JPS63127544A - Semiconductor manufacturing equipment - Google Patents

Abstract

PURPOSE:To shorten the time of measurement by visual inspection and a prober by visually inspecting a semiconductor element after a wafer scribing process through an automatic process and measuring electrical characteristics on the basis of the information of visual inspection. CONSTITUTION:A measuring stage 5 on which a wafer 3 is placed is driven in the X direction and the Y direction, all chips formed to the wafer 3 are image-sensed by an oppositely installed picture processing section such as an ITV camera 9 at every one chip, and converted into electric signals, and the electric signals and a previously stored standard data are compared and decided through a pattern recognizing technique. An electrode pad for the chip decided to be a nondefective by visual inspection and a probing needle electrically connected and wired to a tester are brought into contact, electrical characteristics are measured, the information of the chip decided to be nondefective by probing measurement is overlapped to a wafer map I for visual inspection, and the information of the chip decided to be nondefective by both visual inspection and probing measurement is stored to a memory as a nondefective wafer map II.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to semiconductor manufacturing equipment.

(Prior Art) Conventionally, the electrical characteristics of semiconductor chips regularly formed on a semiconductor wafer have been measured using a semiconductor wafer prober of a semiconductor manufacturing device. This measurement was used to determine whether the semiconductor chip was good or bad, and marks were placed on defective chips. After this process is completed.

A semiconductor wafer on which semiconductor chips are regularly formed is adhered to a heat-stretchable adhesive film and cut into individual semiconductor chips using a dicing saw.

That is, a wafer starving process was performed.

After that, the film is heated and stretched to create a gap between adjacent chips, and when the electrical characteristics are measured, the semiconductor chips judged to be good, that is, the semiconductor chips with no marks, are processed using a dicing tool. In order to recognize the scratches that occur on the semiconductor chips when they are separated into individual semiconductor chips, the operator magnifies the semiconductor chips using a microscope, recognizes whether or not there are scratches, and marks the semiconductor chips with scratches. was attached.

Thereafter, in the above process, unmarked semiconductor chips, that is, non-defective chips, are extracted and separated from defective chips.

(Problem to be solved by the invention) Automated production technology for the semiconductor molding process of ICs, LSIs, etc. has developed significantly in line with technological innovation, and it is now possible to measure ICs and LSIs produced in large quantities using this production technology. Time is also required.

However, if each process were carried out in the conventional order, even chips that were scratched during the wafer scribing process, in which the wafer was cut into chips, would have to be measured using a probe device, which would save time. There were drawbacks that led to losses.

In addition, defective chips determined to be defective in the process of measuring electrical characteristics and defective chips determined to be defective in the process of visual inspection to recognize scratches that occur when semiconductor chips are cut are processed in multiple processes. Then, a mark must be attached to distinguish between good chips and defective chips, and in order to mark these defective chips, approximately 25 mg ~
There was a drawback that it required 50+as of time. Furthermore, when marking, for example, ink is applied to a defective chip that is determined to be defective during the measurement process using a probe device, water is sprayed while cutting the wafer into individual semiconductor chips to blow away powder from the wafer. However, in order to prevent the ink applied to the chip from running off due to this water, there was also the drawback that it was necessary to spend time on a baking operation to dry the ink.

Furthermore, visual inspection is an unreliable and time-consuming method in which an operator performs a sampling inspection, and if there is a chip with a defective appearance, a 100% inspection is performed, which may result in defective products being sent to subsequent processes. there were. This invention was made to improve the above-mentioned points, and by performing the external appearance inspection of semiconductor chips after the wafer scribing process in an automated process, and then measuring the electrical characteristics, automated inspection becomes possible. The present invention provides a semiconductor manufacturing apparatus that reduces inspection time.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a means for imaging a semiconductor wafer after a semiconductor wafer scribing process using an 'rv camera, and a comparison between the imaging signal output by this means and standard data stored in advance. Good/good depending on the presence or absence of scribing errors
It is characterized by comprising a recognition means for determining defectiveness, and a means for connecting a stylus of a wafer prober machine to the electrode portion of a semiconductor chip determined to be good by the recognition means and measuring electrical characteristics. A semiconductor manufacturing device is obtained.

