by the cleaning substrate. Thus, it is characterized in that it is moved so as to perform a predetermined movement in a horizontal plane or in a plane parallel to the surface of the substrate holding means.

Here, the semiconductor substrate transfer means is, for example,
A mechanism for moving the cleaning substrate in the vertical direction and a mechanism for recognizing the moving position are provided, or a means for detecting a force acting on the cleaning substrate in the vertical direction is provided, and based on the output signal thereof. It is provided with a control means and the moving mechanism for bringing the lower surface of the cleaning substrate into contact with the surface of the substrate holding means in the vertical direction at a constant contact pressure with a constant contact pressure. The semiconductor substrate carrying means also has means for detecting a contact pressure between the lower surface of the cleaning substrate and the surface of the substrate holding means, and XY
The stage may move and position the substrate holding means in the vertical direction so that the lower surface of the cleaning substrate and the surface of the substrate holding means come into contact with each other at a constant pressure.

The XY stage has a mechanism for moving the substrate holding means to a predetermined position and positioning it, so that the vertical contact pressure between the lower surface of the cleaning substrate and the surface of the substrate holding means can be selected. You may

The cleaning substrate is, for example, contained in the same container as the semiconductor substrate, or is accommodated in a position different from the semiconductor substrate, and the semiconductor substrate transfer means moves from the position to the above-mentioned position. The cleaning substrate is automatically moved to a predetermined position. A plurality of cleaning substrates are stored in the same storage container as the semiconductor substrate or in a position different from the semiconductor substrate, and the semiconductor substrate transporting means uses any one of them. It may be selected and automatically moved to a predetermined position. Further, a plurality of cleaning substrates having different effects are stored in the same storage container as the semiconductor substrate or in a position different from the semiconductor substrate, and the semiconductor substrate transfer means is any one of them. May be selected to automatically move to a predetermined position.

Further, it has means for pre-storing a plurality of movement patterns of the XY stage such that the predetermined movement is performed, and means for selectively designating one of the plurality of cleaning substrates. A series of operation sequences for cleaning the substrate holding means, which is a combination of the plurality of movement patterns and the plurality of cleaning substrates, is selectively and automatically performed based on a given command. Good.

Further, the semiconductor wafer has a function of counting the number of processed semiconductor substrates, and a series of operations for cleaning the substrate holding means is more than a predetermined number of processed wafers and after the end of the processing lot, or , May be automatically performed immediately before the start of the next processing lot, and has a timer to automatically perform a series of operations for cleaning the substrate holding means at a preset date and time. May be performed at any time.

Further, during the cleaning operation, the horizontal force detected by the semiconductor substrate transfer means is compared with a preset amount of change, and a series of operations for cleaning is automatically performed based on the result. And the consumption of the cleaning substrate is recognized, or the contact pressure between the surface of the substrate holding means and the lower surface of the cleaning substrate is changed to select a predetermined motion pattern of the XY stage, Alternatively, one of a plurality of cleaning substrates having different effects may be selected, or these substrates may be combined to automatically execute a series of operations for cleaning.

[0013]

In this structure, a cleaning substrate as shown in FIG. 2 for effectively cleaning the semiconductor substrate is conventionally used for cleaning the semiconductor substrate by using the semiconductor substrate carrying means that the apparatus has for carrying the semiconductor substrate. The substrate is conveyed and positioned on the substrate holding means for processing, the surface of the substrate holding means to be cleaned is brought into close contact with the lower surface of the cleaning substrate with a constant pressure, and the existing X and Y equipped with the substrate holding means are mounted. The surface of the substrate holding means is effectively cleaned by moving the XY stage movable in any direction so as to perform a predetermined programmed movement. At that time, it is determined whether or not the cleaning is performed based on the detection output from the function of detecting the horizontal force acting on the cleaning substrate.

