Method for obtaining dielectric constant of dielectric sheet

Abstract

The present invention provides a method for obtaining a dielectric constant, which can solve the problem of measurement error by calculating the dielectric constant of a dielectric sheet of a flat capacitor, and can apply a scanning capacitance microscope to the field of measuring the dielectric constant of the dielectric sheet. 【Means for solving the problem】 The method for obtaining the dielectric constant of the dielectric sheet of the present invention is to apply a modulation voltage to a semiconductor capacitor and a first flat capacitor, measure the first scanning capacitance microscope signals of the semiconductor capacitor and the first flat capacitor, then replace the first flat capacitor with a second flat capacitor, measure the second scanning capacitance microscope signals of the semiconductor capacitor and the second flat capacitor, and finally replace the second flat capacitor with a third flat capacitor and measure the third scanning capacitance microscope signals of the semiconductor capacitor and the third flat capacitor. Based on the above signals, the equivalent physical thickness and dielectric constant of the dielectric sheets of the first flat capacitor and the second flat capacitor, the dielectric constant of the dielectric sheet of the third flat capacitor is obtained.

Description

Technical Field

[0001] The present invention relates to a method for obtaining a dielectric constant, and particularly to a method for obtaining the dielectric constant of a dielectric sheet.

Background Art

[0002] Scanning capacitance microscopy (SCM) has found many applications in the analysis of semiconductor materials and semiconductor devices. Among them, the most important one is the analysis of the electrical characteristics of the materials of metal-oxide-semiconductor field-effect transistors (MOSFETs). The most common is to observe the two-dimensional carrier concentration distribution and the images of pn junctions.

[0003] However, the scanning capacitance microscope cannot measure the dielectric constant of the dielectric sheet. The dielectric constant is usually measured by an experimental technique called the Dielectric Resonance Method. In this method, the measurement sample is placed in an experimental apparatus and arranged in an electromagnetic field. As the electromagnetic field changes, a resonance phenomenon occurs in the sample, and more energy is absorbed at a specific frequency. By measuring the resonance frequency, the electromagnetic response characteristics of the sample can be obtained. Based on the resonance frequency of the sample and the characteristics of the experimental apparatus, the dielectric constant of the sample can be calculated using the corresponding mathematical formula. However, the measurement results may be affected by the shape of the sample, and errors may occur due to the geometric shape of a specific sample.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Therefore, in order to solve the above problems, the present invention proposes a method for obtaining the dielectric constant of a dielectric sheet.

[0005] The method for obtaining the dielectric constant of a dielectric sheet provided by the present invention calculates the dielectric constant of the dielectric sheet of the flat capacitor to be measured, thereby solving the problem of measurement error caused by the undulations on the surface of the material of the dielectric sheet and the shape changes due to internal cavities, and also using a scanning capacitance microscope in the field of measuring the dielectric constant of the dielectric sheet, expanding the application range of the scanning capacitance microscope.

Means for Solving the Problems

[0006] In one embodiment of the present invention, the method for obtaining the dielectric constant of a dielectric sheet includes the following steps. A step of connecting a semiconductor capacitor and a first flat capacitor in series, where the first dielectric sheet of the first flat capacitor has a known first equivalent physical thickness d1 and a known first dielectric constant ε1, and the semiconductor capacitor has a depletion region. A step of applying a modulation voltage to the semiconductor capacitor and the first flat capacitor using a scanning capacitance microscope to cause a periodic change in the width of the depletion region, and measuring a first scanning capacitance microscope signal for the semiconductor capacitor and the first flat capacitor. A step of replacing the first flat capacitor with a second flat capacitor, connecting the semiconductor capacitor and the second flat capacitor in series, where the second dielectric sheet of the second flat capacitor has a known second equivalent physical thickness d2 and a known second dielectric constant ε2. A step of applying a modulation voltage to the semiconductor capacitor and the second flat capacitor using a scanning capacitance microscope to cause a periodic change in the width of the depletion region, and measuring a second scanning capacitance microscope signal for the semiconductor capacitor and the second flat capacitor. A step of calculating an impedance ratio based on the first scanning capacitance microscope signal, the second scanning capacitance microscope signal, and Equation 1.

