JPH0713994B2 - Semiconductor manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a semiconductor manufacturing apparatus.

(Prior Art) Conventionally, in order to measure electrical characteristics of semiconductor chips regularly formed on a semiconductor wafer, a semiconductor wafer prober of a semiconductor manufacturing apparatus has been used for measurement. The quality of the semiconductor chip was determined by this measurement, and the defective chip was marked. After completion of this step, the semiconductor wafer on which the semiconductor chips are regularly formed is brought into close contact with the heat-expandable adhesive film,
Each semiconductor chip was cut with a dicing saw. That is, the wafer scribing process was executed. After that, the film is warmed and stretched to give a gap between the adjacent chips, and in the measurement of the above electrical characteristics, in the case of a semiconductor chip determined to be good, that is, a semiconductor chip with no mark, a dicing saw In order to recognize that there are scratches on the semiconductor chip when separating it into each semiconductor chip by the operator, the operator enlarges the semiconductor chip with a microscope etc. and recognizes whether there is a scratch, and on the semiconductor chip with scratches, mark Was attached.

After that, in the above process, semiconductor chips without marks, that is, non-defective chips were taken out and sorted as defective chips.

(Problems to be solved by the invention) Automated production technology of semiconductor manufacturing processes such as IC and LSI has been remarkably developed along with technological innovation, and it takes time to measure a large number of ICs and LSIs produced by this production technology. Is also required.

However, if each process is carried out in the same order as in the past, it means that even the chips with scratches are measured by the probe device during the wafer scribing process for cutting the wafer chip by chip. There was a drawback that led to loss.

In addition, a plurality of processes of a defective chip determined to be defective in the process of measuring electrical characteristics and a defective chip determined to be defective in the visual inspection process for recognizing scratches that occur when the semiconductor chip is cut Therefore, it is necessary to put a mark to distinguish good chips from bad chips, and to put a mark on these bad chips, it takes about 25ms to 50ms for each chip.
It had the disadvantage of having to spend a lot of time. Furthermore, when, for example, ink is attached as a mark to a defective chip that is determined to be defective in the measurement process by the probe device, when cutting the wafer for each semiconductor chip, cutting is performed while spraying water to blow off the powder of the wafer. However, there is also a drawback in that it takes time to perform a baking operation for drying the ink so that the ink attached to the chip does not run off due to this water.

In addition, the visual inspection is a non-reliable and time-consuming method in which the operator conducts a sampling inspection, and if there is a defective appearance in the chip, 100% inspection is performed, which may cause defective products in the subsequent process. there were. The present invention has been made to improve the above points, by performing an appearance inspection of a semiconductor chip after a wafer scribing process in an automatic process, and then performing an electrical characteristic measurement, an automated inspection becomes possible. The present invention provides a semiconductor manufacturing apparatus that shortens the inspection time.

[Structure of Invention]

(Means for Solving Problems) The present invention provides a scribing method by comparing a means for picking up an image of a semiconductor wafer after a semiconductor wafer scribing step with a TV camera, and an image pickup signal output by this means and standard data stored in advance. It is provided with a recognizing means for judging good / bad according to the presence or absence of an error, and a means for connecting a stylus of a wafer prober machine to an electrode portion of a semiconductor chip judged to be good by the recognizing means and measuring an electrical characteristic. The present invention provides a semiconductor manufacturing apparatus characterized by the following.

(Function) It is possible to shorten the time required for the appearance inspection and the measurement by the probe device by performing the appearance inspection of the semiconductor element after the wafer scribing process in an automatic process and measuring the electrical characteristics based on the information. The effect is obtained.

(Example) Next, one example of the semiconductor manufacturing apparatus of the present invention will be described with reference to the drawings.

