JP2000164675A - Notch matching machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage of a device forming area of a wafer by installing a notch sensor of a transparent type and an eccentric sensor of a transparent type, making it possible to retain the outer peripheral part of a wafer from below on a fixed stage, and rotating the wafer on a rotation stage while the outer peripheral part of the wafer is retained from below. SOLUTION: A transparent sensor 50 is constituted of a notch sensor and an eccentric sensor. The eccentric sensor is constituted of an inside sensor and an outside sensor. Before a wafer is carried in a notch matching machine 100 by a carrying robot, a rotation stage 1 is maintained at a lower position L. A hand 300 retaining a wafer 200 is made to progress as far as an upper position of a second receiving part 14 of a fixed stage 2 and then made to descend. When the hand 300 is made to descend as far as a height position of the second receiving part 14, the outer peripheral part of the wafer 200 retained by the hand 300 is made to abut against the second receiving part 14, the wafer is transferred and mounted on the fixed stage 2, and the hand is stopped. Since the wafer is retained from below, damage of a device forming area of the wafer can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a notch matching machine,
More specifically, the present invention relates to a notch aligning machine for adjusting a notch of a wafer having a diameter of 12 inches (about 300 mm) to a reference angle position.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, when a disk-shaped wafer in a cassette is processed or set on a processing stage, a wafer is taken out of the cassette by a transfer robot and set in a notch aligner. Align the notch of the wafer with the reference angle position,
Thereafter, the wafer is processed or set on a processing stage by a transfer robot. The notch is a mark formed on the outer peripheral portion of the wafer such as 12 inches (about 300 mm) in diameter, and is a V-shaped or U-shaped notch having a depth of about 1 mm.

In general, a notch aligner includes a wafer rotating means for rotating a wafer while holding a central portion of the wafer by vacuum suction from below, a driving means for rotating the wafer rotating means, and a non-contacting outer peripheral portion of the wafer. A projector and a line sensor for detecting the notch position and the eccentric state of the rotating wafer, and determining the eccentric state of the wafer from the output of the line sensor, and setting the center position of the wafer to the regular center position. A controller for outputting a control signal for adjusting the wafer rotation means, and a displacement means for displacing the wafer rotation means to correct the planar coordinate position of the wafer rotation means in accordance with the control signal of the controller. The position and the eccentric state are detected, and based on the detection results, the notch of the wafer is adjusted to the reference angle position. The center position of the wafer is configured to match the center position of the normal to.

[0004]

However, in the conventional notch aligner as described above, since the wafer rotating means is of a type that suction-holds the central portion of the wafer, the device forming area of the wafer is rotated by the wafer rotating means. May be damaged.

Further, since the eccentric state of the wafer is detected using a line sensor and the center position of the wafer is adjusted to the regular center position by the displacement means, the arithmetic processing of the controller is relatively complicated and There were problems such as a complicated mechanical structure.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a first object is to
Paying attention to the fact that the outer peripheral portion of the wafer is defined as a non-device formation area where devices are not formed, the object is to prevent damage to the device formation area of the wafer by holding the outer peripheral portion of the wafer. The second object is to detect the eccentricity of the wafer relatively accurately using a light-receiving element such as an inexpensive photodiode instead of detecting the eccentricity of the wafer using an expensive line sensor, and Another object of the present invention is to reduce the arithmetic processing of the controller and, when detecting the eccentricity of the wafer, eliminate the eccentricity of the wafer without providing a special position correcting mechanism such as the above-mentioned displacement means.

