Measurement method for thickness of minority carrier diffusion region and reverse bias leakage current, and related equipment

Abstract

Embodiments of the present disclosure provide a method and related equipment for measuring the thickness of a minority carrier diffusion region and reverse bias leakage current, which are used to measure semiconductor devices. The semiconductor device includes an N-type region, a P-type region, and a PN junction between the N-type region and the P-type region. The measurement method includes: obtaining an alternating current signal flowing through the PN junction when the PN junction is in a reverse bias state, where the alternating current signal is obtained by applying an excitation voltage signal with a predetermined perturbation frequency to the N-type region; obtaining the phase difference between the alternating current signal and the excitation voltage signal according to the predetermined perturbation frequency; obtaining a first parameter according to the phase difference and the predetermined perturbation frequency; and obtaining the thickness of the minority carrier diffusion region according to the first parameter. The measurement method for the thickness of the minority carrier diffusion region in the embodiments of the present disclosure can accurately obtain the thickness of the minority carrier diffusion layer, and the method is simple.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor detection technologies, and in particular, to a method for measuring the thickness of a minority carrier diffusion region of a semiconductor device, a method for measuring reverse bias leakage of a semiconductor device, and related equipment. Background Art

[0002] When a PN junction is in a reverse bias state, reverse bias leakage of the PN junction will occur, thereby increasing the power consumption of the device. The magnitude of the reverse bias leakage of the PN junction is related to the thickness of the minority carrier diffusion region, and there is no good method in the related technologies to measure the thickness of the minority carrier diffusion region.

[0003] The above information disclosed in the background art section is only used to enhance the understanding of the background of the present disclosure, and thus it may include information related to technologies that are not known to those of ordinary skill in the art. Summary of the Invention

[0004] Embodiments of the present disclosure provide a method for measuring the thickness of a minority carrier diffusion region and reverse bias leakage of a semiconductor device, and related equipment, which can accurately measure the thickness of the minority carrier diffusion region and the reverse bias leakage of the semiconductor device when the PN junction is in a reverse bias state, and the method is simple.

[0005] Embodiments of the present disclosure provide a method for measuring the thickness of a minority carrier diffusion region of a semiconductor device. The semiconductor device includes an N-type region, a P-type region, and a PN junction between the N-type region and the P-type region. The method includes: obtaining an alternating current signal flowing through the PN junction when the PN junction is in a reverse bias state, where the alternating current signal is obtained by applying an excitation voltage signal with a predetermined perturbation frequency to the N-type region; obtaining a phase difference between the alternating current signal and the excitation voltage signal according to the predetermined perturbation frequency; obtaining a first parameter according to the phase difference and the predetermined perturbation frequency; and obtaining the thickness of the minority carrier diffusion region according to the first parameter.

[0006] According to some embodiments of the present disclosure, obtaining a first parameter according to the phase difference and the predetermined perturbation frequency includes: obtaining a tangent value of the phase difference; plotting a Bode diagram according to the tangent value and the predetermined perturbation frequency; determining a diffusion region response frequency range of minority carriers; selecting a tangent value to be fitted corresponding to the diffusion region response frequency range in the Bode diagram; and fitting the tangent value to be fitted to obtain the first parameter.

[0007] According to some embodiments of the present disclosure, determining a diffusion region response frequency range of minority carriers includes: obtaining a diffusion impedance at the predetermined perturbation frequency according to the alternating current signal and the excitation voltage signal; splitting the diffusion impedance into a real part and an imaginary part; and obtaining the diffusion region response frequency range of the minority carriers according to the real part and the imaginary part.

[0008] According to some embodiments of the present disclosure, obtaining the response frequency of the diffusion region of the minority carriers based on the real part and the imaginary part includes: plotting a Nyquist diagram based on the real part and the imaginary part; and determining, according to the Nyquist diagram, the frequency corresponding to the second response arc as the response frequency range of the diffusion region of the minority carriers.

[0009] According to some embodiments of the present disclosure, the tangent value is not zero.

[0010] According to some embodiments of the present disclosure, obtaining the thickness of the minority carrier diffusion region based on the first parameter includes: obtaining the angular frequency of the excitation voltage signal and the minority carrier diffusion coefficient; and obtaining the thickness of the minority carrier diffusion region according to the angular frequency, the minority carrier diffusion coefficient, and the first parameter.

[0011] According to some embodiments of the present disclosure, a first power supply voltage is applied to the N-type region, and a second power supply voltage is applied to the P-type region to make the PN junction in the reverse bias state, and the first power supply voltage is greater than the second power supply voltage.

[0012] According to some embodiments of the present disclosure, the semiconductor device is an NMOS transistor, the P-type region is the P-type substrate of the NMOS transistor, and the N-type region is the N-type drain of the NMOS transistor; wherein, a first power supply voltage is applied to the N-type drain, a second power supply voltage is applied to the P-type substrate, and the P-type substrate is short-circuited with the source and the gate of the NMOS transistor to make the PN junction in the reverse bias state, and the first power supply voltage is greater than the second power supply voltage.

[0013] According to some embodiments of the present disclosure, the predetermined perturbation frequency of the excitation voltage signal is 100KHZ to 10mHZ.

[0014] According to some embodiments of the present disclosure, the voltage of the excitation voltage signal is 10mV to 50mV.

[0015] Embodiments of the present disclosure further provide a device for measuring the thickness of the minority carrier diffusion region of a semiconductor device. The semiconductor device includes an N-type region, a P-type region, and a PN junction between the N-type region and the P-type region. The device includes a receiving unit and a processing unit.