(Function) By performing the visual inspection of semiconductor elements after the wafer scribing process in an automatic process and measuring the electrical characteristics based on the inspection, the time required for visual inspection and measurement using a probe device can be shortened. The effect is that it becomes possible.

(Embodiment) Next, an embodiment of the semiconductor manufacturing apparatus of the present invention will be described with reference to the drawings.

This device is configured so that two cassettes can be stored in the cassette storage position of the autoloader (in the autoloader section), which can store 025 wafers that have been cut into semiconductor chips and adhered to the adhesive film (2) with appropriate spacing between each cassette (2). ing. A preliminary stage is set in this autoloader section (A) for loading and unloading the wafer ■ stored in the cassette ■ and preliminarily positioning the wafer ■ to an accuracy of about ±1° using well-known means based on the orientation flat of the wafer ■. An arm is also installed to transfer the wafer (2) positioned on this preliminary stage to the measurement stage (2) by vacuum suction. In the measurement section, the measurement stage ■ is operated in the X direction, Y direction, Z direction, and
It has a configuration that allows driving in the direction, and the mounted wafer (3
) is also set up with a laser recognition mechanism for accurate positioning. A probe card with a probe needle (2) attached facing the measuring stage (2) at the measurement position is attached to the device housing of the gun, and is connected and wired to a tester (not shown). Above this probe card ■, an ITV camera 0 is installed to image the wafer ■ placed on the measurement stage ■, and the CPU built into this device
Wired to connect.

Next, a description will be given of the configuration of the pickup arm (10) that selects and picks up chips determined to be non-defective by both visual inspection and probe measurement. This pickup arm (10) vertically engages an arm (13) with the tip of a rotating shaft (12) whose rotation is controlled by the rotation of an electric motor (11), and rotates this arm (13) 360' horizontally. Configure as possible. At the tip of this arm (13), on the surface facing the measurement stage ■, there is a chip suction part (14).
is provided. In addition, this chip suction part (14) is provided with an air cylinder (air cylinder) that passes from the air @ straightener (15) through the rotating shaft (12) to the suction part (14) in the arm (13).
16) is provided, and the air adjustment D (15) is set to M.
It is configured to be able to adsorb chips by iM.

Next, a method for selecting good chips using this device will be explained.

First, the wafer is placed in close contact with a heat-stretchable adhesive film from the wafer cassette ■, diced into chips (20), and one cut wafer (3) is taken out and automatically transferred from the autoloader section to the measurement stage ■. transport. However, the adhesive film (■) used has a diameter larger than that of the wafer (■). On this measurement stage ■, for example, by laser alignment method using a laser beam, the scribe line 0 of the wafer ■ as shown in Figure 4 is aligned with the X-Y axis of the measurement stage ■ using the orientation flat of the wafer ■ as a reference. Next, position the wafer (■) in close contact with the adhesive film (■).

The positioned wafer ■ is cut into chips (20) as shown in Figure 4 (B) during the wafer scribing process.
Perform a visual inspection to detect flaws (2) as shown in (2).

This visual inspection is performed on the measurement stage on which the wafer is placed.
Drive in the X direction and Y direction, for example, sequentially by step and repeat, one chip at a time.

All the chips (20) formed on the wafer (3) are imaged by an image processing unit, for example, an ITV camera 0, installed opposite the measurement stage (2). This imaging information is converted into an electrical signal (Fig. 3 (A)), and the image output is stored in a memory (Fig. 3 (B)). The data (FIG. 3(C)) is compared and determined using pattern recognition technology (FIG. 3(D)). This comparison is made by comparing the chips (20) after dicing the wafer (2). A chip corresponding to a location where the compared standard data and the image data of the wafer to be measured do not match is determined to be a defective chip (21) (FIG. 3(E)).

Also, the chip corresponding to the matching location is determined to be a good chip (22) (FIG. 3(F)) and is stored in the good wafer map I (FIG. 3(G)).

Probe measurement (3rd step) to measure the electrical characteristics of the chip determined to be a good chip (22) in the above automatic visual inspection
(H)) to sort the chips into good chips (FIG. 3 (1)) and defective chips (FIG. 3 (J)).

