A synchronous measurement system and method for thermal properties and thermal strain of semiconductor chips

Abstract

The present invention provides a synchronous measurement system and method for thermal properties and thermal strain of semiconductor chips, belonging to the field of optical detection technology. The invention uses a pump laser light source module and a detection laser light source module to emit pump laser and detection laser of different wavelengths respectively. After the pump laser is modulated by a modulation signal loading module, it is combined with the detection laser through a colinear focusing module and irradiated on a semiconductor chip sample. The detection laser reflected from the surface of the semiconductor chip sample is separated and filtered by a polarization splitter module and then enters a data acquisition module. The position of the semiconductor chip sample is controlled by adjusting a three-dimensional sample stage module to achieve large-area scanning and automatic alignment. The data acquisition module performs multi-parameter fitting of the collected data to simultaneously obtain the thermal properties and thermal strain distribution of the semiconductor chip sample. The invention has the advantages of non-contact, high-precision, synchronous measurement of the thermal properties and thermal strain distribution of semiconductor chips, simple operation, and stable performance.

Description

Technical Field

[0001] The present invention relates to the field of optical detection technology, and in particular to a synchronous measurement system and method for thermal properties and thermal strain of a semiconductor chip. Background Art

[0002] With the development of advanced packaging technology for integrated chips, the packaging density and power density have risen sharply, posing a major challenge to thermal management. Due to vertical stacking, most of the heat generated by the chip heat source needs to pass through the multi-layer structure to reach the heat dissipation substrate, so the thermal conductivity of the material seriously restricts the heat flux of heat dissipation. At the same time, due to heterogeneous integration, the thermal expansion coefficients of the materials on both sides of the interface are mismatched, and residual stress may exist at the interface when the chip is heated up, and even cause the chip to warp in severe cases. Therefore, conducting high-precision in-situ testing of thermal properties and thermal strains of semiconductor materials is of great significance in supporting the national artificial intelligence strategy and ensuring information security.

[0003] The methods for measuring the thermal properties of semiconductor chips are mainly transient methods, including laser flash method, harmonic method and photothermal reflection method. Although the laser flash method is widely used and has advantages such as a wide temperature measurement range, it is difficult to measure the thermal properties of micro-nanoscale semi-materials; although the harmonic method can test the thermal properties of thin film materials and has advantages such as fast measurement speed, it has a lower limit on the depth of thermal effect, and its sensitivity is two to three orders of magnitude lower than that of the photothermal reflection method. The photothermal reflection method has become a powerful tool for studying phonon transport due to its advantages such as speed and reliability, and is currently the most commonly used measurement technology for characterizing thermal properties.

[0004] The main methods for measuring thermal strain of semiconductor chips include X-ray diffraction, digital image correlation technology and laser confocal microscopy. Among them, although X-ray diffraction can obtain a series of crystal information such as crystal structure, structural defects and strain, the measurement results are not accurate, and the obtained information is an average macroscopic information; although digital image correlation technology has the advantages of real-time, full-field measurement and high precision in measuring material strain, it has too high requirements on the sample surface, requires a lot of computing resources and high costs; laser confocal microscopy has the advantages of high resolution, fast imaging and the ability to form three-dimensional imaging, and can be used in combination with other technologies to provide in-depth analysis of the microstructure and strain distribution of materials.

[0005] Although the above methods can measure the thermal properties and thermal strain of semiconductor materials independently, it is difficult to achieve simultaneous characterization of the thermal and mechanical properties of the sample. Currently, the most widely used non-contact thermal and mechanical synchronous measurement technology is the use of a CCD (Charge-coupled Device) camera combined with an infrared thermal imager, but it is difficult to use for measuring semiconductor chips with micro-nano structures, and the results obtained are of low accuracy. Summary of the invention

