JPH11145255A - Apparatus and method for inspecting semiconductor wafers - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus and method of inspecting semiconductor wafers, providing a high test reliability and high work efficiency. SOLUTION: This apparatus comprises a transfer part 10, a wafer arranger 12 which drives a stage with wafers settled thereon in axes X, Y and θ to arrange to wafers, an image processor 14 for processing the image of regions with arranging marks in a pattern of the wafer settled on the stage, a controller 16 for controlling the drive of the wafer arranger and analyzing the arranging condition of the arrange marks upon the receipt of image signals from the image processor, a particle inspecting section 18 for analyzing the wafer surface with an ultraviolet laser to inspect particles on the wafer, and output part 20 for outputting analysis data of the arranging condition of the arrange marks from the controller 16. Thus it is possible to improve the reliability of the inspected value of the arranging condition of the marks and productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus and an inspection method for a semiconductor wafer, and more particularly, to an alignment mark formed on a wafer for inspecting a pattern of a wafer. The present invention relates to an inspection apparatus and an inspection method for a semiconductor wafer which process the analysis of the alignment state by an image.

[0002]

2. Description of the Related Art Generally, a semiconductor device performs a photolithography process of forming a predetermined film on a wafer and then forming the predetermined film in a predetermined pattern. The photo-etching process includes a photo-resist on a predetermined film formed on the wafer.
st) is applied, and the photoresist is formed into a predetermined pattern by performing an exposure process and a development process. Subsequently, a step of removing the lower film exposed by forming the predetermined pattern and completely removing the photoresist remaining on the wafer is provided. Then, an inspection process for inspecting a predetermined pattern formed on the wafer by performing the photo etching process is performed.

Here, the inspection step is a first inspection step (After Develop Inspection) mainly performed after the development step.
section; hereinafter, referred to as “ADI process”. ) And a second inspection step (After Cleaning Inspection; ACI) performed after the photoresist is removed and a cleaning step is performed.
Divided by

The inspection process is generally performed by analyzing an alignment state of an alignment mark formed on the wafer when the predetermined pattern is formed. In the process, a predetermined pattern formed on the wafer was inspected mainly using a microscope. That is, the operator inspects the predetermined pattern by analyzing the alignment state using alignment marks in the pattern formed on the wafer using the microscope. Then, the ADI process was performed by an operator directly viewing and analyzing a Vernier Key, which is an alignment mark formed for inspecting a predetermined pattern of the wafer, from a microscope.

[0005]

SUMMARY OF THE INVENTION Such a conventional AD
In the process I, the analysis was performed by the operator directly visually recognizing the analysis, so that the reliability of the result of the analysis was lacking.
That is, an error in the analysis data occurs due to an arbitrary judgment of the operator or a difference in resolution of the operator's naked eye when focusing the vernier key. Such an error in the data acts as a cause of inducing a failure in performing the subsequent process. In the ADI process, a cassette (Cassett) loaded with 25 wafers is used.
e) Sampling of about 3 wafers (Samplin
g), so that A
When performing the DI process, a misidentification during the analysis inspection of the alignment state of the alignment mark may generate a large number of defects. Then, since the ADI process was performed directly by visual recognition,
This caused a decrease in work efficiency, such as a decrease in worker's eyesight.

In performing the ADI process, inspection of particles and the like existing on the wafer is not performed, and the inspection of the particles is performed by performing a second inspection process performed after performing a cleaning process. Performed separately.

[0007] Therefore, the conventional ADI is performed by visually recognizing the ADI directly from a microscope, thereby lowering the reliability of the analysis data, lowering the work efficiency, and inducing a defect in the performance of the subsequent process. There is a problem that is reduced.

An object of the present invention is to improve the reliability of analysis results by analyzing an inspection process for analyzing the alignment state of alignment marks on an image in order to inspect a predetermined pattern to be formed on a wafer. An object of the present invention is to provide a semiconductor wafer inspection apparatus and an inspection method capable of increasing productivity by improving efficiency and the like.

