CN111326433B - Semiconductor inspection apparatus and inspection method - Google Patents

Abstract

A semiconductor detection device and detection method. The semiconductor detection device includes: a wafer carrying device for carrying the wafer to be detected; an incident light system for emitting first incident light to the wafer to be detected, and the first incident light passes through the wafer to be detected The reflection forms the first reflected light; the optical signal sorting system is used to sort out the nonlinear optical signal from the first reflected light; the control system is used to obtain the crystal to be detected according to the nonlinear optical signal The first defect information of the circle. The semiconductor detection device can realize non-destructive atomic level defect detection in the manufacturing process.

Description

Semiconductor detection device and detection method

Technical field

The present invention relates to the field of semiconductor manufacturing technology, and in particular, to a semiconductor detection device and a detection method.

Background technique

In the semiconductor manufacturing process, defects in the process or materials can easily lead to a decrease in device yield and an increase in production costs. The existing conventional yield testing methods are divided into electrical testing and online quality testing.

Among them, electrical testing can be used to find defects that affect the electrical performance of the device. However, conventional electrical testing can only be applied to back-end-of-line (BEOL) or packaging testing, and cannot identify and solve problems in real time during the manufacturing process. That is to say, the period from the occurrence of a problem to the time it can be detected in electrical testing is too long, which easily leads to the waste of ineffective processes, and the detection speed is slow, making it impossible to implement batch testing.

Although another type of traditional online quality inspection can achieve real-time inspection in the manufacturing process, such as scanning electron microscope inspection, optical bright field inspection, etc., its inspection type has limitations. Specifically, online mass inspection is usually suitable for macroscopic physical defects, such as particles and pattern defects. Once the detection requirements enter atomic size defects, online mass inspection cannot meet the inspection needs.

In summary, the real-time detection of atomic-level defects caused by the use of new materials and processes in the development and production of advanced processes is one of the current issues that needs to be solved in the field of semiconductor yield testing.

Contents of the invention

The problem solved by the present invention is to provide a semiconductor detection device and detection method for realizing non-destructive atomic level defect detection in the manufacturing process.

In order to solve the above problems, the present invention provides a semiconductor detection device, including: a wafer carrying device for carrying the wafer to be detected; an incident light system for emitting first incident light to the wafer to be detected, the The first incident light is reflected by the wafer to be detected to form a first reflected light; an optical signal sorting system is used to sort out non-linear optical signals from the first reflected light; a control system is used to sort out non-linear optical signals according to the first reflected light The linear optical signal acquires the first defect information of the wafer to be inspected.

Optionally, the nonlinear optical signal includes a second harmonic signal, a third harmonic signal, a sum frequency response signal and a difference frequency response signal.

Optionally, it also includes: a wafer alignment and focusing system, including: an imaging unit for acquiring imaging patterns at different positions on the surface of the wafer to be tested; and a sensor for acquiring images of the wafer to be tested in the first direction. Position information, the first direction is perpendicular to the surface of the wafer to be tested.

Optionally, the control system includes: an imaging operation unit, used to obtain the position information of the wafer to be tested according to the imaging patterns at different positions on the surface of the wafer to be tested; a first position control unit, used to obtain the position information of the wafer to be tested according to the position The information moves the wafer carrying device in a direction parallel to a reference plane, and the reference plane is parallel to the surface of the wafer to be tested.

Optionally, the control system includes: a second position control unit, configured to move the wafer carrying device according to the position information in the first direction, so as to realize the movement of the first incident light on the surface of the wafer to be tested. Focus.

Optionally, the incident light system includes: a first light source, used to emit the first initial incident light; a first incident light modulation unit, used to modulate the first initial incident light to form a light beam emitted to the wafer. the first incident light.

Optionally, the first light source includes a laser emitter.

Optionally, the first incident light modulation unit: a modulation device for changing one or more of the light intensity, polarization parameter and focal length of the initial incident light; a monitoring device for monitoring the first incident light. The incident light information of the incident light is fed back to the control system.

Optionally, the incident light information includes: power, light intensity, polarization parameters and light pulse parameters.

Optionally, the incident light system further includes: a second light source, configured to emit second incident light to the wafer to be inspected, and the second incident light is reflected by the wafer to be inspected to form a second reflected light.

Optionally, it also includes: an additional signal acquisition system, configured to acquire additional optical signals according to the second reflected light, and transmit the additional optical signals to the control system.

Optionally, the incident light system further includes: a second incident light modulation unit, configured to modulate the second incident light and then emit the modulated second incident light to the surface of the wafer to be detected.