[0007]

The notch aligner of the present invention includes a fixed stage, a rotary stage, a transmission type notch sensor, and a transmission type eccentricity sensor, and the fixed stage moves the outer peripheral portion of the wafer from below. The rotation stage is configured to be able to support, the rotation stage is configured to rotate the wafer while supporting the outer peripheral portion of the wafer from below, the fixed stage, the wafer can be transferred between the rotation stage, the notch sensor is A notch light emitting element that irradiates light vertically on the movement trajectory of the notch drawn when the wafer rotates, and a notch light receiving element that can receive light from the notch light emitting element, the eccentricity sensor includes: An inner light emitting element comprising an inner sensor and an outer sensor, wherein the inner sensor irradiates light vertically on a movement trajectory closer to the center of the wafer than the notch. An inner light receiving element capable of receiving light from the inner light emitting element, wherein the outer sensor emits light vertically on a movement trajectory at a position off the wafer, and an outer light emitting element. An outer light-receiving element capable of receiving light from the element, the notch light-emitting element and the inner and outer light-emitting elements are arranged in a line in a plan view, in a direction deviating from a radial direction and an outer peripheral tangential direction of the wafer. The notch light-receiving element and the inner and outer light-receiving elements are arranged in a plan view, in an arrangement state coinciding with the arrangement state of the three light-emitting elements, and a notch position of a wafer is detected by an output of the notch light-receiving element. In addition, the presence or absence of eccentricity of the wafer is determined based on the outputs of the inner and outer light receiving elements and the light receiving element for the notch. After transferring the wafer to et the fixed stage, again transferring the wafer from the fixed stage to the rotary stage, again, and performs the notch detection and eccentric presence determination of the wafer.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are a plan view and a front sectional view, respectively, of a main part of a notch aligner according to an embodiment.

In FIG. 1 and FIG.
Reference numeral 00 includes drop-down stages 1 and 2 as holding means for supporting a wafer 200 having a notch 201 formed in an outer peripheral portion 200a, for example, a silicon wafer having a diameter of 12 inches from below.

The two stages 1 and 2 may be composed of a single stage. However, in order to ensure the notch detection and the like, the rotary stage 1 and the fixed stage 2 are used as in this embodiment. It is preferable that the stage be composed of two stages.

The rotation stage 1 is provided with a fixed rotation position (a rotation position shown in FIG. 1) at a predetermined fixed rotation position in which the outer peripheral portion of the wafer 200 is supported from below to detect the notch position and the presence or absence of eccentricity of the wafer. Corresponding to one rotation).

The rotary stage 1 has a plurality (three in this embodiment) of first receiving portions 3 that support the outer peripheral portion 200a (preferably, a non-device forming area) of the wafer 200 from below.
Having. Each first receiving portion 3 is equiangularly spaced (120 ° in the present embodiment) based on the rotation center position of the rotary stage 1.
At intervals). Each first receiving part 3 is preferably
As shown in FIG. 1, it is formed at the end of a narrow band-shaped first arm 4 that extends linearly toward the center of rotation when viewed in plan.

Below the rotary stage 1, a first driving means 5 for rotating the rotary stage 1 is provided. The first driving unit 5 includes a rotating shaft 6 extending from the lower surface of the rotating stage 1, and the rotating shaft 6 passes through the vertical through hole 2 a of the fixed stage 2 in a non-contact state. The lower end of the rotating shaft 6 is connected to an output shaft of a motor 9 via power transmission means such as gears 7 and 8. As described above, the rotary stage 1 is rotatable by the first driving means 5 using the motor 9 or the like as a power source.

The rotating shaft 6 is fixed to an elevating member 11 provided with a bearing 10 for the rotating shaft 6. The elevating member 11 can be moved up and down by driving means (not shown). As described above, the rotating stage 1 can be moved up and down integrally with the elevating member 11 by the driving means. Note that, in the case of the present embodiment, the rotary stage 1
As shown in the figure, the robot moves up and down between three height positions of an upper position U, an intermediate position M, and a lower position L, and makes one rotation when it is located at the upper position U.

