JP2560002B2 - Wafer prober - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The disclosed technology is an invention relating to a wafer prober for aligning a semiconductor wafer in a semiconductor manufacturing apparatus,
In particular, the invention relates to a wafer prober that accurately detects a characteristic portion of the semiconductor wafer.

<Prior Art> Conventionally, in a wafer prober for aligning a semiconductor wafer (hereinafter simply referred to as “wafer”), a mode for performing alignment by irradiating a laser beam and a mode for performing alignment using an imaging camera are used. was there.

<Problems to be Solved by the Invention> However, in the former, the surface of a semiconductor wafer chip (hereinafter abbreviated as a chip) is irradiated with laser light, and scattered light generated by reflection on the surface of the chip is collected to collect the scattered light. Is converted into an electric signal, and the obtained electric signal is compared with basic recognition information to detect a characteristic portion. The surface of the chip is repeatedly scanned to obtain information for determining the characteristic portion. However, there is a drawback that it takes a long time to process, and there is a drawback that work efficiency is reduced.

On the other hand, the latter is a mode in which a characteristic portion is searched for by an imaging camera in which the surface of the wafer is set at a high magnification. However, as shown in FIG.
30b, ..., 30z are sequentially moved together with the mounting table on which the wafer is adsorbed at a constant speed to search for a characteristic portion, which also has a drawback that a lot of time is required for the work.

<Object of the Invention> An object of the present invention is to solve the problem of alignment of the wafer prober in the semiconductor manufacturing apparatus based on the above-mentioned conventional technique, and to eliminate the above-mentioned drawbacks of the conventional embodiment and solve the difficulties. The present invention aims to provide an excellent wafer prober that benefits the field of measurement technology application in the semiconductor manufacturing industry.

<Means and Actions for Solving the Problems> In order to solve the above-mentioned problems, the structure of the invention of the present application, which is based on the above-mentioned claims, is aimed at solving the above-mentioned problems. The first light information of the feature portion is roughly detected by the first macroscopic light information, a part of the information of the feature portion is limited, and then this is microscopically magnified to obtain the feature information of the feature portion. The detailed position is detected as the second light information. At this time, regarding the wafer alignment, the wafer surface having the information of the characteristic portion is macroscopically captured by the image capturing camera and the center of the image capturing screen is adjusted as much as possible. Is recognized, and the wafer is moved to a position for detecting the second optical information by enlarging and capturing the characteristic portion and enlarged by an imaging camera to microscopically obtain the second optical information. Catch
In this way, the technical means for accurately detecting the position of the characteristic portion is taken.

<Embodiment> Next, an embodiment of the invention of this application will be described below with reference to FIGS.

It should be noted that parts that are the same as those in FIG. 6 will be described using the same symbols.

In the embodiment shown in FIGS. 1 to 4, the surface of the wafer 14 is
When the means for macroscopically detecting as the optical information and the means for microscopically detecting as the second optical information are functionally described by the mode of FIG. 1, the macroscopically detecting as the first optical information is performed. In the means, the light emitted from a predetermined light source 7 is radiated through the lens 6 onto the surface of the wafer 14 (Fig. 2) not shown in Fig. 1, and then the wafer shown in Fig. 2A. The reflected light reflected from the 14 macroscopic areas is reflected by the mirror 5,
The first optical information is made incident on the imaging camera 1 through the lens 4, the mirror 3, and the beam splitter 2.

Next, in the second optical information means for microscopically detecting the surface of the wafer 14, as shown in FIG.
The light emitted from the laser beam illuminates the microscopic area B on the surface of the wafer 14 through the lens 12.

Since the location of the wafer 14 is different when macroscopically detecting the first optical information and when microscopically detecting the second optical information, the distance between the different locations is appropriately calculated. It is calculated by the means, and the mounting table (not shown) on which the wafer 14 is sucked is moved two-dimensionally by the means so that the selected characteristic portion can be detected.

Then, the reflected light of the second optical information reflected from the microscopic area portion of the wafer 14 shown in FIG. 2B is magnified by the lens 11, and the mirror 10, the mirror 9, the lens 8 and the beam splitter 2 Through the image pickup camera 1 as the second light information.