Optionally, it also includes: an additional signal acquisition system for acquiring additional optical signals from the first reflected light, and transmitting the additional optical signals to the control system.

Optionally, it also includes: a main signal acquisition system, used to acquire the nonlinear optical signal and transmit the nonlinear optical signal to the control system.

Optionally, the optical signal sorting system includes: a filter, used to pass part of the first reflected light with a preset wavelength range to form a first transition optical signal; a polarizer, used to pass a part of the first reflected light with a preset polarization parameters of the first transition optical signal to form the nonlinear optical signal.

Optionally, the optical signal sorting system includes: a polarizer, used to pass a part of the first reflected light with a preset polarization parameter to form a second transition optical signal; an optical filter, used to pass a part of the first reflected light with a preset wavelength range of the second transition optical signal to form the nonlinear optical signal.

Optionally, the carrying device includes: a carrying tray for carrying the wafer to be inspected; a fixing device provided on the carrying tray for fixing the wafer to be inspected on the surface of the carrying tray; a mechanical moving component for Drive the carrier plate to move.

Optionally, the fixing device is a vacuum suction cup or a buckle fixed to the edge of the carrier plate.

Optionally, it also includes: a focusing unit: used to focus the first incident light on the surface of the unit to be detected.

Optionally, it also includes: an optical collimation unit: used to collimate the first reflected light, and make the collimated first reflected light incident on the optical signal sorting system.

Correspondingly, the present invention also provides a detection method using the above-mentioned semiconductor detection device, which includes: providing a wafer to be detected; emitting a first incident light to the wafer to be detected, and the first incident light passes through the wafer to be detected. The reflection of the circle forms a first reflected light; the first reflected light is obtained, and a nonlinear optical signal is sorted out from the first reflected light; and a third image of the wafer to be detected is obtained according to the nonlinear optical signal. 1. Defect information.

Optionally, the wafer to be tested includes: a substrate, and a dielectric layer located on the surface of the substrate.

Optionally, the first defect information includes interface electrical property defects at the interface between the substrate and the dielectric layer; the interface electrical property defects include: interface state charge potential well defects, dielectric layer inherent charge distribution and defects, and Base semiconductor doping concentration.

Optionally, the wafer to be tested includes: a substrate and a semiconductor layer located on the surface of the substrate; the material of the semiconductor layer is a compound semiconductor material or a simple semiconductor material.

Optionally, the compound semiconductor material includes gallium arsenide, gallium nitride or silicon carbide; the formation process of the semiconductor layer includes an epitaxial process.

Optionally, the first defect information includes: crystal structure defects, internal stress distribution of the semiconductor layer, and epitaxial thickness of the semiconductor layer.

Compared with the existing technology, the technical solution of the present invention has the following advantages:

In the technical solution of the semiconductor detection device of the present invention, nonlinear optical signals for detection can be sorted out from the first reflected light reflected from the surface of the wafer to be detected. The nonlinear optical signal can be used to characterize interface state charge potential well defects, inherent charges and defects in the dielectric layer, or semiconductor crystal structure defects. This enables real-time non-destructive atomic-level defect detection of semiconductor devices in the semiconductor manufacturing process. Moreover, the real-time semiconductor detection device can realize batch detection, which is beneficial to shortening the semiconductor process cycle and reducing costs.

In the detection method of the present invention, the nonlinear optical signals sorted out from the first reflected light can be used to characterize interface state charge potential well defects, inherent charges and defects of the dielectric layer, or semiconductor crystal structure defects, thereby realizing real-time processing in the semiconductor manufacturing process. Non-destructive atomic-level defect detection of semiconductor devices is conducive to shortening the semiconductor process cycle, reducing costs, and achieving batch defect detection.

Description of the drawings

1 to 8 are schematic structural diagrams of semiconductor detection devices according to various embodiments of the present invention;

Figure 9 is a schematic flowchart of a detection method according to an embodiment of the present invention.

Detailed ways

As mentioned in the background art, realizing real-time detection of atomic-level defects in the manufacturing process is one of the current problems that needs to be solved in the field of semiconductor yield inspection.

In order to solve the problem of real-time detection of atomic-level defects that occur in new materials and processes during the development and production of advanced semiconductor processes, embodiments of the present invention provide a semiconductor detection device and a detection method. In the semiconductor detection device, nonlinear optical signals for detection can be sorted out from the first reflected light to characterize interface state charge potential well defects, dielectric layer inherent charges and defects, or semiconductor crystal structure defects, thereby Achieve non-destructive atomic-level defect detection of semiconductor devices.