A bracket 13 is mounted on the machine base 12, and the bracket 13 can be moved forward and backward toward the rotation axis of the rotary stage 1 by driving means (not shown). The bracket 13 is provided with a transmission sensor 50 for detecting the notch position of the wafer 200 during one rotation of the rotary stage 1 and for detecting the eccentricity of the wafer 200. As will be described in detail later, the transmission sensor 50 includes a transmission notch sensor 51 and a transmission eccentric sensor 52.

The fixed stage 2 receives the wafer 200 to be notch-aligned from the hand 300 of the transfer robot, and thereafter, moves the wafer 20 after the notch alignment is completed.
The wafer 200 is placed when handing 0 to the hand 300.

The fixed stage 2 supports a plurality (three in this embodiment) of supporting the outer peripheral portion 200a (non-device formation area) of the wafer 200 from below similarly to the rotary stage 1.
The second receiving portions 14 are arranged at equal angular intervals (120 ° with respect to the rotation center position of the fixed stage 2).
First) adjacent to the rotary stage 1
It is arranged to be located between the receiving parts 3 (preferably in the middle). Like the first receiving portion 3, each of the second receiving portions 14 is preferably a narrow band-shaped and L-shaped linearly extending toward the center of rotation when viewed in a plan view, as shown in FIG. Second
It is formed at the end of the arm 15.

Below the fixed stage 2, a second driving means 16 for rotating and driving the fixed stage 2 is provided.
The second driving unit 16 includes a rotating shaft 17 that forms the upper and lower through holes 2a through which the rotating shaft 6 of the rotating stage 1 passes. The lower end of the rotating shaft 17 is connected to an output shaft of a motor 20 via power transmission means such as gears 18 and 19. Therefore, the fixed stage 2 is rotatable by the second driving means 16 using the motor 20 or the like as a power source.

The fixed stage 2 forms a space 21 in which the rotary stage 1 is housed so as to be able to move up and down. The space 21 is formed by the second arm 15 of the fixed stage 2, and the second receiving portion 14 is formed at the upper end of the vertical frame portion 15 a of the L-shaped second arm 15.

When the rotating stage 1 is lifted, the rotating stage 1
When the first receiving portion 3 of the fixed stage 2 has risen to the height position of the second receiving portion 14 of the fixed stage 2, the second receiving portion 1 of the fixed stage 2
The wafer 200 supported by 4 is transferred to the first receiving portion 3 of the rotary stage 1.

When the rotary stage 1 is lowered, when the first receiving portion 3 of the rotary stage 1 is lowered to the level of the second receiving portion 14 of the fixed stage 2, the first receiving portion 3
The wafer 200 supported by the receiving part 3 is transferred to the second receiving part 14 of the fixed stage 2.

The loading and unloading of the wafer 200 to and from the notch aligner 100 is performed by the hand 300 of the transfer robot.
Done by

The hand 300 of the transfer robot enters the position W which does not hinder the elevating operation of the rotary stage 1, in other words, the elevating operation of the first arm 4, while performing the notch alignment on the loaded wafer 200. Wait in state.

Next, the operation of the notch matching machine 100 configured as described above will be described in order with reference to FIG.

(1) Initial state of notch aligner 100 Wafer 2 to notch aligner 100 by transfer robot
Before carrying in 00, the rotary stage 1 is maintained at the lower position L. The bracket 13 is in a retracted position as shown by a two-dot chain line in FIGS.

(2) Wafer 2 to notch aligner 100
The carry-in transfer robot advances the hand 300 supporting the wafer 200 to a position above the second receiving portion 14 of the fixed stage 2 (S1), and then lowers the hand 300 (S2). When the hand 300 descends to the height position of the second receiving portion 14 when the hand 300 descends, the outer peripheral portion 200a of the wafer 200 supported by the hand 300 comes into contact with the second receiving portion 14 and the wafer 300 200 is fixed stage 2 from hand 300
Will be transferred to Thereafter, the hand 300 stops descending at the height position shown in FIG. 2, and moves to the tip position W shown in FIG.
Stage 1 without interference between the hand and the hand 300
Retreats to a position W that does not hinder the rise of the vehicle and waits (S
3). When the hand 300 descends, the hand 300
The fixed stage 2 can be lowered without interfering with the fixed stage 2 due to the relative positional relationship with the second receiving portion 14.

