Wafer defect multichannel detection system based on dark field and photoluminescence

Abstract

The utility model belongs to the technical field of wafer detection, and particularly relates to a wafer defect multichannel detection system based on a dark field and photoluminescence. Comprising a light source module for emitting a light source to the surface of a wafer, a first optical function module for performing imaging detection on a wafer bulge defect in a dark field imaging light path, and a second optical function module for performing imaging detection on a wafer pit defect in the dark field imaging light path, the third optical function module is used for collecting the light of the first wave band for imaging detection; and the fourth optical function module is used for collecting the light of the second wave band for imaging detection. A light source module is arranged to emit a light source, and different optical modules are utilized, so that dark field and photoluminescence wafer defect multi-channel acquisition detection is realized, and the detection efficiency and the detection capability of the system are improved; meanwhile, simultaneous imaging of light of different wave bands can be achieved, and different wafer defect types can be distinguished conveniently; the whole device is high in light path integration level, saves workpieces, is simple in structure and is convenient to detect.

Description

TECHNICAL FIELD

[0001] The utility model belongs to wafer detection technical field, concretely relates to a kind of wafer defect multichannel detection system based on dark field and photoluminescence. BACKGROUND

[0002] The basic material wafer of semiconductor is prone to breakage, hidden crack, scratch and other defects in production process.The abnormality of internal crystal structure of semiconductor wafer can cause subsequent IC chip to appear defective.

[0003] Some photoetching semiconductor chip products exist regular pattern array on wafer, these patterns have certain period frequency, so it is convenient to convert to frequency domain for filtering by the way of Fourier transform, eliminate background pattern, only extract breakage, hidden crack, scratch, dirt and other defects without fixed frequency existing on wafer.

[0004] Generally used laser mainly uses laser bright field illumination mode, and the bright field illumination image of optical microscope is formed by reflected light, laser is illuminated to wafer surface through microscope barrel lens and microscope objective, that is, the incident light of light source is vertically shot to sample surface, then re-enters objective lens and microscope barrel lens after being reflected from sample surface, most of reflected light is returned, so the illumination intensity is large, and it is suitable for sample with flat surface.The dark or unclear area observed by bright field observation can be caused by surface unevenness.But the defect resolution is difficult to improve by using laser bright field illumination mode, and it is difficult to capture tiny particle defects, so that the capture ability of particle defects is poor, and the defect detection precision is low. UTILITY MODEL CONTENTS

[0005] The utility model provides a kind of wafer defect multichannel detection system based on dark field and photoluminescence, by setting one light source module emits light source, and utilizes different optical modules, realizes the multichannel acquisition detection of wafer defect based on dark field and photoluminescence, improves the detection efficiency and detection capacity of system;And it can realize the simultaneous imaging of different waveband light, it is convenient to distinguish different wafer defect types;The whole device light path integration degree is high, saves workpiece, and the structure is simple, and it is convenient to detect.

[0006] A kind of wafer defect multichannel detection system based on dark field and photoluminescence, comprising:

[0007] Light source module, it is along first direction setting, for emitting light source to wafer surface;

[0008] First optical function module, it includes filter, first objective lens, first barrel lens and first camera sequentially arranged along third direction, for imaging detection to wafer convex defect in dark field imaging light path;

[0009] A second optical functional module comprising a second objective lens, a first dichroic mirror, a second barrel lens and a second camera, is used for imaging detection of wafer pit defects in a dark field imaging light path;

[0010] A third optical functional module comprising a second objective lens, a first dichroic mirror, a second dichroic mirror, a third barrel lens and a third camera, is used for collecting light of a first wave band for imaging detection in a photoluminescence light path;

[0011] A fourth optical functional module comprising a second objective lens, a first dichroic mirror, a second dichroic mirror, a fourth barrel lens and a fourth camera arranged in sequence along a fourth direction, is used for collecting light of a second wave band for imaging detection in a photoluminescence light path;

[0012] The first dichroic mirror, the second barrel lens and the second camera are arranged in sequence along a second direction; the second dichroic mirror, the third barrel lens and the third camera are arranged in sequence along the second direction; the first direction, the second direction, the third direction and the fourth direction are arranged in a counterclockwise direction, the included angle between the first direction and the second direction is an acute angle, and the second direction and the fourth direction are perpendicular.