Here, on the back surface of the cleaning substrate,
For example, as shown in FIG. 2 (a), orthogonal grooves with equal intervals are formed, but the shape of the groove is not limited to this, but may be radial, concentric, or spiral. Existing or a combination of these,
Various things are possible. The cross section of the groove of the cleaning substrate has, for example, a shape as shown in FIG. 2B or 2C, and various cross sectional shapes other than those shown in the figure are considered, but omitted here. .

The operator can give a command for the cleaning operation at any time from the control console of the apparatus. Further, as described above, the cleaning timing is set in advance and the processing of the semiconductor substrate is completed. When, when a certain number of sheets have been processed, or
The command may be such that the cleaning operation is automatically performed during a time period when the apparatus is not processing a normal semiconductor substrate.

[0016]

Embodiment 1 FIG. 1 is a perspective view showing the structures of a semiconductor substrate transfer apparatus and a wafer stage of a semiconductor manufacturing apparatus according to a first embodiment of the present invention. This device utilizes a semiconductor substrate (wafer) transfer device and a wafer stage mechanism for sequentially transferring a circuit pattern on a reticle to the semiconductor substrate, which is capable of positioning in the X, Y, and Z directions. It is equipped with a cleaning function. Here, description of functions other than the cleaning function is omitted.

In a normal exposure operation, the wafer 3 is moved by the transfer hand 2 from the wafer container 1 called a wafer cassette.
The first wafer on the rough wafer positioning station 4
The carrier hand 2 is transported and placed on the chuck 5, and the transport hand 2 is retracted. The wafer 3 on the first chuck 5 is rotated on the rough wafer positioning station 4, and the detector 6 configured in the station 4 is used to change the orientation flat as shown in FIG. 3A or the orientation flat shown in FIG. The position of a notch called a notch as shown is detected, and the direction is aligned in a predetermined direction. Next, the carrying-in hand 7 sucks the back surface of the aligned wafer 3, and the carrying-in hand 7 is moved up by the up / down mechanism 10 to move the first chuck 5
The wafer 3 is picked up from and is transferred onto the second chuck 9 on the wafer stage 8 which is movable in the horizontal direction (X, Y) and the vertical direction (Z). Next, the wafer up / down mechanism 10 of the carry-in hand 7 is operated to operate the second chuck 9
The wafer 3 is placed on the wafer transfer pins 11 projecting from the upper surface of the wafer 3 and the carry-in hand 7 is slightly lowered.
The carrying-in hand 7 is retracted so that the back surface of the carrying-in hand 7 does not come into contact with the carrying-in hand 7. After that, the second chuck 9 is raised to adsorb the wafer 3 on the pins 11 from the back surface,
After moving the wafer stage 8 to a predetermined position, autofocus in the Z direction is performed, and the exposure sequence starts. In the exposure sequence, the wafer stage 8 is sequentially moved to expose the entire surface of the wafer 3 and return it to the wafer unloading position.

The wafer 3 which has been processed is again supported on the transfer pin 11 by the second chuck 9 being lowered at the carry-out position. Next, the carry-out hand 12 is inserted into the gap between the back surface of the wafer 3 and the front surface of the second chuck 9, and the carry-out hand 12 is moved up to suck the wafer 3 from the back surface and move the wafer 3 into the wafer cassette 13. To do.
Here, when the carry-in hand 7 and the carry-out hand 12 use a common mechanism as shown in FIG. 4, the carry-in position and the carry-out position of the wafer 3 on the wafer stage 8 may be the same position. Further, it is also possible to store the processed wafers in the vacant portion of the wafer cassette 1 without using the wafer cassette 13.