(3) From fixed stage 2 to rotary stage 1
The notch aligner 100 raises the elevating member 11 by driving means (not shown), and rotates the rotary stage 1 at the lower position L.
Is raised to the upper position U (S4). When the rotary stage 1 is raised, when the first receiving portion 3 of the rotary stage 1 is raised to the height position of the second receiving portion 14 of the fixed stage 2,
The outer peripheral portion 200a of the wafer 200 supported by the second receiving portion 14 comes into contact with the first receiving portion 3, and the wafer 200 is transferred from the fixed stage 2 to the rotary stage 1. afterwards,
The rotation stage 1 stops rising at the upper position U. When the rotary stage 1 is raised, the hand 300 is in the standby state as described above, and the rotary stage 1 is housed in the space 21 opened above the fixed stage 2, and Since the second receiving portion 14 has a planar phase difference, the rotary stage 1 can move up without interfering with the hand 300 and the fixed stage 2.

(4) Advancement of the transmission sensor 50 The bracket 13 is advanced by a drive mechanism (not shown). As the bracket 13 advances, the sensor 50 advances (S5).

(5) Rotation of Rotation Stage 1 and Detection of Notch Position Rotation stage 1 supporting wafer 200 is rotated once from a fixed rotation position by first driving means 5 (S
6). During this rotation, the transmission sensor 50 moves the wafer 200
The controller outputs a signal corresponding to the displacement of the outer peripheral portion to a controller (not shown), and the controller detects the notch position and the presence or absence of eccentricity of the wafer based on the signal from the transmission sensor 50 (S7).

Here, the transmission type sensor 50 is shown in FIG.
As shown in (1), a notch sensor 51 and an eccentricity sensor 52 are provided.

The notch sensor 51 detects the movement trajectory L 1 of the notch 201 drawn when the wafer 200 without any misalignment is rotated.
(FIG. 4 (B)) The light emitting device includes a notch light emitting element 51A for vertically emitting light and a notch light receiving element 51B capable of receiving light from the notch light emitting element 51A. The notch light emitting element 51A is constituted by an LED,
The light receiving element for notch 51B is constituted by a photodiode.

On the other hand, the eccentricity sensor 52 is
And an outer sensor 54. The inner sensor 53 has a movement locus L2 at a position closer to the center of the wafer than the notch 201.
(FIG. 4B) Inner light emitting element 5 for vertically irradiating light
3A and an inner light receiving element 53B capable of receiving light from the inner light emitting element 53A. Outside sensor 54
Is the movement trajectory L3 of the position off the wafer 200 (FIG. 4).
(B)) Outer light emitting element 54A for vertically irradiating light upward
And an outer light receiving element 54B capable of receiving light from the outer light emitting element 54A. Inner light emitting element 53A
The outer light emitting element 54A and the outer light emitting element 54A are formed by LEDs, respectively.
B is each formed by a photodiode.

As shown in FIG. 4B, the notch light emitting elements 51A and the inner and outer light emitting elements 53A and 54A are arranged in a row in a direction deviating from the radial direction a and the outer peripheral tangential direction b of the wafer 200. (Corresponding to the straight line indicated by the alternate long and short dash line L0), and the notch light-receiving element 51B and the inner and outer light-receiving elements 53B, 54B are arranged in plan view, and the arrangement of the three light-emitting elements 51A, 53A, 54A. Are arranged in an array state that matches Here, the interval between adjacent elements is set to about several mm.

Then, a controller (not shown) detects the notch position of the wafer 200 based on the output of the notch light receiving element 51B, and also detects the inside and outside light receiving elements 53B, 53B.
The presence or absence of eccentricity of the wafer 200 is determined from the three outputs of the light receiving element 54B and the notch light receiving element 51B.