[0013] By setting one light source module to emit light sources and using different optical modules, multi-channel collection and detection of wafer defects in dark field and photoluminescence are realized, the detection efficiency and detection capacity of the system are improved, different wave band lights can be imaged at the same time, different wafer defect types are distinguished, the whole device has high light path integration, saves workpieces, has simple structure and is convenient for detection.

[0014] Further, the light source module comprises:

[0015] A laser for emitting laser light; the laser light is a Gaussian circular spot with a wavelength of 375 mm;

[0016] A shaping device arranged on the light path of the laser for shaping the Gaussian circular spot emitted by the laser into a linear light spot with uniform energy distribution.

[0017] Further, the filter is used for transmitting scattered light with a wavelength of 375 mm and filtering other wavelength stray light.

[0018] Further, the first dichroic mirror is used for reflecting the collected scattered light and transmitting visible wave band fluorescence and infrared wave band fluorescence.

[0019] Further, the second dichroic mirror is used for reflecting visible wave band fluorescence and transmitting infrared wave band fluorescence.

[0020] Further, the third optical function module collects infrared band fluorescence when performing imaging detection.

[0021] Further, the fourth optical function module collects visible light band fluorescence when performing imaging detection.

[0022] The present application has the advantages that:

[0023] The present application has the advantages that: BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The present application has the advantages that:

[0025] Figure 2 The present application has the advantages that:

[0026] Figure 3 The present application has the advantages that:

[0027] REFERENCE SIGNS

[0028] 11, laser; 12, shaping device;

[0029] 2, optical filter;

[0030] 31, first objective lens; 32, second objective lens;

[0031] 41, first dichroic mirror; 42, second dichroic mirror;

[0032] 51, first cylindrical lens; 52, second cylindrical lens; 53, third cylindrical lens; 54, fourth cylindrical lens;

[0033] 61, first camera; 62, second camera; 63, third camera; 64, fourth camera;

[0034] 7, wafer. DETAILED DESCRIPTION

[0035] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0036] In the description of the utility model, it needs to explain, the term "center", "upper", "lower", "left", "right", "vertical", "horizontal", "internal", "external" and so on indicate the orientation or position relation based on the orientation or position relation shown in the drawing, only for the convenience of describing the utility model and simplifying the description, and not indicate or imply that the device or element indicated must have a particular orientation, a particular orientation and operation, therefore, it cannot be understood as the limitation of the utility model. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0037] In the description of the utility model, it needs to explain, the term "center", "upper", "lower", "left", "right", "vertical", "horizontal", "internal", "external" and so on indicate the orientation or position relation based on the orientation or position relation shown in the drawing, only for the convenience of describing the utility model and simplifying the description, and not indicate or imply that the device or element indicated must have a particular orientation, a particular orientation and operation, therefore, it cannot be understood as the limitation of the utility model. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0038] Figure 1 As shown is a kind of wafer defect multichannel detection system based on dark field and photoluminescence, by setting a light source module emits light source, and using different optical modules, realize the dark field and photoluminescence wafer 7 defect multichannel acquisition detection, improve the detection efficiency and detection capacity of system;And it can realize the simultaneous imaging of different waveband light, it is convenient to distinguish different wafer 7 defect types;The whole device light path integration degree is high, saves workpiece, simple structure, and it is convenient to detect.

[0039] In the embodiment, from the perspective of optical device, wafer defect multichannel detection system based on dark field and photoluminescence includes light source module, filter 2, objective lens module, dichroic mirror module, barrel lens module, camera module.

[0040] Specifically, light source module, it is arranged along the first direction, for emitting light source to wafer 7 surface;Including:

[0041] Laser 11, for emitting laser;Laser is the Gaussian circular spot with wavelength 375mm;

[0042] Shaping device 12, it is arranged on the light path of laser 11, for shaping the Gaussian circular spot emitted by laser 11 into line light spot with uniform energy distribution.

[0043] Specifically, the filter 2 is arranged on the light path of the third direction reflected by the wafer 7, and is used for transmitting the scattered light with a wavelength of 375 mm and filtering other stray light.