[0016] The receiving unit is configured to obtain an alternating current signal flowing through the PN junction when the PN junction is in the reverse bias state. The alternating current signal is obtained by applying an excitation voltage signal with a predetermined perturbation frequency to the N-type region.

[0017] The processing unit is configured to obtain the phase difference between the alternating current signal and the excitation voltage signal according to the predetermined perturbation frequency.

[0018] The processing unit is further configured to obtain a first parameter according to the phase difference and the predetermined perturbation frequency.

[0019] The processing unit is further configured to obtain the thickness of the minority carrier diffusion region according to the first parameter.

[0020] According to some embodiments of the present disclosure, the processing unit is further configured to obtain the tangent value of the phase difference; draw a Bode plot according to the tangent value and the predetermined perturbation frequency; determine the diffusion region response frequency of the minority carriers, and select the tangent value to be fitted corresponding to the diffusion region response frequency in the Bode plot; fit the tangent value to be fitted to obtain the first parameter.

[0021] Embodiments of the present disclosure further provide a method for measuring the reverse bias leakage current of a semiconductor device. The semiconductor device includes an N-type region, a P-type region, and a PN junction between the N-type region and the P-type region. The PN junction includes a depletion region. The method includes: obtaining an alternating current signal flowing through the PN junction when the PN junction is in a reverse bias state, where the alternating current signal is obtained by applying an excitation voltage signal with a predetermined perturbation frequency to the N-type region; obtaining the phase difference between the alternating current signal and the excitation voltage signal according to the predetermined perturbation frequency; obtaining a first parameter according to the phase difference and the predetermined perturbation frequency; obtaining the thickness of the minority carrier diffusion region according to the first parameter; obtaining the edge minority carrier concentration at the junction of the depletion region and the N-type region; and obtaining the reverse bias leakage current according to the thickness of the minority carrier diffusion region and the edge minority carrier concentration.

[0022] Embodiments of the present disclosure further provide a computer device, including a processor, a memory, and an input / output interface; the processor is respectively connected to the memory and the input / output interface. Among them, the input / output interface is used to receive and output data, the memory is used to store a computer program, and the processor is used to call the computer program so that the computer device executes the method described in any one of the above embodiments.

[0023] Embodiments of the present disclosure further provide a computer-readable storage medium, which stores a computer program, and the computer program is adapted to be loaded and executed by a processor so that a computer device having the processor executes the method described in any one of the above embodiments.

[0024] It can be seen from the above technical solutions that the method for measuring the thickness of the minority carrier diffusion region of the semiconductor device and related devices in the embodiments of the present disclosure have at least one of the following advantages and positive effects:

[0025] In the embodiments of the present disclosure, by applying an excitation voltage signal with a predetermined perturbation frequency to the N-type region, a corresponding alternating current signal can be obtained, and then the phase difference between the alternating current signal and the excitation voltage signal at the predetermined perturbation frequency can be obtained. According to the phase difference and the predetermined perturbation frequency, a first parameter is obtained, and then the thickness of the minority carrier diffusion region is obtained. In the embodiments of the present disclosure, the thickness of the minority carrier diffusion region can be obtained only by applying perturbation signals with different frequencies (i.e., excitation voltage signals with a predetermined perturbation frequency) to the PN junction in the reverse bias state. The method is simple and has high accuracy. Description of the Drawings

[0026] By describing its exemplary embodiments in detail with reference to the drawings, the above and other features and advantages of the present disclosure will become more apparent.

[0027] Figure 1 It is a flowchart of a method for measuring the thickness of a minority carrier diffusion region shown in some embodiments of the present disclosure;

[0028] Figure 2 It is a schematic diagram of a semiconductor device shown in some embodiments of the present disclosure;

[0029] Figure 3 It is a Bode plot drawn according to the tangent value and the predetermined perturbation frequency shown in some embodiments of the present disclosure;

[0030] Figure 4 It is a Nyquist plot of the diffusion impedance shown in some embodiments of the present disclosure;

[0031] Figure 5 It is a framework diagram of a method for measuring the thickness of a minority carrier diffusion region shown in some embodiments of the present disclosure;

[0032] Figure 6 It is a block diagram of a device for measuring the thickness of a minority carrier diffusion region shown in some embodiments of the present disclosure;

[0033] Figure 7 It is a schematic structural diagram of a computer device shown in some embodiments of the present disclosure;

[0034] Figure 8 It is a schematic diagram of a computer-readable storage medium shown in some embodiments of the present disclosure. Detailed Embodiments

[0035] Example embodiments will now be described more fully with reference to the drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. Like reference numerals in the figures denote like or similar structures, and thus their detailed description will be omitted.

[0036] In the following description of different exemplary embodiments of the present disclosure, reference is made to the accompanying drawings which form a part of the present disclosure and in which different exemplary structures are shown by way of example in which various aspects of the present disclosure can be implemented. It should be understood that other specific solutions of components, structures, exemplary devices, systems and steps can be used and structural and functional modifications can be made without departing from the scope of the present disclosure. Moreover, although terms such as "above", "between", "within" etc. may be used in this specification to describe different exemplary features and elements of the present disclosure, these terms are used herein only for convenience, for example, according to the orientation of the examples in the drawings. Nothing in this specification should be construed as requiring a specific three-dimensional orientation of the structure to fall within the scope of the present disclosure. In addition, the terms "first", "second" etc. in the claims are used only as labels and are not numerical limitations on their objects.

[0037] The flowcharts shown in the accompanying drawings are only illustrative and not necessarily include all the contents and operations / steps, nor are they necessarily executed in the order described. For example, some operations / steps can be decomposed, while some operations / steps can be combined or partially combined, so the actual execution order may change according to the actual situation.

