JPS60171736A - Examining device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an inspection technique suitable for inspecting defects in semiconductor wafers.

[Background technology]

In the manufacturing process of semiconductor devices such as ICs and LSIs, foreign matter such as dust and scratches (hereinafter referred to as defects) attached to semiconductor substrates (wafers) are important factors in determining the yield of semiconductor devices. Therefore, in this type of manufacturing process, it is required to inspect defects in the wafer, remove the causes of these defects, and monitor the level of occurrence, and various defect inspection devices are provided for this purpose. .

For example, FIG. 1 shows an example of a device developed by the present inventor, in which a ridge 2 containing a wafer to be inspected 1, an inspection section 3, and a cartridge 5 containing a wafer 4 that has been inspected. A wafer transport means 6 such as a belt is provided in each of the wafers, and a scanning drive system 7 is provided in the inspection section 3 to scan the entire surface of the wafer. A defect determination circuit 8 for distinguishing between defects and noise is connected to the inspection section 3, and a coordinate indexing circuit 9 for recognizing the wafer position when a defect is detected is connected to the scanning drive system 7. By combining these, the plotter 10 can display the distribution of defects X on the wafer 1 as shown in FIG. 2, and the counter 11 can display the number of defects.

Therefore, in this inspection apparatus, once the cartridge 2 is set, the wafers \1 are sequentially conveyed to the inspection section 3 by the wafer conveying means 6, where the distribution and number of defects shown in FIG. 2 are inspected, and then the wafers are conveyed. It is housed in the cartridge 5 by means 6 and all inspections are completed.

However, with this inspection equipment, even if the number of defects on the wafer and their distribution (coordinate positions) can be inspected, it is unclear which chip on the wafer this defect belongs to, and therefore each The inventor of the present invention has clearly recognized that there is a problem in that it is not possible to immediately determine whether a chip is good or bad or to inspect its defective rate.

Furthermore, the above-mentioned inspection apparatus is configured to inspect only the wafer stored in the cartridge 2, and therefore, when inspecting only one wafer 71, the wafer is required to be placed in the cartridge. This causes the generation of foreign matter (defect generation) and reduces workability. Furthermore, in the above-mentioned configuration, since all the wafers 1 in the cartridge 2 are inspected, it is not possible to inspect only a small number of wafers as in the case of sampling inspection, and from this point of view, the work efficiency is also reduced. The inventors have discovered that there is a problem in that the

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an inspection technique that can inspect which chips on a wafer have defects and can immediately inspect defective chips and their defective rate.

Another object of the present invention is to provide an inspection technique that can perform inspections on all items, samples, and only one sheet, thereby improving inspection workability.

The above and other objects and novel features of the present invention include:
It will become clear from the description of this specification and the accompanying drawings.

[Summary of the Invention J A brief overview of typical inventions disclosed in this application is as follows.

In other words, by merging the defect position information on the surface to be inspected and the classification information of the object formed by dividing the surface to be inspected, it is possible to determine the presence or absence of defects in the object formed by dividing the surface to be inspected. This makes it possible to immediately check the quality and defective rate of each item.

In addition, by providing a manual handling section and a bypass path on the conveyance path of the supply section, inspection section, and storage section for inspection objects, only the necessary inspection objects or only those supplied to the manual handling section can be transported to the inspection section. This makes it possible to omit unnecessary inspections, prevent new defects from occurring, and improve workability.

〔Example〕

3 to 5 show an embodiment of the inspection apparatus of the present invention. In FIG. 3, 12 is a cartridge on the loader side that houses a wafer 11 as an object to be inspected, and 13 is a cartridge after the inspection has been completed. This is a cartridge on the unloader side that stores wafers 14 (including those that were not inspected), and both of these cartridges 12 and 13 are placed side by side with a slight distance between them facing the same direction. An inspection section 15 for inspecting defects on the wafer surface is provided at a position in front of the cartridge 12 on the loader side, and is equipped with a scanning drive system 16 for scanning the wafer and extracting its coordinate information. Then, an outbound conveyance path 17 having a belt structure is extended between the loader-side car) IJ straightener 12 and the inspection section 15, and an L-shaped return conveyance path 18 is extended between the inspection section 15 and the unloader-side cartridge 130. It is set up. These forward transport path 17 and return transport path 18 are moved only in the directions of arrows A and B, respectively. Further, a manual handling section (station) 19 is formed in an intermediate part of the forward transport path 17, and a bypass path 2 is formed between this manual handling section 19 and the intermediate portion of the return transport path 18.
Connected with 0. Similarly, this bypass path 20)
It is configured as a structure, but its operation causes arrows C,,C
, can be switched in both directions.