Incidentally, the optical axis incident on the beam splitter 2 or the imaging camera 1 is preliminarily coaxial with the means for the first optical information for macroscopically detecting and the means for the second optical information for microscopically detecting. Set it.

Thus, the first optical information incident on the imaging camera 1 by means of macroscopic detection and the second optical information incident on the imaging camera 1 by means of microscopic detection are mutually switched by the switching means. The switching means comprises a shield plate 21 positioned in front of the beam splitter 2 and a cylinder type drive unit 22 for the shield plate 21, and the shield plate 21 is driven by the drive unit. It can be switched by driving with 22.

A signal for switching between the macroscopically detecting means and the microscopically detecting means is input to the switching means as control means.

As the processing means, the first optical information detected by the macroscopic detection means is input, and the first optical information determined by comparing the basic recognition information with predetermined determination means First, predetermined characteristic information close to the center is microscopically detected by the second optical information to record a characteristic position.

Next, regarding the operation of the wafer prober, as shown in FIG. 2, the wafer 14 is measured by means for macroscopically detecting the first optical information.
As shown in FIG. 3 (a), the first optical information of the pattern of the macroscopic area of the part A captured by the imaging camera 1 is as follows: For example, after comparing the data of the intersections of the script lines with the data already recorded as the basic recognition information by the judging means, a plurality of characteristic portions 31 are detected, but the first optical information captured by the imaging camera 1 is detected. Select the feature closest to the center of the pattern.

Next, as shown in FIG. 2 again, the second microscopic detection is performed.
The minimum area of B is magnified by the means of optical information and captured by the imaging camera 1, and the pattern of the second optical information of the minimum area of the portion B captured by the imaging camera 1 is shown in FIG. As shown, the position of one feature 31E is recorded.

At that time, the characteristic portion closest to the center of the pattern of the first optical information obtained by capturing the macroscopic area portion of A by the imaging camera 1 is selected, and at the same time, the driving device 22 of the shield plate 21 of the switching means selects the characteristic portion. The shield plate 21 is driven to switch from the macroscopic lens system axis to the microscopic lens system axis to obtain the second optical information.

The control by the switching signal of the switching means and the like are all performed by the control means.

In the above operation, as shown in FIG. 4, the straight line component connecting at least two characteristic portions has an inclination θ with respect to the basic straight line component.
In the case of occurrence, a predetermined calculation is performed, and a control signal is output from the control means based on the calculation result, and the moving means of the mounting table on which the wafer is adsorbed is controlled to correct the mounting table by a corresponding angle rotation. Then, they are matched.

FIG. 5 shows another embodiment. In FIG. 5, the image pickup camera 1, the mirror 5, the lens 6, the light source 7,
The wafer 14 is the same as that shown in FIG. 4, and 40 is a means for detecting the characteristics of the surface of the wafer 14, which macroscopically and microscopically images the surface of the wafer 14 on the same optical axis. Camera 1
It is composed of a zoom lens system for capturing.

The operation of this embodiment will be described. In the zoom lens system 40, the light from the light source 7 is radiated through the lens 6 onto the surface (not shown) of the wafer 14, and the reflected light reflected from the macroscopic area A is reflected. The first optical information passes through the mirror 5, and enters the imaging camera 1 through the zoom lens system 40 set so as to capture the macroscopic area A.

Then, the incident pattern is captured as shown in FIG. 3 (a), and is detected macroscopically on the surface of the wafer 14.

Next, the means for microscopically detecting the surface of the wafer 14 passes through the mirror 5 the reflected light reflected from the macroscopic area A irradiated with the light on the surface of the wafer 14 from the light source 7 through the lens 6. The microscopic area portion B is made incident on the image pickup camera 1 as second optical information through the zoom lens system 40 set so as to capture the microscopically selected area portion B.

The pattern thus entered is captured as shown in FIG. 3 (b), and the surface of the wafer 14 is microscopically detected.