The above is the ordinary wafer 3 in the exposure apparatus.
However, the second chuck 9 can be cleaned by diverting this series of operations. That is, in FIG. 1, the carry-in hand 7 is configured to be able to adsorb also the upper surface of the cleaning substrate 15, and the cleaning substrate 15 is placed in an area where the carry-in hand 7 can move.
The storage place 16 is provided, the upper surface of the cleaning substrate 15 is adsorbed by the carry-in hand 7, is transported onto the second chuck 9 on the wafer stage 8, and is fixed at that position. next,
The second chuck 9 is moved up in the Z direction by the wafer stage 8, and the front surface of the second chuck 9 to be cleaned is brought into contact with the back surface (lower surface) of the cleaning substrate 15. At this time, depending on the amount to be raised in the Z direction,
Since the pressing pressure can be adjusted, the output of the detector 18 for detecting the force in the vertical direction incorporated in the carry-in hand 7 is monitored and brought into contact with a predetermined pressure, and then the wafer stage 8
A horizontal swinging motion, a reciprocating motion in random directions,
The cleaning operation is performed by moving the robot so that it follows a pre-programmed locus such as a continuous rotary swing motion.

During the cleaning operation, the force (reaction force) acting on the cleaning substrate 15 is measured by the detector 19 incorporated in the carry-in hand 7 for detecting the force in the horizontal direction, and this value becomes smaller than the preset value. At that point, it is determined that the cleaning is finished, and the sequence is finished.

After the cleaning is completed, the second chuck 9 is moved down in the Z direction, and the carrying-in hand 7 returns the cleaning substrate 15 to the cleaning substrate storage space 16. If a sequence of such a series of cleaning operations is prepared, the second chuck 9 can be automatically cleaned. In this case, the outer diameter of the cleaning substrate 15 does not depend on the outer diameter of the chuck 9 to be cleaned, and the thickness can be freely selected. Further, as shown in FIG. 5, it is possible to configure a cassette 17 capable of storing a plurality of cleaning substrates in the cleaning substrate storage space 16.

Alternatively, as shown in FIG. 6, a plurality of cleaning substrates 15 having different effects are housed in the wafer cassette 1 and set in the apparatus as in the case of processing a normal semiconductor substrate to perform a series of cleaning operations. By starting the sequence, it is possible to select a substrate to be used for cleaning depending on the type of foreign matter attached to the chuck, and in addition to the selection of the stage movement locus described above, more effective cleaning can be performed. .

The detector 19 capable of detecting the force applied in the horizontal direction of the carry-in hand 7 is composed of, for example, a strain gauge,
The reaction force applied to the cleaning substrate by the horizontal movement of the chuck during the cleaning operation can be measured, the end of cleaning is detected from the change in the reaction force, and the series of cleaning operations is ended. Generally, the horizontal force (reaction force) that acts on the cleaning substrate during the cleaning operation is the force that presses the cleaning substrate against the chuck surface (contact pressure x effective contact area), and the shearing force required to shear foreign matter. , Determined by the friction coefficient of both contact surfaces (which has a nearly constant value in the dry state), etc., when foreign matter is sheared and removed from the chuck surface,
When it becomes smaller and the foreign matter is almost completely removed, it becomes a constant value determined by the product of the friction coefficient of both contact surfaces and the force pressing the cleaning substrate against the chuck surface.

Therefore, not only can the completion of cleaning be known by detecting the force applied to the carry-in hand in the horizontal direction, but also the effect of cleaning can be estimated by the magnitude of the change in the reaction force after cleaning for a certain period of time. If it is determined that the effect is small, the maximum effect is obtained by changing the contact pressure, selecting another cleaning substrate, or changing the drive pattern of the XY stage. It is also possible. in this case,
If these combinations can be decided in advance by experiments, etc., the judgment criteria can be programmed in the command part of the device and a series of effective chuck cleaning operations can be automatically selected and executed. it can.

Furthermore, it is possible to judge the wear (life) of the cleaning substrate based on the magnitude of the change in reaction force after cleaning for a certain period of time.