[0044] In the embodiment, the wafer 7 is a silicon carbide wafer.

[0045] Specifically, the objective lens module comprises:

[0046] The first objective lens 31 is arranged on the light path of the filter 2, and is used for collecting the scattered light transmitted by the filter 2;

[0047] The second objective lens 32 is arranged on the light path of the fourth direction reflected by the wafer 7, and is used for collecting the fluorescence and scattered light excited by the wafer 7;

[0048] Specifically, the dichroic mirror module comprises:

[0049] The first dichroic mirror 41 is arranged on the light path of the second objective lens 32, and is used for reflecting the scattered light collected by the second objective lens 32 along the second direction and transmitting the fluorescence collected by the second objective lens 32 along the fourth direction;

[0050] The second dichroic mirror 42 is arranged on the light path of the light transmitted by the first dichroic mirror 41, and is used for reflecting the infrared waveband fluorescence collected by the first dichroic mirror 41 along the second direction and transmitting the visible waveband fluorescence collected by the first dichroic mirror 41 along the fourth direction;

[0051] Specifically, the barrel lens module comprises:

[0052] The first barrel lens 51 is arranged on the light path of the first objective lens 31, and is used for imaging the scattered light collected by the first objective lens 31;

[0053] The second barrel lens 52 is arranged on the light path of the light reflected by the first dichroic mirror 41, and is used for imaging the scattered light reflected by the first dichroic mirror 41;

[0054] The third barrel lens 53 is arranged on the light path of the light reflected by the second dichroic mirror 42, and is used for focusing and imaging the infrared waveband fluorescence reflected by the second dichroic mirror 42;

[0055] The fourth barrel lens 54 is arranged on the light path of the light transmitted by the second dichroic mirror 42, and is used for focusing and imaging the visible waveband fluorescence transmitted by the second dichroic mirror 42;

[0056] Specifically, the camera module comprises:

[0057] The first camera 61 is arranged on the light exit path of the first barrel lens 51, and is used for imaging detection of the wafer 7 protrusion and particle defects in the dark field imaging light path.

[0058] The second camera 62 is arranged on the light exit path of the second barrel lens 52, and is used for imaging detection of the wafer 7 pit and scratch defects in the dark field imaging light path.

[0059] The third camera 63 is arranged on the light exit path of the third barrel lens 53, and is used for imaging detection of infrared waveband fluorescence collected in the photoluminescence light path.

[0060] The fourth camera 64 is arranged on the light exit path of the fourth barrel lens 54, and is used for imaging detection of visible light waveband fluorescence collected in the photoluminescence light path.

[0061] Among them, from the perspective of optical function, the optical filter 2, the first objective lens 31, the first barrel lens 51 and the first camera 61 constitute a first optical function module, which concentrates scattered light in a wide channel, and is used for imaging detection of wafer 7 protrusion and particle defects in the dark field imaging light path; the second objective lens 32, the first dichroic mirror 41, the second barrel lens 52 and the second camera 62 constitute a second optical function module, which concentrates scattered light in a narrow channel, and is used for imaging detection of wafer 7 pit and scratch defects in the dark field imaging light path; the second objective lens 32, the first dichroic mirror 41, the second dichroic mirror 42, the third barrel lens 53 and the third camera 63 constitute a third optical function module, which is used for imaging detection of infrared waveband fluorescence collected in the photoluminescence light path; the second objective lens 32, the first dichroic mirror 41, the second dichroic mirror 42, the fourth barrel lens 54 and the fourth camera 64 constitute a fourth optical function module, which is used for imaging detection of visible light waveband fluorescence collected in the photoluminescence light path.

[0062] In the embodiment, the first direction, the second direction, the third direction and the fourth direction are arranged in the counterclockwise direction, the included angle between the first direction and the second direction is an acute angle, the second direction and the fourth direction are perpendicular, and the first direction and the third direction are symmetrical along the axis on which the second direction is located.