[0038] In addition, in the description of the present disclosure, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0039] A semiconductor device has an N-type region and a P-type region, and there is a PN junction between the N-type region and the P-type region. Taking an NMOS (N-Metal-Oxide-Semiconductor) transistor as an example, its N-type drain is connected to a high potential and its P-type substrate is connected to a low potential, resulting in the PN junction being in a reverse bias state and there being reverse bias leakage, and the reverse bias leakage will affect the performance of the semiconductor device. The magnitude of the reverse bias leakage is usually controlled by minority carrier diffusion. The minority carrier diffusion rate is related to the thickness of the minority carrier diffusion region. Therefore, obtaining the thickness of the diffusion region can reflect the reverse bias leakage situation, and in the structural design of the semiconductor device, information about the thickness of the minority carrier diffusion region is also required. Therefore, it is particularly important to obtain information about the thickness of the minority carrier diffusion region. However, in the related art, the method for obtaining the thickness of the minority carrier diffusion region is relatively complex and the accuracy needs to be improved. [[ID=X]] [[ID=X]]

[0040] Based on this, as Figures 1 to 5 shown, the embodiments of the present disclosure provide a method for measuring the thickness of the minority carrier diffusion region of a semiconductor device. Among them, Figure 1 shows a flowchart of the method for measuring the thickness of the minority carrier diffusion region, Figure 2 shows a schematic diagram of the semiconductor device, Figure 3 and Figure 4 respectively show a Bode plot and a Nyquist plot, Figure 5A framework diagram showing a method for measuring the thickness of a minority carrier diffusion region is shown. As Figure 1 shown, the method for measuring the thickness of the minority carrier diffusion region according to the embodiments of the present disclosure may include the following steps: S110 to S140.

[0041] S110: Obtain an alternating current signal flowing through the PN junction when the PN junction is in a reverse bias state. The alternating current signal is obtained by applying an excitation voltage signal with a predetermined perturbation frequency to the N-type region.

[0042] As Figure 2 shown, the semiconductor device according to the embodiments of the present disclosure includes an N-type region, a P-type region, and a PN junction between the N-type region and the P-type region. The PN junction includes a depletion region A. For example, an NMOS transistor has a P-type substrate, N-type source and drain electrodes. Then, carrier diffusion will occur between the P-type substrate and the N-type source and drain electrodes. For example, holes diffuse from the P-type substrate to the N-type source and drain electrodes, and electrons diffuse from the P-type source and drain electrodes to the P-type substrate. When equilibrium is reached, a depletion region A will appear in the PN junction at the boundary between the two. When a reverse bias voltage is applied across the PN junction, the width of the depletion region A will increase, forming a small reverse bias current, which is the reverse bias leakage current and will cause unnecessary power consumption.

[0043] In the embodiments of the present disclosure, a first power supply voltage (such as Figure 2 VDD in Figure 2 ) is applied to the N-type region, and a second power supply voltage (such as

[0044] VSS in Figure 5 ) is applied to the P-type region to make the PN junction in a reverse bias state. The first power supply voltage is greater than the second power supply voltage, that is, an external electric field is applied, a high potential is applied to the N-type region, and a low potential is applied to the P-type region. The direction of the external electric field is the same as the direction of the built-in electric field formed by the carrier diffusion movement in the PN junction, making the PN junction in a reverse bias state.

[0045] As Figure 2As shown, the PN junction of the semiconductor device is located between the N-type region and the P-type region. There is a depletion region A in the PN junction, and there are a minority carrier diffusion region and a bulk region B in the N-type region and the P-type region respectively. That is, the parts of the N-type region and the P-type region close to the depletion region A are the minority carrier diffusion regions. The thickness L of the minority carrier diffusion region is the thickness of the minority carrier diffusion region to be measured in the embodiments of the present disclosure. The bulk region B is the region provided by the multi-carrier electromigration, and its doping concentration is determined, that is, the bulk minority carrier concentration of the bulk region B is determined.

[0046] S120: Obtain the phase difference between the alternating current signal and the excitation voltage signal according to the predetermined perturbation frequency.

[0047] In the embodiments of the present disclosure, the alternating current signal is a response signal output in response to the excitation voltage signal. At the predetermined perturbation frequency, there is a phase difference between the two. The phase difference can also be called the argument, and the phase difference can be represented by Φ. At different predetermined perturbation frequencies, there are different phase differences Φ between the alternating current signal and the excitation voltage signal, and the phase difference Φ between the two can be obtained by measurement.

[0048] S130: Obtain the first parameter according to the phase difference and the predetermined perturbation frequency.

[0049] In the embodiments of the present disclosure, S130 may include the following A to E.

[0050] A: Obtain the tangent value of the phase difference.

[0051] Specifically, after obtaining the phase difference Φ between the alternating current signal and the excitation voltage signal at different predetermined perturbation frequencies, the tangent value tanΦ of each phase difference Φ is obtained by calculation.

[0052] B: Draw a Bode plot according to the tangent value and the predetermined perturbation frequency.

[0053] After obtaining the tangent value tanΦ of the phase difference Φ, corresponding to the predetermined perturbation frequency, obtain the set of points of the tangent value of the phase difference and the corresponding predetermined perturbation frequency {(tanΦ1, f1), (tanΦ2, f2)... (tanΦ n , f n ), where n is a positive integer greater than 2. The predetermined perturbation frequency is represented by f. As Figure 3 shown, draw a Bode plot according to this set of points to more clearly and intuitively show the corresponding relationship between the tangent value tanΦ and the predetermined perturbation frequency f.