The manual handling section 19 and the transport path intersection section 18.20 (detailed explanation of this part will be omitted hereinafter) are connected to the parallel plate that constitutes the forward transport path 17, as shown in a schematic diagram in FIG. 4 (4). 7) One of the parallel bells 21 and 21 is passed through a plurality of pulleys 22 in a concave shape, and one end of the parallel bell 23 and 23 constituting the bypass path 20 is positioned together with the pulley 24. The spindle 25 of this pulley 24 is connected to a vertically moving solenoid 26, etc., so that the parallel belt 23 can be moved vertically. In addition, the parallel belts 21 and 21 of the outward conveyance path 17
In between is a support rod 2 with a small-diameter mounting table 27 fixed to its upper end.
8 is vertically installed and can be moved up and down by a vertical movement cylinder 29 or the like.

Therefore, in this manual handling section 19, the bypass path 2
When the parallel belt 23 and the mounting table 27 are in the downward movement position as shown in the figure, the wafer 11 is conveyed to the left in the figure (towards the pole section 15) by the bells 21 and 21 of the forward conveyance path 17.

In addition, if the mounting table 27 is moved upward as shown by the imaginary line in the figure and one wafer 11 is placed there, and then moved downward again, the wafer 11 will be transferred to the bell (21.21) of the forward transport path 17. It is then transferred to and similarly transported to the left. Furthermore, when the belt 23 of the bypass path 20 is moved upward as shown in FIG.
23 and moved along the bypass road in the direction of the arrow C8.

On the other hand, a defect determination circuit 30 for discriminating between a defect signal and a noise signal is connected to the detection section 15, and a scanning drive system 16 is connected to the detection section 15.
A coordinate indexing circuit 31 for recognizing the wafer position when a defect is detected is connected to the wafer. These defect determination circuit 30 and coordinate indexing circuit 31 are connected to a signal synthesis circuit 32 and further connected to a plotter 33. In addition,
The defect determination circuit 30 is also connected to a defect number display counter 34, and the signal synthesis circuit 32 has an input section 35 for inputting wafer size, chip size, etc., and a chip that outputs the chip arrangement on the wafer as information based on this input signal. An array circuit 36 is connected thereto.

According to the above structure, the entire surface of the wafer S11 moved from the forward transport path 17 to the inspection section 15 is scanned in the inspection section 15, and the existing defect information is sent from the defect determination circuit 30, and the coordinate information at this time is used as the coordinate index. Each signal is output from the circuit 31 to a signal synthesis circuit 32. At this time, the number of defects is displayed on the counter 34. Meanwhile, at the same time, the input section 35
and the waveform to be tested from the chip array circuit 36.
Information such as the wafer size and chip size of No. 11 is input to the signal synthesis circuit 32. As a result, the signal synthesis circuit 3
In Step 2, the chip classification, defect distribution, etc. of the wafer 11 are plotted by the plotter 33 based on all of this information. As a result, the chip lla classification and the defects X distributed on it are displayed as shown in Figure 5, and therefore the quality of each chip and the number of defective chips (defective rate) are displayed.
can be inspected immediately.

By the way, when inspecting all the wafers in the cartridge 12 on the loader side, the bypass path 2 is
0 and the mounting table 27 in the downward movement position, the wafer 11
All of them reach the inspection section 15 from the forward transport path 17, and further pass through the return transport path 1B to the cartridge 1 on the unloader side.
3 (arrow S in Figure 3).

On the other hand, when performing a sampling inspection of wafers in the cartridge 12, the belt 23 of the bypass path 2o is moved in accordance with the timing of the wafer being moved on the forward transport path 17 as shown in FIG.
All you have to do is move up like this.

As a result, the manual handling section 1
The wafer passing through the wafer 9 is transferred to the belt 23, 23, is moved to the return path 18 through the bypass path 2o, and is stored in the cartridge 13 without being inspected (arrow R in FIG. 3). .