In order to make the above objects, features and advantages of the present invention more obvious and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

1 to 8 are schematic structural diagrams of a semiconductor detection device according to an embodiment of the present invention.

Please refer to Figure 1. The structure of the semiconductor detection device includes:

The wafer carrying device 100 is used to carry the wafer 101 to be inspected;

The incident light system 200 is used to emit the first incident light 210 to the wafer to be inspected, and the first incident light 210 is reflected by the wafer to be inspected to form the first reflected light 211;

The optical signal sorting system 300 is used to sort out the nonlinear optical signal 212 from the first reflected light 211;

The control system 400 is configured to obtain the first defect information of the wafer to be inspected 101 according to the nonlinear optical signal 212 .

A detailed description will be given below with reference to the accompanying drawings.

The semiconductor detection device can characterize atomic-level defects in the wafer 101 to be detected through non-linear optical signals 212, thereby achieving real-time and non-destructive acquisition of atomic-level defects or crystal defects in the wafer during the process. .

Specifically, the first incident light 210 is incident on the position to be measured on the surface of the wafer 101 to be inspected, causing the material of the wafer to be inspected 101 to interact with the light field emission of the first incident light 210. An optical response is generated, and the nonlinear optical signal 212 in the optical response can be used to characterize atomic-level defects in the wafer 101 to be tested. Since the optical inspection method is used, there is no need to conduct destructive inspection of the wafer to be tested 101. Moreover, the optical inspection can be performed at certain key nodes in the process, thereby realizing real-time discovery and timely detection of defects. Process improvements.

The nonlinear optical signal 212 includes sum frequency response (SFG), difference frequency response (DFG), second harmonic signal (SHG), third harmonic signal (THG) and higher order nonlinear optical signals.

In this embodiment, please refer to Figure 2. The wafer to be inspected 101 includes: a substrate 110 and a dielectric layer 111 located on the surface of the substrate 110; in this embodiment, the material of the substrate 110 is single crystal silicon. The material of the dielectric layer 111 is silicon oxide. In other embodiments, the material of the substrate 110 can also be other semiconductor materials with central symmetry; the material of the dielectric layer 111 can be other dielectric materials, such as silicon nitride, silicon oxynitride, high-K dielectric materials (medium Dielectric constant greater than 3.9), low K dielectric materials (dielectric constant greater than 2.5 and less than 3.9) or ultra-low K dielectric materials (dielectric constant less than 2.5).

The nonlinear optical signal 212 can characterize the interface state charge trap density (Dit: interfacial trap density) at the interface between the dielectric layer 111 and the substrate 110 as well as the inherent charges and defects in the dielectric layer. Among them, the interface state charge potential well defects are distributed at the interface between the semiconductor and the oxide film; the inherent charges and defects in the dielectric layer are distributed inside the dielectric layer, and the inherent charges and defects of the dielectric layer 111 are due to Inherent defects introduced by process factors during the film formation process of the dielectric layer 111 may also be material damage caused by subsequent processes. The interface state charge potential well defects or the inherent charges and defects of the dielectric layer may cause the deterioration of the electrical performance between the dielectric layer 111 and the substrate 110 .

Specifically, since the material of the substrate 110 is single crystal silicon, and the single crystal silicon is a centrosymmetric material, when there is an interface state charge A at the interface between the dielectric layer 111 and the substrate 110, or the dielectric layer 111 When there is intrinsic charge B inside, the interface state charge A or intrinsic charge B will induce changes in the space charge distribution within the substrate 110 . Once the space charge distribution within the substrate changes, it will cause the single crystal silicon material to produce an electric field-induced signal due to the destruction of the central symmetry. After the nonlinear optical signal 212 is coupled with the electric field-induced signal, it can reflect the change of space charge distribution in the substrate 110, and then characterize the interface state charge potential well defect distribution at the interface between the dielectric layer 111 and the substrate 110. , or the inherent charge and defect distribution inside the dielectric layer 111 .

In one embodiment, the dielectric layer 111 is patterned. In another embodiment, the dielectric layer 111 is not patterned.

In another embodiment, please refer to FIG. 3 , the wafer to be tested 100 includes: a substrate 120 and a semiconductor layer 121 located on the surface of the substrate 120; the material of the semiconductor layer 121 is a compound or a simple semiconductor material; a compound semiconductor Materials include gallium arsenide, gallium nitride, and silicon carbide. The nonlinear optical signal 212 can respond to crystal structure defects in the compound semiconductor material, thereby enabling real-time monitoring of the crystal quality of the semiconductor layer 121 .

