KR20060105856A - Apparatus of defect inspection in semiconductor device and method of using the same - Google Patents

Abstract

The semiconductor wafer defect detection apparatus of the present invention and a defect detection method for a semiconductor wafer using the same include an optical system that emits light in different optical paths to a semiconductor wafer to be detected, and a light that is irradiated from the optical system and scattered from the semiconductor wafer. A photodetector for detecting is provided. In particular, the optical system may include a light source, a beam splitter for separating light emitted from the light source, and a lens for irradiating the semiconductor wafer with light separated from the beam splitter on different optical paths. In some cases, the light emitting device may include a plurality of light sources that irradiate the semiconductor wafer with light at different optical paths.

Light source, beam splitter, lens, optical path, optical system, defect detection device

Description

Apparatus of defect inspection in semiconductor device and method of using the same}

1 to 3 and 4A and 4B are diagrams illustrating a failure detection apparatus for a semiconductor wafer and a failure detection method for a semiconductor wafer using the same according to the related art.

5 and 6 are views illustrating a defect detection apparatus of a semiconductor wafer and a defect detection method of a semiconductor wafer using the same according to an embodiment of the present invention.

7 and 8 illustrate examples of the optical system of FIG. 5, respectively.

9 and 10 are diagrams for explaining the operation of the failure detection apparatus of FIG.

Explanation of symbols on the main parts of the drawing

500: semiconductor wafer 600,710,720: light source

610 beam splitter 620630 lens

800: detector 900: signal conversion device

1000: display device

The present invention relates to a semiconductor wafer defect detection device and a method for detecting a defect of a semiconductor wafer using the same, and more particularly, a semiconductor wafer defect detection device for more accurately detecting a defect on a semiconductor wafer to improve the overall manufacturing yield of the device. And a defect detection method for a semiconductor wafer using the same.

Generally, in order to form line patterns such as gate patterns, bit line patterns, and metal lines on a semiconductor wafer, a material film for forming each line pattern is formed on the semiconductor wafer, and then a mask film pattern is formed on the material film. An etching process using the same is performed to form line patterns. However, even after the mask layer pattern is removed after the etching process for forming the line patterns, a residue of the mask layer pattern may remain or particles derived from the material layer may be unnecessarily present on the semiconductor wafer. As a result, the device may not be formed normally but is poorly formed. Therefore, in order to detect such a badly formed element, a defect detection method of a semiconductor wafer using a defect detection apparatus is currently implemented.

 Current defect detection apparatuses for semiconductor wafers include a dark field (DF) and a bright field (BF) detection apparatus. The dark field detection device detects light scattered from the semiconductor wafer after the light emitted from the light source is obliquely irradiated to a predetermined region of the semiconductor wafer to be inspected by a detector and converts the signal from the signal conversion device. The detected signal is compared with a signal detected in another area of the semiconductor wafer to check whether there is a defect in the semiconductor wafer, and the bright field detection device irradiates light to the semiconductor wafer to be inspected in a vertical direction and then reverses the direction of the irradiation direction. This method detects defects in a semiconductor wafer by detecting the light reflected by the detector and comparing the signal converted by the signal converter.

1 to 4 are diagrams for explaining a defect detection apparatus of a semiconductor wafer according to the prior art and a defect detection method of a semiconductor wafer using the same. In particular, the dark field failure detection apparatus will be described in detail.

First, referring to FIG. 1, a conventional failure detection apparatus includes a single light source 110 for irradiating light onto a semiconductor wafer 100 to detect whether a defect is present, and the light emitted from the light source 110 is a semiconductor wafer. A detector 120 for detecting light 115 scattered from 100. The light detected by the detector 120 is displayed as a signal through the signal conversion device 130, and the black spot in the display device 150 is compared with the signals detected in the adjacent line patterns 105. The defect is indicated by the semiconductor wafer 100.

FIG. 2 is a diagram showing such a defect in the display device, and as shown in FIG. 2, it can be confirmed that a defect exists at a point indicated by a large amount of black spot (“A”) in the semiconductor wafer 100.

Hereinafter, a failure detection method using the failure detection apparatus of the semiconductor wafer will be described.