[0026]

As described above, according to the present invention, the substrate holding means is configured by applying various functions originally possessed by the semiconductor manufacturing apparatus and adding an additional detector and control device thereto. Since it is possible to perform cleaning of the substrate and the human body does not touch the substrate holding means itself, not only the problem of contamination can be avoided but also the time loss required for stabilizing the temperature of the apparatus is eliminated. Further, the cleaning operation itself can be programmed in advance, a plurality of driving sequences, a plurality of cleaning substrates can be selected, and these can be used in combination. In addition, it is possible to set the cleaning interval by the number of processed substrates, and perform the cleaning operation when the device is idle based on the timer.
There are also advantages such as planned maintenance of the device. In addition, by automatically cleaning, it is possible to avoid forgetting the work and to reduce the defects of semiconductor products due to human error. In addition to these effects, when trying to perform the above-mentioned function by another independent substrate holding means cleaning mechanism, it is necessary to secure a space for installing this independent substrate holding means cleaning mechanism,
Although the installation area of the semiconductor manufacturing apparatus is increased and the number of apparatuses that can be installed in the clean room is limited, as described in the above embodiments, the present invention provides the semiconductor manufacturing apparatus. Since the mechanism is configured to have another function additionally, there is also an advantage that the installation area of the device does not increase.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a semiconductor substrate transfer device and a wafer stage of a semiconductor manufacturing apparatus according to an embodiment of the present invention.

2A and 2B are a perspective view and a cross-sectional view showing an example of the shape of a groove on the back surface of a chuck cleaning substrate applied to the apparatus of FIG.

FIG. 3 is a perspective view of a notch called an orientation flat for identifying the orientation of a semiconductor substrate and a notch called a notch.

FIG. 4 is a perspective view showing a configuration of a semiconductor substrate transfer device and a wafer stage of a semiconductor manufacturing apparatus according to another embodiment of the present invention.

FIG. 5 is a perspective view showing configurations of a semiconductor substrate transfer device and a wafer stage of a semiconductor manufacturing apparatus according to still another embodiment of the present invention.

FIG. 6 is a perspective view showing configurations of a semiconductor substrate transfer device and a wafer stage of a semiconductor manufacturing apparatus according to still another embodiment of the present invention.

[Explanation of symbols]

1; wafer cassette, 2; transfer hand, 3; wafer,
4; wafer rough positioning station, 5; first chuck, 6; detector, 7; loading hand, 8; wafer stage, 9; second chuck, 10; loading hand up-
Down mechanism, 11; Wafer transfer pin, 12; Unloading hand, 13; Wafer cassette, 14; Up-down mechanism of unloading hand, 15; Cleaning substrate, 16; Cleaning substrate storage place, 17; Multiple cleaning A cassette capable of accommodating a substrate, 18; a detector for detecting a vertical force, 19: a detector for detecting a horizontal force.

Claims (15)