[0009]

According to an aspect of the present invention, there is provided an apparatus for inspecting a semiconductor wafer, comprising: a wafer aligning unit for aligning the wafer by driving a stage on which the wafer is mounted; An image processing unit that processes an area in which alignment marks are formed in the formed wafer pattern with an image, and controls driving of the wafer alignment unit to receive an image signal of the image processing unit and perform the alignment. And a control unit for analyzing an alignment state of the marks.

Preferably, the inspection apparatus further includes a transfer unit for transferring the wafer from the cassette to the stage or from the stage to the cassette. Preferably, the apparatus for inspecting a semiconductor wafer according to the present invention further comprises an output unit for outputting an analysis result of an analysis of an alignment state of the alignment mark to the control unit. The inspection apparatus for a semiconductor wafer according to the present invention may further include a particle inspection unit for inspecting particles existing on the wafer. Further, it is preferable that the particle inspection unit analyzes the surface of the wafer with an ultraviolet laser.

Further, the wafer alignment section has an X-axis and a Y-axis.
It is desirable to align the wafer by driving to an axis and θ. The image processing unit further includes a microscope that enlarges the image of the alignment mark on the wafer, a camera that captures an image of the microscope, and a video signal converter that processes the captured video into a video signal. It is desirable. The image processing unit may further include a monitor for monitoring an image captured by the camera.

[0012] In the inspection apparatus for semiconductor wafers according to the present invention, the transfer unit for transferring the wafers from the cassette to the stage or from the stage to the cassette, and the stage on which the wafers are seated are placed on the X-axis. A wafer alignment unit for aligning the wafer by driving the wafer in the Y axis and θ, and the wafer so that an area where the alignment mark is formed in the pattern of the wafer seated on the stage can be processed by an image. The microscope for enlarging the image of the alignment mark, the camera for capturing an image of the microscope, the monitor for monitoring a video captured by the camera, and the video signal for processing the captured video into the video signal The image processing unit comprising a converter, and controls the drive of the wafer alignment unit,
The controller for analyzing the alignment state of the alignment mark in response to the input of the image signal of the image processing unit, and analyzing the surface of the wafer with the ultraviolet laser so as to inspect the particles present on the wafer. The particle inspection unit, and the output unit configured to output an analysis result of an alignment state of the alignment mark by the control unit.

[0013] In the inspection method of a semiconductor wafer according to the present invention, the stage on which the wafer is seated may be moved along the X axis and the Y axis.
Driving the axis and the θ to align the wafer;
Processing an image of the area where the alignment mark is formed in the pattern of the wafer seated on the stage into an image, and receiving an input of the image signal processed into the image to change an alignment state of the alignment mark. It is characterized by having a step of analyzing.

It is preferable that the method for inspecting a semiconductor wafer according to the present invention further includes a step of inspecting the particles existing on the wafer. The method for inspecting a semiconductor wafer according to the present invention may further include a step of outputting an analysis result of an alignment state of the alignment mark.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a specific embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 is a block diagram showing a semiconductor wafer inspection apparatus according to an embodiment of the present invention.
FIG. 3 is a process diagram showing a semiconductor wafer inspection method according to an embodiment of the present invention.

As shown in FIG. 1, an apparatus for inspecting a semiconductor wafer according to an embodiment of the present invention includes a transfer unit 10 for transferring a wafer from a cassette to a stage or from a stage to a cassette, and the wafer being seated thereon. A wafer alignment unit 12 for aligning the wafers by driving the stage to the X-axis, Y-axis, and θ, and further processing an area where alignment marks are formed in the pattern of the wafer seated on the stage with an image. A microscope 142 for enlarging the image of the alignment mark on the wafer, a camera 144 for photographing the image of the microscope 142, and monitoring of an image photographed by the camera 144.
And a video processing unit 14 including a video signal converter 148 for processing the captured video into a video signal. The video processing unit 14 further controls the driving of the wafer alignment unit 12 and controls the video of the video processing unit 14. A control unit 16 for receiving an input signal and analyzing an alignment state of the alignment mark; and a particle inspection unit 18 for analyzing a surface of the wafer with an ultraviolet laser so as to inspect particles existing on the wafer. Further, an output unit 20 for outputting data of analysis of the alignment state of the alignment marks by the control unit 16 is provided.