The determination of the presence or absence of eccentricity of the wafer 200 is performed as follows. With respect to the notch sensor 51, the inner sensor 53, and the outer sensor 54, the wafer outer peripheral portion 200a is in a state shown by a solid line in FIG. Is determined, and only when the inner light receiving element 53B always outputs a light-shielded signal and the outer light receiving element 54B always outputs a light receiving signal, it is determined that the wafer 200 is not eccentric, that is, normal. On the other hand, with respect to the notch sensor 51, the inner sensor 53, and the outer sensor 54, the wafer outer peripheral portion 200a is in a state shown by a broken line, a dashed line, or a two-dot chain line in FIG. If the light receiving signal other than the light receiving signal is output, or if the inner light receiving element 53B outputs the light receiving signal, or if the outer light receiving element 54B outputs the light shielding signal, it is determined that the wafer 200 is eccentric. Strictly speaking, when the first receiving portion 3 of the rotary stage 1 passes through the transmission sensor 50, the output signals of the notch light receiving element 51B, the inner light receiving element 53B, and the outer light receiving element 54B are light-shielded signals. Since the output timing can be calculated in advance, these output signals may be excluded from the criterion.

(6) a When the wafer 200 is not eccentric and the notch position can be detected. Notch alignment The first drive means 5 is controlled based on the notch position detected by the notch sensor 51, and the rotation of the rotary stage 1 Then, the wafer 200 is rotated until the notch 201 comes to a predetermined reference rotation position (S8).

Determination of Presence or Absence of Interference between Rotating Stage 1 and Fixed Stage 2 It is determined whether or not lowering the rotating stage 1 after the notch alignment will cause interference with the fixed stage 2 (S 9). This judgment is made by the first stage of the rotary stage 1.
This is performed based on each rotational position of the receiving part 3 and the second receiving part 14 of the fixed stage 2. If it is determined that the stages 1 and 2 interfere with each other, the fixed stage 2 is rotated by an angle that can avoid the interference (S10). On the other hand, when it is determined that the stages 1 and 2 do not interfere, the fixed stage 2 is not rotated.

The bracket 13 is retracted by a drive mechanism (not shown). Due to the retreat of the bracket 13, the sensor 50 retreats (S11).

Transferring Wafer 200 from Rotary Stage 1 to Fixed Stage 2 The elevating member 11 is lowered, and the rotary stage 1 at the upper position U is lowered to the intermediate position M (S 12). Since the lowering operation of the rotary stage 1 is performed after the rotating operation for avoiding the interference of the stages 1 and 2 with the fixed stage 2 as described above, the lowering operation is smoothly performed without interfering with the fixed stage 2. It is. When the rotary stage 1 is lowered, when the first receiving portion 3 of the rotary stage 1 is lowered to the height position of the second receiving portion 14 of the fixed stage 2, the wafer supported by the first receiving portion 3 The outer peripheral portion 200a of the second
The wafer 200 is transferred from the rotary stage 1 to the fixed stage 2 in contact with the receiving portion 14.

Return of Rotation Stage 1 Rotation stage 1 at intermediate position M is rotated to the original fixed rotation position, and then rotation stage 1 is lowered to the original lower position L (S13). During this descent, the rotating stage 1
Has already returned to the fixed rotation position,
It can descend without interfering with zero.

The wafer 2 from the notch aligner 100
00 unloading The transfer robot advances the hand 300 in the standby state to a position below the second receiving portion 14 of the fixed stage 2 (S1).
4) Then, it is raised (S15). This hand 300
When the hand 300 rises to the height position of the second receiving portion 14 at the time of rising, the hand 300 comes into contact with the wafer 200, and the wafer 200 is transferred from the fixed stage 2 to the hand 300. Thereafter, the hand 300 is moved backward, and the wafer 200 is unloaded from the notch aligner 100 (S1).
6).