Thus, the switching means for switching between the means for macroscopically detecting and the means for microscopically detecting controls the signal in which one is selected from the plurality of characteristic parts 31 macroscopically captured as described above. Then, the control means outputs a switching signal to a driving means (not shown) of the zoom lens system 40 to move the lens so as to be a lens system means for microscopically detecting.

Then, after detecting the position of the characteristic portion 31, the wafer 14 is aligned by operating in the same manner as described above.

It should be noted that the relative arrangement and quantity of the components described in each of the above-described embodiments are not intended to limit the scope of the invention of this application to them, but are merely examples of explanation.

<Effects of the Invention> As described above, according to the wafer prober of the invention of this application, the chip on the wafer is kept in an enlarged state and searched endlessly as in the conventional case, and the characteristic part is not searched. , After macroscopically grasping the surface of the wafer as the first optical information, after roughly grasping a specific characteristic portion as close to the center as possible of the first optical information, the grasped specific characteristic portion Can be microscopically magnified to accurately detect the position of the characteristic portion based on the second optical information, and input of the first optical information and the second optical information to the imaging camera can be blocked by an optical path. The wafer can be automatically imaged without changing the position of the imaging camera in the wafer prober by simply switching the switching means including the driving device linked to the wafer. Required to align the wafer within the prober It is possible to satisfy the high accuracy required and to reliably detect the characteristic portion, and there is an excellent effect that more accurate alignment can be performed.

Further, when detecting the characteristic portion of the surface of the wafer, the step of performing scanning until the characteristic information is extracted in the state in which the entire surface of the wafer is enlarged as in the related art is eliminated. The time required for extracting the specific feature portion as close to the center portion as possible is greatly reduced, and the excellent effect of dramatically improving the extraction process of the feature portion is achieved.

[Brief description of drawings]

1 to 4 are perspective views showing an embodiment of the invention of this application,
FIG. 2 is an enlarged perspective view of the wafer surface, FIG. 3 (a) is a plan view of the wafer surface macroscopically captured, and FIG. 3 (b) is a plan view of the same wafer microscopically captured. FIGS. 4 (a) and 4 (b) are plan views showing the inclination θ of the wafer, FIG. 5 is a perspective view showing another embodiment of the invention of this application, and FIG. 6 is a conventional embodiment. It is a top view. 1 ... Imaging camera, 2 ... Beam splitter 3,5,9,10 ... Mirror, 4,6,8,11,12 ... Lens 7,13 ... Light source, 14 ... Wafer 16 ... Scrap line , 21 Shield plate 22 ...... Drive device, 30a, 30b, 30z ...... Search position 31A to 31F ...... Features

Continuation of the front page (56) Reference JP-A-57-167651 (JP, A) JP-A-58-86739 (JP, A) JP-B-56-25775 (JP, B2)

Claims (2)

(57) [Claims] 1. First optical information in which reflected light from a macroscopic area portion on the surface of a semiconductor wafer is incident on an image pickup camera, and microscopic information in the first optical information on the surface of the semiconductor wafer. In a wafer prober provided with second light information in which reflected light from the area portion is incident on the image pickup camera, a judgment means for comparing the first light information with basic recognition information stored in advance, By detecting means for detecting the position of the second optical information of the specific characteristic portion in the portion as close to the center as possible of the imaging screen corresponding to the basic recognition information by the output from the determining means, and the output of the detecting means. Moving means for moving the semiconductor wafer from a position where the first optical information is detected to a position where the second optical information is detected, and the image pickup camera for the first optical information and the second optical information. A shield plate for optical information that is generated and a drive that is linked to the shield plate. Wafer prober, characterized in that it comprises a switching means comprising a unit. 2. The characteristic information position of at least two parts of the semiconductor wafer surface where the characteristic information position is detected from the macroscopic first optical information is obtained to obtain the microscopic second optical information. The wafer prober according to claim 1, wherein the semiconductor wafer is aligned by obtaining a rotational deviation of the semiconductor wafer from a virtual line connecting the two parts and a direction in which the semiconductor wafer moves.