JP2001007188A - Suction mounting table and foreign matter inspection device using the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a suction mounting table for sucking an object to be measured only around a table surface and a foreign matter inspection device using the same. SOLUTION: A suction chuck is formed only in a peripheral portion on a table surface of a suction mounting table.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suction mounting table for sucking an object to be measured only at a peripheral portion thereof and a foreign matter inspection apparatus using the same.

[0002]

2. Description of the Related Art In a conventional optical particle inspection apparatus, a table surface of a suction mounting table is a suction chuck surface of a full-surface suction type that suctions substantially the entire surface of a wafer. Many suction holes are formed on the table surface of the conventional suction mounting table at substantially equal intervals and in a uniform arrangement pattern.

However, in a suction mounting table for suctioning and suctioning an object to be measured for inspection and measurement, it is possible to adsorb and mount only at a peripheral portion of the object to be measured (wafer) where contamination is allowed. desirable.

[0004]

However, since the conventional suction mounting table has a suction chuck surface of a full-surface suction type, there is a problem that almost the entire surface of the wafer is suctioned and dust adheres to the back surface of the wafer. Was.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a suction mounting table capable of suctioning an object to be measured only at a peripheral portion of the table, and a foreign matter inspection apparatus using the same.

[0006]

A preferred solution of the present invention is a suction mounting table according to claims 1 to 4.

Another preferred solution of the invention is claim 5
The foreign matter inspection device according to the above.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a suction mounting table for sucking an object to be measured only at the periphery of the table and a foreign matter inspection apparatus using the same.

In the conventional example, the table surface of the suction mounting table is a suction chuck surface of a full-surface suction type that suctions almost the entire surface of the wafer. However, in the present invention, only the peripheral portion of the table of the suction mounting table is used. A suction chuck is formed on the surface, and the table is set to a suction chuck surface of a peripheral suction type.

SUMMARY OF THE INVENTION The present invention provides a suction mounting table for suction-mounting only a peripheral portion of a wafer in order to solve the problem of dust adhesion on the back surface of an object to be measured (for example, a wafer) to be suction-mounted. It is.

Preferably, the suction mounting table is a rotation suction mounting table having a central portion formed in a concave portion. Then, a guide is provided on the outer peripheral portion of the table along the contour of the object to be measured.

[0012] More preferably, the suction chuck is divided into a plurality of parts, a part of the suction chuck is sucked by a first system, and the other part is separated from the first system. It is configured to be sucked by the independent second system.

Another embodiment of the present invention is a suction mounting table on which the suction chuck is formed, a suction unit for generating a negative pressure, and a passage connecting the suction unit and the suction chuck of the suction mounting table. Unit, an irradiation optical system that irradiates light to the object to be measured, a light receiving optical system that receives reflected light from the object to be measured, a height detection unit that measures the height of the object to be measured, Light from the irradiation optical system based on the output of the height detection unit, from the position adjustment unit that adjusts the positional relationship between the irradiation optical system and the object to be measured so as to irradiate the object to be measured under predetermined conditions. Foreign matter inspection device.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] A first embodiment will be described with reference to FIGS. The suction mounting table is a peripheral suction type.

First, an outline of the apparatus will be described with reference to FIG.

FIG. 1A is a conceptual diagram of a foreign matter inspection apparatus showing a first embodiment. FIG. 1B is a schematic explanatory view of a measuring unit of the foreign matter inspection / measuring device of FIG. It is a figure showing signs that it is adsorbed.

The foreign substance inspection apparatus is composed of a suction mounting table 11
And an inspection optical system 3 (for example, an inspection optical system including an autofocus mechanism). The transfer device 2 includes a cassette 4, a robot 5, an alignment pin 6, and a lock pin 7. The cassette 4 stores wafers 8 inside the cassette 4. The alignment pin 6 is provided on a frame (not shown) of the foreign matter inspection device.
Are mounted so as to be movable in the Z direction. The alignment pin (positioning pin) 6 has four rod-shaped members 6a. A recess is formed in the upper end 6b of the rod-shaped member. The wafer 8 is placed on the upper end 6b of the rod-shaped member.

The lock pin 7 is fixed to a frame (not shown) of the foreign matter inspection device. The lock pin 7 pushes up a claw member of a later-described wafer detachment prevention safety claw.