When the fixed stage 2 is rotated (S 10), the fixed stage 2 is rotated to the original fixed rotation position (S 17), and the operation is terminated.

(6) b When the wafer 200 is not eccentric but the notch position cannot be detected Even if the wafer 200 is not eccentric, the notch 201 is located on the first receiving portion 3 of the rotary stage 1. Therefore, the notch position may not be detected. In such a case, the operation is performed as follows.

Retraction of Transmission Sensor 50 The bracket 13 is retracted by a drive mechanism (not shown). Due to the retreat of the bracket 13, the sensor 50 retreats (S19).

Transferring Wafer 200 from Rotary Stage 1 to Fixed Stage 2 The elevating member 11 is lowered, and the rotary stage 1 at the upper position U is lowered to the intermediate position M (S 20). When the rotary stage 1 is lowered, when the first receiving portion 3 of the rotary stage 1 is lowered to the height position of the second receiving portion 14 of the fixed stage 2, the wafer supported by the first receiving portion 3 The outer peripheral portion 200a of the wafer 200 contacts the second receiving portion 14 and the wafer 200
Is transferred from the rotary stage 1 to the fixed stage 2. Thereafter, the rotation stage 1 stops descending at the intermediate position M.

Rotation of Fixed Stage 2 The fixed stage 2 is rotated by a predetermined angle, for example, 10 ° by the second driving means 16 (S 21). Note that this angle is
Is determined based on the circumferential width of the first receiving portion 3, and
The rotation of the fixed stage 2 causes the second arm 15 to move the hand 3
00 is set within a range in which a problem of interference with 00 can be avoided.

Transferring Wafer 200 from Fixed Stage 2 to Rotary Stage 1 The elevating member 11 is raised, and the rotary stage 1 at the intermediate position M is raised to the upper position U (S 22). When the rotary stage 1 is raised, the wafer 200 is transferred from the fixed stage 2 to the rotary stage 1, and thereafter, the rotary stage 1 stops rising at the upper position U. Since the wafer 200 transferred to the rotating stage 1 is transferred to the rotating stage 1 after the rotation of the fixed stage 2 described above, the wafer 200 is transferred to the rotating stage 1 by the operation (3). Compared to the case, the rotating stage 1 is supported with a phase difference of a predetermined angle.

Return of Fixed Stage 2 The fixed stage 2 is returned to the original rotation position (S 2
3).

Counting up the number of retries The number of retries for notch detection is counted up (S2).
4).

Advancement of the transmission sensor 50, rotation of the rotary stage 1, and detection of the notch position
The sensor 50 is advanced (S5). Next, the rotating stage 1 supporting the wafer 200 is driven by the first driving unit 5.
Is rotated once from the fixed rotation position (S6). During this rotation, the transmission sensor 50 performs a detection operation for detecting the notch position of the wafer 200 and determining the presence or absence of eccentricity again (S7).

A) When the notch position can be detected: Notch alignment, transfer of wafer 200 from rotary stage 1 to fixed stage 2, return of rotary stage 1, unloading of wafer 200 from notch aligner 100, etc. (S8 to S17)
And end the operation.

B When notch position could not be detected Transfer of wafer 200 from rotary stage 1 to fixed stage 2, rotation of fixed stage 2, transfer of wafer 200 from fixed stage 2 to rotary stage 1, transfer of rotary stage 1 Rotation, notch position detection, fixed stage 2 return, etc. (S2
0 to S24). When the number of retries reaches a predetermined value (S18), the notch alignment is stopped (S2).
5) Optionally, the wafer 200 may be unloaded from the notch aligner 100 and the operation may be terminated.

(6) c When the wafer 200 is eccentric The retreating of the transmission sensor 50 retreats the bracket 13 by a driving mechanism (not shown).
The sensor 50 is moved backward (S19).