Light is emitted from the light source 110 to the semiconductor wafer 100 to be inspected for defects. In this case, the semiconductor wafer 100 has an example in which the horizontal and vertical line patterns 105 have a stripe shape with respect to the flat zone 107. The light source exits at an inclination angle of approximately 20 ° to 30 °. Next, the light scattered from the semiconductor wafer 100 is detected by the detector 320, and the signal passing through the signal conversion device is detected in the semiconductor wafer 100 in which the same line patterns 105 are disposed. It is determined whether or not the semiconductor wafer 100 is defective by comparison with a signal detected at another part.

However, as shown in FIG. 3, when the optical path 111 irradiated from the light source 110 (in FIG. 1) and the line patterns 105 formed in the semiconductor wafer 100 have the same direction of formation, the detection of the signal of the defect B is difficult. Although easy, as shown in FIG. 4, when the direction of the line patterns formed in the semiconductor wafer 100 and the light path 111 irradiated from the light source 110 of FIG. 1 are different, the line patterns 105 may be the light source 110. Because it serves to block the defects, it is difficult to distinguish the difference between the light scattered in the portion where the defect exists and the portion where the defect does not exist, and thus there is a problem that it is difficult to detect the defect C between the line patterns.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and the technical problem to be achieved by the present invention is a semiconductor wafer failure detection device for improving the overall manufacturing yield of the device by detecting defects on the semiconductor wafer more accurately and using the same A defect detection method for a semiconductor wafer is provided.

In order to achieve the above technical problem, the semiconductor wafer failure detection apparatus according to the present invention comprises an optical system for emitting light in different optical paths to the semiconductor wafer to be detected; And a photodetector for detecting light emitted from the optical system and scattered from the semiconductor wafer.

The optical system includes a light source; A beam splitter for separating light emitted from the light source; And a lens for irradiating the semiconductor wafer with light separated from the beam splitter to different optical paths.

In some cases, the optical system may include a plurality of light sources that irradiate the semiconductor wafer with light at different optical paths.

In this case, the light source emits a laser, ultraviolet light, deep ultraviolet light and / or visible light.

In the present invention, the signal conversion device for converting the signal generated from the detector into an electrical signal; And a display device for analyzing whether a signal changed by the signal conversion device is displayed and whether the semiconductor wafer is defective.

In order to achieve the above technical problem, the semiconductor wafer wiper failure detection apparatus according to the present invention and a failure detection method of a semiconductor wafer using the same, comprising: irradiating light having a different optical path to the semiconductor wafer having line patterns; Generating an electrical signal by detecting light scattered from the semiconductor wafer by the irradiated light; And determining whether the semiconductor wafer is defective by analyzing the electrical signal.

The irradiating the light may be performed by using a light source that separates the light emitted from the light source from the light source, and a lens that irradiates the semiconductor wafer with light separated from the beam splitter in different paths. Can be.

In some cases, the irradiating the light may be performed by using a plurality of light sources that irradiate the semiconductor wafer with light in different optical paths.

The determining of whether the semiconductor wafer is defective may be performed by comparing electrical signals in adjacent regions of the semiconductor wafer.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification.

5 and 6 are cross-sectional views illustrating a defect detection apparatus of a semiconductor wafer according to an embodiment of the present invention. 7 and 8 illustrate examples of the optical system of FIG. 5, respectively.

First, referring to FIG. 5, a failure detection apparatus for a semiconductor wafer according to the present invention includes an optical system (not shown), a photodetector 800, a signal converter 900, and a display device 1000. In this case, as illustrated in FIG. 6, stripe-shaped line patterns 502 arranged in the vertical direction are disposed on the semiconductor wafer 500 to detect the defect.

Specifically, the optical system is to emit light to the semiconductor wafer 500 to be detected in different optical paths (610a, 610b). Such an optical system may be composed of one light source or a plurality of light sources, and may include an appropriate lens system to limit the optical path emitted from the light source.