The robot 5 includes an arm unit 10 and a suction unit 12 as a part thereof is shown. Suction unit 1
2 can employ a known suction mechanism. By bending or extending the arm part 10, the suction part 12 is moved in the front-back direction. By moving the arm unit 10 in the Z direction, the suction unit 12 is moved in the Z direction. Robot 5
By rotating the arm unit 10 in the S direction about the point D, the suction unit 12 is turned in the S direction. Suction unit 1
2 holds the wafer 8 by suction. Then, the suction unit 1
2 and hold the wafer 8 with the alignment pins 6
Place on.

The suction mounting table 11 can be moved in the X direction by a driving mechanism using a screw rod 13. The suction mounting table 11 is moved from the alignment pin 6 to the measuring section 3.
Move to. The suction mounting table 11 can also be moved from the measuring section 3 to the alignment pins 6.

FIG. 2 is a view showing a state where a wafer is sucked on the suction mounting table of the present invention.

The suction mounting table 11 has a table surface 11
The wafer 8 is sucked by b (that is, the suction chuck surface). The table surface 11b of the suction mounting table 11 rotates. The table surface is formed in a concave portion over a wide range from the center of the table surface. Therefore, the contact area between the wafer 8 and the table surface 11b can be reduced.

Table surface 11b of suction mounting table 11
The suction grooves 11c, 11d, 1
1e and 11f are formed in a circular shape. The suction grooves 11c, 11d, 11e, 11f thus formed in a circular shape.
Forms a chuck for suction. That is, the suction mounting table 11 has a peripheral suction type suction chuck surface. The suction grooves 11c, 11d, 11e, 11f are connected to a suction device (suction unit, not shown) through a passage (not shown). The suction unit creates a negative pressure (negative pressure). The passage connects the suction unit and the suction chucks (suction grooves 11c, 11d, 11e, 11f) of the suction mounting table. Therefore, the suction mounting table 11 suctions the wafer 8 to the table surface 11b.

Table surface 11b of suction mounting table 11
Is provided with a guide 32 along the contour of the wafer. The guide 32 allows the wafer 8 to be smoothly positioned and mounted on the table surface 11b of the suction mounting table.

Table surface 11b of suction mounting table 11
Are provided at four locations on the outer periphery of the device. As shown in FIG. 3, the wafer detachment preventing safety claw 34 has a claw member 36 having an arrow T
Rotate in the direction of. The claw member 36 rotated in the direction of the arrow T in FIG. 3 is locked at the position shown in FIG. 4 to prevent the wafer 8 from being detached.

Next, the measuring section shown in FIG. 1 will be described.

The inspection optical system of the measuring section 3 has a light emitting system (irradiation optical system) 14 and a light receiving system (light receiving optical system) 15 as shown in FIG. As shown in FIG. 5, the light receiving system 15 includes a scattered light receiving system 16 and a specular reflection light receiving system 19. The light emitting system 14 has a light source (not shown), and irradiates the surface of the wafer 8 with a laser beam from the light source,
The scattered reflected light generated by the surface abnormality is received by the light receiving system 15. As shown in FIG. 5, the light receiving signal of the light receiving system 15 is extracted as an electric signal and sent to the control calculation unit 25.
Predetermined data processing is performed to detect the presence / absence of a scratch, dust, dirt, or the like on the wafer surface and the position of the defect.

The measuring section 3 can be configured in the same manner as the measuring section of the conventional inspection apparatus. The measuring unit 3 includes an automatic focusing mechanism, that is, an automatic focusing system 20 (FIG. 5), in addition to the inspection optical system described above.

FIG. 5 is a block diagram schematically showing the foreign matter inspection apparatus shown in FIG.

The foreign matter inspection apparatus includes a height detection unit 38 and a position adjustment unit 39. The position adjusting unit 39 is provided with the table X
A direction moving unit 22, a table Z direction moving unit 23, and a table rotating unit 24 are provided. Height detector 38 measures the height of wafer 8 (FIG. 1) from a predetermined level. Based on the output from the height detector 38, the position adjuster 39
Adjusts the positional relationship between the light emitting system 14 and the wafer 8 such that the light beam from the light emitting system 14 is irradiated on the wafer 8 (FIG. 1) under predetermined conditions.

