JPS58154247A - Apparatus for positioning wafer - Google Patents

Abstract

PURPOSE:To realize simultaneous use of two positioning apparatuses having different prealignment reference by calculating and compensating deviation of a distance between the specified position and external circumference of wafer from the reference position after a wafer is preliminarily positioned for the external circumference. CONSTITUTION:When a wafer 11 of the desired size is inserted into the fixed prealignment references 12, 13, 14, while measuring probes 16, 17 are pressing the wafer 11 to the fixed standards 12, 13, 14 respectively, measuring instruments 18, 19 read displacements DELTAx, DELTAy from the reference values based on the reference wafer 10. Outputs of the measuring instruments 18, 19 are sent to an operation unit 20 and the center position of the wafer 11 is calculated therein. When the wafer center is considered as 15' and displacements of center are considered as deltax, deltay, following relation can be obtained: deltax=DELTAx/2, deltay=DELTAy-DELTAx/2. Compensation as much as these values is given.

Description

[Detailed description of the invention] The present invention relates to one or eight positioning devices.

Mask aligners, bonders, probers, and the like, which are generally devices for manufacturing ICs, LSIs, etc., require positioning of semiconductor wafer patterns in each geographical process. Regarding this positioning, generally a preliminary positioning (clear alignment) is performed on the surface of the main positioning, reducing the accuracy by one level.

In other words, after preliminary positioning using the outer shape, the position of the pattern is corrected (main positioning) to the target accuracy using an optical means, such as a tf-type jumper. That's exposure)K
It is customary to enter.

However, there are various means for this preliminary positioning, and the same means for preliminary positioning is not necessarily used in each I & ring process of the woofer, and the order in which each woofer is introduced is not constant in each process process, and generally As shown in Figs. 1 and 2, in different processing steps, the observation field of view of the pattern in the previous step tends to become smaller; for example, in some aligners, -0.2M If the predetermined pattern is not found by preliminary positioning, a rounding groping operation is forced to search for the predetermined pattern,
The time wasted in this way is a problem for this type of equipment, which is a production machine.

That is, as shown in 1st IIK, each size of woo-
In contrast to 1, there is a movable positioning member 3 with two bases in the center.
After that, in the next step, as shown in Fig. 2, for each size, the circumference s is determined.
When positioning is performed using the fixed positioning members 7 and 8.9 using the O1 point and the orientation flat (straight line part of the wafer) as a reference, the pattern position on C is aligned with the center reference of the wafer. (c) As the center shifts, the pattern position is shifted from its original position. This is the same even if the order of preliminary positioning in FIGS. 1 and 2 is changed.

The relationship between the woofer l outer diameter and the pattern is in the tH1 process of the photo, and the deviation of the pre-alignment error of the aligner used at that time is defined as the deviation, and the error deviation value of the device used in the NO process is defined as σ. If the pre-alignment standards of the 1-stroke and N-stroke devices are the same, the overall accuracy σ tube seen under the N-stroke microscope is σ? −M +Jlη2
4 g, l.

M is the difference between the distribution center values of l and N. Efforts to reduce C in glial alignment have been proposed in many patents in the past, and the forces that reduce 19M are carried out by those who manage the semiconductor manufacturing process.

However, the situation is different when the prealignment standards of the 1-stroke device and the N-stroke device are different.The prealignment accuracy is largely influenced by the 1-woofer size.

According to a certain standard, the outer diameter D = 1 for -41 and C.
00±11 olive 0F=315±2.5. For example, if one process of photo is processed using the Dahlia 2 image standard shown in Figure 811 and the N process is processed using the pre-alignment standard shown in Figure aI2, then 6=σM=
Even if M""O is used, an error exceeding about φ1as will occur. SUMMARY OF THE INVENTION An object of the present invention is to provide a positioning device of the order of 8, which can guarantee a sufficient angle of 1'11 degrees even when two devices having different prealignment standards are used together.

The purpose of this is to provide means for pre-positioning the hemlock relative to its outer periphery and from being in position.