That is, the apparatus for inspecting a semiconductor wafer according to the embodiment of the present invention performs the conventional ADI process performed by the direct visual recognition using the image processing unit 14 and the control unit 16 as a process on a screen. To achieve.

As shown in FIG. 2, a method for inspecting a semiconductor wafer according to an embodiment of the present invention includes a step of transferring a wafer to a stage, and driving the stage on which the wafer is seated in the X-axis, Y-axis and θ. And aligning the wafer. Processing an area where the alignment mark is formed in the pattern of the wafer seated on the stage with an image, and analyzing an alignment state of the alignment mark by receiving an image signal processed with the image; It has a process. The method further includes a step of inspecting particles existing on the wafer and a step of outputting data of analysis of an alignment state of the alignment mark.

When using a semiconductor wafer inspection apparatus according to the semiconductor wafer inspection method according to the embodiment of the present invention,
When performing an inspection process for inspecting a pattern formed on the wafer, that is, an ADI process, the alignment state of the alignment marks is processed into a video signal and analyzed, thereby improving the reliability of the analysis data. In addition, by using the monitor 146 or the output unit 20 of the video processing unit 14, the work efficiency can be improved.

The operation and effects of the specific embodiment of the present invention having the above-described configuration will be described. First, the wafer loaded on the cassette is transferred to the stage using the transfer unit 10. Next, the control unit 16 causes the wafer alignment unit 12 to move the stage on which the wafer is seated to X
The wafers are aligned by driving them along the axis, the Y axis, and theta. That is, after the wafer is transferred to the stage using the transfer unit 10, the wafer is aligned.
Generally, after aligning the flat zone of the wafer first, the wafer is driven by the X-axis, the Y-axis, and the like as described above to align the wafer. Subsequently, the alignment mark formed on the wafer is stored in the image processing unit 14.
To process video. Here, in the image processing of the alignment marks on the wafer, generally, five samples are inspected, but the operator can arbitrarily determine the increase or decrease of the number of sample inspections due to the characteristics of the pattern and perform the inspection. That is, the image of the alignment mark is monitored using the microscope 142, the camera 144, and the monitor 146, and the image is processed into an image signal using the image signal converter 148 and input to the control unit 16. .

Here, the operator can check the alignment state of the alignment marks as an image monitored on the monitor 146 of the image processing unit 14, and the control unit 16 can control the alignment by inputting an image signal. The alignment state of the alignment mark can be confirmed as data obtained by analyzing the alignment state of the mark. That is, since the analysis result of the control unit 16 is provided using the output unit 20, the operator can analyze the alignment state of the alignment marks.

Subsequently, the particles existing on the wafer are inspected using the particle analyzer 18.
That is, particles existing on the wafer are analyzed by analyzing the surface of the wafer using an ultraviolet laser. Then, it outputs not only the data of the analysis of the alignment state of the alignment marks of the wafer but also the analysis result of the particles. Here, the analysis of the alignment state can be displayed on a screen of the monitor 146 of the image processing unit 14, and the output unit 20 can provide an analysis result output to a map of a wafer or the like.

According to the embodiment of the present invention, the pattern formed on the wafer is inspected, that is, the ADI process is performed on a screen, so that defects generated during the ADI process can be prevented. Can be prevented.
That is, when performing the ADI process performed by sampling or the like,
It is possible to minimize errors in analyzing the alignment state of the alignment marks. Since the sampling inspection can be performed by inspection of all 25 sheets, defects that cannot be found by the sampling inspection can be reduced as much as possible. Also, by confirming the analysis result of the ADI process, a transition analysis or the like is performed based on the analysis result,
It is possible to efficiently grasp problems of the ADI process that may occur later. The use of the video processing unit 14 can protect the worker's eyesight and the like, so that the working efficiency and the like can be improved. In addition, by simultaneously performing the particle inspection using the particle analyzer 18, it is possible to quickly cope with the defect due to the particles or the like.