Transferring Wafer 200 from Rotary Stage 1 to Fixed Stage 2 The elevating member 11 is lowered, and the rotary stage 1 at the upper position U is lowered to the intermediate position M (S 20).

Transferring Wafer 200 from Fixed Stage 2 to Rotary Stage 1 The elevating member 11 is raised, and the rotary stage 1 at the intermediate position M is raised to the upper position U (S 22). When the rotary stage 1 is raised, the wafer 200 is transferred from the fixed stage 2 to the rotary stage 1, and thereafter, the rotary stage 1 stops rising at the upper position U. This wafer transfer may eliminate the eccentricity of the wafer 200.

Counting up the number of retries The number of retries for notch detection is counted up (S2).
4).

Advancement of the transmission type sensor 50, rotation of the rotary stage 1 and detection of a notch The bracket 13 is advanced by a drive mechanism (not shown),
The sensor 50 is advanced (S5). Next, the rotating stage 1 supporting the wafer 200 is driven by the first driving unit 5.
Is rotated once from the fixed rotation position (S6). During this rotation, the transmission sensor 50 performs a detection operation for detecting the notch position of the wafer 200 and determining the presence or absence of eccentricity again (S7).

A) When the eccentricity has been eliminated The notch alignment, the transfer of the wafer 200 from the rotary stage 1 to the fixed stage 2, the unloading of the wafer 200 from the notch alignment machine 100, and the like (S8 to S17) are performed, and the operation ends.

B When the eccentricity could not be eliminated Transfer of the wafer 200 from the rotary stage 1 to the fixed stage 2 and transfer of the wafer 200 from the fixed stage 2 to the rotary stage 1
0 transfer, rotation of the rotary stage 1, notch detection, etc. (S20
To S24). When the number of retries reaches a predetermined value (S18), the notch alignment is stopped (S2).
5) Optionally, the wafer 200 may be unloaded from the notch aligner 100 and the operation may be terminated.

As described above, according to the notch aligner 100 according to the present embodiment, since the fixed stage 2 and the rotary stage 1 are configured to support the wafer outer peripheral portion 200a where no device is normally formed from below,
Damage to the device formation area of the wafer 200 can be prevented.

The notch sensor 51 is a notch light emitting element 51A that irradiates light vertically on the movement trajectory L1 of the notch 201 drawn when the wafer 200 without any misalignment is rotated.
And a notch light receiving element 51B capable of receiving light from the notch light emitting element 51A.
2 includes an inner sensor 53 and an outer sensor 54. The inner sensor 53 irradiates light vertically on a movement trajectory L2 closer to the center of the wafer than the notch 201, and the inner light emitting element 53A. And an inner light receiving element 53B capable of receiving light from the outer sensor 53A.
Reference numeral 4 denotes an outer light emitting element 54A for vertically irradiating light on a movement locus L3 at a position off the wafer 200, and an outer light receiving element 54B capable of receiving light from the outer light emitting element 54A.
The notch light emitting elements 51A and the inner and outer light emitting elements 53A and 54A are arranged in a line in a direction deviating from the radial direction a and the outer peripheral tangential direction b of the wafer 200 in plan view, and Light receiving element 51B and the inside,
The outer light receiving elements 53B and 54B are arranged in a plan view, in an arrangement state coinciding with the arrangement state of the three light emitting elements 51A, 53A and 54A. Inner and outer light receiving elements 53B, 54B and notch light receiving element 51B
The presence or absence of eccentricity of the wafer 200 is determined by the three outputs of
When it is determined that "wafer eccentricity exists", the wafer 200 is once transferred from the rotating stage 1 to the fixed stage 2, then the wafer 200 is transferred again from the fixed stage 2 to the rotating stage 1, and the notch of the wafer 200 is detected again. And eccentricity determination. Therefore, instead of detecting the eccentric state of the wafer using an expensive line sensor, the presence or absence of the eccentricity of the wafer can be relatively accurately detected using an inexpensive light receiving element such as a photodiode. When the eccentricity of the wafer is detected, the eccentricity of the wafer can be eliminated without providing a special mechanism for correcting the position such as a conventional displacement unit.