In this embodiment, the semiconductor layer is formed on the surface of the substrate through an epitaxial process. When the epitaxial process causes crystal structure defects to occur in the semiconductor layer, the crystal structure defects will interact with the nonlinear optical signal. 212 coupling such that the nonlinear optical signal 212 can characterize the lattice defects or crystal uniformity defects. Wherein, the crystal structure defects include crystal lattice defects or crystal uniformity defects, and the crystal uniformity defects refer to defects where the orderly arrangement of the crystal lattice is distorted.

In one embodiment, the semiconductor layer 121 is patterned. In another embodiment, the semiconductor layer 121 is not patterned.

The optical signal sorting system 300 is used to separate the nonlinear optical signal 212 from the first reflected light 211 .

Please refer to FIG. 4 , the optical signal sorting system 300 includes: an optical filter 301 and a polarizer 302 . In this embodiment, the filter 301 is used to pass part of the first reflected light 211 with a preset wavelength range to form a first transition optical signal; the polarizer 302 is used to pass a portion of the first reflected light 211 with a preset polarization parameter. The first transition optical signal forms the nonlinear optical signal 212 . That is, the first reflected light 211 is first filtered by the optical filter 301 and then passes through the polarizer 302 to filter out the nonlinear optical signal 212 with preset polarization parameters.

Please refer to Figure 5. In another embodiment, the polarizer 302 is used to pass a part of the first reflected light with preset polarization parameters to form a second transition optical signal; the optical filter 301 is used to pass a part of the first reflected light with preset polarization parameters. The second transition optical signal in a preset wavelength range is used to form the nonlinear optical signal 212 .

Please continue to refer to Figure 1. In this embodiment, the semiconductor inspection device further includes a wafer alignment and focusing system 500. The wafer alignment and focusing system 500 is used to align the first incident light 210 on the surface of the wafer 100 to be tested. Set the position to be detected and focus.

The wafer alignment and focusing system 500 includes: an imaging unit 501, used to obtain imaging patterns at different positions on the surface of the wafer 101 to be tested; and a sensor 502, used to obtain imaging patterns of the wafer 101 to be tested in the first direction Z. Position information, the first direction Z is perpendicular to the surface of the wafer 101 to be tested.

In this embodiment, the control system 400 includes: an imaging operation unit 401, used to obtain the position information of the wafer to be tested according to the imaging patterns at different positions on the surface of the wafer to be tested 101; a first position control unit 402, Used to move the wafer carrying device 100 in a direction parallel to the reference plane XY according to the position information. The reference plane XY (ie, the plane formed by the X coordinate and the Y coordinate) is parallel to the surface of the wafer 101 to be tested. , to achieve the alignment of the wafer 101 to be tested.

After the imaging unit 501 obtains the imaging patterns at different positions on the surface of the wafer 101 to be inspected, the control system 400 can obtain the position information of the wafer 101 to be inspected through the imaging patterns, and then control the wafer carrying device 100 to move to the required position. position for alignment.

In this embodiment, the control system 400 further includes: a second position control unit 403, configured to move the wafer carrying device 100 according to the position information of the wafer 101 to be tested in the first direction Z.

After the sensor 502 obtains the position information of the wafer to be tested 101 in the first direction Z, it sends the position information to the second position control unit 403, and the second position control unit 403 responds according to The position information in the first direction Z moves the wafer carrying device 100 until the first incident light 210 can be focused at a specified height on the surface of the wafer 101 to be inspected.

The incident light system 200 includes: a first light source 201 for emitting a first initial incident light; a first incident light modulation unit 202 for modulating the first initial incident light to form a light beam that is emitted to the wafer 101 The first incident light 210.

In this embodiment, the first light source 201 includes a laser emitter.

Please refer to Figure 6. In this embodiment, the first incident light modulation unit 202 includes: a modulation device 220, used to change one or more of the light intensity, polarization parameter and focal length of the initial incident light 222. ; Monitoring device 221, used to monitor the incident light information of the first incident light 210, and feed back the incident light information to the control system 400.

Among them, the incident light information includes: power, light intensity, polarization parameters, focal length, etc. The modulation device 220 is used to regulate the optical parameters of the first incident light 210 incident on the surface of the wafer 101 to be tested. The monitoring device 221 can monitor the parameters of the first incident light 210 in real time and feed back the monitored incident light information to the control system 400. The control system 400 can control the modulation according to the acquired incident light information. The device adjusts the optical parameters of the first incident light 210 .

