JP3512789B2 - Wafer shape measuring device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat thin wafer shape such as a silicon wafer (flatness, warpage,
The present invention relates to a wafer shape measuring device used for measuring (thickness).

[0002]

2. Description of the Related Art Conventionally, a wafer shape measuring apparatus used in a semiconductor device manufacturing process or the like holds a central portion of a silicon wafer 100 as shown in FIG. 7 with a holding member 101 such as a vacuum chuck. Holding member 101
The wafer 100 is rotated on a horizontal plane by rotating the rotary shaft 102 of the wafer through a rolling rotary bearing 103, and two sensors 110 are provided at the tip of the U-shaped portion.
Rolling linear motion bearings 1 each having an arm 111
The sensor 110 is moved by moving
In some cases, the wafer 100 is scanned so as to be sandwiched, and the flatness, warpage, thickness, and other shapes of the wafer 100 are measured.

[0003]

However, the wafer shape measuring apparatus shown in FIG. 7 has the following problems. 1) Error due to bending due to its own weight Since the structure is such that the central portion of the wafer 100 is held and rotated on a horizontal plane, there is a problem in that the peripheral portion of the wafer 100 causes bending measurement error due to its own weight. In particular, this phenomenon becomes more remarkable as the wafer 100 has a larger diameter, which is a large error factor in the measurement of the warp. 2) Error due to the method of holding the wafer 100 Since the central portion of the wafer 100 is held, if the contact area with the holding member 101 is too large, the wafer 100 warps in accordance with its flatness. ,
On the other hand, if the contact area with the holding member 101 is too small, the peripheral portion of the wafer 100 vibrates during rotation, which makes accurate measurement impossible. 3) Wafer 10 at the contact portion with holding member 101
Since the central portion of the wafer 100 whose thickness is 0 cannot be measured is held by the holding member 101, the holding member 10 is used for thickness measurement and the like.
The thickness of the wafer 100 at the contact portion with 1 cannot be measured, and the position of the holding member 101 has to be shifted and then measured again, which is time-consuming and inefficient. It was Moreover, the holding member 10
When the position of 1 is shifted and the measurement is performed again, there is a problem that accurate measurement cannot be performed because the deflection due to its own weight becomes large. 4) The rolling type bearings 103 and 112 used for the rotation mechanism of the error holding member 101 by the rolling type bearings 103 and 112 and the linear motion mechanism of the sensor 110 have a ball or a cylindrical roller which is a rotating element as a contact surface and a point. Due to the contact or the line contact, a slight vibration is liable to occur, which causes a measurement error.

As described above, the conventional wafer shape measuring apparatus which measures a flat thin object to be measured such as the silicon wafer 100 by rotating it on a horizontal plane has various measurement error factors and improves the measurement accuracy. It was very difficult.

Further, since the central portion is held by the holding member 101 such as a vacuum chuck, it is difficult to not only damage the wafer but also to hold the wafer on the holding member 101 for measurement and to automate the measurement. There was also.

[0006]

Means for Solving the Problems] The present invention has been made in view of the above problems, an annular holder with holding mechanism for holding the peripheral edge surfaces of the wafer to be measured into the inner hole, rotatably annular holder fixing member and the two detection members for measuring the shape of the wafer held on said annular holder, the weather at the two detection members vertically formed by hydrostatic supported
The ring-shaped holder that holds the
The static pressure type scan that scans the above two detection members on the har.
A wafer shape measuring apparatus comprising a ride apparatus .

Further, the holding mechanism includes a flange portion formed on the inner hole side of the annular holder and abutting against one surface of the wafer peripheral portion, and the annular holder corresponding to the flange portion having the wafer peripheral portion other than the wafer peripheral portion. It is characterized in that it is composed of a clamp member that abuts on a surface.