[0007]

Equation

[0008] Replace the second plate capacitor with a third plate capacitor, connect the semiconductor capacitor and the third plate capacitor in series, the third dielectric sheet of the third plate capacitor has a known third equivalent physical thickness d3, and the first dielectric sheet, the second dielectric sheet and the third dielectric sheet have the same area. Apply a modulation voltage to the semiconductor capacitor and the third plate capacitor using a scanning capacitance microscope to cause a periodic change in the width of the depletion region, and measure the third scanning capacitance microscope signal for the semiconductor capacitor and the third plate capacitor. Obtain the third dielectric constant of the third dielectric sheet of the third plate capacitor based on the first scanning capacitance microscope signal, the third scanning capacitance microscope signal, the third equivalent physical thickness and the impedance ratio.

[0009] In one embodiment of the present invention, the semiconductor capacitor is a MOS capacitor.

[0010] In one embodiment of the present invention, the semiconductor capacitor includes a conductive probe electrically connected to a ground terminal.

[0011] In one embodiment of the present invention, the materials of the first dielectric sheet, the second dielectric sheet and the third dielectric sheet are insulating materials.

[0012] In one embodiment of the present invention, the first scanning capacitance microscope signal, the second scanning capacitance microscope signal, the first equivalent physical thickness, the second equivalent physical thickness and the impedance ratio satisfy Equation 2.

[0013]

Equation

[0014] Here, S1 is the first scanning capacitance microscope signal, S2 is the second scanning capacitance microscope signal, and ZR is the impedance ratio.

[0015] In one embodiment of the present invention, the first scanning capacitance microscope signal, the third scanning capacitance microscope signal, the first equivalent physical thickness, the third equivalent physical thickness, and the impedance ratio satisfy Equation (3).

[0016]

Equation

[0017] Here, S1 is the first scanning capacitance microscope signal, S3 is the third scanning capacitance microscope signal, ZR is the impedance ratio, and ε3 is the third dielectric constant.

[0018] In one embodiment of the present invention, Impedance ratio = Impedance for the first dielectric sheet / (Impedance for the semiconductor capacitor + Impedance for the first dielectric sheet) becomes.

Advantages of the Invention

[0019] From the above, the method for obtaining the dielectric constant of a dielectric sheet uses three known equivalent physical thicknesses and impedance ratios, calculates the dielectric constant of the dielectric sheet of the parallel plate capacitor to be measured, and thus solves the problem of measurement error caused by fluctuations on the surface of the material of the dielectric sheet and shape changes due to internal cavities, enables the use of a scanning capacitance microscope in the field of measuring the dielectric constant of a dielectric sheet, and can broaden the application range of the scanning capacitance microscope.

[0020] For a further understanding and recognition of the structural features and achieved effects of the present invention, preferred embodiments are illustrated and described in detail below.

Brief Description of the Drawings

[0021]

Fig. 1a

Fig. 1b

Fig. 1c

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Fig. 8

Embodiments for Carrying Out the Invention

[0022] Regarding the embodiments of the present invention, further explanations will be given below in conjunction with the relevant drawings. In the drawings and the specification, as much as possible, the same or similar members are denoted by the same reference numerals. In the drawings, for the sake of simplicity and convenience, the shape and thickness may be shown enlarged. Elements not particularly shown in the drawings or described in the specification can be interpreted as forms known to those skilled in the art. Those skilled in the art can make various changes and modifications based on the content of the present invention.

[0023] When an element is described as "on...", generally it means that the element is directly on another element, and there may be cases where other elements are present in between. In contrast, when an element is described as "directly" on another element, no other element can be present in between. As used in this text, "and / or" includes any combination of one or more of the listed related items.

[0024] The description "one embodiment" or "an embodiment" in the following text refers to specific elements, structures, or features related within at least one embodiment. Therefore, multiple descriptions such as "one embodiment" or "an embodiment" in many places in the following text do not refer to the same embodiment. Furthermore, specific members, structures, and features in one or more embodiments can be combined based on an appropriate method.