The control calculation unit 25 controls the robot arm drive unit 26 to rotate the robot arm 10 (FIG. 1). The control calculation unit 25 controls the robot arm driving unit 26 to move the robot arm 10 up and down and back and forth. The control calculation unit 25 includes the table X-direction moving unit 22
, Table Z direction moving unit 23, table rotating unit 24
Control. The control calculation unit 25 includes the suction mounting table 11
(FIG. 1) is moved in the X direction and the Z direction, and the suction mounting table 11 is rotated. By controlling the table Z-direction moving unit 23 by the control calculation unit 25, it is possible to focus on the measuring unit 3 (FIG. 1). Control operation unit 25
By controlling the table Z-direction moving unit 23, the suction mounting table 11 is moved in the Z direction.

The control arithmetic unit 25 includes an automatic focusing system (autofocus mechanism) 20, a light emitting system 14, and a scattered light receiving system 1.
6, the specular reflection light receiving system 19 and the drive unit 29 are controlled.
The control operation unit 25 displays the inspection result on the display 30 as necessary.
To display. The display 30 displays the position and number of foreign substances, the level of scattered light, and the like.

FIG. 6 is a diagram showing a schematic flowchart of the inspection by the foreign substance inspection apparatus of FIG.

When the inspection is started, in step S1, the type of the inspection object 8 (FIG. 1) is determined, and the type of the surface scattering is small (for example, a bare wafer or a wafer with a SiO ₂ film) or the surface scattering is large. (E.g., a wafer with a metal film).

When the inspection object 8 (FIG. 1) is an inspection object with a small surface scattering, the process proceeds to step S2, and the sensitivity is set to a setting suitable for the inspection object with a small surface scattering (first condition).
Proceed to step S3. In step S3, scanning is performed,
Proceed to step S4.

In step S4, the control calculation section 25 receives the light receiving signal from the light receiving system 15, selects a light receiving signal to be subjected to signal processing, and proceeds to step S5.

In step S5, the control calculation unit 25 performs predetermined signal processing on the selected light receiving signal, and determines the type of inspection object (for example, a convex foreign substance, a concave crystal defect, etc .; not shown here). ) Is extracted, and data such as the start coordinates, end coordinates, and peak coordinates are obtained, and step S6 is performed.
Proceed to.

In step S6, the type of inspection object (not shown) (for example, a convex foreign substance or a concave crystal defect) is determined based on the extracted data, and the flow advances to step S7.

In step S7, it is determined whether or not to end the scanning. If not, return to step S4,
The process is repeated until the end of the scan. If scanning is completed,
Proceed to step S8.

In step S8, the inspection data to be inspected is stored, and the flow advances to step S9.

In step S9, the inspection data to be inspected is displayed on the display 30 in a predetermined format, and the flow advances to step S10.

In step S10, it is determined whether the measurement has been completed. If the measurement is not completed, the process returns to step S1, and a new measurement is performed. Otherwise, the process ends.

If it is determined in step S1 that the object to be inspected has a large amount of surface scattering (for example, a wafer with a metal film), the process proceeds to step S11, and the sensitivity is set to a value suitable for the object to be inspected with large surface scattering. (Second condition). In this case, the process proceeds to step S3, and the inspection is performed in the same manner as described above.

The outline of the usage of the foreign matter inspection apparatus using the wafer adapter having the above-described configuration will be described below with reference to FIG.

The suction portion 12 enters the lower surface of the wafer 8 in the cassette 4 and suctions the wafer 8 (position A).

The wafer 8 is taken out of the cassette 4 and transferred to the alignment pins 6 (position B). The alignment pins 6 move up. The wafer 8 moves up (B position).

The suction mounting table 11 moves to the lower surface of the wafer 8 on the alignment pins 6 (position B).

The alignment pins 6 are lowered to transfer the wafer 8 to the suction mounting table 11 (position B).

At the position B, the suction mounting table 11 is lowered, and the claw member 36 of the wafer separation preventing safety claw 34 hits the lock pin 7, and the wafer separation prevention safety claw 34 is operated (position B).

The suction mounting table rises to the measurement position, moves to the position C, and starts measurement.

[Second Embodiment] Next, a second embodiment will be described with reference to FIG.

Suction chucks such as suction grooves 11c and 1c
1d, 11e, and 11f are divided into a plurality of portions, and a part of the suction grooves 11c, 11d, 11e, and 11f is configured to be sucked by a first system (not shown). The portion is configured to be sucked by a second system (not shown) independent of the first system.