Further, an annular holder with holding mechanism for sucking and holding a peripheral portion one side of the wafer to be measured in an inner hole, a fixing member made rotatably vertically hydrostatic supporting the annular holder , Two detection members for measuring the shape of the wafer held in the annular holder, and the two detection units
The ring-shaped holder holding the above wafer is sandwiched by the material.
To scan the above two detection members on the wafer
This is a constitution of a wafer shape measuring device characterized by comprising a static pressure type slide device .

Further, the holding mechanism is characterized in that a flange portion that abuts one surface of the wafer peripheral portion is formed on the inner hole side of the annular holder, and a suction port is formed in the flange portion. .

[0010]

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 is a perspective view showing an example of a wafer shape measuring apparatus according to the present invention, which is a ring-shaped annular holder 1 provided with a holding mechanism for holding a peripheral portion of a wafer to be measured.
And three fixing members 2 for statically supporting the peripheral portion of the annular holder 1, and the groove 1 formed on the outer peripheral surface of the annular holder 1.
a spindle motor 5 and a pulley 6 for controlling the rotation and stop of the annular holder 1 by stretching a wire 7 on a.
It comprises a sensor 4 as a detection member for measuring the shape of the wafer, and a slide device 3 for scanning the sensor 4 on the wafer.

Next, each component of the wafer shape measuring apparatus shown in FIG. 1 will be described in detail. FIG. 2 is a perspective view showing a measuring unit of the wafer shape measuring apparatus according to the present invention,
FIG. 3 is a sectional view taken along line XX of FIG.

The annular holder 1 has an inner hole 11 having an inner diameter equal to or larger than the outer diameter of the wafer, and three flange portions 12 for holding the wafer are projected into the hole 11 at equal intervals. It is set up. Further, a clamp member 13 such as a clip is arranged on the surface of the annular holder 1 corresponding to the flange portion 12, and the flange portion 12 and the clamp member 13 of the annular holder 1 hold both sides of the peripheral edge of the wafer. I keep it.

As described above, by holding the peripheral portion of the wafer at three points, it is possible to measure the entire surface of the wafer by scanning the sensor 4 once on the wafer.

The annular holder 1 shown in FIG. 1 shows an example in which three flange portions 12 for holding the wafer and three clamp members 13 are provided, but three or more flange portions 12 and clamp members 13 are provided if the wafer can be accurately held. It doesn't matter.
When it is not necessary to measure the thickness of the peripheral portion of the wafer, a ring-shaped flange portion 12 may be provided so as to project along the inner hole 11 of the annular holder 1 in order to hold the wafer more reliably.

Further, the three fixing members 2 for statically supporting the annular holder 1 are arranged at equal intervals on the convex wall portion 51 of the base 50, and the annular holder 1 is provided in the concave portion 21 of each fixing member 2. The annular holder 1 is held vertically by gripping the peripheral portion of the annular holder 1. Further, a supply hole 23 is formed on the inner wall surface 21a of the recess 21 of the fixing member 2 for ejecting a compressed fluid into a gap between the annular holder 1 and the annular holder 1 by the compressed fluid ejected from the supply hole 23. A pressure generating groove 22 for forming a hydrostatic fluid layer is formed in the gap, and by supplying a compressed fluid to the supply hole 23 of the fixing member 2, the annular holder 1 is rotatably hydrostatically on the vertical plane. I support it.

As described above, in the present invention, since the wafer held by the annular holder 1 is arranged vertically, the wafer is not bent by gravity, and the original shape of the wafer can be measured. it can. Moreover, since the static pressure fluid layer is formed between the annular holder 1 and the concave portion 21 of the fixing member 2 to support the annular holder 1 under static pressure, the shape measurement of the wafer is adversely affected. The ring-shaped holder 1 can be smoothly rotated with a small driving force without causing a slight vibration.

