JPS63265441A - Measuring device - Google Patents

Abstract

PURPOSE:To enable the high magnification detecting of a matter to be measured, by carrying/positioning the matter to be measured within the usable range of an optical system and using this optical system to picture the matter to be measured and displaying it on a TV monitor whenever a state of the matter to be measured is required to be detected. CONSTITUTION:A semiconductor wafer whose pre-alignment is finished is carried/ positioned on a measurement stage by a carrier arm 5. Whenever a state of a chip on measurement is required to be observed, the semiconductor wafer 8 on measurement is moved within a usable range of an optical system 6, and its position alignment to the optical system is performed on the basis of a predetermined reference point. Subsequently, light from a light source 9 is radiated on a surface of the semiconductor wafer 8 whose state is required to be observed. Since the image picturing by the use of a CCD camera 12 is occasionally hindered due to a dark field of vision, light sources 9 are installed on a plurality of positions, for example, on three positions. The light source 9 installed above perpendicularly to the semiconductor wafer 8 is used on a bright field of vision. In succession, a CCD camera is used to picture the surface of this semiconductor wafer 8 through a half mirror 10, and this pictured image is displayed on a TV monitor 11.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a measuring device.

(Prior art) Currently, measuring devices for determining the quality of semiconductor chips, etc.
There is a type called a prober that comes with a tester attached.

In measurement using this prober, a semiconductor wafer is placed on a mounting table, and a probe card equipped with probe needles is placed above the prober. Then, the mounting table is moved directly below the probe card equipped with probe needles, and the mounting table is rotated to align the moving direction of the mounting table with the direction of the scribe line between the semiconductor chips formed on the semiconductor wafer. Thereafter, the probe needles are aligned with the electrode pads on the semiconductor chips, measurements are made using electrical signals, and then the mounting table is moved according to the size of the semiconductor chips to test each chip one by one.

At this time, it is used to detect the state of chips, markings, needle marks, etc. on the semiconductor wafer.

A probe card was used, which was placed through the test head and a microscope.

(Problems to be Solved by the Invention) However, in the conventional technique described above, since detection is performed using a microscope of a prober, the magnification is poor and detailed detection cannot be performed. For that reason.

When special detection is required, the semiconductor wafer being measured is manually removed from the measuring device and detected using a microscope capable of high magnification, which is a time-consuming problem.

Furthermore, there is also a problem with the position of lighting, etc., which makes it difficult to detect the semiconductor wafer surface because the probe needle gets in the way when using a microscope for detection.

The present invention has been made in view of the above-mentioned problems, and provides a measuring device capable of detecting the state of an object to be measured at a high magnification according to the need.

[Structure of the invention]

(Means for Solving the Problems) The present invention, in measuring the object to be measured, transports and positions the object to be measured from the measuring section within the field of view of the imaging optical system when observing the measurement object in the rest state. The present invention is characterized in that it is provided with means for taking an image of the object to be measured and displaying the image on a TV monitor.

(Function) Whenever it becomes necessary to detect the state of the object to be measured, the object to be measured is transported and positioned within the usable range of the optical system, and an image of the object to be measured is taken by the optical system and displayed on a TV monitor. By projecting the image, it becomes possible to detect it at high magnification.

(Example) Hereinafter, an example in which the measuring device of the present invention is applied to a semiconductor inspection process will be described with reference to the drawings.

In FIG. 1, for example, two wafer cassettes ω are provided to accommodate a plurality of objects to be measured, such as semiconductor wafers, and
Vacuum suction tweezers (2) are provided to allow the semiconductor wafer to be inserted into and taken out from the wafer cassette (ω). The semiconductor wafer inserted from the wafer cassette using the vacuum suction tweezers (■) is placed on the pre-alignment stage (■) for pre-aligning the semiconductor wafer and the measurement stage (A) on which the semiconductor wafer is placed when measuring the semiconductor wafer, as necessary. A transport arm (2) is provided rotatably around one end. An optical system bridge (2) incorporating the optical system 0 for the semiconductor wafer is provided at the end of the measuring device.

As shown in FIG. 2, the optical system described above includes a plurality of light sources (2) arranged at three locations, for example, in order to irradiate light onto the surface of a semiconductor wafer (2) placed on a measurement stage (2). An imaging system such as a CCD camera (12) is provided which is connected to a TV monitor (11) via a half mirror (10) so as to freely take images of the surface of the semiconductor sea urchin. The measuring device is configured in this way.

Next, a method of measuring a semiconductor wafer using the above-mentioned measuring device will be explained.

In FIG. 1, a semiconductor wafer is suctioned and held by vacuum suction tweezers (2) and inserted from a wafer cassette (2) containing a plurality of semiconductor wafers.