The embodiment of the present invention can reduce the number of wafers to be rejected or reworked during a subsequent process, thereby improving the operation efficiency of manufacturing equipment. That is, the inspection of the alignment state of the alignment mark, which is performed to inspect the pattern of the wafer, is processed on the screen, so that the reliability of the analysis result by the inspection can be improved, and the inspection error can be minimized. Can be

[0025]

Therefore, according to the present invention, the reliability of the analysis result of the inspection of the alignment state of the alignment mark can be improved, the inspection error and the like can be minimized, and the working efficiency and the like can be improved. By doing so, there is an effect that productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a semiconductor wafer inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a process chart of a semiconductor wafer inspection method according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 transfer unit 12 wafer alignment unit 14 image processing unit 16 control unit 18 particle inspection unit 20 output unit 142 microscope 144 camera 146 monitor 148 image signal converter

Claims (12)

[Claims] A wafer alignment unit for aligning the wafer by driving a stage on which the wafer is mounted, and processing an image of an area where alignment marks are formed in a pattern of the wafer mounted on the stage. An image processing unit, comprising: a control unit configured to control driving of the wafer alignment unit, receive an image signal of the image processing unit, and analyze an alignment state of the alignment mark. apparatus. 2. The semiconductor wafer inspection apparatus according to claim 1, further comprising a transfer unit configured to transfer the wafer from a cassette to the stage or from the stage to the cassette. 3. The semiconductor wafer inspection apparatus according to claim 1, further comprising: an output unit configured to output an alignment state of the alignment mark by the control unit as an analysis result. 4. The semiconductor wafer inspection apparatus according to claim 1, further comprising a particle inspection unit for inspecting particles existing on the wafer. 5. The semiconductor wafer inspection apparatus according to claim 4, wherein the particle inspection unit analyzes the surface of the wafer with an ultraviolet laser. 6. The semiconductor wafer inspection apparatus according to claim 1, wherein the wafer alignment unit aligns the wafer by driving the X axis, the Y axis, and θ. 7. The image processing unit includes a microscope that enlarges an image of the alignment mark on the wafer, a camera that captures an image of the microscope, and a video signal converter that processes the captured video with a video signal. The semiconductor wafer inspection device according to claim 1, further comprising: 8. The semiconductor wafer inspection apparatus according to claim 7, wherein the image processing unit includes a monitor capable of monitoring the image photographed by the camera. 9. A transfer unit for transferring a wafer from a cassette to a stage or from the stage to the cassette, and driving the stage on which the wafer is seated in X, Y and θ directions to align the wafer. A wafer aligning unit, a microscope for enlarging an image of the alignment mark on the wafer so that a region where the alignment mark is formed in the pattern of the wafer seated on the stage can be processed with an image. A camera that captures an image, a monitor that monitors an image captured by the camera, and an image processing unit that has an image signal converter that processes the captured image into an image signal, and controls driving of the wafer alignment unit. A control unit that receives an input of the video signal from the video processing unit and analyzes an alignment state of the alignment mark; A particle inspection unit that analyzes the surface of the wafer with an ultraviolet laser so that existing particles can be inspected; and an output unit that outputs data of the analysis of the alignment state of the alignment marks by the control unit as an analysis result. A semiconductor wafer inspection device, comprising: 10. A stage on which a wafer is seated,
Driving the wafer along the axis, the Y-axis, and θ to align the wafer; processing an area where alignment marks are formed in the pattern of the wafer seated on the stage with an image; Analyzing the alignment state of the alignment mark in response to an input of a video signal. 11. The method according to claim 1, further comprising the step of inspecting the particles present on the wafer.
0. A semiconductor wafer inspection method according to item 0. 12. The method according to claim 1, further comprising the step of outputting data of an analysis result of the alignment state of the alignment mark.
0. A semiconductor wafer inspection method according to item 0.