In this probe measurement, the measurement stage (c) on which the wafer after the visual inspection is placed is driven in the X and Y directions according to the information on the non-defective wafer from the visual inspection, and the wafer is judged to be non-defective by the visual inspection using well-known means. The probe needle electrically connected to the tester is brought into contact with the electrode butt of the chip (22), and the electrical characteristics are measured.

The information on the chips that were determined to be good by the probe measurement is combined with the wafer map for visual inspection, and the information for the chips that were determined to be good by both the visual inspection and the probe measurement is combined with the information for the chips that were determined to be good by the visual inspection and probe measurement. 3 (K)) is stored in the memory.

The measurement stage on which the wafer (3) that has undergone probe measurement is mounted is driven in the X and Y directions to select and pick up only good chips (Fig. 3 (L)) Setting position of the pickup arm (10) The wafer (29) is transported to the point where the wafer (29) is transferred to the arm of the pick-up arm (10) by driving the measurement stage 0 on which the wafer (2) is placed in the X and Y directions using the information from the above-mentioned good wafer pin (2). Set it in a position facing the suction part (4). At this setting position, move the day setting stage ■ vertically to the suction part (14) and adjust the air regulator (15) II#I. (14) picks up a good chip, and the arm (13) that has picked up a good chip moves around the rotation axis (12).
It rotates 80 degrees, adjusts the air regulator (15) to the good chip pickup tray (17), and transports the good chip that was adsorbed to the arm suction part (14).

After the transfer, the arm (13) is rotated 180' and set again at a predetermined position for adsorbing good chips. This arm (13
) during the rotational conveyance of good chips by the measuring stage (c).
By driving in the X direction and the Y direction, the good chip is set at the opposite position where the suction part (14) is set. This pick-up operation is repeated for all good chips on wafer (2) until the pick-up operation is completed.

In addition, since all the good chips were removed by the pickup operation, only the defective chips were in close contact with the adhesive film (2). The adhesive film (2) to which only the defective chips are adhered is returned from the measurement stage (3) through the loader section (A) to its original position in the cassette (2).

In the above embodiment, the wafer visual inspection, probe measurement, and pickup operation were performed by driving one measurement stage in the X and Y directions. It is also possible to increase the processing speed for selecting good chips by providing two stages for picking up good chips.

Furthermore, in the above example, the external appearance inspection and probe measurement of the chips on the wafer after dicing and the operation of picking up good chips were carried out with one device, but the external appearance inspection and probe measurement of the wafer after the unifer scribing process were performed using one device. One device may be provided that only performs a non-defective product pickup operation. In addition, when the apparatus is separated in this way, it is possible to mark, for example, ink, as necessary on chips determined to be defective by the external appearance inspection and probe measurement of the chips on the wafer after the wafer scribing process.

〔Effect of the invention〕

By configuring the semiconductor device of the present invention as described above, it is possible to shorten the time required for visual inspection and measurement of electrical characteristics.

[Brief explanation of the drawing]

1 is a state explanatory diagram for explaining one embodiment of the semiconductor manufacturing apparatus of the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a block diagram for explaining FIG. 1. FIG. 4 is a diagram showing the wafer after the scribing process shown in FIG. 1. 3 wafer 5 measurement stage 8 chip
9 ITV camera 10 Pick up arm

Claims (2)

[Claims] (1) A means for imaging a semiconductor wafer after the semiconductor wafer scribing process with a TV camera, and recognition that compares the imaging signal output by this means and standard data stored in memory in advance to determine whether it is good or bad based on the presence or absence of scribing errors. 1. A semiconductor manufacturing apparatus comprising: means for connecting a stylus of a wafer prober to an electrode portion of a semiconductor chip determined to be good by the recognition means, and measuring electrical characteristics of the semiconductor chip. (2) The device is characterized by comprising means for sorting out good and defective semiconductor chips based on the results obtained from the recognition means for determining whether the semiconductor chip is good or bad and the means for measuring the electrical characteristics of the semiconductor chip. A semiconductor manufacturing apparatus according to claim 1.