[0025] Specific examples are given below for illustration, but these examples are only used for illustration purposes. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure. The protection scope of the present disclosure is based on the content specified in the claims. In this specification and the claims, unless otherwise clearly specified, the terms "one" and "the foregoing" include the meaning of "one or at least one". Also, as in the present disclosure, unless it is clear from a specific context that it is plural, the singular form also includes a plural meaning. Furthermore, unless otherwise clearly specified in the content of this specification and the claims, the terms "herein" and "therein" may include the meanings of "therein" and "thereon". The terms used in this specification and the claims have the same meaning as those commonly used in the relevant field, the content of the present disclosure, and the specific context, unless otherwise clearly explained. For the terms used to explain the present disclosure, separate explanations are provided in the following paragraphs or the specification to enable a person skilled in the art (practitioner) to understand the explanation of the present disclosure more clearly. Any example in any part of this specification is included in the illustrative use of the terms described herein, and these examples are only used for illustration purposes and do not limit the scope and meaning of the present disclosure or any of the terms exemplified. Similarly, the present disclosure is not limited to the various embodiments proposed in this specification.

[0026] Also, it can be seen that the terms "comprising", "including", "involving", "having", "containing", etc. used in this specification are in an open-ended form, that is, they are not intended to be limited to the listed ones. Also, any embodiment or claim of the present invention does not need to achieve all the objectives, advantages, or features disclosed by the present invention. Also, the abstract and the title of the invention are used for searching patent documents and do not limit the claims of the present invention.

[0027] Also, when the phrases "electrically coupled (electrical coupling)" or "electrically connected (electrical connection)" are used in this specification, any direct and indirect electrical connection means are included. For example, if there is a description in the text that the first device is electrically coupled to the second device, it indicates that the first device can be directly connected to the second device, or can be indirectly connected to the second device through other devices or connection means. Furthermore, when there is a description about the transmission and provision of electrical signals, although attenuation or other non-ideal changes may occur in the process of electrical signal transmission, those skilled in the art should understand that when there is no specific explanation about the source and receiving end of the electrical signal transmission or provision, they are regarded as substantially the same signal. For example, when transmitting (or providing) an electrical signal S from endpoint A of an electronic circuit to endpoint B of the electronic circuit, the voltage may be reduced by the source and drain ends of the transistor switch and / or possible parasitic capacitances. However, according to the purpose of this design, when achieving a specific technical effect by utilizing the attenuation or other non-ideal changes that occur unintentionally during transmission (or provision), the electrical signal S should be regarded as substantially the same signal at endpoint A and endpoint B of the electronic circuit.

[0028] Unless otherwise specified, some conditional clauses or phrases, such as "can", "could", "might", or "may", etc., usually represent the embodiments of the present invention, but may also be interpreted as features, members, or steps that are unnecessary and may exist. In other embodiments, these features, members, or steps may be unnecessary.

[0029] The method for obtaining the dielectric constant of the dielectric sheet of the present invention proposed below utilizes three known equivalent physical thicknesses and impedance ratios, and calculates the dielectric constant of the dielectric sheet of the flat capacitor to be measured, thereby solving the problem of measurement errors caused by undulations on the surface of the dielectric sheet material and shape changes due to internal cavities, and also using a scanning capacitance microscope in the field of measuring the dielectric constant of the dielectric sheet, which can broaden the application range of the scanning capacitance microscope.

[0030] Figures 1a to 1c are diagrams showing each measurement step of the method for obtaining the dielectric constant of a dielectric sheet in an embodiment of the present invention. Please refer to Figures 1a to 1c for the following description of the method for obtaining the dielectric constant of the dielectric sheet of the present invention. First, as shown in Figure 1a, a semiconductor capacitor 16 and a first parallel-plate capacitor 18 are connected in series. The first dielectric sheet 180 of the first parallel-plate capacitor 18 has a known first equivalent physical thickness d1 and a known first dielectric constant ε1. The semiconductor capacitor 16 has a depletion region 160. Here, the interface defects between the semiconductor capacitor 16 and the first parallel-plate capacitor 18 are not considered. In some embodiments, the semiconductor capacitor 16 may be a MOS capacitor including a semiconductor substrate 161, an oxide layer 162, a conductive probe 163, and an electrode layer 164, but the present invention is not limited thereto. The depletion region 160 is formed in the semiconductor substrate 161, and the semiconductor substrate 161 is provided between the oxide layer 162 and the electrode layer 164. The conductive probe 163 contacts the oxide layer 162 and is electrically connected to the scanning capacitance microscope measurement system 20 and the ground terminal. The scanning capacitance microscope measurement system 20 includes an ultra-high frequency capacitance sensor and a lock-in amplifier. The first parallel-plate capacitor 18 includes two first contact electrodes 181 and the first dielectric sheet 180 sandwiched therebetween. By the electrode layer 164 contacting one of the two first contact electrodes 181, the semiconductor capacitor 16 and the first parallel-plate capacitor 18 are connected in series, and the other first contact electrode 181 is electrically connected to the modulation voltage source 22. The modulation voltage source 22 is used to generate a modulation voltage Vm, and the modulation voltage Vm is an alternating voltage. The material of the first dielectric sheet 180 may be an insulating material such as borosilicate glass, quartz, zirconia, or sapphire, but the present invention is not limited thereto.