Please continue to refer to FIG. 1 . In this embodiment, the semiconductor detection device further includes an additional signal acquisition system 600 . In addition to generating the first reflected light 211 on the surface of the wafer 101 to be tested, the first incident light 210 also generates additional reflected light 213; the additional signal acquisition system 600 is used to obtain additional reflected light 213 from the additional reflected light 213. optical signal 214 and transmit the additional optical signal 214 to the control system 400 . The additional optical signal 214 can be used to characterize the second defect information, and the second defect information can be complementary to the first defect information to make the detection result more comprehensive.

In one embodiment, the nonlinear optical signal 212 is used to characterize the first type of defect, and the additional optical signal 214 is used to characterize the second type of defect. Therefore, the nonlinear optical signal 212 and the additional optical signal 214 can achieve Complementarity of test results.

In another embodiment, the additional optical signal 214 is capable of responding to both the third type of defect and the fourth type of defect. However, the additional optical signal 214 is unable to respond to the third type of defect and the fourth type of defect. distinguish. The nonlinear optical signal 212 can respond to the third type of defect but cannot respond to the fourth type of defect, so that the detection results of the additional optical signal 214 can be classified through the nonlinear optical signal 212 to improve the accuracy of the detection results. improve.

In this embodiment, the additional signal acquisition system 600 acquires additional optical signals through the additional reflected light 213, that is, the additional signal acquisition system 600 and the optical signal sorting system 300 acquire incident light provided by the same light source and reflect it. Or scattered reflected or scattered light.

In another embodiment, the additional signal acquisition system 600 and the optical signal sorting system 300 acquire reflected or scattered light that is reflected or scattered by incident light provided by different light sources.

Specifically, please refer to Figure 7. The incident light system 200 also includes: a second light source 203 for emitting a second incident light 215 to the wafer to be inspected 101. The second incident light 215 passes through the wafer to be inspected. The circular reflection forms second reflected light 216 . In one embodiment, the incident light system 200 further includes: a second incident light modulation unit 204, configured to modulate the second incident light 215 and then emit the modulated second incident light 215 to the object to be detected. Wafer 101 surface. The additional signal acquisition system 600 is used to acquire additional optical signals according to the second reflected light 216 and transmit the additional optical signals to the control system 400 .

In this embodiment, it also includes: a main signal acquisition system 310 for acquiring the nonlinear optical signal 212 and transmitting the nonlinear optical signal to the control system 400 .

The carrying device 100 includes: a carrying tray for carrying the wafer 101 to be inspected; a fixing device provided on the carrying tray for fixing the wafer 101 to be inspected on the surface of the carrying tray; and a mechanical moving component for driving. The carrier plate moves. Wherein, the fixing device is a vacuum suction cup or a buckle fixed on the edge of the bearing plate. The mechanical moving component can move the carrier tray to a designated position according to a signal provided by the first position control unit 402 (shown in FIG. 1 ) or the second position control unit 403 (shown in FIG. 1 ).

Referring to Figure 8, the semiconductor detection device also includes: a focusing unit 230, used to focus the first incident light 210 on the surface of the wafer 101 to be detected; an optical collimation unit 231, used to collimate the first reflected light 211, And the collimated first reflected light 211 is incident on the optical signal sorting system 300 .

Correspondingly, an embodiment of the present invention also provides a detection method using the above-mentioned semiconductor detection device. Please refer to Figure 9, which is a schematic flow chart of a detection method according to an embodiment of the present invention, including:

Step S1: Provide the wafer to be inspected;

Step S2: Emit first incident light to the wafer to be inspected, and the first incident light is reflected by the wafer to be inspected to form a first reflected light;

Step S3, obtain the first reflected light and sort out nonlinear optical signals from the first reflected light;

Step S4: Obtain first defect information of the wafer to be inspected according to the nonlinear optical signal.

A detailed description will be given below with reference to the accompanying drawings.

Please refer to Figure 1, Figure 2 and Figure 5 in conjunction to provide a wafer 101 to be inspected.

In this embodiment, the wafer to be inspected 101 includes: a substrate 110 and a dielectric layer 111 located on the surface of the substrate 110; in this embodiment, the material of the substrate 110 is single crystal silicon, and the dielectric layer 111 The material is silicon oxide. In other embodiments, the material of the substrate 110 can also be other semiconductor materials with central symmetry; the material of the dielectric layer 111 can be other dielectric materials, such as silicon nitride, silicon oxynitride, high-K dielectric materials (medium Dielectric constant greater than 3.9), low K dielectric materials (dielectric constant greater than 2.5 and less than 3.9) or ultra-low K dielectric materials (dielectric constant less than 2.5).