[0006] In order to solve the problems in the above-mentioned prior art, the present invention provides a synchronous measurement system and method for thermal properties and thermal strain of semiconductor chips. The invention includes a pump laser light source module, a detection laser light source module, a modulation signal loading module, a polarization splitter module, a collinear focusing module, a three-dimensional sample stage module and a data acquisition module. The pump laser light source module and the detection laser light source module emit pump laser and detection laser of different wavelengths respectively. After the pump laser is modulated by the modulation signal loading module, it is combined with the detection laser through the collinear focusing module and irradiated on the semiconductor chip sample. The detection laser reflected from the surface of the semiconductor chip sample is separated and filtered by the polarization splitter module and then enters the data acquisition module. The position of the semiconductor chip sample is controlled by adjusting the three-dimensional sample stage module to realize large-area scanning and automatic alignment. The data acquisition module performs multi-parameter fitting of the collected data to simultaneously obtain the thermal properties and thermal strain distribution of the semiconductor chip sample. The invention has the advantages of non-contact, high precision, synchronous measurement of the thermal properties and thermal strain distribution of semiconductor chips, simple operation and stable performance, and solves the problems of contact measurement, low precision, inability to synchronously measure the thermal properties and thermal strain distribution of semiconductor chips and complex operation. To achieve the above purpose, the technical solution is as follows:

[0007] In one aspect, the present invention provides a system for synchronously measuring thermal properties and thermal strain of a semiconductor chip, the system comprising:

[0008] Pump laser light source module, used to provide continuous and stable pump laser;

[0009] A detection laser light source module is used to provide a continuous and stable detection laser, the wavelength of the detection laser is different from the wavelength of the pump laser;

[0010] The modulation signal loading module is used to load the pump laser with a frequency of The modulation signal;

[0011] A polarization splitting module, used for converting the polarization state of the detection laser and separating the beam of the detection laser;

[0012] A co-linear focusing module, used for combining the pump laser and the detection laser and focusing them on the surface of the semiconductor chip sample;

[0013] A three-dimensional sample stage module is used to carry the semiconductor chip sample and realize large-area scanning and automatic alignment of the semiconductor chip sample;

[0014] The data acquisition module is used to collect the detection laser reflected by the surface of the semiconductor chip sample, and perform multi-parameter fitting on the collected data to obtain the thermal properties and thermal strain distribution of the semiconductor chip sample.

[0015] Optionally, the pump laser light source module comprises:

[0016] A continuous laser, used to provide the pump laser;

[0017] The optical isolator is used to prevent the continuous laser from being damaged or unstable due to back reflection, and the optical isolator is placed right in front of the continuous laser.

[0018] Optionally, the polarization splitting module includes:

[0019] A 1 / 2 wave plate, used for adjusting the power of the detection laser, and the 1 / 2 wave plate is placed right in front of the detection laser light source module;

[0020] A quarter wave plate, used to convert the polarization state of the detection laser;

[0021] The polarization beam splitter is used to separate the detection laser reflected back after passing through the 1 / 4 wave plate.

[0022] Optionally, the polarization state of the detection laser is converted, comprising:

[0023] When the horizontal linear polarized light of the detection laser is directly incident through the 1 / 4 wave plate, circular polarized light of the detection laser is obtained;

[0024] Reflecting the circularly polarized light of the detection laser through the surface of the semiconductor chip sample to obtain reflected circularly polarized light;

[0025] The reflected circularly polarized light passes through the 1 / 4 wave plate again to obtain the vertically linearly polarized light of the detection laser.

[0026] Optionally, the co-linear focusing module comprises:

[0027] A dichroic mirror, used for combining the pump laser and the detection laser;

[0028] The objective lens is used for co-focusing the pump laser and the detection laser on the surface of the semiconductor chip sample.

[0029] Optionally, the three-dimensional sample stage module includes an x-axis, a y-axis and a z-axis; the plane formed by the x-axis and the y-axis realizes a large-area scanning of the thermal properties and thermal strain of the semiconductor chip sample, and the z-axis realizes automatic alignment with the position with the greatest sensitivity of the thermal response signal.