[0031] Next, using a scanning capacitance microscope and a modulation voltage source 22, a modulation voltage Vm is applied to the semiconductor capacitor 16 and the first flat capacitor 18 to cause a periodic change in the width of the depletion region 160, and a first scanning capacitance microscope signal for the semiconductor capacitor 16 and the first flat capacitor 18 is measured using the scanning capacitance microscope measurement system 20. The unit of the first scanning capacitance microscope signal is volts, and the value obtained by dividing the change amount of the capacitance value by the change amount of the voltage value is proportional to the first scanning capacitance microscope signal. The first scanning capacitance microscope signal is denoted as S1, the impedance of the depletion region 160 is denoted as Zd, the impedance of the oxide layer 162 is denoted as Zоx, the impedance of the conductive probe 163 is denoted as Zprо, the impedance of the semiconductor substrate 161 is denoted as Zsub, the impedance of the electrode layer 164 is denoted as Zbc, Zоx, Zprо, Zsub, and Zbc are fixed values, and only Zd changes with the modulation voltage Vm, so it is expressed as in Equation (4).

[0032]

Equation

[0033] Here, α is a system parameter, and Z1 is the impedance with respect to the first dielectric sheet 180,

Equation

[0034] After measuring the first scanning capacitance microscope signal, as shown in Fig. 1b, the first flat capacitor 18 is replaced with the second flat capacitor 24, and the semiconductor capacitor 16 and the second flat capacitor 24 are connected in series. The second dielectric sheet 240 of the second flat capacitor 24 has a known second equivalent physical thickness d2 and a known second dielectric constant ε2, and the second dielectric sheet 240 and the first dielectric sheet 180 have the same area. Here, the interface defects of the second flat capacitor 24 are not considered. The second flat capacitor 24 includes two second contact electrodes 241 and the second dielectric sheet 240 sandwiched therebetween. When the electrode layer 164 contacts one of the two second contact electrodes 241, the semiconductor capacitor 16 and the second flat capacitor 24 are connected in series, and the other second contact electrode 241 is electrically connected to the modulation voltage source 22. The material of the second dielectric sheet 240 may be an insulating material such as borosilicate glass, quartz, zirconia, or sapphire, but the present invention is not limited thereto.

[0035] Next, using the scanning capacitance microscope and the modulation voltage source 22, a modulation voltage Vm is applied to the semiconductor capacitor 16 and the second flat capacitor 24 to cause a periodic change in the width of the depletion region 160, and the second scanning capacitance microscope signal for the semiconductor capacitor 16 and the second flat capacitor 24 is measured using the scanning capacitance microscope measurement system 20. The unit of the second scanning capacitance microscope signal is volts, and the value obtained by dividing the change amount of the capacitance value by the change amount of the voltage value is proportional to the second scanning capacitance microscope signal. The second scanning capacitance microscope signal is represented as S2, and Zоx, Zprо, Zsub, and Zbc are fixed values, and only Zd changes with the modulation voltage Vm, so it becomes as in Equation (5).

[0036]

Equation

[0037] Here, Z2 is the impedance with respect to the second dielectric sheet 240.