[0054] C: Determine the diffusion region response frequency range of the minority carriers.

[0055] Obtain the diffusion impedance at a predetermined perturbation frequency based on the alternating current signal and the excitation voltage signal. In the embodiments of the present disclosure, the diffusion impedance at each frequency is the ratio of the excitation voltage signal to the output alternating current signal. Define the diffusion impedance as Z, the excitation voltage signal as ΔV, and the alternating current signal as ΔI. Then, the diffusion impedance at each frequency can be obtained by the following formula (1):

[0056]

[0057] Split each diffusion impedance into a real part and an imaginary part. Specifically, Z = Z RE +jZ IM , where Z represents the diffusion impedance, Z RE represents the real part, Z IM represents the imaginary part, and j represents the imaginary unit. Based on this, split the diffusion impedance at each frequency into a real part and an imaginary part (Z RE , Z IM ).

[0058] Based on the real part and the imaginary part, obtain the diffusion region response frequency range of minority carriers. Specifically, according to the real part and the imaginary part (Z RE , Z IM ) split from each predetermined perturbation frequency, as Figure 4 shown, draw a Nyquist plot.

[0059] According to the Nyquist plot, determine that the frequency corresponding to the second response arc is the diffusion region response frequency range of minority carriers (the second response arc is the Figure 4 rightmost response arc among the two response arcs in). Specifically, the Nyquist plot contains two response arcs. The frequency corresponding to the first response arc is a predetermined perturbation frequency much greater than the minority carrier diffusion characteristic frequency. The frequency corresponding to the second response arc is the diffusion region response frequency range, and this frequency range is lower than the frequency corresponding to the first response arc. As Figure 4 shown by the dashed box in, select the frequency corresponding to the second response arc as the diffusion region response frequency range.

[0060] D: Select the tangent value to be fitted corresponding to the diffusion region response frequency range in the Bode plot.

[0061] After selecting the diffusion region response frequency range, determine the corresponding diffusion region response frequency range in the Figure 3 Bode plot, and then determine the tangent value tanΦ of the phase difference corresponding to each predetermined perturbation frequency within this diffusion region response frequency range, such as {tanΦ1, tanΦ2... tanΦ m}, where m can be a positive integer greater than 2. These determined tangent values are called tangent values to be fitted. That is to say, the tangent values of the phase differences selected through the diffusion region response frequency range are the tangent values for fitting in the subsequent steps.

[0062] E: Fit the tangent values to be fitted to obtain the first parameter.

[0063] After obtaining the tangent values to be fitted, fit them. When the minority carrier diffusion layer is a finite layer, the phase difference satisfies the following formula (2):

[0064]

[0065] where sinhX represents the hyperbolic sine function of the first parameter X, and sinX represents the sine function of the first parameter X. Fit tanΦ through the above formula (2) to obtain a fitting curve, and the value of the first parameter X at each predetermined perturbation frequency can be obtained through the fitting curve.

[0066] In some embodiments, the value of tanΦ is not zero, and the above fitting is performed to obtain a fitting curve.

[0067] S140: Obtain the minority carrier diffusion region thickness L according to the first parameter X.

[0068] In the embodiments of the present disclosure, the angular frequency of the excitation voltage signal and the minority carrier diffusion coefficient are obtained, and the minority carrier diffusion region thickness is obtained according to the angular frequency, the minority carrier diffusion coefficient, and the first parameter.

[0069] Among them, the angular frequency of the excitation voltage signal is represented by ω, ω = 2πf, where f is the predetermined perturbation frequency. The minority carrier diffusion coefficient is represented by D, which can be obtained through query. After obtaining the angular frequency ω, the minority carrier diffusion coefficient D, and the first parameter X, the minority carrier diffusion region thickness L can be obtained according to the following formula (3):

[0070]

[0071] In some embodiments, the first parameter X can be the value of the first parameter X corresponding to a relatively low predetermined perturbation frequency, and no special limitation is made here.

[0072] It can be seen from the above that the method for measuring the minority carrier diffusion region thickness in the embodiments of the present disclosure can obtain the minority carrier diffusion region thickness only by applying perturbation signals with different frequencies to the PN junction in the reverse bias state. The method is simple and has high accuracy.

[0073] In some embodiments, the semiconductor device is an NMOS transistor, the P-type region is the P-type substrate of the NMOS transistor, and the N-type region is the N-type drain of the NMOS transistor. Among them, a first power supply voltage is applied to the N-type drain, a second power supply voltage is applied to the P-type substrate, and the P-type substrate is short-circuited with the source and gate of the NMOS transistor to make the PN junction in a reverse bias state. The first power supply voltage is greater than the second power supply voltage, the first power supply voltage is at a high potential, for example, it can be VDD, and the second power supply voltage is at a low potential, for example, it can be VSS. In other embodiments, the semiconductor device can also be a PMOS transistor.

[0074] The measurement method of the embodiments of the present disclosure can accurately measure the thickness L of the minority carrier diffusion layer when the semiconductor device (such as an NMOS transistor) in the above embodiments is in a reverse bias state, and the method is simple. In addition, according to the thickness L of the minority carrier diffusion layer, the reverse bias leakage of the semiconductor device can be obtained, so as to further perform adaptive adjustment on the semiconductor device to ensure the optimal electrical performance of the above semiconductor device. At the same time, the obtained thickness L of the minority carrier diffusion layer can also be used in the structural design of the semiconductor device to provide data support for the design of the semiconductor device.