 As an example, as shown in FIG. 7, the optical systems 600, 610, 620 and 630 are composed of one light source 600 and the lens systems 610, 620 and 630. The light source 600 may emit a laser, ultraviolet (UV) light, deep ultraviolet light (DUV), or visible light. In this case, the laser is used at a power of approximately 1W to 10,000,000W, the ultraviolet and deep ultraviolet light and visible light at a power of approximately 10W to 10,000W and may use a wavelength range of approximately 200nm to 800nm. In this case, since one light source is used, the power and the wavelength band of the light source can be used in combination.

The lens systems 610, 620 and 630 are for limiting the path of the light 601 emitted from the light source 600. The lens system 610, 620, 630 includes a beam splitter 610 and a plurality of lenses 620, 630. As shown in the drawing, the beam splitter 610 is disposed at the same position as the light source to separate the light 601 emitted from the light source into a horizontal path and a vertical path. Of the light separated from the beam splitter 610, the light separated by the horizontal path is irradiated onto the semiconductor wafer 500 by the same first light path 601a, and the light separated by the vertical path is a plurality of lenses properly disposed. The semiconductor wafer 500 is irradiated to the second optical path 601b perpendicular to the first optical path 601a through the 620 and 630. In some cases, the lens may be further disposed.

 As another example, as shown in FIG. 8, the optical systems 710 and 720 are composed of a plurality of first and second light sources 710 and 720. In this case, the first light source 710 is disposed on the side of the semiconductor wafer 500, and the second light source 720 is disposed below the semiconductor wafer 500. Even in this case, the light source 600 may emit a laser, ultraviolet (UV) light, deep ultraviolet light (DUV), or visible light. In this case, the laser is used at a power of approximately 1W to 10,000,000W, the ultraviolet and deep ultraviolet light and visible light at a power of approximately 10W to 10,000W and may use a wavelength range of approximately 200nm to 800nm. Since the plurality of first light sources and the second light sources 710 and 720 are disposed on the semiconductor wafer 500, a plurality of the same light sources may be used or, in some cases, mixed light sources may be used. For example, a mixed light source of laser and ultraviolet light or a mixed light source of laser and deep ultraviolet light may be used. When the same light source is used, the power or wavelength band of the light source may be different. For example, a mixed light source of a 500W laser and a 1000W laser or a mixed light source of 150W ultraviolet light and 300W ultraviolet light may be used.

The light emitted from the first light source 710 disposed on the side part is irradiated onto the semiconductor wafer 500 by the first light path 701 which is a horizontal path, and the light emitted from the second light source 720 disposed below the The semiconductor wafer 500 is irradiated with a second optical path 702 which is a vertical path. In some cases, the semiconductor wafer 500 may be disposed at different positions to have the above optical path through another lens system (not shown).

The photodetector 800 is for detecting light 603 irradiated from an optical system (not shown) and scattered from the semiconductor wafer 500. As shown in the figure, only one photodetector 800 may be disposed, but in some cases, a plurality of photodetectors 800 may be provided to detect light scattered in a different direction from the semiconductor wafer 500.

The signal conversion device 900 is for converting a signal generated from the photodetector 800 into an electrical signal. The signal converter 900 may include a digital to analog converter for converting an analog signal generated from the photodetector 800 into a digital form. The signal converting apparatus 900 displays and displays stripe-shaped line patterns as signals, and accordingly, compares signals from neighboring line patterns with each other to determine whether there is a defect.

The display device 1000 displays whether the semiconductor wafer 500 is defective by analyzing a signal changed by the signal conversion apparatus 900. In general, the display device 1000 displays a point where the defect is located by a black dot. Whether the wafer 500 is defective is displayed to the user.

Hereinafter, a failure detection method using the failure detection apparatus of such a semiconductor wafer will be described.

First, light is irradiated onto a semiconductor wafer 500 to detect defects using different optical paths using an optical system (not shown). In the semiconductor wafer 500, a case in which the horizontal and vertical line patterns 502 have a stripe shape with respect to the flat zone 510 is taken as an example. First, when one light source 600 is used as shown in FIG. 7, the light 601 emitted from the light source 600 is separated into light of different paths through the beam splitter 610. One of the separated lights is irradiated onto the semiconductor wafer 500 while maintaining the same first optical path 601a. The other light of the separated light is irradiated to the semiconductor wafer 500 through the lenses 620 and 630 with the second optical path 601b perpendicular to the first optical path 601a. At least one of the lights may have a light path parallel to the line patterns of the semiconductor wafer 500 to prevent the light from being blocked by the line patterns.