[0038] For the same parallel plate capacitor having a dielectric sheet, its capacitance = dielectric constant of the dielectric sheet × area of the dielectric sheet / thickness of the dielectric sheet, so the impedance for the parallel plate capacitor is proportional to the reciprocal of the capacitance of the parallel plate capacitor and also proportional to the thickness of the dielectric sheet / dielectric constant of the dielectric sheet. From this, the capacitance ratio Rc12 obtained by dividing the capacitance of the first parallel plate capacitor 18 by the capacitance of the second parallel plate capacitor 24 is Rc12 = impedance for the second parallel plate capacitor 24 / impedance for the first parallel plate capacitor 18, that is, [Equation] It becomes as follows.

[0039] Therefore, it is expressed as in Equation 7. [Equation]

[0040] From this, the signal ratio Rs12 obtained by dividing the first scanning capacitance microscope signal S1 by the second scanning capacitance microscope signal S2 is expressed by Equation 8. [Equation] That is, it can also be expressed as in Equation 9. [Equation]

[0041] Furthermore, the impedance ratio ZR is calculated based on the first scanning capacitance microscope signal S1, the second scanning capacitance microscope signal S2, and Equation 1. [Equation] Rs12 is as in Equation 9, [Equation] Since both Rs12 and Rc12 are known, the number 9a defined as ZR can be obtained.

Number

[0042] That is, the impedance ratio ZR is ZR = impedance for the first dielectric sheet 180 / (impedance for the semiconductor capacitor 16 + impedance for the first dielectric sheet 180), and becomes like the formula of Equation 2.

Number

[0043] After obtaining the impedance ratio ZR, as shown in FIG. 1c, the second flat capacitor 24 is replaced with the third flat capacitor 26, and the semiconductor capacitor 16 and the third flat capacitor 26 are connected in series. The third dielectric sheet 260 of the third flat capacitor 26 has a known third equivalent physical thickness d3, and the third dielectric sheet 260 has the same area as the first dielectric sheet 180. Here, the interface defects of the third flat capacitor 26 are not considered. The third flat capacitor 26 includes two third contact electrodes 261 and the third dielectric sheet 260 sandwiched therebetween. The materials and manufacturing processes of the third contact electrode 261, the second contact electrode 241, and the first contact electrode 181 are all the same. The semiconductor capacitor 16 and the third flat capacitor 26 are connected in series by the electrode layer 164 contacting one of the two third contact electrodes 261, and the other third contact electrode 261 is electrically connected to the modulation voltage source 22. The material of the third dielectric sheet 260 may be an insulating material such as borosilicate glass, quartz, zirconia, or sapphire, but the present invention is not limited thereto.

[0044] Next, using the scanning capacitance microscope and the modulation voltage source 22, a modulation voltage Vm is applied to the semiconductor capacitor 16 and the third parallel-plate capacitor 26 to cause a periodic change in the width of the depletion region 160, and a third scanning capacitance microscope signal for the semiconductor capacitor 16 and the third parallel-plate capacitor 26 is measured using the scanning capacitance microscope measurement system 20. The unit of the third scanning capacitance microscope signal is volts, and the value obtained by dividing the change amount of the capacitance value by the change amount of the voltage value is proportional to the third scanning capacitance microscope signal. The third scanning capacitance microscope signal is represented as S3, and Zоx, Zprо, Zsub, and Zbc are fixed values, and only Zd changes with the modulation voltage Vm, so there are dozens of them.

Equation

[0045] Finally, based on the first scanning capacitance microscope signal S1, the third scanning capacitance microscope signal S3, the third equivalent physical thickness d3, and the impedance ratio ZR, the third dielectric constant ε3 of the third dielectric sheet 260 of the third parallel-plate capacitor 26 is obtained. By analogy from the formula of Equation 2,

Equation

Equation

Equation

[0046] Figures 2 to 8 are diagrams showing the signal ratio and capacitance ratio of the dielectric sheet in various embodiments of the present invention. The experimental data of the dielectric constant acquisition method using the dielectric sheet of the present invention will be described below. Table 1 shows the numbers, materials, and equivalent physical thicknesses of the dielectric sheets of the parallel plate capacitors used in the experiment.

[0047]

Table 1

[0048] The square in Figure 2 represents Q1, which is a value for the dielectric sheet of the first parallel plate capacitor. The capacitance ratio and the signal ratio of the scanning capacitance microscope signal with respect to Q1 are both defined as 1. The circle represents Q2, which is a value for the dielectric sheet of the second parallel plate capacitor. The triangle represents G1, which is a value for the dielectric sheet of the third parallel plate capacitor. The dashed line is drawn based on the number 9 of Rs12.