Furthermore, when only one wafer is to be inspected, the mounting table 27 is moved upward as shown by the imaginary line in FIG. 4(2), and after the wafer 11 is placed thereon, it is moved downward. As a result, the wafer 11 is transferred to the inspection section 1 by the forward transport path 17.
5. At the same time, the bypass path 20 is moved in the opposite direction as indicated by the arrow Ct, and when the inspected wafer comes to the intersection of the transport path 18 and the bypass path 20, the wafer is moved up the transport path 18 and transferred. It is returned from the return route 18 to the manual handling section 19 through the bypass route 20 (
Figure 3 arrow T).

By switching the above-mentioned functions according to the inspection purpose, each inspection can be performed optimally, and workability in each inspection can be improved.

〔effect〕

(1) It is configured to combine defect position (coordinate) information on the wafer and chip classification information on the wafer, and is configured to detect the distribution of defects on the classified chips. It is possible to immediately inspect not only the quality of chips but also the number of defective chips and the defective rate.

(2) A manual handling section is provided on the forward transport path that connects the wafer loader position and the inspection section, while a bypass path is formed across the return transport path and the forward transport path that connect the inspection section and unloader position. Alternatively, only wafers fed to the manual handling section can be inspected;
Inspection processability for sampling inspection and single-sheet inspection can be improved.

(3) In single-wafer inspection, it is only necessary to place the wafer on the manual handling section, so there is no need to set the wafer in a cartridge or the like, and new defects can be prevented from occurring.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Nor. For example, instead of the belt means that constitutes the conveyance path, a progressive mechanism (step mechanism) is used.
Use [mayoi]. Further, the manual handling section may have a planar direction changer structure. Furthermore, the conveyance path may have a three-dimensional structure.

[Application field]

The above explanation has mainly been about the case where the invention made by the present inventor is applied to a defect inspection device for semiconductor wafers, which is the background field of application.
The present invention is not limited thereto, and can be applied to, for example, defect inspection of photomasks and other objects, especially those in which the object to be inspected is later separated into multiple sections.

[Brief explanation of the drawing]

Fig. 1 is a plan configuration diagram of the device developed by the present inventor, Fig. 2 is a diagram plotting defect distribution, Fig. 3 is a plan configuration diagram of the inspection device of the present invention, and Fig. 4
5 is a diagram showing the schematic structure of the manual handling section, and FIG. 5 is a drawing of defect distribution by the apparatus of the present invention. DESCRIPTION OF SYMBOLS 11--Wafer, 11a=-chip, 12--cartridge (loader side), 13--cartridge (unloader side), 15--inspection section, 16--scanning drive system, 17-- Conveyance outward route, 18... Conveyance return route, 19.
...Manual handling section, 20...Bypass path, 30...
Defect determination circuit, 31... Coordinate indexing circuit, 32...
Signal synthesis circuit, 33... Plotter, 34... Counter, 35... Input section, 36... Chip array circuit.

Claims (1)

[Scope of Claims] 1. Means for detecting positional information of the object to be inspected, such as defects, on the inspection surface of the inspected object, and outputting classification information for later dividing the inspected object into a plurality of regions or parts. and a means for synthesizing each piece of information from the position information detecting means and the classification information outputting means, and plotting and displaying the defect distribution and classification together corresponding to the surface of the object to be inspected. Inspection equipment. 2. A defect determination circuit and coordinate indexing circuit that detect defect position information on the wafer surface, a chip array circuit that outputs the chip array of chips on the wafer, and a signal synthesis circuit and plotter that synthesizes each of these output information. An inspection device according to claim 1, having: 3. An inspection device in which a loader section, an inspection section, and an unloader section of an object to be inspected are connected through a conveyance path, and the object to be inspected is manually transferred during the outward transportation path between the loader section and the inspection section. A settable manual handling part is provided, and the manual handling part and the inspection part. An inspection device characterized in that a bypass path is provided between the unloader section and the return path. 4. The manual handling section is configured to be able to switch the conveyance direction of the object to be inspected in the loader section to either the inspection section or the bypass path, and to convey the object to be inspected set thereon toward the inspection section. An inspection device according to claim 3 comprising: 5. The bypass path is configured to be able to move in the forward and reverse directions, and is capable of transporting the object to be inspected that has been moved to the manual handling section to the return path, or returning the object to be inspected on the return path to the manual handling section. An inspection device according to claim 3 or 4, which comprises: