JPH07283291A - Wafer pre-alignment device - Google Patents

Abstract

PURPOSE:To prevent damages to a wafer in positioning and improve operability of positioning, by detecting the type of the site when wafer causing the substrate to float, supplying air in an amount corresponding to the detected type of the substrate, and changing arrangement of a pressure member and a reference member. CONSTITUTION:When a wafer cassette 10 is set on a cassette base 12, sensors 11a to 11c detect the type of a semiconductor wafer l from the size of the wafer cassette 10, and send detection signals to a controller 13. If the detected type of the semiconductor wafer 1 is 8'', the controller 13 transmits a control signal corresponding to the 8''-type semiconductor wafer 1 to an air supply amount adjusting device 7 and air cylinders 3 and 9. When the adjusting device 7 is selected from adjusting devices 5 to 7, only a solenoid valve 7a of solenoid valves 5a to 7a opens, so that air is supplied to a lower surface of the semiconductor wafer 1 with the flow rate adjusted suitably for the 8''-type semiconductor wafer 1 by a speed controller 7b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pre-alignment apparatus for substrates such as semiconductor wafers.

[0002]

2. Description of the Related Art As a conventional substrate pre-alignment device, a semiconductor wafer is placed and a substrate placement device for sending air to the lower surface of the semiconductor wafer to float the semiconductor wafer and positioning the semiconductor wafer with respect to the center as a reference. There is a center positioning mechanism for adjusting the position of the semiconductor wafer in the direction of rotation with respect to the center of the semiconductor wafer.

The center positioning mechanism comprises a plurality of center positioning pieces arranged so as to surround the outer periphery of the semiconductor wafer, and a drive device for moving these center positioning pieces in the center direction.

In the substrate alignment mechanism, two positioning pieces are brought into contact with the orientation flat of the semiconductor wafer, one positioning piece is brought into contact with the outer periphery of the semiconductor wafer, and the semiconductor wafer is used as the three positioning pieces. It is provided with one moving piece for pressing and a drive device for moving this moving piece.

[0005]

In the above-described conventional substrate pre-alignment apparatus, when the type (size, for example) of the semiconductor wafer to be processed changes, the positioning of the semiconductor wafer in the rotation direction with respect to the center of the semiconductor wafer is performed. The positions of the three positioning pieces have to be manually moved according to the size of the semiconductor wafer, resulting in poor workability.

In the positioning of the center of the semiconductor wafer with respect to the reference, for example, when the type is changed from 8 inch semiconductor wafer to 5 inch semiconductor wafer, the distance from the outer periphery of the semiconductor wafer to the center positioning piece becomes long. As a result, when the center positioning piece is moved and pressed against the outer periphery of the semiconductor wafer, the impact received by the semiconductor wafer becomes large and the semiconductor wafer may be damaged. Further, if the distance from the outer circumference of the semiconductor wafer to the wafer center positioning piece becomes long, the time required for the moving piece to reach the outer circumference of the semiconductor wafer also becomes long, and there is a problem that the semiconductor wafer may tilt.

Further, at the time of each of the above-mentioned positioning, the semiconductor wafer is floated by the substrate mounting device, but the air supply amount for that purpose is constant, so that the air supply amount depends on the type (size or weight) of the semiconductor wafer. May be too little or too much.If it is too little, the semiconductor wafer may not float sufficiently, the lower surface of the wafer may be worn and dust may be generated, or the semiconductor wafer may be damaged. There was a problem that the wafer slipped too much.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a substrate pre-alignment apparatus capable of preventing damage to the substrate during positioning and improving the workability of positioning. That is.

[0009]

In order to solve the above-mentioned problems, a substrate pre-alignment apparatus according to a first aspect of the present invention is characterized in that at least three pressing members are arranged so as to surround the outer periphery of the substrate. Center positioning means for positioning the center with respect to a predetermined reference, and substrate alignment for aligning the position of the substrate in the rotation direction with respect to the center by pressing the substrate against a reference member arranged in the vicinity of the substrate. Means and a substrate mounting means for mounting the substrate and supplying gas to the lower surface of the substrate, wherein the gas is supplied to the lower surface of the substrate to float the substrate, In a pre-alignment apparatus for a substrate that performs positioning and the alignment, a detection unit that detects the type of the substrate, and the type detected by the detection unit Comprises changing means for changing the arrangement of the pressing member and the reference member corresponding to, and a supply amount control means for controlling the supply amount of the gas in accordance with the type detected by said detection means.

Further, in the substrate pre-alignment apparatus according to the present invention, the supply amount control means stores a plurality of gas supply amounts corresponding to the types of the substrate in advance, and the plurality of gas supply amounts are stored. From the inside, the gas supply amount according to the type detected by the detection means is selected.

Further, in the substrate pre-alignment apparatus according to the invention of claim 3, the changing means stores the positions of arrangement of the plurality of pressing members and the reference member according to the type of the substrate, The position of the arrangement is changed according to the type.

[0012]

When the substrate is levitated, the type of the substrate is detected by the detecting means, and the gas is supplied in an amount corresponding to the detected type of the substrate. Therefore, the supply amount is too small and the lower surface of the substrate is worn. There is no too much supply, no damage to the substrate and no too much slippage of the substrate.

If the positions of the pressing member and the reference member are changed according to the size of the substrate detected by the detecting means, the positions of the pressing member and the reference member can be manually changed to the size of the substrate. It is not necessary to move according to the above, workability is improved, and the distance from the outer periphery of the substrate to the pressing member can always be kept at a constant short distance.
When positioning the center of the substrate with respect to the reference, it is possible to suppress the impact that the substrate receives when the pressing member is pressed against the outer periphery of the substrate, and prevent damage to the substrate and inclination of the substrate.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram of a substrate pre-alignment apparatus according to an embodiment of the present invention.

The substrate pre-alignment apparatus includes sensors (detection means) 11a to 11c for detecting the type (size and weight) of the semiconductor wafer (substrate) 1 housed in the wafer cassette 10 on the cassette table 12. The semiconductor wafer 1 is placed, and a substrate placing device (substrate placing means) for sending air (gas) to the lower surface of the semiconductor wafer 1 to float the semiconductor wafer 1 and positioning the center of the semiconductor wafer 1 with respect to a reference. A center positioning mechanism (center positioning means) and a substrate alignment mechanism (substrate alignment means) for aligning the position of the semiconductor wafer 1 in the rotation direction with respect to the center of the semiconductor wafer 1 are provided.

The substrate mounting device includes a table 4 and air supply amount adjusting devices 5 to 7 for sending air to the lower surface of the semiconductor wafer 1 on the table 4. The air supply amount adjusting devices 5 to 7 are composed of electromagnetic valves 5a to 7a that open and close the flow paths and speed controllers 5b to 7b that adjust the flow rate. The speed controller 5b is adjusted so as to supply an appropriate amount of air to the five semiconductor wafers 1, the speed controller 6b to the six semiconductor wafers 1, and the speed controller 7b to the eight semiconductor wafers 1, respectively. There is.

The center positioning mechanism is used for the semiconductor wafer 1.
7 center positioning pieces (pressing members) 2a to 2g arranged so as to surround the outer periphery thereof and an air cylinder 3 for moving the center positioning pieces 2a to 2g toward the center.

The substrate aligning mechanism includes two positioning pieces (reference members) 8a and 8b which are brought into contact with the orientation flat 1a of the semiconductor wafer 1 and the positioning pieces 8a and 8b.
Air cylinder 9 for moving b, one positioning piece 8c for contacting the outer periphery of semiconductor wafer 1, and positioning piece 8
a driving device (not shown) for moving c, one positioning piece 8d for pressing the semiconductor wafer 1 against the three positioning pieces, and a driving device (not shown) for moving the positioning piece 8d. I have it.

The solenoid valves 5a of the sensors 11a to 11c, the air cylinders 3 and 9, and the air supply amount adjusting devices 5 to 7 are described.
7a are electrically connected to the control unit (supply amount control means) 13. The control unit 13 controls the supply amount of air according to the type of the semiconductor wafer 1 detected by the sensors 11a to 11c and the positions of the central positioning pieces 2a to 2g and the positioning pieces 8a to 8c, respectively. The control unit 13 has a storage device (storage means) not shown, and the storage device supplies three types of air according to the type of the semiconductor wafer 1 (for example, three types of semiconductor wafers of 5, 6, and 8). The amount is stored, and the control unit 13 selects the air supply amount according to the type detected by the sensors 11a to 11c from the three types of air supply amounts. In addition, the storage device has three types of positions of the center positioning pieces 2a to 2g and the positioning pieces 8a to 8d according to the type of the semiconductor wafer 1 (for example, three types of semiconductor wafers of 5, 6, and 8). The control unit 13 stores the sensor 11a from among the three types of positions.
The position of the arrangement corresponding to the type detected by 11c is selected.

Next, the operation of this substrate pre-alignment apparatus will be described.

When the wafer cassette 10 is placed on the cassette table 12, the sensors 11a to 11c detect the type of the semiconductor wafer 1 from the size of the wafer cassette 10, and the control unit 13
Send a detection signal to. For example, when the types of the semiconductor wafers 1 detected are eight, the control unit 13 sends a control signal corresponding to the eight semiconductor wafers 1 to the air supply amount adjusting device 7, the air cylinders 3, 9 and the like.

When the air supply amount adjusting device 7 is selected from the air supply amount adjusting devices 5 to 7, only the inner solenoid valve 7a of the solenoid valves 5a to 7a is opened, and the speed controller 7b allows the semiconductor wafers 1 of 8 types. The air whose flow rate is adjusted to suit the above conditions is supplied to the lower surface of the semiconductor wafer 1.

Further, the air cylinders 3 and 9 are actuated, and the central positioning pieces 2a to 2g and the positioning pieces 8a to 8d are arranged in eight positions.
The semiconductor wafer 1 is moved to the standby position according to the semiconductor wafer 1.

After that, the center positioning work is performed first, and then the orientation flat 1a positioning work is performed.

When the processing of 8 semiconductor wafers 1 is completed and the type of the semiconductor wafer 1 is changed from 8 to 5, the sensors 11a to 11c change the type of the semiconductor wafer 1 to 5 from the size of the wafer cassette 10. Then, the control unit 13 detects
Control signals corresponding to the semiconductor wafers 1 in 5 are transmitted.

When the air supply amount adjusting device 5 is selected from the air supply amount adjusting devices 5 to 7, this time the solenoid valves 5a to 7 are selected.
Only the solenoid valve 5a in a opens and the speed controller 5
Air whose flow rate is adjusted to be suitable for the five semiconductor wafers 1 by b is supplied to the lower surface of the semiconductor wafer 1. Further, the air cylinders 3 and 9 are actuated toward the center, and the center positioning pieces 2a to 2g and the positioning pieces 8a to 8d are moved to the standby positions corresponding to the five semiconductor wafers 1. As a result, the outer periphery of the semiconductor wafer 1 and the center positioning piece 2 that have been conveyed
The distance from a to 2g or the positioning pieces 8a to 8d is always kept constant.

According to the substrate pre-alignment apparatus of this embodiment, when the semiconductor wafer 1 is levitated, the sensor 1
Since the optimum amount of air is supplied according to the size and weight of the semiconductor wafer 1 detected by 1a to 11c, the lower surface of the semiconductor wafer is less likely to be worn, and the semiconductor wafer may be damaged or the semiconductor wafer may slip too much. Can be prevented.

Further, since the standby positions of the center positioning pieces 2a to 2g and the positioning pieces 8a to 8d are changed according to the size of the semiconductor wafer 1 detected by the sensors 11a to 11c, the positioning is performed manually. There is no need to move the standby positions of the pieces 8a to 8d according to the size of the semiconductor wafer 1, workability is improved, and the distance from the outer periphery of the semiconductor wafer 1 to the center positioning pieces 2a to 2g is always a constant short distance. So you can keep
When positioning the center of the semiconductor wafer 1 with respect to the reference, the impact received by the semiconductor wafer 1 when the center positioning pieces 2a to 2g are pressed against the outer periphery of the semiconductor wafer 1 can be suppressed, and the semiconductor wafer 1 can be prevented from being damaged or damaged. It can prevent tilting.

[0030]

As described above, according to the substrate pre-alignment apparatus of the present invention, when the substrate is levitated,
The type of substrate is detected by the detection means, and the amount of gas corresponding to the detected type of substrate is supplied.Therefore, the supply amount is too small, the lower surface of the substrate is not worn, and the supply amount is too large. The substrate is not damaged and the substrate is not slipped too much.

If the positions of the pressing member and the reference member are changed according to the size of the substrate detected by the detecting means, the positions of the pressing member and the reference member can be manually changed to the size of the substrate. It is not necessary to move according to the above, workability is improved, and the distance from the outer periphery of the substrate to the pressing member can always be kept at a constant short distance.
When positioning the center of the substrate with respect to the reference, it is possible to suppress the impact that the substrate receives when the pressing member is pressed against the outer periphery of the substrate, and prevent damage to the substrate and inclination of the substrate.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a substrate pre-alignment apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 1 semiconductor wafer 2a to 2g center positioning piece 3,9 air cylinder 4 table 5 to 7 air supply amount adjusting device 5a to 7a solenoid valve 5b to 7b speed controller 8a to 8d positioning piece 11a to 11c sensor 13 controller

Claims (3)

[Claims] 1. A center positioning means for positioning the center of the substrate with respect to a predetermined reference by at least three pressing members arranged so as to surround the outer periphery of the substrate, and a reference member arranged in the vicinity of the substrate. Substrate aligning means for aligning the position of the substrate in the rotational direction with respect to the center by pressing the substrate against the substrate, and substrate placing means for placing the substrate and supplying gas to the lower surface of the substrate A substrate pre-alignment device that performs the positioning and the alignment in a state where the gas is supplied to the lower surface of the substrate and the substrate is levitated, and a detection unit that detects the type of the substrate, Changing means for changing the arrangement of the pressing member and the reference member according to the type detected by the detecting means, and detecting by the detecting means A substrate pre-alignment apparatus, comprising: a supply amount control means for controlling the supply amount of the gas according to the type. 2. The supply amount control means stores a plurality of gas supply amounts according to the type of the substrate in advance and the type is detected from the plurality of gas supply amounts according to the type detected by the detecting means. 2. The substrate pre-alignment apparatus according to claim 1, wherein a gas supply amount is selected. 3. The changing means stores the positions of arrangement of a plurality of the pressing members and the reference member according to the type of the substrate, and selects the position of the arrangement according to the type of the substrate. The substrate pre-alignment apparatus according to claim 1.