[0075] The embodiments of the present disclosure also provide a method for measuring the reverse bias leakage of a semiconductor device, which is used to measure the reverse bias leakage of the PN junction in the semiconductor device. The semiconductor device includes an N-type region, a P-type region, and a PN junction between the N-type region and the P-type region, and the PN junction includes a depletion region A. The measurement method includes: obtaining an alternating current signal flowing through the PN junction when the PN junction is in a reverse bias state, and the alternating current signal is obtained by applying an excitation voltage signal with a predetermined perturbation frequency to the N-type region; obtaining the phase difference between the alternating current signal and the excitation voltage signal according to the predetermined perturbation frequency; obtaining a first parameter according to the phase difference and the predetermined perturbation frequency; obtaining the thickness of the minority carrier diffusion region according to the first parameter; obtaining the edge minority carrier concentration at the junction of the depletion region and the N-type region; and obtaining the reverse bias leakage according to the thickness of the minority carrier diffusion region and the edge minority carrier concentration.

[0076] Specifically, the thickness of the minority carrier diffusion region can be obtained according to the measurement method of the thickness of the minority carrier diffusion region in any of the above embodiments, and will not be elaborated here.

[0077] In some embodiments, in order to further obtain the reverse bias leakage, the edge minority carrier concentration C0 can be obtained according to the following embodiments.

[0078] In some embodiments, according to the diffusion impedance obtained in the above embodiments, as Figure 4 shown, a Nyquist plot is drawn to further obtain the equivalent resistance R of the depletion region at the junction of the depletion region A and the N-type region when the edge minority carriers are in a non-responsive state t and the equivalent resistance R of the diffusion region when the edge minority carriers are in a diffusion response state d .

[0079] The minority carriers at the edge have a minority carrier diffusion characteristic frequency, which is the reciprocal of the time constant of the minority carriers and can also be understood as the reciprocal of the relaxation time of the minority carriers. That is to say, the minority carrier diffusion characteristic frequency is a characterization parameter of the response speed of the minority carrier diffusion to the perturbation signal. The larger the minority carrier diffusion characteristic frequency, the shorter the delay time of the diffusion response of the minority carriers after the perturbation signal is sent. When the predetermined perturbation frequency is much higher than the minority carrier diffusion characteristic frequency, the minority carriers have not yet responded, and the excitation voltage signal starts to be reverse-excited. In this case, the minority carrier diffusion has no response to the perturbation, and this state is called the non-response state of the minority carriers at the edge. However, due to the applied excitation voltage signal, there will still be an alternating current signal output. The impedance obtained in this state is the impedance of the depletion region A, and the equivalent resistance of the depletion region is the resistance of the depletion region A. When the predetermined perturbation frequency is much lower than the minority carrier diffusion characteristic frequency, the diffusion response of the minority carriers is in the same frequency as the excitation voltage signal, and this state is called the diffusion response state of the minority carriers at the edge. And the impedance obtained in this state is the impedance of the minority carrier diffusion region, and the equivalent resistance of the diffusion region is the resistance of the minority carrier diffusion region.

[0080] The real part corresponding to the end point with zero imaginary part on the left side of the first response arc in the figure is the first real part, and the real part corresponding to the end point with zero imaginary part on the right side is the second real part (refer to the dotted part in Figure 4 ). The first real part is the equivalent resistance of the bulk region B, that is, the first equivalent resistance R1 is the equivalent resistance of the bulk region B. The second equivalent resistance R2 corresponding to the second real part is the sum of the equivalent resistance of the bulk region B (the first equivalent resistance R1) and the equivalent resistance R of the depletion region. t The equivalent resistance R of the depletion region is the equivalent resistance of the depletion region A, then R t = R2 - R1. To simplify the processing process, the first real part of the first response arc is zero, that is, the equivalent resistance R2 corresponding to the second real part is the equivalent resistance R of the depletion region. t t t

[0081] The end point with zero imaginary part on the left side of the second response arc in the figure coincides with the end point with zero imaginary part on the right side of the first response arc. The real part corresponding to the end point with zero imaginary part on the right side of the second response arc in the figure is the third real part. The third equivalent resistance R3 corresponding to the third real part is the sum of the equivalent resistance of the bulk region B, the equivalent resistance R of the depletion region, and the equivalent resistance R of the diffusion region. t The equivalent resistance R of the depletion region is the equivalent resistance of the depletion region A, then R d The equivalent resistance R of the diffusion region is the equivalent resistance of the diffusion region.

[0082] In some embodiments, the minority carrier concentration at the edge is obtained according to the equivalent resistance R of the depletion region and the equivalent resistance R of the diffusion region. t The equivalent resistance R of the depletion region is the equivalent resistance of the depletion region A, then R d The equivalent resistance R of the diffusion region is the equivalent resistance of the diffusion region.

[0083] ​Specifically, obtain the direct current, the diffusion region thickness of the minority carriers at the edge, and the diffusion coefficient of the minority carriers at the edge, where the direct current is the current flowing through the PN junction when no AC voltage signal is applied to the N-type region; obtain the minority carrier concentration at the edge according to the direct current, the diffusion region thickness, the diffusion coefficient, the equivalent resistance of the depletion region, and the equivalent resistance of the diffusion region.

[0084] Specifically, in the case of finite-layer diffusion, the equivalent resistance of the diffusion impedance (the equivalent resistance of the diffusion region R d ) satisfies the following formula (4):

[0085]

[0086] where, R d is the equivalent resistance of the minority carrier diffusion region, R t is the equivalent resistance of the depletion region A, I is the direct current of the external electric field applied to the semiconductor device, L is the diffusion region thickness of the minority carriers at the edge, F is the Faraday constant, and D is the diffusion coefficient of the minority carriers at the edge.

[0087] After obtaining the minority carrier concentration C0 at the edge, obtain the diffusion coefficient D of the minority carriers at the edge, the bulk minority carrier concentration C1, and the diffusion region thickness L of the minority carriers at the edge; obtain the reverse bias leakage current of the PN junction according to the diffusion coefficient D of the minority carriers at the edge, the bulk minority carrier concentration C1, the diffusion region thickness L, and the minority carrier concentration C0 at the edge.

[0088] Specifically, the reverse bias leakage current satisfies the following formula (5):

[0089]

[0090] Therefore, after obtaining the minority carrier concentration at the edge, the reverse bias leakage current can be directly obtained through the above formula (5), and the semiconductor device can be appropriately adjusted according to the situation of the reverse bias leakage current to ensure the optimal electrical performance of the semiconductor device. In some embodiments, the predetermined perturbation frequency of the excitation voltage signal is 100 kHz to 10 mHz. Wherein, kHz is kilohertz and mHz is millihertz. Specifically, except for the above two end values, the predetermined perturbation frequency can also be 90 kHz, 80 kHz, 60 kHz, 50 kHz, 30 kHz, 20 kHz, 9000 Hz, 5000 Hz, 2000 Hz, 1000 Hz, 800 Hz, 500 Hz, 50 Hz, 900 mHz, 500 mHz, 200 mHz, 90 mHz, 50 mHz, 30 mHz, and no special limitation is made here. Wherein, when the predetermined perturbation frequency is kilohertz, it is much greater than the minority carrier diffusion characteristic frequency, so that the minority carriers are in the non-responsive state in the above embodiments, and when the predetermined perturbation frequency is millihertz, it is much less than the minority carrier diffusion characteristic frequency, so that the minority carriers are in the diffusion response state in the above embodiments.

[0091] In some embodiments, the voltage value of the excitation voltage signal is 10 mV to 50 mV, where mV is millivolt. In addition to the above two end values, the voltage value of the excitation voltage signal can also be 20 mV, 25 mV, 30 mV, 35 mV, 40 mV, 45 mV, and no special limitation is made here. This voltage value is much smaller than the voltage of the external electric field applied by the semiconductor device and is only used to form a perturbation to avoid affecting the electrical performance of the semiconductor device.

[0092] An embodiment of the present disclosure also provides a device 600 for measuring the thickness of the minority carrier diffusion region of a semiconductor device. The semiconductor device includes an N-type region, a P-type region, and a PN junction between the N-type region and the P-type region. The semiconductor device can be the semiconductor device in any of the above embodiments, which will not be elaborated here. As Figure 6 shown, the measuring device of the embodiment of the present disclosure includes a receiving unit 601 and a processing unit 602.

[0093] The receiving unit 601 is configured to obtain an alternating current signal flowing through the PN junction when the PN junction is in the reverse bias state. The alternating current signal is obtained by applying an excitation voltage signal with a predetermined perturbation frequency to the N-type region.

[0094] The processing unit 602 is configured to obtain the phase difference between the alternating current signal and the excitation voltage signal according to the predetermined perturbation frequency.

[0095] The processing unit 602 is further configured to obtain a first parameter according to the phase difference and the predetermined perturbation frequency, and obtain the thickness of the minority carrier diffusion region according to the first parameter.

[0096] In some embodiments, the processing unit 602 is further configured to obtain the tangent value of the phase difference; draw a Bode plot according to the tangent value and the predetermined perturbation frequency; determine the diffusion region response frequency of the minority carriers, and select the tangent value to be fitted corresponding to the diffusion region response frequency in the Bode plot; perform fitting on the tangent value to be fitted to obtain the first parameter.

[0097] In some embodiments, the processing unit 602 is further configured to obtain the diffusion impedance at the predetermined perturbation frequency according to the alternating current signal and the excitation voltage signal; split the diffusion impedance into a real part and an imaginary part; obtain the diffusion region response frequency range of the minority carriers according to the real part and the imaginary part.

[0098] In some embodiments, the processing unit 602 is further configured to draw a Nyquist plot according to the real part and the imaginary part; determine that the frequency corresponding to the second response arc in the Nyquist plot is the diffusion region response frequency range of the minority carriers.

[0099] In some embodiments, the processing unit 602 is further configured to obtain the angular frequency of the excitation voltage signal and the minority carrier diffusion coefficient; obtain the thickness of the minority carrier diffusion region according to the angular frequency, the minority carrier diffusion coefficient, and the first parameter.

[0100] In some embodiments, the predetermined perturbation frequency of the excitation voltage signal is 100 kHz to 10 mHz. Here, kHz stands for kilohertz and mHz stands for millihertz. Specifically, in addition to the above two end values, the predetermined perturbation frequency can also be 90 kHz, 80 kHz, 60 kHz, 50 kHz, 30 kHz, 20 kHz, 9000 Hz, 5000 Hz, 2000 Hz, 1000 Hz, 800 Hz, 500 Hz, 900 mHz, 500 mHz, 200 mHz, 90 mHz, 50 mHz, 300 mHz, and no special limitation is made here.

[0101] In some embodiments, the voltage value of the excitation voltage signal is 10 mV to 50 mV. Here, mV stands for millivolt. In addition to the above two end values, the voltage value of the excitation voltage signal can also be 20 mV, 25 mV, 30 mV, 35 mV, 40 mV, 45 mV, and no special limitation is made here. This voltage value is much smaller than the voltage of the external electric field applied by the semiconductor device and is only used to form a perturbation to avoid affecting the electrical performance of the semiconductor device.