[0030] Optionally, the data acquisition module includes:

[0031] A short-wave pass filter, used for filtering out the pump laser from the linearly polarized light of the detection laser;

[0032] A photoelectric detector, used for collecting the detection laser light passing through the short-wave pass filter and converting the detection laser light passing through the short-wave pass filter into an electrical signal;

[0033] The phase-locked amplifier is used to provide a reference signal for the modulated signal loading module and to extract the frequency from the electrical signal collected by the photodetector. The detection signal is converted into a digital signal and transmitted to a computer;

[0034] The computer is used to control the reference signal and the detection signal output by the lock-in amplifier, and to perform multi-parameter fitting on the collected data to obtain the thermal properties and thermal strain distribution of the semiconductor chip sample.

[0035] Optionally, the signal extracted by the lock-in amplifier is a Gaussian distribution that varies with the working distance.

[0036] Optionally, collecting the detection laser reflected by the surface of the semiconductor chip sample, and performing multi-parameter fitting on the collected data to obtain the thermal properties and thermal strain distribution of the semiconductor chip sample, including:

[0037] The pump laser is irradiated on the surface of the semiconductor chip sample to heat the semiconductor chip sample by converting light energy into heat energy, thereby obtaining a semiconductor chip sample with a periodic temperature change;

[0038] The detection laser is irradiated through the polarization beam splitting module on the semiconductor chip sample with periodic temperature changes to obtain the periodic reflectivity of the semiconductor chip sample;

[0039] The thermal model is solved by the periodically varying reflectivity of the semiconductor chip sample to obtain the thermal properties and thermal strain distribution of the semiconductor chip sample.

[0040] On the other hand, the present invention provides a method for synchronously measuring thermal properties and thermal strain of a semiconductor chip, which is implemented by a synchronous measurement system for thermal properties and thermal strain of a semiconductor chip, and the method comprises:

[0041] S1. Processing and treating the surface of a semiconductor chip to obtain a semiconductor chip sample;

[0042] S2. By adjusting the synchronous measurement system, signal tuning and testing are performed to obtain a stable synchronous measurement system;

[0043] S3, placing the semiconductor chip sample at the middle position of the three-dimensional sample stage module, turning on the stable synchronous measurement system, and obtaining the semiconductor chip sample irradiated by the laser;

[0044] S4, according to the z-axis of the three-dimensional sample stage module being automatically adjusted, a position where the thermal response signal sensitivity of the semiconductor chip sample irradiated by the laser is the maximum is obtained;

[0045] S5, according to the x-axis and y-axis of the three-dimensional sample stage module that are automatically adjusted, the data acquisition module collects data to obtain the signal value extracted by the phase-locked amplifier at each scanning point of the semiconductor chip sample irradiated by the laser;

[0046] S6. According to the position with the maximum sensitivity of the thermal response signal and the signal value extracted by the phase-locked amplifier at each scanning point, the data acquisition module uses a multi-parameter fitting processing method to solve the thermal model and draw a graph to obtain the thermal properties and thermal strain distribution of the semiconductor chip sample.

[0047] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0048] The above scheme emits pump laser and detection laser of different wavelengths respectively through the pump laser light source module and the detection laser light source module. After the pump laser is modulated by the modulation signal loading module, it is combined with the detection laser through the colinear focusing module and irradiated on the semiconductor chip sample. The detection laser reflected from the surface of the semiconductor chip sample is separated and filtered by the polarization splitting module and then enters the data acquisition module. The position of the semiconductor chip sample is controlled by adjusting the three-dimensional sample stage module to realize large-area scanning and automatic alignment. The data acquisition module can simultaneously obtain the thermal properties and thermal strain distribution of the semiconductor chip sample by multi-parameter fitting of the collected data. The invention has the advantages of non-contact, high-precision, synchronous measurement of the thermal properties and thermal strain distribution of semiconductor chips, simple operation and stable performance, and solves the problems of contact measurement, low precision, inability to measure the thermal properties and thermal strain distribution of semiconductor chips in situ and complex operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0050] Figure 1 It is a system block diagram of an embodiment of a system for synchronously measuring thermal properties and thermal strain of a semiconductor chip of the present invention;