In this device, a cassette (1) capable of accommodating 25 wafers (3) that are in close contact with an adhesive film (2) and cut into semiconductor chips at appropriate intervals is provided in an autoloader section (4).
2 cassettes can be stored in the cassette storage position of. The wafer (3) stored in the cassette (1) is carried in and out of the autoloader section (4), and the wafer (3) is spared to an accuracy of about ± 1 ° by a well-known means with reference to the orientation flat of the wafer (3). A preliminary stage for positioning is set, and the wafer (3) positioned by this preliminary stage
An arm for vacuum-adsorbing and transporting to the measurement stage (5) is also installed. In the measuring section, the measuring stage (5)
Is configured so that it can be driven in the X direction, Y direction, Z direction, and θ direction by known means, and a laser recognition mechanism for accurately positioning the mounted wafer (3) is also set.
At the measurement position, the probe card (8) is attached to the device housing of the probe card (8) to which the probe needle (7) is attached so as to face the measurement stage (5), and is connected and wired to a tester (not shown). An image of the wafer (3) mounted on the measurement stage (5) is imaged above the probe card (8).
An ITV camera (9) is installed and is connected and wired to the CPU incorporated in this device.

Next, the configuration of the pick-up arm (10) for selecting and picking up a chip determined to be a non-defective product in both the visual inspection and the probe measurement will be described. The pick-up arm (10) vertically engages the arm (13) with the tip of the rotary shaft (12) whose rotation is controlled by the rotation of the electric motor (11), and horizontally rotates the arm (13) 360 °. Configure as possible. A tip suction section (14) is provided on the surface of the end of the arm (13) facing the measurement stage (5). Further, the tip suction part (14) is provided with an air cylinder (16) from the air regulator (15) to the suction part (14) in the arm (13) passing through the rotary shaft (12). The chip can be sucked by adjusting the air conditioner (15).

Next, a method of selecting non-defective chips by this device will be described.

First, the wafer cassette (1) is brought into close contact with the heat-expandable adhesive film (2), and each chip (20) is diced,
One of the cut wafers (3) is taken out and automatically transferred from the autoloader unit (4) to the measurement stage (5).
However, the adhesive film (2) having a larger diameter than the wafer (3) is used. The measurement stage (5) and the scribe line (6) as shown in FIG. 4 of the wafer (3) are based on the orientation flat of the wafer (3) by, for example, a laser alignment method using laser light on the measurement stage (5). XY
The axes of the wafers (3) are aligned and the wafer (3) closely attached to the adhesive film (2) is accurately positioned.

The positioned wafer (3) is subjected to a visual inspection in order to find a flaw (7) as shown in FIG. 4 (B) formed during the wafer scribing process in which each chip (20) is cut.

In this visual inspection, the measurement stage (5) on which the wafer (3) is mounted is driven in the X direction and the Y direction, for example, sequentially driven by step-and-repeat, and is sequentially faced to the measurement stage (5) chip by chip. An image processing unit installed, for example, an ITV camera (9) images all the chips (20) formed on the wafer (3). This imaging information is converted into an electric signal (Fig. 3 (A)), and the image output is stored in the memory (Fig. 3 (B)). Memory to be measured (3)
Image information and standard data (3rd
Figure (C)) is compared and judged by pattern recognition technology (3rd
(Figure (D)). This comparison is to compare the chips (20) after dicing the wafer (3). A chip corresponding to a portion where the compared standard data and the image data of the wafer under measurement (3) do not match is determined to be a defective chip (21) (FIG. 3 (E)). Further, the chip corresponding to the coincident portion is judged to be a non-defective chip (22) (Fig. 3 (F)) and stored in the non-defective wafer map I (Fig. 3 (G)).

A probe measurement (FIG. 3 (H)) for measuring the electrical characteristics is performed on the chip determined to be the non-defective chip (22) in the above-described automatic visual inspection, and the non-defective chip (FIG. 3 (I)) is not detected. Sorted into non-defective chips (Fig. 3 (J)).