[0102] In summary, for the device for measuring the thickness of the minority carrier diffusion region according to the embodiments of the present disclosure, only by obtaining the alternating current signal flowing through the PN junction when the PN junction is in the reverse bias state through the receiving unit 601 and using the processing unit 602 to calculate and process the alternating current signal and the externally applied excitation voltage signal, the thickness of the minority carrier diffusion region can be obtained. The method is simple and has high accuracy.

[0103] The embodiments of the present disclosure further provide a computer device. As Figure 7 shown, the computer device in the embodiments of the present disclosure may include one or more processors 701, a memory 702, and an input / output interface 703. The processor 701 is respectively connected to the memory 702 and the input / output interface 703. As Figure 7 shown, the processor 701, the memory 702, and the input / output interface 703 are connected through a bus 704. The memory 702 is used to store a computer program, and the computer program includes program instructions. The input / output interface 703 is used to receive data and output data, such as for data interaction between the host and the computer device, or for data interaction between virtual machines in the host; the processor 701 is used to execute the program instructions stored in the memory 702.

[0104] Among them, the processor 701 may perform the following operations: obtaining an alternating current signal flowing through the PN junction when the PN junction is in a reverse bias state, where the alternating current signal is obtained by applying an excitation voltage signal with a predetermined disturbance frequency to the N-type region; obtaining the phase difference between the alternating current signal and the excitation voltage signal according to the predetermined disturbance frequency; obtaining a first parameter according to the phase difference and the predetermined disturbance frequency; and obtaining the thickness of the minority carrier diffusion region according to the first parameter.

[0105] Alternatively, the processor 701 may perform the following operations: obtaining an alternating current signal flowing through the PN junction when the PN junction is in a reverse bias state, where the alternating current signal is obtained by applying an excitation voltage signal with a predetermined disturbance frequency to the N-type region; obtaining the phase difference between the alternating current signal and the excitation voltage signal according to the predetermined disturbance frequency; obtaining a first parameter according to the phase difference and the predetermined disturbance frequency; obtaining the thickness of the minority carrier diffusion region according to the first parameter; obtaining the minority carrier concentration at the edge of the depletion region and the N-type region junction; and obtaining the reverse bias leakage current according to the thickness of the minority carrier diffusion region and the minority carrier concentration at the edge.

[0106] In some feasible embodiments, the processor 701 may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0107] The memory 702 may include a read-only memory and a random access memory, and provide instructions and data to the processor 701 and the input / output interface 703. A part of the memory 702 may also include a non-volatile random access memory. For example, the memory 702 may also store information about the device type.

[0108] In a specific implementation, the computer device may execute the implementation manners provided in each step of any of the above method embodiments through its built-in various functional modules. For specific reference, see the implementation manners provided in each step of the figures shown in the above method embodiments, which will not be elaborated here.

[0109] Embodiments of the present disclosure provide a computer device, including a processor 701, an input / output interface 703, and a memory 702. The processor 701 obtains a computer program in the memory 702 and executes each step of the method shown in any of the above embodiments.

[0110] An embodiment of the present disclosure also provides a computer-readable storage medium 800. The computer-readable storage medium 800 stores a computer program, and the computer program is adapted to be loaded and executed by the processor 701 to perform the method for measuring the thickness of the minority carrier diffusion layer or the method for measuring the reverse bias leakage current of the semiconductor device provided in each step of any of the above embodiments. For the specific implementation manner provided in each step of any of the above embodiments, reference may be made thereto, and details are not described herein again.

[0111] In addition, the description of the beneficial effects of adopting the same method will not be repeated. For the technical details not disclosed in the embodiment of the computer-readable storage medium 800 involved in the present disclosure, please refer to the description of the method embodiment of the present disclosure. As an example, the computer program can be deployed to be executed on a computer device, or on multiple computer devices located at one place, or on multiple computer devices distributed at multiple places and interconnected through a communication network.

[0112] The computer-readable storage medium 800 may be an internal storage unit of the computer device provided in any of the foregoing embodiments, such as the hard disk or memory of the computer device. The computer-readable storage medium 800 may also be an external storage device of the computer device, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the computer device. Further, the computer-readable storage medium 800 may also include both the internal storage unit and the external storage device of the computer device. The computer-readable storage medium 800 is used to store the computer program and other programs and data required by the computer device. The computer-readable storage medium 800 may also be used to temporarily store the data that has been output or will be output.

[0113] An embodiment of the present disclosure also provides a computer program product or a computer program. The computer program product or the computer program includes computer instructions, and the computer instructions are stored in the computer-readable storage medium 800. The processor of the computer device reads the computer instructions from the computer-readable storage medium 800, and the processor executes the computer instructions, so that the computer device executes the methods provided in various alternative manners in any of the above embodiments.

[0114] It should be understood that the present disclosure is not limited in its application to the detailed construction and arrangement of components set forth in this specification. The present disclosure is capable of other embodiments and of being practiced and carried out in various ways. The foregoing variations and modifications fall within the scope of the present disclosure. It should be understood that the disclosure of the present disclosure as set forth in this specification extends to all alternative combinations of two or more separate features mentioned or evident in the text and / or drawings. All such different combinations constitute various alternative aspects of the present disclosure. The embodiments described in this specification illustrate the best mode known for practicing the present disclosure and will enable those skilled in the art to utilize the present disclosure.