Among them, the interface between the dielectric layer 111 and the substrate 110 has an interface state charge trap density (Dit: interfacial trap density); or, the dielectric layer has inherent charges and defects. The interface state charge potential well defects are distributed at the interface between the semiconductor and the oxide film; the inherent charges and defects in the dielectric layer 111 are distributed inside the dielectric layer 111 , and the inherent charge defects in the dielectric layer 111 are due to the dielectric Inherent defects introduced by process factors during the film formation process of layer 111 may also cause material damage caused by subsequent processes. The interface state charge potential well defects or the inherent charges and defects of the dielectric layer 111 may cause the degradation of the electrical performance between the dielectric layer 111 and the substrate 110 .

In another embodiment, please refer to FIG. 1 , FIG. 3 and FIG. 5 , the wafer to be tested 100 includes: a substrate 120 and a semiconductor layer 121 located on the surface of the substrate 120 ; the material of the semiconductor layer 121 is Compound or elemental semiconductor materials; compound semiconductor materials include gallium arsenide, gallium nitride, and silicon carbide; the formation process of the semiconductor layer includes an epitaxial process.

With reference to FIG. 5 and FIG. 1 , the first incident light 210 is emitted to the wafer to be inspected 101 , and the first incident light 210 is reflected by the wafer to be inspected to form a first reflected light 211 .

With reference to FIG. 5 and FIG. 1 , the first reflected light 211 is obtained, and the nonlinear optical signal 212 is sorted from the first reflected light 211 .

The nonlinear optical signal 212 represents the atomic level defects in the wafer 101 to be detected, thereby realizing non-destructive acquisition of atomic level defects or crystal defects in the wafer in real time during the process.

Specifically, the first incident light 210 is incident on the position to be measured on the surface of the wafer 101 to be inspected, causing the material of the wafer to be inspected 101 to interact with the light field emission of the first incident light 210. An optical response is generated, and the nonlinear optical signal 212 in the optical response can be used to characterize atomic-level defects in the wafer 101 to be tested. Since the optical inspection method is used, there is no need to conduct destructive inspection of the wafer to be tested 101. Moreover, the optical inspection can be performed at key nodes in the process, thereby realizing real-time discovery of defects and timely inspection of the process. Improve.

The nonlinear optical signal 212 includes sum frequency response (SFG), difference frequency response (DFG), second harmonic signal (SHG), third harmonic signal (THG) and higher order nonlinear optical signals.

In this embodiment, please refer to FIG. 2 . The wafer 101 to be inspected includes: a substrate 110 and a dielectric layer 111 located on the surface of the substrate 110 .

The nonlinear optical signal 212 can characterize the interface state charge trap density (Dit: interfacial trap density) at the interface between the dielectric layer 111 and the substrate 110 as well as the inherent charges and defects in the dielectric layer. Among them, the interface state charge potential well defects are distributed at the interface between the semiconductor and the oxide film; the inherent charges and defects in the dielectric layer are distributed inside the dielectric layer, and the inherent charges and defects of the dielectric layer 111 are due to Inherent defects introduced by process factors during the film formation process of the dielectric layer 111 may also be material damage caused by subsequent processes. The interface state charge potential well defects or the inherent charges and defects of the dielectric layer may cause the deterioration of the electrical performance between the dielectric layer 111 and the substrate 110 .

Specifically, since the material of the substrate 110 is single crystal silicon, and the single crystal silicon is a centrosymmetric material, when there is an interface state charge A at the interface between the dielectric layer 111 and the substrate 110, or the dielectric layer 111 When there is intrinsic charge B inside, the interface state charge A or intrinsic charge B will induce changes in the space charge distribution within the substrate 110 . Once the space charge distribution within the substrate changes, it will cause the single crystal silicon material to produce an electric field-induced signal due to the destruction of the central symmetry. After the nonlinear optical signal 212 is coupled with the electric field induced signal, it can reflect the change of space charge distribution in the substrate 110, and then characterize whether there is an interface state charge at the interface between the dielectric layer 111 and the substrate 110, or Whether there is inherent charge inside the dielectric layer 111.

In another embodiment, please refer to FIG. 3 , the wafer to be tested 100 includes: a substrate 120 and a semiconductor layer 121 located on the surface of the substrate 120; the material of the semiconductor layer 121 is a compound or a simple semiconductor material; a compound semiconductor Materials include gallium arsenide, gallium nitride, and silicon carbide.