[0051] Figure 2 It is a system schematic diagram of an embodiment of a system for synchronously measuring thermal properties and thermal strain of a semiconductor chip of the present invention;

[0052] Figure 3 It is a flow chart of detecting laser polarization state conversion of an embodiment of a synchronous measurement system for thermal properties and thermal strain of a semiconductor chip of the present invention;

[0053] Figure 4 It is a flow chart of obtaining the distribution of thermal properties and thermal strain of a semiconductor chip sample in an embodiment of a synchronous measurement system for thermal properties and thermal strain of a semiconductor chip of the present invention;

[0054] Figure 5 is a relationship diagram of a signal extracted by a lock-in amplifier and a z-axis of a three-dimensional sample stage module in an embodiment of a synchronous measurement system for thermal properties and thermal strain of a semiconductor chip of the present invention;

[0055] Figure 6 is a system sensitivity curve of an embodiment of a system for synchronously measuring thermal properties and thermal strain of a semiconductor chip of the present invention;

[0056] Figure 7 It is a scanning diagram of a semiconductor chip sample of an embodiment of the synchronous measurement system of thermal properties and thermal strain of a semiconductor chip of the present invention on a plane formed by the x-axis and y-axis of a three-dimensional sample stage module;

[0057] Figure 8 is a thermal property distribution diagram of a semiconductor chip sample in an embodiment of the system for synchronously measuring thermal properties and thermal strain of a semiconductor chip of the present invention;

[0058] Fig. 9 is a thermal strain distribution diagram of a semiconductor chip sample in an embodiment of the system for synchronously measuring thermal properties and thermal strain of a semiconductor chip of the present invention;

[0059] Fig.10 It is a flow chart of an embodiment of the method for synchronously measuring thermal properties and thermal strain of a semiconductor chip of the present invention.

[0060] Explanation of the numbers in the figure: pump laser light source module 10, continuous laser 101, optical isolator 102, detection laser light source module 20, modulation signal loading module 30, polarization splitting module 40, 1 / 2 wave plate 401, polarization beam splitter 402, 1 / 4 wave plate 403, collinear focusing module 50, dichroic mirror 501, objective lens 502, three-dimensional sample stage module 60, data acquisition module 70, shortwave pass filter 701, photodetector 702, phase-locked amplifier 703, computer 704. DETAILED DESCRIPTION

[0061] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0062] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0063] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0064] like Figure 1 The system block diagram of the embodiment of the synchronous measurement system of the thermal properties and thermal strain of the semiconductor chip of the present invention is shown in FIG. Figure 2 The system schematic diagram of the embodiment of the synchronous measurement system of thermal properties and thermal strain of semiconductor chips of the present invention is shown. The present invention provides a synchronous measurement system of thermal properties and thermal strain of semiconductor chips, which can implement a synchronous measurement method of thermal properties and thermal strain of semiconductor chips. The system includes: a pump laser light source module 10, a detection laser light source module 20, a modulation signal loading module 30, a polarization splitting module 40, a collinear focusing module 50, a three-dimensional sample stage module 60 and a data acquisition module 70;

[0065] The pump laser light source module 10 is used to provide continuous and stable pump laser;

[0066] Specifically, the pump laser light source module 10 includes:

[0067] A continuous laser 101, used to provide the pump laser;

[0068] The optical isolator 102 is used to prevent the continuous laser from being damaged or unstable due to back reflection. The optical isolator 102 is placed right in front of the continuous laser 101.

[0069] Furthermore, the continuous laser 101 uses the continuous laser diode module LQC980-220E produced by Newport, the central wavelength of the continuous laser diode module LQC980-220E is 980 nm, and the output power is 220mW; the optical isolator 102 uses the IO-3D-980-VLP free space isolator produced by Thorlabs, the maximum beam of the IO-3D-980-VLP free space isolator is Ø2.7mm, and the maximum power is 0.7W; the pump laser is a Gaussian beam.