Claims

1. A method for measuring the thickness of the minority carrier diffusion region of a semiconductor device, the semiconductor device including an N-type region, a P-type region, and a PN junction between the N-type region and the P-type region, characterized in that, The method includes: Obtaining an alternating current signal flowing through the PN junction when the PN junction is in a reverse-biased state, where the alternating current signal is obtained by applying an excitation voltage signal with a predetermined perturbation frequency to the N-type region; Obtaining a phase difference between the alternating current signal and the excitation voltage signal according to the predetermined perturbation frequency; Obtaining a first parameter according to the phase difference and the predetermined perturbation frequency; Obtaining the thickness of the minority carrier diffusion region according to the first parameter.

2. The method according to claim 1, wherein Obtaining a first parameter according to the phase difference and the predetermined perturbation frequency includes: Obtaining a tangent value of the phase difference; Plotting a Bode plot according to the tangent value and the predetermined perturbation frequency; Determining the diffusion region response frequency range of minority carriers; Selecting a tangent value to be fitted corresponding to the diffusion region response frequency range in the Bode plot; Fitting the tangent value to be fitted to obtain the first parameter.

3. The method according to claim 2, characterized in that Determining the diffusion region response frequency range of minority carriers includes: Obtaining a diffusion impedance at the predetermined perturbation frequency according to the alternating current signal and the excitation voltage signal; Splitting the diffusion impedance into a real part and an imaginary part; Obtaining the diffusion region response frequency range of the minority carriers according to the real part and the imaginary part.

4. The method according to claim 3, wherein Obtaining the diffusion region response frequency of the minority carriers according to the real part and the imaginary part includes: Plotting a Nyquist plot according to the real part and the imaginary part; Determining that the frequency corresponding to the second response arc in the Nyquist plot is the diffusion region response frequency range of the minority carriers.

5. The method according to any one of claims 2 to 4, characterized in that The tangent value is not zero.

6. The method according to any one of claims 1 to 4, characterized in that, Obtaining the thickness of the minority carrier diffusion region according to the first parameter includes: Obtaining the angular frequency of the excitation voltage signal and the minority carrier diffusion coefficient; Obtaining the thickness of the minority carrier diffusion region according to the angular frequency, the minority carrier diffusion coefficient and the first parameter.

7. The method according to any one of claims 1 to 4, characterized in that, Applying a first power supply voltage to the N-type region and a second power supply voltage to the P-type region to make the PN junction in the reverse-biased state, where the first power supply voltage is greater than the second power supply voltage.

8. The method according to claim 1, characterized in that, The semiconductor device is an NMOS transistor, the P-type region is the P-type substrate of the NMOS transistor, and the N-type region is the N-type drain of the NMOS transistor; Wherein, a first power supply voltage is applied to the N-type drain, a second power supply voltage is applied to the P-type substrate, and the P-type substrate is short-circuited with the source and gate of the NMOS transistor to make the PN junction in the reverse-biased state, and the first power supply voltage is greater than the second power supply voltage.

9. The method according to claim 1, wherein The predetermined perturbation frequency of the excitation voltage signal is 100 kHz to 10 mHz.

10. The method according to claim 1, characterized in that, The voltage of the excitation voltage signal is 10 mV to 50 mV.

11. A device for measuring the thickness of the minority carrier diffusion region of a semiconductor device, the semiconductor device including an N-type region, a P-type region, and a PN junction between the N-type region and the P-type region, characterized in that, The device includes: A receiving unit for obtaining an alternating current signal flowing through the PN junction when the PN junction is in a reverse-biased state, where the alternating current signal is obtained by applying an excitation voltage signal with a predetermined perturbation frequency to the N-type region; A processing unit for obtaining a phase difference between the alternating current signal and the excitation voltage signal according to the predetermined perturbation frequency; The processing unit is further configured to obtain a first parameter according to the phase difference and the predetermined perturbation frequency; The processing unit is further configured to obtain the thickness of the minority carrier diffusion region according to the first parameter.

12. The device according to claim 11, wherein The processing unit is further configured to obtain the tangent value of the phase difference; draw a Bode plot according to the tangent value and the predetermined perturbation frequency; determine the diffusion region response frequency of the minority carriers, and select the tangent value to be fitted corresponding to the diffusion region response frequency in the Bode plot; fit the tangent value to be fitted to obtain the first parameter.

13. A method for measuring the reverse bias leakage current of a semiconductor device, the semiconductor device comprising an N-type region, a P-type region, and a PN junction between the N-type region and the P-type region, the PN junction including a depletion region, characterized in that, The method includes: Obtaining an alternating current signal flowing through the PN junction when the PN junction is in a reverse bias state, where the alternating current signal is obtained by applying an excitation voltage signal with a predetermined perturbation frequency to the N-type region; Obtaining the phase difference between the alternating current signal and the excitation voltage signal according to the predetermined perturbation frequency; Obtaining a first parameter according to the phase difference and the predetermined perturbation frequency; Obtaining the thickness of the minority carrier diffusion region according to the first parameter; Obtaining the edge minority carrier concentration at the junction of the depletion region and the N-type region; Obtaining reverse bias leakage current according to the thickness of the minority carrier diffusion region and the edge minority carrier concentration.

14. A computer device, characterized in that, Including a processor, a memory, and an input / output interface; The processor is respectively connected to the memory and the input / output interface, where the input / output interface is used to receive and output data, the memory is used to store a computer program, and the processor is used to call the computer program so that the computer device executes the method according to any one of claims 1 to 10; or, the method according to claim 13.

15. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, and the computer program is suitable for being loaded and executed by a processor so that a computer device having the processor executes the method according to any one of claims 1 to 10; or, the method according to claim 13.

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