[Claims] 1. A semiconductor substrate carrying means for carrying a semiconductor substrate and placing it at a predetermined position, and a substrate holding means for sucking and fixing the semiconductor substrate carried and placed by the semiconductor substrate carrying means.
And an XY for moving this substrate holding means to a predetermined position.
In a semiconductor manufacturing apparatus having a stage, a semiconductor substrate transfer means transfers a cleaning substrate of the substrate holding means having a cleaning function on its lower surface to a predetermined position and fixes it in a horizontal plane or holds the substrate. The XY stage is fixed so as to be parallel to the surface of the cleaning means, and has a function of detecting a horizontal force acting on the cleaning substrate. The substrate holding means is moved below the substrate, and the substrate holding means is moved up and down so that the surface of the substrate holding means and the lower surface of the cleaning substrate come into contact with each other at a constant pressure. In order to clean the surface of the substrate by the cleaning substrate, the surface of the substrate may be flush with the surface of the substrate holding means. The semiconductor manufacturing apparatus characterized by the at a surface is to move to perform a predetermined motion. 2. The semiconductor manufacturing apparatus according to claim 1, wherein the semiconductor substrate carrying means includes a mechanism for moving the cleaning substrate in a vertical direction and a mechanism for recognizing the moving position. 3. The semiconductor substrate carrying means has means for detecting a force acting on the cleaning substrate in a vertical direction, and the lower surface of the cleaning substrate is vertically moved at a constant contact pressure based on an output signal thereof. 3. The semiconductor manufacturing apparatus according to claim 2, further comprising a control unit and the moving mechanism for bringing the surface of the substrate holding unit into contact with the surface of the substrate holding unit with a constant contact pressure. 4. The semiconductor substrate carrying means has means for detecting a contact pressure between the lower surface of the cleaning substrate and the surface of the substrate holding means, and the XY stage has a lower surface of the cleaning substrate and the substrate holding means. 2. The semiconductor manufacturing apparatus according to claim 1, wherein the substrate holding means is moved and positioned in the vertical direction so that the surface of the means comes into contact with the surface of the means at a constant pressure. 5. The XY stage has a mechanism for moving and positioning the substrate holding means to a predetermined position, and selects a contact pressure in a vertical direction between the lower surface of the cleaning substrate and the surface of the substrate holding means. The semiconductor manufacturing apparatus according to claim 1, wherein the semiconductor manufacturing apparatus is capable of being formed. 6. The semiconductor manufacturing apparatus according to claim 1, wherein the cleaning substrate is contained in the same container as the semiconductor substrate. 7. The cleaning substrate is stored in a position different from that of the semiconductor substrate, and the semiconductor substrate transfer means automatically moves the cleaning substrate from that position to a predetermined position. The semiconductor manufacturing apparatus according to claim 1, wherein: 8. A plurality of cleaning substrates are stored in the same storage container as the semiconductor substrate or in a position different from the semiconductor substrate, and the semiconductor substrate transfer means is any one of them. 2. The semiconductor manufacturing apparatus according to claim 1, wherein one piece is selected and automatically moved to a predetermined position. 9. A plurality of cleaning substrates having different effects are stored in the same storage container as the semiconductor substrate or in a position different from the semiconductor substrate, and the semiconductor substrate transfer means is any one of them. 2. The semiconductor manufacturing apparatus according to claim 1, wherein one of the selected ones is automatically moved to a predetermined position. 10. A means for pre-storing a plurality of movement patterns of the XY stage for performing the predetermined movement, and a means for selectively designating one of the plurality of cleaning substrates. A series of operation sequence for cleaning the substrate holding means, which is a combination of the plurality of movement patterns and the plurality of cleaning substrates, is selectively and automatically performed based on a given command. The semiconductor manufacturing apparatus according to claim 1, wherein: 11. A function for counting the number of processed semiconductor substrates, wherein a series of operations for cleaning the substrate holding means is equal to or more than a predetermined number of processed substrates and after the end of the processing lot, or The semiconductor manufacturing apparatus according to claim 1, wherein the processing is automatically performed immediately before the start of the next processing lot. 12. A semiconductor manufacturing method according to claim 1, further comprising a timer, wherein a series of operations for cleaning the substrate holding means is automatically performed at a preset date and time. apparatus. 13. During the cleaning operation, the horizontal force detected by the semiconductor substrate transfer means is compared with a preset change amount, and a series of operations for cleaning is automatically performed based on the result. The semiconductor manufacturing apparatus according to claim 1, further comprising means for ending the processing. 14. During the cleaning operation, the horizontal force detected by the semiconductor substrate transfer means is compared with a preset amount of change, and based on the result, the surface of the substrate holding means and the cleaning substrate are compared. The contact pressure with the lower surface of the XY stage is changed, a predetermined movement pattern of the XY stage is selected, or one of a plurality of cleaning substrates having different effects is selected, or a combination of these is automatically selected. The semiconductor manufacturing apparatus according to claim 1, wherein a series of operations for cleaning is executed. 15. During the cleaning operation, the horizontal force detected by the semiconductor substrate transfer means is compared with a preset change amount, and the consumption of the cleaning substrate is recognized based on the result. The semiconductor manufacturing apparatus according to claim 1, which is characterized in that.