[0070] A detection laser light source module 20 is used to provide a continuous and stable detection laser, the wavelength of which is different from that of the pump laser;

[0071] Specifically, the detection laser light source module 20 uses a PL252 small laser module produced by Thorlabs, the central wavelength of the PL252 small laser module is 639 nm, and the output power is 4.5 mW; the detection laser is a Gaussian beam.

[0072] The modulation signal loading module 30 is used to load the pump laser with a frequency of The modulation signal;

[0073] Specifically, the modulation signal loading module 30 uses the EO-AM-NR-C2 electro-optical amplitude modulator produced by Thorlabs, and the wavelength of the EO-AM-NR-C2 electro-optical amplitude modulator is 900~1250nm;

[0074] A polarization splitting module 40, used for converting the polarization state of the detection laser and separating the beam of the detection laser;

[0075] Specifically, the polarization splitting module 40 includes:

[0076] A 1 / 2 wave plate 401 is used to adjust the power of the detection laser, and the 1 / 2 wave plate is placed in front of the detection laser light source module 20;

[0077] A quarter wave plate 403 is used to convert the polarization state of the detection laser;

[0078] The polarization beam splitter 402 is used to separate the detection laser reflected back through the 1 / 4 wave plate 403.

[0079] Furthermore, if Figure 3 The flowchart of the conversion of the polarization state of the detection laser of the embodiment of the synchronous measurement system of the thermal physical property and thermal strain of the semiconductor chip of the present invention is shown, and the polarization state of the detection laser is converted, including:

[0080] When the horizontal linear polarized light of the detection laser is directly incident through the 1 / 4 wave plate 403, circular polarized light of the detection laser is obtained;

[0081] Reflecting the circularly polarized light of the detection laser through the surface of the semiconductor chip sample to obtain reflected circularly polarized light;

[0082] The reflected circularly polarized light passes through the 1 / 4 wave plate 403 again to obtain the vertically linearly polarized light of the detection laser.

[0083] A co-linear focusing module 50, used for combining the pump laser and the detection laser and focusing them on the surface of the semiconductor chip sample;

[0084] Specifically, the collinear focusing module 50 comprises:

[0085] A dichroic mirror 501, used for combining the pump laser and the detection laser;

[0086] The objective lens 502 is used to co-focus the pump laser and the detection laser on the surface of the semiconductor chip sample.

[0087] Furthermore, the pump laser and the detection laser are combined by a dichroic mirror 501 and focused onto the surface of the semiconductor chip sample by an objective lens 502. The objective lens 502 is used to focus the combined pump laser and detection laser on the sample surface, which helps to generate an accurate, high-energy-density light spot on the surface of the semiconductor chip sample when measuring thermal properties and thermal strain, thereby more effectively stimulating thermal effects and performing measurements.

[0088] A three-dimensional sample stage module 60 is used to carry the semiconductor chip sample and realize large-area scanning and automatic alignment of the semiconductor chip sample;

[0089] Specifically, Figure 5 The relationship diagram of the signal extracted by the phase-locked amplifier and the z-axis of the three-dimensional sample stage module of the synchronous measurement system of the thermal properties and thermal strain of the semiconductor chip of the present invention is shown in FIG. Figure 6 The system sensitivity curve of the embodiment of the synchronous measurement system of thermal properties and thermal strain of semiconductor chips of the present invention is shown in FIG. The three-dimensional sample stage module 60 includes an x-axis, a y-axis and a z-axis; the z-axis is automatically aligned with the position where the thermal response signal has the highest sensitivity. When the z-axis is aligned with the position where the thermal response signal has the highest sensitivity, as shown in FIG. Figure 7 The shown scanning diagram of a semiconductor chip sample in the plane formed by the x-axis and y-axis of the three-dimensional sample stage module in the embodiment of the system for synchronously measuring thermal properties and thermal strain of a semiconductor chip of the present invention is realized. The plane formed by the x-axis and the y-axis realizes a large-area scanning of the thermal properties and thermal strain of the semiconductor chip sample.