[0063] The working principle of the embodiment is as follows:

[0064] As Figure 2As shown, in the optical path of dark-field imaging, laser 11 emits laser light along the first direction, and the laser light is shaped onto the surface of wafer 7. For bumps and particle defects on wafer 7, the scattered light is concentrated in the wide channel, that is, after being reflected along the third direction, the scattered light passes through the filter 2, is collected by the first objective lens 31, and is imaged onto the first camera 61 by the first tube lens 51 to collect images of bumps and particle defects on wafer 7; for dents and scratches on wafer 7, the scattered light is concentrated in the narrow channel, that is, after being reflected along the fourth direction, the scattered light passes through the second objective lens 32, is reflected by the first dichroic mirror 41, and is imaged onto the second camera 62 by the second tube lens 52 to collect images of dents and scratches on wafer 7.

[0065] like Figure 3 As shown, in the photoluminescence optical path, laser 11 emits laser light along the first direction, and the laser light is shaped by laser 11 onto the surface of wafer 7 for excitation. For collecting infrared fluorescence images, the fluorescence is reflected along the fourth direction and then sequentially collected by the second objective lens 32, transmitted through the first dichroic mirror 41, reflected by the second dichroic mirror 42, and imaged onto the third camera 63 by the third tube lens 53. For collecting visible light fluorescence images, the fluorescence is reflected along the fourth direction and then sequentially collected by the second objective lens 32, transmitted through the first dichroic mirror 41, transmitted through the second dichroic mirror 42, and imaged onto the fourth camera 64 by the fourth tube lens 54.

[0066] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A multi-channel dark field and photoluminescence based wafer defect detection system, comprising: The application relates to a wafer defect detection device and method. The light source module is arranged along a first direction and used for emitting a light source to a wafer surface; The first optical function module comprises a filter, a first objective lens, a first tube lens and a first camera arranged along a third direction in sequence and is used for imaging detection of wafer convex defect in a dark field imaging light path; The second optical function module comprises a second objective lens, a first dichroic mirror, a second tube lens and a second camera and is used for imaging detection of wafer pit defect in the dark field imaging light path; The third optical function module comprises a second objective lens, a first dichroic mirror, a second dichroic mirror, a third tube lens and a third camera and is used for collecting light of a first wave band in a photo luminescence light path for imaging detection; The fourth optical function module comprises a second objective lens, a first dichroic mirror, a second dichroic mirror, a fourth tube lens and a fourth camera arranged along a fourth direction in sequence and is used for collecting light of a second wave band in the photo luminescence light path for imaging detection; The first dichroic mirror, the second tube lens and the second camera are arranged along a second direction in sequence; the second dichroic mirror, the third tube lens and the third camera are arranged along the second direction in sequence; the first direction, the second direction, the third direction and the fourth direction are arranged in an anticlockwise direction, the included angle between the first direction and the second direction is an acute angle, and the second direction and the fourth direction are perpendicular.

2. The multi-channel dark field and photoluminescence based wafer defect detection system of claim 1, wherein, The light source module comprises: A laser used for emitting laser light; the laser light is a Gaussian circular light spot with a wavelength of 375 mm; A shaping device arranged on the light path of the laser and used for shaping the Gaussian circular light spot emitted by the laser into a linear light spot with uniform energy distribution.

3. The multi-channel dark field and photoluminescence based wafer defect detection system of claim 2, wherein, The filter is used for transmitting scattered light with a wavelength of 375 mm and filtering other wavelength stray light.

4. The multi-channel dark field and photoluminescence based wafer defect detection system of claim 1, wherein, The first dichroic mirror is used for reflecting collected scattered light and transmitting visible wave band fluorescence and infrared wave band fluorescence.

5. The multi-channel dark field and photoluminescence based wafer defect detection system of claim 1, wherein, The second dichroic mirror is used for reflecting visible wave band fluorescence and transmitting infrared wave band fluorescence.

6. The multi-channel dark field and photoluminescence based wafer defect detection system of claim 1, wherein, When the third optical function module performs imaging detection, the collected light of the first wave band is infrared wave band fluorescence.

7. The multi-channel dark field and photoluminescence based wafer defect detection system of claim 1, wherein, When the fourth optical function module performs imaging detection, the collected light of the second wave band is visible light wave band fluorescence.

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