The nonlinear optical signal 212 can respond to crystal structure defects in the compound semiconductor material, thereby enabling real-time monitoring of the crystal quality of the semiconductor layer 121 .

In this embodiment, the semiconductor layer is formed on the surface of the substrate through an epitaxial process. When the epitaxial process causes crystal structure defects to occur in the semiconductor layer, the crystal structure defects will interact with the nonlinear optical signal. 212 coupling such that the nonlinear optical signal 212 can characterize the lattice defects or crystal uniformity defects. Wherein, the crystal structure defects include crystal lattice defects or crystal uniformity defects, and the crystal uniformity defects refer to defects where the orderly arrangement of the crystal lattice is distorted.

With reference to FIG. 5 and FIG. 1 , the first defect information of the wafer to be inspected 101 is obtained according to the nonlinear optical signal 212 .

In this embodiment, as shown in Figure 2, the wafer 101 to be inspected includes: a substrate 110 and a dielectric layer 111 located on the surface of the substrate 110; the first defect information includes the interface between the substrate and the dielectric layer Interface electrical property defects at the interface; the interface electrical property defects include: interface state charge potential well defects, inherent charge distribution and defects of the dielectric layer, and base semiconductor doping concentration.

In another embodiment, as shown in FIG. 3 , the wafer to be tested 100 includes: a substrate 120 and a semiconductor layer 121 located on the surface of the substrate 120; the first defect information includes: crystal structure defects, internal defects of the semiconductor layer Stress distribution and epitaxial thickness of the semiconductor layer.

In addition to generating the first reflected light 211 on the surface of the wafer 101 to be tested, the first incident light 210 also generates additional reflected light 213; the detection method also includes: acquiring additional optical signals from the additional reflected light 213. 214, and obtain the second defect information according to the additional optical signal 214. The second defect information is complementary to the first defect information, making the detection results more comprehensive.

In this embodiment, the additional optical signal 214 and the nonlinear optical signal 212 are both reflected from the first incident light 210 provided by the first light source 201 .

In another embodiment, please refer to FIG. 7 , the detection method includes: emitting a second incident light 215 to the wafer 101 to be detected, and the second incident light 215 is reflected or scattered by the wafer 101 to be detected. A second reflected light 216 is formed; an additional optical signal is obtained according to the second reflected light 216, and second defect information is obtained according to the additional optical signal.

In this embodiment, before the second incident light 215 is emitted to the wafer to be inspected, the second incident light 215 can also be modulated, and then the modulated second incident light 215 is emitted to the wafer to be inspected. Circle 101 surface.

Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

Claims (25)

1. A semiconductor inspection apparatus, comprising:

the wafer bearing device is used for bearing a wafer to be detected;

the incident light system is used for emitting first incident light to the wafer to be detected, and the first incident light is reflected by the wafer to be detected to form first reflected light;

the optical signal sorting system is used for sorting nonlinear optical signals from the first reflected light, wherein the nonlinear optical signals are coupled with an electric field induction signal generated by the wafer to be detected, and the electric field induction signal is generated due to the change of space charge distribution in an interface state charge or an inherent charge induction substrate;

the control system is used for acquiring first defect information of the wafer to be detected according to the nonlinear optical signal, wherein the first defect information comprises interface electrical attribute defects, and the interface electrical attribute defects comprise: interface state charge well defects, dielectric layer intrinsic charge distribution and defects, and substrate semiconductor doping concentration, the control system comprising: the imaging operation unit is used for acquiring the position information of the wafer to be detected according to imaging patterns of different positions on the surface of the wafer to be detected; and the first position control unit is used for moving the wafer bearing device along the direction parallel to a reference plane according to the position information, and the reference plane is parallel to the surface of the wafer to be tested.

2. The semiconductor inspection device of claim 1, wherein the nonlinear optical signal comprises a second harmonic signal, a third harmonic signal, a sum frequency response signal, and a difference frequency response signal.

3. The semiconductor inspection device according to claim 1, further comprising: a wafer alignment focus system comprising: the imaging unit is used for acquiring imaging patterns at different positions on the surface of the wafer to be detected; and the sensor is used for acquiring the position information of the wafer to be tested in a first direction, and the first direction is perpendicular to the surface of the wafer to be tested.

4. The semiconductor inspection device of claim 3, wherein the control system comprises: and the second position control unit is used for moving the wafer bearing device according to the position information in the first direction so as to realize focusing of the first incident light on the surface of the wafer to be tested.

5. The semiconductor inspection apparatus of claim 1, wherein the incident light system comprises: a first light source for emitting a first initial incident light; and the first incident light modulation unit is used for modulating the first initial incident light to form the first incident light emitted to the wafer.