[0090] The data acquisition module 70 is used to collect the detection laser reflected by the surface of the semiconductor chip sample, and perform multi-parameter fitting on the collected data to obtain the thermal properties and thermal strain distribution of the semiconductor chip sample.

[0091] Specifically, the data acquisition module 70 includes:

[0092] A short-wave pass filter 701, used for filtering out the pump laser in the linearly polarized light of the detection laser;

[0093] The photodetector 702 is used to collect the detection laser light passing through the short-wave pass filter 701 and convert the detection laser light passing through the short-wave pass filter 701 into an electrical signal;

[0094] The phase-locked amplifier 703 is used to provide a reference signal for the modulation signal loading module 30 and extract the frequency from the electrical signal collected by the photodetector 702. The detection signal is converted into a digital signal and transmitted to the computer 704;

[0095] The computer 704 is used to control the reference signal and the detection signal output by the lock-in amplifier, and perform multi-parameter fitting on the collected data to obtain the thermal properties and thermal strain distribution of the semiconductor chip sample.

[0096] Specifically, the signal extracted by the lock-in amplifier 703 is a Gaussian distribution that varies with the working distance.

[0097] Furthermore, if Figure 4 The flowchart of obtaining the thermal properties and thermal strain distribution of a semiconductor chip sample in the embodiment of the synchronous measurement system of thermal properties and thermal strain of a semiconductor chip of the present invention is shown, collecting the detection laser reflected by the surface of the semiconductor chip sample, and performing multi-parameter fitting on the collected data to obtain the thermal properties and thermal strain distribution of the semiconductor chip sample, including:

[0098] The pump laser is irradiated on the surface of the semiconductor chip sample to heat the semiconductor chip sample by converting light energy into heat energy, thereby obtaining a semiconductor chip sample with a periodic temperature change;

[0099] The detection laser is irradiated through the polarization beam splitting module on the semiconductor chip sample with periodic temperature changes to obtain the periodic reflectivity of the semiconductor chip sample;

[0100] The thermal model is solved by the periodically varying reflectivity of the semiconductor chip sample to obtain the thermal properties and thermal strain distribution of the semiconductor chip sample.

[0101] like Figure 8 The thermal property distribution diagram of the semiconductor chip sample of the embodiment of the synchronous measurement system of the thermal property and thermal strain of the semiconductor chip of the present invention and the Fig. 9 The thermal strain distribution diagram of the semiconductor chip sample of the embodiment of the semiconductor chip thermal property and thermal strain synchronous measurement system of the present invention is shown. The thermal model is solved by the reflectivity of the semiconductor chip sample at different temperatures to obtain the thermal property and thermal strain distribution diagram of the semiconductor chip sample.

[0102] like Fig.10 The flowchart of the embodiment of the method for synchronously measuring thermal properties and thermal strain of a semiconductor chip of the present invention is shown in FIG. The present invention provides a method for synchronously measuring thermal properties and thermal strain of a semiconductor chip, which is implemented by a system for synchronously measuring thermal properties and thermal strain of a semiconductor chip, and the method comprises:

[0103] S1. Processing and treating the surface of a semiconductor chip to obtain a semiconductor chip sample;

[0104] S2. By adjusting the synchronous measurement system, signal tuning and testing are performed to obtain a stable synchronous measurement system;

[0105] S3, placing the semiconductor chip sample at the middle position of the three-dimensional sample stage module, turning on the stable synchronous measurement system, and obtaining the semiconductor chip sample irradiated by the laser;

[0106] S4, according to the z-axis of the three-dimensional sample stage module being automatically adjusted, a position where the thermal response signal sensitivity of the semiconductor chip sample irradiated by the laser is the maximum is obtained;

[0107] S5, according to the x-axis and y-axis of the three-dimensional sample stage module that are automatically adjusted, the data acquisition module collects data to obtain the signal value extracted by the phase-locked amplifier at each scanning point of the semiconductor chip sample irradiated by the laser;

[0108] S6. According to the position with the maximum sensitivity of the thermal response signal and the signal value extracted by the phase-locked amplifier at each scanning point, the data acquisition module uses a multi-parameter fitting processing method to solve the thermal model and draw a graph to obtain the thermal properties and thermal strain distribution of the semiconductor chip sample.