This is achieved by a configuration having means for comparing and measuring the distance to the outer circumference of the eighth grade with a reference value, and means for calculating the deviation from the reference position of the eighth grade from the measured value of the means. When feeding the woofer under the rounding microscope for this positioning, the above deviation J
It is sufficient to anticipate t (ono set amount) and send it to compensate for this. Hereinafter, an embodiment of the present invention will be explained based on FIG. It is assumed that I&Salt will be used with a device that has.

Reference numeral 10 denotes a reference wafer with an outer diameter, an orientation flat (orientation flat), and a distance between circular arcs F. In this woofer, the pattern in the first process and #IN line machine matches. 15 is X
The center of the Y locus and the reference point coincide with the center of 1G. 12.13°14 is a fixed pre-alignment reference. When a woofer 11 of any size is inserted, the measurement probe 16.17 identifies the wafer 11 with the identification criteria 12.13,
14, the delimiters 18 and 19 determine the deviation amount ΔX, Δ from the reference position based on the reference position □HAIO.
y respectively.

Measurements 618 and 19 can be of any type as long as the dominant quantity can be converted into an electrical signal or other 0 Δ as an electrical signal! , .DELTA.y are sent to a computing unit 20 to calculate the center position of the woofer 1.

The center of woofer 1 is set at 15' and the deviation amount of the center is Jx.

δy, and the diameter is D÷ΔD, and three points A on the circumference.

Taking B and C into consideration, the following equation holds true.

(1no'D)! =<River+Jx)”+ (Jy)”2 − (No+Δy−−1)3÷(Jx)”=(8+Δz−
1x)"+(J7)" Jx, J7, H11 offset amount, 9-J,
, -a7, it is possible to correct the running time processed by the first batting machine, the outer shape of C, and the pattern position relative to .

Generally, in a device with a difference of 0@, the optical system (pink mirror)
It is equipped with a stage that can move the position of Hatake, and if #J constant scale is added to this stage, the above offset correction can be easily performed. Adding these functions to the alignment mechanism would be amazing.

Note that the present invention is not limited to this embodiment, and the measured value K
'x*' It is arbitrary as long as the condition that the value of y can be calculated is satisfied.

As is clear from the above equation, it is possible to calculate the steepness D+ΔD of the woofer diameter from the measurement of ΔX and Δy, and this value can also be used additionally as a take-up for each ridge.

As described above, according to the present invention, it is possible to provide a positioning device for a woofer, etc., which can ensure sufficient pre-alignment accuracy even when two devices having different pre-alignment standards are used.

[Brief explanation of the drawing]

Figure 1 and Figure 2- are explanatory diagrams of different conventional pre-alignments. Figure 3 is a diagram of an embodiment of the present invention. In the figures, lO is a reference point, C11 is a beam, and C12, 13, and 14 are hard-carved toads. 15, 16 and 17 are measuring blocks 18 and 19 are calculators 20 and 20, respectively. Applicant Canon Co., Ltd.

Claims (1)

[Claims] 1. Means for preliminarily positioning the Umha group with respect to its outer periphery; Means for comparing and adjusting the distance from a predetermined position to the outer periphery S of the Umha group with a reference value; and Measurement of the scissor hand setting. 8. A positioning device, characterized in that it has means for calculating a deviation from a reference position of a woofer or the like from a value. 2. The base position cover of the woofer etc. is in the preliminary position,
The first range of the registration license corresponding to the position of the woofer, etc., which is pre-positioned by a pre-positioning means different from the fixing means.
One and eight positioning devices as described in Section 1. 3. The preliminary positioning means mentioned above is for positioning based on at least two points on the outer periphery of the six groups, and the preliminary positioning means different from the preliminary positioning means is for positioning at the center of the group III. A positioning device for a woofer or the like according to Claim 2]J. t. The woofer positioning device according to claim 3, wherein the measuring means is provided at at least two positions corresponding to the outer peripheral reference of the preliminary positioning means.