JP4883679B2 - Element substrate, inspection method, and manufacturing method of semiconductor device - Google Patents

Description

  The present invention relates to an element substrate, an inspection method thereof, and a method for manufacturing a semiconductor device using the inspection method.

In recent years, development of semiconductor devices (referred to as wireless chips, RFID tags, and the like) that transmit and receive information wirelessly has progressed.
Generally, when an LSI chip is manufactured, a characteristic evaluation element or circuit called a TEG (test elementary group) is formed on a substrate on which the LSI chip is formed. By evaluating the TEG, it is possible to verify the manufacturing process of the LSI chip or the parameters used for the LSI design. The wireless chip is also composed of an LSI chip, and a TEG is provided on a substrate on which the LSI chip is formed for the purpose of verifying the manufacturing process.

In addition, a non-contact inspection process has been proposed in a semiconductor device inspection process (see Patent Document 1).
JP 2003-31814 A

  Although LSI chips that make up wireless chips are currently formed on silicon wafers, development related to chips provided on flexible substrates (hereinafter referred to as flexible chips) has been made. It is being advanced. Since the chip having flexibility is very thin and flexible, it can be used for various applications.

  By the way, evaluation of the above-mentioned chip is usually performed by bringing a needle called a prober into contact with a substrate on which a TEG is formed and measuring electrical characteristics. That is, measurement by contact is performed. However, since a flexible chip has a high risk of damaging a thin semiconductor layer, it is difficult to perform automatic measurement by bringing a needle into contact with the chip. Therefore, in order to perform measurement by contact, it is necessary to manually contact the needle with accuracy or to use a predetermined anisotropic conductive film, which requires time and labor.

  As described above, it has been difficult to measure the chip having flexibility efficiently and with high reliability.

  Further, TEG has a risk of electrostatic breakdown through the electrode pad. Such problems arise because the electrodes are exposed to the surface. Therefore, a TEG with the number of electrode pads reduced as much as possible, or a TEG that does not have any, and a method for evaluating such a TEG are effective in improving the reliability of TEG evaluation.

  Accordingly, the present invention provides a TEG capable of evaluating semiconductor element characteristics by using wireless technology without contacting an electrode as much as possible or without contacting an electrode, and an element substrate on which the TEG is formed. The issue is to provide. It is another object of the present invention to provide a measurement method.

  In order to solve the above problems, the present invention takes the following measures.

  In the present invention, a characteristic evaluation element (TEG) having a closed loop circuit in which an antenna coil and a semiconductor element are connected in series is provided, and the surface of the region where the closed loop circuit is provided is covered with an insulating film It is a board | substrate, The characteristic of a semiconductor element can be evaluated using the said board | substrate.

  Another aspect of the present invention is an element substrate characterized in that a characteristic evaluation element having a closed loop circuit in which an antenna coil and a semiconductor element are connected in series is provided and has flexibility. Can be used to evaluate the characteristics of the semiconductor element.

  In another embodiment of the present invention, a characteristic evaluation element having a closed loop circuit in which an antenna coil, a capacitor element, and a semiconductor element are connected in series is provided, and the surface of the region where the closed loop circuit is provided is covered with an insulating film. The element substrate is characterized in that the characteristics of the semiconductor element can be evaluated using the substrate.

  Another embodiment of the present invention is an element substrate characterized in that a characteristic evaluation element having a closed loop circuit in which an antenna coil, a capacitor element, and a semiconductor element are connected in series is provided and has flexibility. Thus, the characteristics of the semiconductor element can be evaluated using the substrate.

  According to another aspect of the present invention, a characteristic evaluation element including an antenna coil, a power supply circuit, a ring oscillator, and a transistor is provided, and the power supply circuit has a function of supplying a power supply voltage to the ring oscillator. Is connected to a circuit that performs load modulation at the oscillation frequency of the ring oscillator, and the surface of the region where the power supply circuit, the ring oscillator, and the transistor are provided is covered with an insulating film. Thus, the characteristics of the semiconductor element can be evaluated using the substrate.

  Another embodiment of the present invention includes a characteristic evaluation element including an antenna coil, a power supply circuit, a ring oscillator, and a transistor, and the power supply circuit has a function of supplying a power supply voltage to the ring oscillator. The coil is connected to a circuit that performs load modulation at the oscillation frequency of the ring oscillator and has flexibility, and the characteristics of the semiconductor element can be evaluated using the substrate. .

  Another embodiment of the present invention is provided with a characteristic evaluation element having an antenna coil, a ring oscillator, a transistor, and an electrode pad for supplying a power supply voltage to the ring oscillator, and the antenna coil has an oscillation frequency of the ring oscillator. A circuit board to which load modulation is performed is connected, and a surface of a region where a power supply circuit, a ring oscillator, and a transistor are provided is configured by an electrode pad or an insulating film. The characteristics of the semiconductor element can be evaluated using the substrate.

  Another embodiment of the present invention is provided with a characteristic evaluation element having an antenna coil, a ring oscillator, a transistor, and an electrode pad for supplying a power supply voltage to the ring oscillator, and the antenna coil has an oscillation frequency of the ring oscillator. An element substrate characterized in that a circuit to which load modulation is performed is connected and has flexibility, and the characteristics of the semiconductor element can be evaluated using the substrate.