6. The semiconductor inspection device of claim 5, wherein the first light source comprises a laser emitter.

7. The semiconductor detection device according to claim 5, wherein the first incident light modulation unit: modulating means for changing one or more of the intensity, polarization parameter and focal length of the initial incident light; and the monitoring device is used for monitoring the incident light information of the first incident light and feeding the incident light information back to the control system.

8. The semiconductor inspection device according to claim 7, wherein the incident light information includes: power, light intensity, polarization parameters, and light pulse parameters.

9. The semiconductor inspection apparatus of claim 5, wherein the incident light system further comprises: and the second light source is used for emitting second incident light to the wafer to be detected, and the second incident light is reflected by the wafer to be detected to form second reflected light.

10. The semiconductor inspection device according to claim 9, further comprising: and the additional signal acquisition system is used for acquiring an additional optical signal according to the second reflected light and transmitting the additional optical signal to the control system.

11. The semiconductor inspection apparatus of claim 9, wherein the incident light system further comprises: the second incident light modulation unit is used for modulating the second incident light and then transmitting the modulated second incident light to the surface of the wafer to be detected.

12. The semiconductor inspection device according to claim 1, further comprising: and the additional signal acquisition system is used for acquiring an additional optical signal from the first reflected light and transmitting the additional optical signal to the control system.

13. The semiconductor inspection device according to claim 1, further comprising: and the main signal acquisition system is used for acquiring the nonlinear optical signal and transmitting the nonlinear optical signal to the control system.

14. The semiconductor inspection apparatus of claim 1, wherein the optical signal sorting system comprises: a filter for forming a first transition optical signal by a portion of the first reflected light having a preset wavelength range; and a polarizer for passing the first transition optical signal having a preset polarization parameter to form the nonlinear optical signal.

15. The semiconductor inspection apparatus of claim 1, wherein the optical signal sorting system comprises: a polarizer for passing a portion of the first reflected light having a predetermined polarization parameter to form a second transition optical signal; and a filter for passing the second transition optical signal having a preset wavelength range to form the nonlinear optical signal.

16. The semiconductor inspection device according to claim 1, wherein the carrier device comprises: the bearing disc is used for bearing the wafer to be detected; the fixing device is arranged on the bearing disc and used for fixing the wafer to be detected on the surface of the bearing disc; and the mechanical moving assembly is used for driving the bearing disc to move.

17. The semiconductor inspection device of claim 16, wherein the securing means is a vacuum chuck or a snap fit secured to an edge of the carrier plate.

18. The semiconductor inspection device according to claim 1, further comprising: focusing unit: for focusing the first incident light on the surface of the unit to be inspected.

19. The semiconductor inspection device according to claim 1, further comprising: an optical collimation unit: the optical signal sorting system is used for collimating the first reflected light and enabling the collimated first reflected light to be incident to the optical signal sorting system.

20. A detection method using the semiconductor detection device according to any one of claims 1 to 19, comprising:

providing a wafer to be detected;

transmitting first incident light to the wafer to be detected, wherein the first incident light is reflected by the wafer to be detected to form first reflected light, the nonlinear optical signal is coupled with an electric field induction signal generated in the wafer to be detected, and the electric field induction signal is generated due to the change of space charge distribution in an interface state charge or an inherent charge induction substrate;

acquiring the first reflected light and sorting nonlinear optical signals from the first reflected light;

acquiring first defect information of the wafer to be detected according to the nonlinear optical signal, wherein the first defect information comprises interface electrical attribute defects, and the interface electrical attribute defects comprise: interface state charge well defects, intrinsic charge distribution of the dielectric layer and defects, and substrate semiconductor doping concentration.

21. The inspection method of claim 20, wherein the wafer under test comprises: the substrate and the dielectric layer positioned on the surface of the substrate.

22. The inspection method of claim 21, wherein the first defect information includes an interface electrical property defect at an interface between the substrate and a dielectric layer.

23. The inspection method of claim 20, wherein the wafer under test comprises: a substrate, and a semiconductor layer located on the surface of the substrate; the semiconductor layer is made of a compound semiconductor material or an elemental semiconductor material.

24. The method of detecting according to claim 23, wherein the compound semiconductor material comprises gallium arsenide, gallium nitride, or silicon carbide; the forming process of the semiconductor layer includes an epitaxial process.

25. The inspection method of claim 23, wherein the first defect information includes: crystal structure defects, stress distribution within the semiconductor layer, and epitaxial thickness of the semiconductor layer.