As shown in FIG. 6, the transmission type sensor 50 has an aperture 6 on the front surface of the light receiving elements 51B, 53B and 54B.
0 is provided to improve the resolution. As shown in FIG. 7, a light-collecting lens 70 is disposed in front of the light-emitting elements 51A, 53A, and 54A to form the light-receiving elements 51B, 53B, and 5A.
4B may be configured to increase the amount of received light.

[0064]

According to the present invention, damage to the device formation area of the wafer can be prevented. Further, the presence or absence of eccentricity of the wafer can be relatively accurately detected using an inexpensive light receiving element such as a photodiode, and the calculation processing of the controller can be reduced. Further, when the eccentricity of the wafer is detected, the eccentricity of the wafer can be eliminated without providing a special position correcting mechanism such as a conventional displacement unit.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of a notch aligner according to an embodiment.

FIG. 2 is a front sectional view of a main part of the same.

FIG. 3 is a flowchart showing an operation example of the notch matching machine.

FIG. 4 shows a configuration diagram of a transmission sensor.

FIG. 5 is an explanatory diagram of a method of determining the presence or absence of wafer eccentricity.

FIG. 6 shows another configuration diagram of a transmission sensor.

FIG. 7 shows still another configuration diagram of the transmission sensor.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 notch aligner 1 rotary stage 2 fixed stage 50 transmission sensor 51 notch sensor 51A notch light emitting element 51B notch light receiving element 52 eccentricity sensor 53 inner sensor 53A inner light emitting element 53B inner light receiving element 54 outer sensor 54A outer light emitting element 54B outer Light receiving element 200 Wafer 200a Outer peripheral portion 201 Notch L1, L2, L3 Moving locus

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takashi Yoshimura 28, Kitaimaji, Seta, Onishi-shi, Aichi Pref. (72) Inventor Shinichi Kawase 28, Kitaimaji Seta, Onishi-shi, Aichi Mexnai F-term (reference) 5F031 HA58 HA59 JA05 JA15 JA17 JA29 JA35 KA08

Claims (1)

[Claims] 1. A fixed stage, a rotary stage, a transmission type notch sensor, and a transmission type eccentricity sensor, wherein the fixed stage is configured to be able to support an outer peripheral portion of a wafer from below, and the rotary stage includes a wafer. Is configured to rotate the wafer while supporting the outer peripheral portion of the wafer from below, and the wafer can be transferred between the fixed stage and the rotating stage. The notch sensor is a notch drawn when the wafer is rotated without misalignment. A notch light-emitting element that irradiates light vertically on the movement locus of the notch, and a notch light-receiving element that can receive light from the notch light-emitting element, wherein the eccentricity sensor includes an inner sensor and an outer sensor. The inner sensor is an inner light emitting element that irradiates light vertically on a movement locus at a position closer to the center of the wafer than the notch, and from the inner light emitting element. An outer light-emitting element that irradiates light vertically on a movement trajectory of a position deviated from the wafer, and receives light from the outer light-emitting element. A light emitting element for the notch and the inner and outer light emitting elements are arranged in a line in a direction deviated from a radial direction and an outer peripheral tangential direction of the wafer in plan view, and The light receiving elements and the inner and outer light receiving elements are arranged in a plan view, in an arrangement state coinciding with the arrangement state of the three light emitting elements, and detect the notch position of the wafer by the output of the notch light receiving element, The presence or absence of eccentricity of the wafer is determined based on the three outputs of the outer light receiving element and the light receiving element for the notch. After transferring the wafer to, the wafer is again transferred from the fixed stage to the rotary stage,
A notch aligner characterized by performing notch detection and eccentricity determination of a wafer again.