 Next, when using a plurality of light sources as shown in FIG. 8, for example, the first light source 710 and the second light source 720, the first light source 710 and the second light source 720 may be appropriately disposed to provide a first light source. The light emitted from the light source 710 is irradiated onto the semiconductor wafer 500 by the first light path 701, and the light emitted from the second light source 720 is perpendicular to the first light path 701. The light path 702 is emitted to the semiconductor wafer 500. Appropriate lenses may be used if necessary to set such an optical path. Although the example of the two optical paths 701 and 702 are perpendicular to each other in this embodiment, it may have a different angle in some cases.

Next, light scattered from the semiconductor wafer 500 (603 in FIG. 5) is detected by a detector (800 in FIG. 5). The signal generated from the detector 800 is converted into an electrical signal through the signal converter 900, and compares a signal from the signal converter 900 with a signal detected in adjacent line patterns. .

9 and 10 are diagrams for explaining the operation of the failure detection device of FIG. First, as shown in FIG. 9, signals corresponding to signals detected in mutually adjacent line patterns have the same magnitude, whereas in the presence of particles, signals having different magnitudes (signals indicated by "D" in the drawing). ) Appears. Accordingly, it is possible to know the existence of particles and the position of the particles. That is, as shown in FIG. 10, when a signal having a different size exists, a signal indicating the existence of particles (signal indicated by “E” in the drawing) is generated.

Next, through the signal comparison, the signal changed from the signal converter 900 is analyzed to display the detected signal as a black dot on the display device 1000 to determine whether the semiconductor wafer 500 is defective.

As described above, when the semiconductor wafer defect detection apparatus and the semiconductor wafer defect detection method using the same are applied, the light emitted from the light source is separated using a beam splitter, or a plurality of different light sources are arranged to provide different Since the light is irradiated to the semiconductor wafer with the optical path, the defect can be detected even if the direction of the line patterns in which the defect to be detected exists in the semiconductor wafer does not match the optical path of the light source emitted to the semiconductor wafer. In addition, it is possible to obtain a strong bad signal to improve the defect detection and noise (noise) effect can improve the overall manufacturing yield of the device.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention as defined in the following claims are also provided. It is within the scope of rights protection.

Claims (9)

An optical system for emitting light in different optical paths to the semiconductor wafer to be detected; And And a photodetector for detecting the light emitted from the optical system and scattered from the semiconductor wafer. The method of claim 1, wherein the optical system, Light source; A beam splitter for separating light emitted from the light source; And And a lens for irradiating the semiconductor wafer with the light separated from the beam splitter to different optical paths. The method of claim 1, And the optical system includes a plurality of light sources for irradiating the semiconductor wafer with light in different optical paths. The method according to claim 2 or 3, The light source emits a laser, ultraviolet light, deep ultraviolet light and / or visible light. The method of claim 1, A signal converter converting the signal generated from the detector into an electrical signal; And And a display device for analyzing whether or not the semiconductor wafer is defective by analyzing a signal changed by the signal conversion device. Irradiating light having different light paths onto a semiconductor wafer having line patterns; Detecting light scattered from the semiconductor wafer by the irradiated light to generate an electrical signal; And Analyzing the electrical signal to determine whether the semiconductor wafer is defective. The method of claim 6, The irradiating of light may be performed by using a light source that separates one light source, a beam splitter separating light emitted from the light source, and a lens that irradiates the semiconductor wafer with light separated from the beam splitter through different paths. The defect detection method of a semiconductor wafer characterized by the above-mentioned. The method of claim 6, The irradiating of the light may be performed by using a plurality of light sources that irradiate the semiconductor wafer with light in different optical paths. The method of claim 6, The determining of whether the semiconductor wafer is defective is performed by comparing electrical signals in adjacent regions of the semiconductor wafer with each other.

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