Number

[0049] The square in Figure 3 represents Q1, which is a value for the dielectric sheet of the first parallel plate capacitor. The capacitance ratio and the signal ratio of the scanning capacitance microscope signal with respect to Q1 are both defined as 1. The circle represents Q4, which is a value for the dielectric sheet of the second parallel plate capacitor. The triangle represents G1, which is a value for the dielectric sheet of the third parallel plate capacitor. The dashed line is drawn based on the number 9 of Rs12.

Number

[0050] The square in FIG. 4 represents Q1, which is a numerical value for the dielectric sheet of the first parallel-plate capacitor. The capacitance ratio with respect to Q1 and the signal ratio of the scanning capacitance microscope signal are both defined as 1. The circle represents Q5, which is a numerical value for the dielectric sheet of the second parallel-plate capacitor. The triangle represents G1, which is a numerical value for the dielectric sheet of the third parallel-plate capacitor. The dashed line is a line drawn based on the number 9 of Rs12.

Number

[0051] The square in FIG. 5 represents Q1, which is a numerical value for the dielectric sheet of the first parallel-plate capacitor. The capacitance ratio with respect to Q1 and the signal ratio of the scanning capacitance microscope signal are both defined as 1. The circle represents Q3, which is a numerical value for the dielectric sheet of the second parallel-plate capacitor. The triangle represents G1, which is a numerical value for the dielectric sheet of the third parallel-plate capacitor. The dashed line is a line drawn based on the number 9 of Rs12.

Number

[0052] The square in FIG. 6 represents Q1, which is a numerical value for the dielectric sheet of the first parallel-plate capacitor. The capacitance ratio with respect to Q1 and the signal ratio of the scanning capacitance microscope signal are both defined as 1. The circle represents Q5, which is a numerical value for the dielectric sheet of the second parallel-plate capacitor. The rhombus, parallelogram, hexagon, triangle, pentagon and trapezoid represent Q5, which are numerical values for the dielectric sheet of the third parallel-plate capacitor after undergoing microwave annealing (MWA) treatment. The numerical values for the square and the circle are not those after undergoing microwave annealing treatment. The dashed line is a line drawn based on the formula number of Rs12.

Number

[0053]

Table 2

[0054] The square in Fig. 7 represents Q1, which is the numerical value for the dielectric sheet of the first parallel-plate capacitor. The capacitance ratio and signal ratio of the scanning capacitance microscope signal for Q1 are both defined as 1. The circle represents G1, which is the numerical value for the dielectric sheet of the second parallel-plate capacitor. The triangle represents Zr1, which is the numerical value for the dielectric sheet of the third parallel-plate capacitor. The dashed line is drawn based on the number 9 of Rs12.

Number

[0055] The square in Fig. 8 represents Q1, which is the numerical value for the dielectric sheet of the first parallel-plate capacitor. The capacitance ratio and signal ratio of the scanning capacitance microscope signal for Zr1 are both defined as 1. The circle represents G1, which is the numerical value for the dielectric sheet of the second parallel-plate capacitor. The triangle represents Zr1, which is the numerical value for the dielectric sheet of the third parallel-plate capacitor. The dashed line is drawn based on the number 9 of Rs12.

Number

[0056] According to the above embodiment, the method for obtaining the dielectric constant of the dielectric sheet utilizes three known equivalent physical thicknesses and impedance ratios, and calculates the dielectric constant of the dielectric sheet of the flat capacitor to be measured, thereby solving the problem of measurement error caused by undulations on the surface of the material of the dielectric sheet and shape changes due to internal cavities, and also using the scanning capacitance microscope in the field of measuring the dielectric constant of the dielectric sheet, and the application range of the scanning capacitance microscope can be expanded.

[0057] The above description is only an example of the preferred embodiment of the present invention, and does not limit the scope of implementation of the present invention. Therefore, all equivalent changes and modifications based on the shape, structure, features and spirit described in the claims of the present invention are included within the scope of the claims of the present invention.