[0109] The present invention provides a synchronous measurement system and method for thermal properties and thermal strain of a semiconductor chip. The invention comprises a pump laser light source module 10, a detection laser light source module 20, a modulation signal loading module 30, a polarization splitting module 40, a collinear focusing module 50, a three-dimensional sample stage module 60 and a data acquisition module 70. The pump laser light source module 10 and the detection laser light source module 20 emit pump laser and detection laser of different wavelengths respectively. After the pump laser is modulated by the modulation signal loading module 30, it is combined with the detection laser through the collinear focusing module 50 and irradiated on the semiconductor chip sample. The detection laser reflected from the sample surface is separated and filtered by the polarization splitter module 40 and then enters the data acquisition module 70. The position of the semiconductor chip sample is controlled by adjusting the three-dimensional sample stage module 60 to achieve large-area scanning and automatic alignment. The data acquisition module 70 performs multi-parameter fitting on the collected data to simultaneously obtain the thermal properties and thermal strain distribution of the semiconductor chip sample. The invention has the advantages of non-contact, high-precision, synchronous measurement of the thermal properties and thermal strain distribution of semiconductor chips, simple operation and stable performance, and solves the problems of contact measurement, low precision, inability to synchronously measure the thermal properties and thermal strain distribution of semiconductor chips, and complex operation.

[0110] It is to be understood that the present invention is described by the above embodiments and should not be construed as limiting the embodiments of the present invention and the scope of the present invention. It is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A synchronous measurement system for thermal properties and thermal strain of semiconductor chips, characterized in that: The system comprises: Pump laser light source module, used to provide continuous and stable pump laser; A detection laser light source module, used for providing continuous and stable detection laser, wherein the wavelength of the detection laser is different from the wavelength of the pump laser; A modulation signal loading module is used to load the pump laser with a frequency of The modulation signal; A polarization splitting module, used for converting the polarization state of the detection laser and separating the beam of the detection laser; A co-linear focusing module, used for combining the pump laser and the detection laser and focusing them on the surface of the semiconductor chip sample; A three-dimensional sample stage module, used for carrying the semiconductor chip sample and realizing large-area scanning and automatic alignment of the semiconductor chip sample; A data acquisition module, used to collect the detection laser reflected by the surface of the semiconductor chip sample, and perform multi-parameter fitting on the collected data to obtain the thermal properties and thermal strain distribution of the semiconductor chip sample; The three-dimensional sample stage module includes an x-axis, a y-axis and a z-axis; the plane formed by the x-axis and the y-axis realizes a large-area scanning of the thermal properties and thermal strain of the semiconductor chip sample, and the z-axis realizes automatic alignment with the position with the maximum sensitivity of the thermal response signal; When the z-axis is aligned with the position where the thermal response signal has the highest sensitivity, the plane formed by the x-axis and the y-axis realizes a large-area scan of the thermal properties and thermal strain of the semiconductor chip sample; The step of collecting the detection laser reflected from the surface of the semiconductor chip sample and performing multi-parameter fitting on the collected data to obtain the thermal properties and thermal strain distribution of the semiconductor chip sample includes: irradiating the pump laser onto the surface of the semiconductor chip sample, heating the semiconductor chip sample by converting light energy into heat energy, and obtaining a semiconductor chip sample with a periodic temperature change; irradiating the detection laser through the polarization beam splitting module onto the semiconductor chip sample with periodic temperature changes to obtain a periodically changing reflectivity of the semiconductor chip sample; The thermal model is solved by the periodically changing reflectivity of the semiconductor chip sample to obtain the thermal properties and thermal strain distribution of the semiconductor chip sample.