For example, the suction chuck formed on the periphery of the table surface 11b of the rotary suction mounting table 11 has four parts, that is, four suction grooves 11c, 11c.
d, 11e, and 11f. The suction grooves 11c and 11e, which are parts of the suction chuck, are configured to be sucked by the first system. The suction grooves 11d and 11f, which are other portions of the suction chuck, are configured to be sucked by a second system independent of the first system.

Therefore, the suction can be performed by only one of the first system and the second system. Suction can be performed in both the first system and the second system. In other words, a suction position on the table surface 11b of the suction mounting table 11 can be selected as needed. For example, suction is performed by the first system, and the suction grooves 11c, 1
The wafer can be sucked only by 1e.

[0056]

According to the suction mounting table of the present invention, it is possible to suction only the peripheral portion of the object to be measured mounted on the suction mounting table. When the object to be measured is a wafer, it is possible to mount by suction only at the peripheral portion of the wafer where contamination is allowed.

According to the suction mounting table of the present invention, a suction position on the table surface can be selected. Therefore, suction suction can be performed according to the shape of the object to be measured mounted on the suction mounting table. Further, only a necessary portion of the object to be measured can be sucked.

[Brief description of the drawings]

FIG. 1A is a conceptual diagram of a foreign matter inspection apparatus showing a first preferred embodiment of the present invention. (B) is a schematic explanatory view of a measuring unit of the foreign matter inspection and measurement device of (a).

FIG. 2 is a diagram showing a state where a wafer is sucked on a suction mounting table of the present invention.

FIG. 3 is a diagram showing a state in which a wafer detachment preventing safety claw is not locked;

FIG. 4 is a diagram showing a state in which a safety hook for preventing wafer detachment is locked.

FIG. 5 is a block diagram schematically showing the foreign matter inspection device of FIG. 1;

FIG. 6 is a view showing a schematic flowchart of an inspection by the foreign matter inspection apparatus of FIG. 1;

FIG. 7 is a view showing a foreign matter inspection apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

 2 Conveying device 3 Measuring unit 4 Cassette 5 Robot 6 Alignment pin 7 Lock pin 8 Wafer 10 Arm 11 Table 11b Table surface 11c, 11d, 11e, 11f Suction groove 12 Suction unit 13 Screw rod 14 Light emitting system 15 Light receiving system 16 Light receiving system 16 Scattered light reception System 19 Specular reflection light receiving system 20 Automatic focusing system 22 Table X direction moving unit 23 Table Y direction moving unit 24 Table rotating unit 25 Control operation unit 26 Robot arm drive unit 29 Drive unit 30 Display 32 Guide 34 Wafer separation prevention safety claw 36 Claw member 38 Height detector 39 Position adjuster

Continued on the front page F term (reference) 2G051 AA51 AB01 AB07 BA10 CA02 CB01 CB05 DA03 DA07 DA08 EA14 FA10 4M106 AA01 BA04 BA05 CA41 DB02 DB08 DJ02 5F031 CA02 HA14 HA58 JA06 JA32 PA16 PA23

Claims (5)

[Claims] 1. A suction mounting table in which a suction chuck is formed only in a peripheral portion. 2. The suction mounting table according to claim 1, wherein a guide is provided on an outer peripheral portion along a contour of the object to be measured. 3. The suction mounting table according to claim 1, wherein the central portion is formed in a concave portion. 4. The suction chuck is divided into a plurality of parts, a part of the suction chuck is sucked by a first system, and the other part is separated from the first system. The suction mounting table according to any one of claims 1 to 3, wherein the suction mounting table is configured to be sucked by an independent second system. 5. A suction mounting table on which the suction chuck according to claim 1 is formed, a suction unit for generating a negative pressure, and a suction unit and a suction unit for suctioning the suction mounting table. A passage connecting the chuck, an irradiation optical system for irradiating light to the object to be measured, a light receiving optical system for receiving reflected light from the object to be measured, and a height for measuring the height of the object to be measured The positional relationship between the irradiation optical system and the object to be measured is adjusted so that the light from the irradiation optical system is irradiated on the object to be measured under predetermined conditions based on the output of the detection unit and the height detection unit. A foreign matter inspection device, comprising: a position adjustment unit.