In this probe measurement, the measurement stage (5) on which the wafer (3) after the appearance inspection is mounted is driven in the X direction and the Y direction according to the information of the non-defective wafer map I of the appearance inspection, and the appearance inspection is performed by a known means. The electrical characteristics are measured by bringing the electrode pad of the chip (22) determined as a non-defective product into contact with the probe needle electrically connected and wired to the tester.

The information of the chip judged to be non-defective by the above probe measurement,
The memory is stored as a non-defective wafer map II (FIG. 3 (K)) with information on the chips which are determined to be non-defective in both the visual inspection and the probe measurement by overlaying on the wafer map I of the visual inspection.

The measurement stage on which the wafer (3) for which the probe measurement has been completed is placed is driven in the X and Y directions, and only non-defective chips are selected and picked up (FIG. 3 (L)) Pickup arm (10) setting position The wafer (3) is transferred to.
Here, based on the information from the non-defective wafer map II, the measurement stage (5) on which the wafer (3) is placed is driven in the X and Y directions to pick up the non-defective chip from the pickup arm (10).
It is set at a position facing the arm suction part (14). At this setting position, the measurement stage (5) is vertically Zup to the suction part (14) and the air adjuster (15) is adjusted to adjust the suction part (14).
Adsorb good chips with. The arm (13) that adsorbs the good chip rotates 180 ° around the rotating shaft (12), adjusts the air adjuster (15) on the good pick-up tray (17) and adsorbs it on the arm adsorbing part (14). Transfer the good chips that had been used. After transfer, the arm (13) is rotated 180 ° and set again at a predetermined position for picking up good chips. The non-defective chip is set at a facing position where the suction section (14) is set by driving the measurement stage (5) in the X and Y directions while the non-defective chip is being rotationally conveyed by the arm (13). This pickup operation is repeated for all non-defective chips on the wafer (3) to complete the pickup operation.

Further, since all the good chips are removed by the pickup operation, only the defective chips are adhered to the adhesive film (2). The adhesive film (2) to which only the defective chips are adhered is returned from the measuring stage (5) to the original position of the cassette (1) via the loader section (4).

In the above embodiment, the appearance inspection of the wafer, the probe measurement, and the pick-up operation are performed by driving one measurement stage in the X direction and the Y direction. It is also possible to increase the non-defective chip selection processing speed by providing two stages for picking up non-defective chips.

Further, in the above-described embodiment, the appearance inspection of the chip of the wafer after dicing, the probe measurement and the non-defective chip pickup operation are performed by one device, but the appearance inspection and the probe measurement of the wafer after the wafer scribing process are performed by one device. As the device, one device that only picks up a non-defective product may be provided. When the devices are divided in this way, it is possible to attach a mark, for example, ink to the chip determined to be defective by the visual inspection of the chip of the wafer after the wafer scribing step and the probe measurement as needed.

〔The invention's effect〕

By configuring the semiconductor device of the present invention as described above, there is an effect that it is possible to shorten the time of appearance inspection and measurement of electrical characteristics.

[Brief description of drawings]

1 is a state explanatory view for explaining an embodiment of a semiconductor manufacturing apparatus of the present invention, FIG. 2 is a plan view of FIG. 1, FIG. 3 is a block diagram for explaining FIG. 1, and FIG. The figure shows the wafer after the scribing step of FIG. 3 ... Wafer, 5 ... Measurement stage 8 ... Chip, 9 ... ITV camera 10 ... Pickup arm

Claims (2)

[Claims] 1. A semiconductor wafer after a scribing step is compared with a means for picking up an image of a semiconductor wafer with a TV camera, and the image signal output by this means and standard data stored in advance are compared to determine whether a scribing error is present or not. And a means for measuring electrical characteristics by connecting a stylus of a wafer prober to the electrode portion of the semiconductor chip judged to be good by the recognizing means. . 2. A device for recognizing whether a semiconductor chip is good or defective and a device for selecting a good semiconductor chip from a defective semiconductor chip based on a result obtained from a means for measuring an electric characteristic of the semiconductor chip. Claim 1 characterized
The semiconductor manufacturing apparatus according to the item.