On the other hand, the sensor 4 for measuring the shape of the wafer is attached to the slide device 3 arranged in parallel with the annular holder 1 on the convex wall portion 51 of the base 50, and the structure of the slide device 3 is shown in FIG. As shown in (a) and (b), a prismatic fixed part 31 and a movable part 32 surrounding the fixed part 31,
And a U-shaped support member 33 having a recess equal to or longer than the diameter of the annular holder 1 provided in the movable portion 32, and the sensor 4 is attached to the tip of the support member 33. . Further, a slight gap is provided between the fixed portion 31 and the movable portion 32, and the movable portion 3
2, a supply hole 35 for ejecting a compressed fluid into a gap between the fixed portion 31 and the movable portion 32, and the supply hole 3
A pressure generating groove 34 for forming a static pressure fluid layer by the compressed fluid ejected from No. 5 is formed.

Then, a compressed fluid is supplied to the supply hole 35 of the movable portion 32 to support the movable portion 32 on the fixed portion 31 by static pressure, and a driving means (not shown) such as a linear motor.
The movable portion 32 is moved by, and the annular holder 1 holding the wafer is sandwiched by the sensor 4 attached to the tip of the support member 33, whereby the flatness and the warp of the wafer,
Furthermore, the thickness can be measured by one scanning.

The wafer shape measuring apparatus shown in FIG. 1 includes a wafer magazine 10 for storing wafers,
Performs extraction and storage of the wafer from the wafer magazine 10, the transfer arm 8 of the vacuum suction method for moving the wafer to a predetermined position, and is disposed on the convex wall portion 51 of the base 50, and the transfer arm 8 A vacuum suction type transfer arm 9 for transferring a wafer and transferring the wafer to the annular holder 1 is provided.

Next, a wafer measuring procedure by the wafer shape measuring apparatus shown in FIG. 1 will be described. First, the wafer is taken out from the wafer magazine 10 by the transfer arm 8, moved to the front of the annular holder 1, and then vertically inverted. After the wafer is transferred to the transfer arm 9 , the flange portion 12 of the annular holder 1 is arranged vertically.
After being conveyed until it comes into contact with the wafer, the both sides of the peripheral edge of the wafer are clamped by the clamp member 13 to hold the wafer in the center of the annular holder 1. At this time, a compressed fluid is supplied between the annular holder 1 and the concave portion 21 of the fixing member 2, and the annular holder 1 is rotatably supported by vertical static pressure in advance.

Then, the annular holder 1 holding the wafer is rotated by the spindle motor 5 and the movable portion 32 of the slide device 3 supported by static pressure is moved to attach the sensor 4 attached to the tip of the support member 33 on the wafer. By scanning with, the shape of the wafer such as flatness, warpage, and thickness can be measured.

As described above, since the wafer shape measuring apparatus according to the present invention holds the wafer vertically, the wafer shape measuring apparatus can measure the original shape of the wafer without bending due to gravity. Further, since the inner diameter of the annular holder 1 is made equal to or larger than the outer diameter of the wafer to hold the peripheral portion of the wafer, it is possible to measure the entire surface of the wafer by scanning the sensor 4 once. The measurement time can be greatly shortened.

Moreover, since the annular holder 1 and the movable portion 32 of the slide device 3 are both rotated and moved by the hydrostatic bearing mechanism, the play caused by the abrasion and sliding resistance of the conventional rolling bearing is caused. There is no sticking and no slight vibration is generated in the wafer and the sensor 4. Therefore, the annular holder 1 for holding the wafer can be smoothly rotated with a small force, and the original shape of the wafer can be accurately measured.

Next, another embodiment of the present invention will be described. FIG. 5 is a perspective view showing another example of the measuring unit of the wafer shape measuring apparatus according to the present invention, and FIG. 6 is a sectional view taken along line ZZ of FIG.

In this measuring unit, the wafer holding mechanism has a vacuum suction structure, and an annular ring groove 1b is formed on the surface of the annular holder 1, and a suction port 1c is formed in the flange portion 12 of the annular holder 1. The suction port 1c is provided so as to communicate with the ring groove 1b of the annular holder 1 through the through hole 1d. Further, a ring body 24 that covers the ring groove 1b of the annular holder 1 is provided on the three fixing members 2 that statically support the annular holder 1, and a vacuum pump is provided from an exhaust hole 25 provided in the ring body 24. By vacuum suction (not shown), one surface of the peripheral edge of the wafer is sucked and held by the flange portion 12 of the annular holder 1.