Explanation of Reference Numerals

[0058] 16 Semiconductor capacitor 160 Depletion region 161 Semiconductor substrate 162 Oxide layer 163 Conductive probe 164 Electrode layer 18 First flat capacitor 180 First dielectric sheet 181 First contact electrode 20 Scanning capacitance microscope measurement system 22 Modulation voltage source 24 Second flat capacitor 240 Second dielectric sheet 241 Second contact 26 Third flat capacitor 260 Third dielectric sheet 261 Third contact electrode Vm: Modulation voltage

Claims

【Claim 1】 Connecting a semiconductor capacitor and a first parallel-plate capacitor in series, wherein the first dielectric sheet of the first parallel-plate capacitor has a known first equivalent physical thickness d1 and a known first dielectric constant ε1, and the semiconductor capacitor has a depletion region; Applying a modulation voltage to the semiconductor capacitor and the first parallel-plate capacitor using a scanning capacitance microscope (SCM) to cause a periodic change in the width of the depletion region, and measuring a first SCM signal for the semiconductor capacitor and the first parallel-plate capacitor; Replacing the first parallel-plate capacitor with a second parallel-plate capacitor, connecting the semiconductor capacitor and the second parallel-plate capacitor in series, and the second dielectric sheet of the second parallel-plate capacitor having a known second equivalent physical thickness d2 and a known second dielectric constant ε2; Applying the modulation voltage to the semiconductor capacitor and the second parallel-plate capacitor using the scanning capacitance microscope to cause a periodic change in the width of the depletion region, and measuring a second SCM signal for the semiconductor capacitor and the second parallel-plate capacitor; Calculating an impedance ratio based on the first SCM signal, the second SCM signal, and the capacitance ratio Rc12 represented by Equation 1; 【Number 1】 Calculating an impedance ratio based on the first SCM signal, the second SCM signal, and the capacitance ratio Rc12 represented by Equation 1; Replacing the second parallel-plate capacitor with a third parallel-plate capacitor, connecting the semiconductor capacitor and the third parallel-plate capacitor in series, the third dielectric sheet of the third parallel-plate capacitor having a known third equivalent physical thickness d3, and the first dielectric sheet, the second dielectric sheet, and the third dielectric sheet having the same area; Applying the modulation voltage to the semiconductor capacitor and the third parallel-plate capacitor using the scanning capacitance microscope to cause a periodic change in the width of the depletion region, and measuring a third SCM signal for the semiconductor capacitor and the third parallel-plate capacitor; Obtaining the third dielectric constant of the third dielectric sheet of the third parallel-plate capacitor based on the first SCM signal, the third SCM signal, the third equivalent physical thickness, and the impedance ratio; comprising In the step of obtaining the third dielectric constant, when the first scanning capacitance microscope signal is S1, the second scanning capacitance microscope signal is S2, and the impedance ratio is Zr, the first scanning capacitance microscope signal, the second scanning capacitance microscope signal, the first equivalent physical thickness, the second equivalent physical thickness, and the impedance ratio satisfy Equation (2), 【Number 2】 A method for obtaining the dielectric constant of a dielectric sheet, where the impedance ratio = impedance with respect to the first dielectric sheet / (impedance with respect to the semiconductor capacitor + impedance with respect to the first dielectric sheet). **Claim 2** The method for obtaining the dielectric constant of a dielectric sheet according to claim 1, wherein the semiconductor capacitor is a MOS capacitor. **Claim 3** The method for obtaining the dielectric constant of a dielectric sheet according to claim 1, wherein the semiconductor capacitor includes a conductive probe electrically connected to a ground terminal. **Claim 4** The method for obtaining the dielectric constant of a dielectric sheet according to claim 1, wherein the materials of the first dielectric sheet, the second dielectric sheet, and the third dielectric sheet are insulating materials. **Claim 5** The first scanning capacitance microscope signal, the third scanning capacitance microscope signal, the first equivalent physical thickness, the third equivalent physical thickness, and the impedance ratio satisfy Equation (3), 【Number 3】 where S1 is the first scanning capacitance microscope signal, S3 is the third scanning capacitance microscope signal, ZR is the impedance ratio, and ε3 is the third dielectric constant. The method for obtaining the dielectric constant of a dielectric sheet according to claim 1.

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