2. The synchronous measurement system of thermal properties and thermal strain of semiconductor chips according to claim 1, characterized in that: The pump laser light source module comprises: A continuous laser, used to provide the pump laser; An optical isolator is used to prevent the continuous laser from being damaged or unstable due to back reflection, and the optical isolator is placed right in front of the continuous laser.

3. The synchronous measurement system of thermal properties and thermal strain of semiconductor chips according to claim 1, characterized in that: The polarization splitting module comprises: A 1 / 2 wave plate, used for adjusting the power of the detection laser, wherein the 1 / 2 wave plate is placed directly in front of the detection laser light source module; A quarter wave plate, used for converting the polarization state of the detection laser; A polarization beam splitter is used to separate the detection laser reflected back after passing through the 1 / 4 wave plate.

4. The synchronous measurement system of thermal properties and thermal strain of semiconductor chips according to claim 3, characterized in that: The polarization state of the detection laser is converted, comprising: When the horizontal linear polarized light of the detection laser is directly incident through the 1 / 4 wave plate, circularly polarized light of the detection laser is obtained; Reflecting the circularly polarized light of the detection laser through the surface of the semiconductor chip sample to obtain reflected circularly polarized light; The reflected circularly polarized light passes through the 1 / 4 wave plate again to obtain the vertical linear polarized light of the detection laser.

5. The synchronous measurement system of thermal properties and thermal strain of semiconductor chips according to claim 1, characterized in that: The collinear focusing module comprises: A dichroic mirror, used for combining the pump laser and the detection laser; The objective lens is used to co-focus the pump laser and the detection laser on the surface of the semiconductor chip sample.

6. The synchronous measurement system for thermal properties and thermal strain of semiconductor chips according to claim 4, characterized in that: The data acquisition module comprises: A short-wave pass filter, used for filtering out the pump laser in the linearly polarized light of the detection laser; A photoelectric detector, used for collecting the detection laser light passing through the short-wave pass filter and converting the detection laser light passing through the short-wave pass filter into an electrical signal; A phase-locked amplifier is used to provide a reference signal for the modulation signal loading module and to extract the frequency from the electrical signal collected by the photodetector. The detection signal is converted into a digital signal and transmitted to a computer; The computer is used to control the reference signal output by the lock-in amplifier and the detection signal, and to perform multi-parameter fitting on the collected data to obtain the thermal properties and thermal strain distribution of the semiconductor chip sample.

7. The synchronous measurement system for thermal properties and thermal strain of a semiconductor chip according to claim 6, characterized in that: The signal extracted by the lock-in amplifier is a Gaussian distribution that varies with the working distance.

8. A method for synchronously measuring thermal properties and thermal strain of a semiconductor chip, wherein the method is implemented by the method for synchronously measuring thermal properties and thermal strain of a semiconductor chip according to any one of claims 1 to 7, and is characterized in that: The method comprises: S1. Processing and treating the surface of a semiconductor chip to obtain a semiconductor chip sample; S2. By adjusting the synchronous measurement system, signal tuning and testing are performed to obtain a stable synchronous measurement system; S3, placing the semiconductor chip sample in the middle position of the three-dimensional sample stage module, turning on the stable synchronous measurement system, and obtaining the semiconductor chip sample irradiated by the laser; S4, according to the z-axis of the three-dimensional sample stage module being automatically adjusted, obtaining the position where the thermal response signal sensitivity of the semiconductor chip sample irradiated by the laser is the maximum; S5, according to the x-axis and y-axis of the three-dimensional sample stage module that are automatically adjusted, the data acquisition module collects data to obtain the signal value extracted by the phase-locked amplifier at each scanning point of the semiconductor chip sample irradiated by the laser; S6. According to the position with the maximum sensitivity of the thermal response signal and the signal value extracted by the phase-locked amplifier at each scanning point, the data acquisition module uses a multi-parameter fitting processing method to solve the thermal model and draw a graph to obtain the thermal properties and thermal strain distribution of the semiconductor chip sample.

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