This inserted semiconductor wafer is placed on a pre-alignment stage by a transfer arm that is rotatable around one end.
Transport to. This pre-alignment stage (1) detects the orientation flat of the semiconductor wafer using a transmission type sensor (not shown), such as a photointerrupter, and performs pre-alignment.The semiconductor wafer that has undergone pre-alignment is transferred to the measurement stage by the transfer arm (1). ) and place it there. This measurement stage) holds the semiconductor wafer, for example, holds it by suction, moves it directly under the optical system bridge and performs alignment using the built-in optical system, and at least one reference point on the standard semiconductor wafer. and store it in advance. This is a semiconductor wafer (ha) as shown in Figure 3.
For example, set the center as the reference point (A) and the left end as the reference point (B).
, the upper end is checked as a reference point (C), the right end as a reference point (D), and the lower end as a reference point (E). (2) Detect and store the size, position, etc. of (on the measurement stage). This semiconductor wafer (c) is then transported by an X-Y moving mechanism (not shown) to the measurement section directly under the probe card (not shown), and the electrode pads formed on the chip are connected to the probe card. Needle alignment is performed to align the positions of multiple probe needles, and then the characteristics of the semiconductor wafer are measured.At this time, for example, if it is necessary to clearly see the state of the chip being measured, it may be necessary to change the position of the probe needles at any time during the measurement. A certain semiconductor wafer (2) is moved to a range where optical system 0 can be used, and aligned with optical system 0 based on a predetermined reference point. Light is then irradiated from light source 0 onto the surface of the semiconductor wafer (c) that requires clear vision in the above-mentioned state, but since it may be difficult to image with the CCD camera (12) due to the dark field, there are multiple locations, for example, three locations. Light source 0 is provided at The light sources (2) provided at the two locations are switched depending on the degree of dark field.

Then, the surface of this semiconductor wafer 0 is scanned by a CCD camera (12).
An image is captured through a half mirror (lO), and the captured image is displayed on a TV monitor (11).

When imaging the surface of the semiconductor wafer 0 with the CCD camera (12), the magnification is set to be switchable in a plurality of stages, for example, two stages, and for example, as a low magnification, an image of 14 vaginal angles on the semiconductor wafer is displayed on the entire 9-inch TV monitor; High magnification as 800mm on semiconductor wafer across 9 inch TV monitor
By setting the magnification to display a p-angle image,
Change the magnification as necessary.

Then, when clear vision of the semiconductor wafer ■ is completed,
If it is necessary to resume the interrupted measurement of the semiconductor wafer (c) and also check other parts of the semiconductor wafer (c), manually move the semiconductor wafer (c), for example, by moving the semiconductor wafer (c) manually. (not shown) to perform state clear vision in the same way.

A flowchart for detecting the state of the semiconductor wafer (c) described above is shown in FIG.

In the above embodiment, the process of clearly viewing the state during semiconductor wafer measurement has been described, but 81! The present invention is not limited to the measurement, and the same effect can be obtained by performing similar processing before and after measurement.

As described above, according to this embodiment, the optical system used for alignment of the semiconductor wafer is used to clearly see the state of the semiconductor wafer, so that the alignment can be performed at low cost.

〔Effect of the invention〕

As explained above, according to the present invention, whenever it becomes necessary to clearly see the state of the object to be measured, the object to be measured is transported and positioned within a usable range of the optical system, and the object to be measured is transported and positioned within the usable range of the optical system. By capturing an image of the body and displaying it on a TV monitor, it becomes possible to see clearly at high magnification.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a measuring device to explain an embodiment of the device of the present invention, Fig. 2 is a configuration diagram of an optical system to explain an embodiment of the device of the present invention, and Fig. 3 is a reference point diagram. FIG. 4 shows a flowchart of an embodiment of the processing of the apparatus of the present invention. 6...Optical system, 7...Optical system bridge,
8... Semiconductor wafer, 9... Light source, 10...
Half mirror, 11...TV monitor, 12...C
CD camera. Patent applicant: Tokyo Electron Ltd. Figure 1 Figure 2 Figure 3

Claims (3)

[Claims] (1) In measuring the object to be measured, when observing the state of the object to be measured, the object to be measured is transferred from the measuring section to the field of view of the imaging optical system, and the object to be measured is imaged, and this is displayed on the TV. A measuring device characterized by being provided with means for displaying images on a monitor. (2) The positioning and imaging means for the object to be measured is provided with at least one reference point on a standard object to be measured and memorized in advance so that the reference point of the object to be measured and the pre-stored reference point are 2. The measuring device according to claim 1, wherein after the imaging system and the object to be measured are relatively moved and aligned so as to match, the optical system is focused at this reference point. (3) Claim 1, characterized in that the magnification of imaging by the optical system can be switched in at least two stages.
Measuring device as described in section.