As described above, by making the wafer holding mechanism a vacuum suction structure, it is possible to further suppress the damage of the wafer as compared with the clamp system shown in FIG. 1 and to completely automate the measurement of the wafer. You can

In the wafer shape measuring apparatus according to the present invention, the wafer holding mechanism may be any one other than the above-mentioned holding mechanism as long as it can hold the wafer without damaging it. Needless to say.

[0029]

As described above, according to the present invention, the wafer is not bent by gravity . Also, the inner diameter of the annular holder should be equal to or larger than the outer diameter of the wafer to hold both sides or one side of the wafer periphery .
Because of this , the entire surface of the wafer can be measured by scanning the sensor once, and the measurement time can be greatly shortened.

Moreover, since the annular holder and the movable portion of the slide device are both rotated and moved by the hydrostatic bearing mechanism, there is no backlash due to wear or sliding resistance, which is the case with conventional rolling bearings. It does not occur and does not generate microvibration on the wafer and the sensor. Therefore, the annular holder for holding the wafer can be smoothly rotated with a small force, and the original shape of the wafer can be accurately measured.

[0031]

[0032]

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a wafer shape measuring apparatus according to the present invention.

FIG. 2 is a perspective view showing a measuring unit of FIG.

3 is a cross-sectional view taken along line XX of FIG.

4A and 4B are views showing the slide device of FIG. 1, in which FIG. 4A is a perspective view and FIG. 4B is a sectional view taken along line YY.

FIG. 5 is a perspective view showing another example of the measuring unit in the wafer shape measuring apparatus according to the present invention.

FIG. 6 is a sectional view taken along line ZZ in FIG.

FIG. 7 is a front view showing an outline of a conventional wafer shape measuring apparatus.

[Explanation of symbols]

1-annular holder 2 ... Fixing member 3 ... Slide device 4 ... Sensor 5: Spindle motor 6 ... pulley 7 ... Wire 8 ... First transfer arm (first transfer means) 9 ... Second transfer arm (transfer means for disconnection 2) 10 ... Wafer magazine

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-8-152319 (JP, A) JP-A-5-79828 (JP, A) JP-A-61-292336 (JP, A) JP-A-5- 23936 (JP, A) JP-A-6-158444 (JP, A) Actual development: 6-49958 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01B 21/00-21 / 32 G01B 11/00-11/30

Claims (4)

(57) [Claims] To 1. A bore and an annular holder with holding mechanism for holding the peripheral edge surfaces of the wafer to be measured, and the fixing member formed by rotatably vertically hydrostatic supporting the annular holder, the cyclic and two detection members for measuring the shape of the wafer held on the annular holder, in the above two detection member holding the wafer Hol
The above two detections are performed on the wafer by sandwiching the wafer
It consists of a static pressure type slide device that scans the member.
A wafer shape measuring device characterized by: 2. The holding mechanism comprises a flange portion formed on the inner hole side of the annular holder and abutting on one surface of the wafer peripheral portion, and the annular holder corresponding to the flange portion having the other wafer peripheral portion. 2. The wafer shape measuring apparatus according to claim 1, further comprising a clamp member that abuts on the surface. 3. An annular holder having a holding mechanism for sucking and holding one side surface of a peripheral edge portion of a wafer, which is an object to be measured, in an inner hole; , and two detection members for measuring the shape of the wafer held on said annular holder and hold the wafer in the two detection members annular Hol
The above two detections are performed on the wafer by sandwiching the wafer
It consists of a static pressure type slide device that scans the member.
A wafer shape measuring device characterized by: 4. The holding mechanism is characterized in that a flange portion that abuts one surface of the wafer peripheral portion is formed on the inner hole side of the annular holder, and a suction port is formed in the flange portion. The wafer shape measuring apparatus according to claim 3.