The inspection method of the present invention evaluates the characteristics of a semiconductor element by applying an electromagnetic wave to any one of the element substrates described above and measuring the power absorbed by the element substrate.
In addition, the characteristics of the semiconductor element are evaluated by measuring the power consumed by the element substrate.

  The present invention also applies electromagnetic waves using a measuring device capable of emitting controllable electromagnetic waves from an antenna.

  The inspection method of the present invention includes a step of measuring the power absorbed by the element substrate by the magnetic field prober.

  Further, by using the inspection method of the present invention, the static characteristics or dynamic characteristics of a semiconductor element provided on an element substrate can be evaluated without contact.

  In addition, a method for manufacturing a semiconductor device of the present invention includes forming a characteristic evaluation element having a first semiconductor layer and a thin film transistor having a second semiconductor layer over a non-flexible substrate. The contact type inspection is performed, the non-flexible substrate is peeled off, the element for characteristic evaluation and the thin film transistor are transferred onto the flexible substrate, and the element for characteristic evaluation transferred onto the flexible substrate is non-exposed. The characteristics of the thin film transistor are evaluated by performing a contact type inspection, and the substrate in which the characteristics of the thin film transistor satisfy the allowable range is cut.

  According to another embodiment of the present invention, there is provided a method for manufacturing a semiconductor device, in which a characteristic evaluation element having a first semiconductor layer and a thin film transistor having a second semiconductor layer are formed over a non-flexible substrate. The contact type inspection is performed, the non-flexible substrate is peeled off, the characteristic evaluation element and the thin film transistor are transferred onto the flexible substrate, and the characteristic evaluation element transferred onto the flexible substrate is transferred. Then, a non-contact type inspection is performed to evaluate the characteristics of the thin film transistor, a substrate in which the characteristics of the thin film transistor satisfy an allowable range is cut, and the thin film transistor on the cut substrate is inspected.

  According to the method for manufacturing a semiconductor device of the present invention, the voltage-current characteristic of the element for characteristic evaluation is obtained by contact type inspection, and the element for characteristic evaluation transferred on the flexible substrate is inspected in a non-contact type. It has the process of evaluating the characteristic of a thin-film transistor by performing and cut | disconnecting the board | substrate which satisfy | filled the allowable range of the voltage-current characteristic of a thin-film transistor.

  According to the present invention, even when it is difficult to perform measurement by bringing a needle into contact with an electrode pad, it is possible to perform element characteristic evaluation efficiently and with high reliability. Further, by reducing the area of the exposed electrode surface as much as possible, electrostatic breakdown of the evaluation element can be suppressed, and highly reliable element characteristic evaluation can be performed. As a result, it is possible to efficiently verify the manufacturing process or design parameters.

  Embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following description, and it will be easily understood by those skilled in the art that various modifications can be made without departing from the spirit of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below. Moreover, in the structure of this invention demonstrated below, the code | symbol which points to the same thing may be common between different drawings.

(Embodiment 1)
An element substrate having the TEG of the present invention and a method for measuring semiconductor element characteristics using the same will be described with reference to FIG.

  The element substrate 107 of the present invention has a configuration in which an antenna coil 105 and a semiconductor element 106 are connected in series as a TEG, that is, a closed loop circuit.

  A thin film transistor evaluated by TEG is provided on the element substrate. The thin film transistor forms a semiconductor device such as a wireless chip. The thin film transistor and the TEG have the same configuration, and include, for example, a semiconductor layer formed on a base film. The semiconductor layers included in each of the TEG and the thin film transistor are simultaneously formed in the same process. Furthermore, a gate insulating film provided to cover the semiconductor layer, a gate electrode provided on the semiconductor layer via the gate insulating film, an insulating film provided to cover the gate electrode and the semiconductor layer, and an opening in the insulating film And a wiring connected to the impurity region of the semiconductor layer, a protective film provided on the wiring, and the like. The protective film is preferably formed of an insulating film containing nitrogen, and is provided over the entire element substrate 107 in order to prevent an impurity element such as an alkali metal from entering the semiconductor layer. Since the protective film covers the wiring and the like, it is difficult to perform a contact type inspection.

  When a wireless chip, that is, a non-contact type chip is formed as an example of a semiconductor device, an antenna coil is mounted on the chip, specifically, an antenna coil is connected to a wiring connected to the impurity region. Become. Therefore, the antenna coil can be formed simultaneously with the wiring. Of course, the antenna coil can be formed at the same time as the gate electrode. However, since it is necessary to connect to the wiring, it is necessary to connect with the conductive layer through the contact hole.

  In some cases, a contact chip is formed as an example of a semiconductor device. In this case, the wiring for connecting to the antenna coil can be exposed.

  Since the TEG has a configuration in which the antenna coil 105 and the semiconductor element 106 are connected in series, the TEG has a form in which the antenna coil is mounted, and the antenna coil can be formed simultaneously with the wiring or the gate electrode. The material of the antenna coil is a conductive material such as copper (Cu), silver (Ag), gold (Au), or indium tin oxide (ITO), a material obtained by adding silicon oxide to indium tin oxide (ISO), or the like. It can be formed from a transparent conductive material. The antenna coil can be formed by a printing method, a droplet discharge method typified by inkjet, a sputtering method, a vapor deposition method, or the like. By mounting such an antenna coil, the TEG can be inspected in a non-contact manner.

  The measuring device 104 includes a radio wave interface 102, an antenna coil 103, a control circuit 101, and the like, and can radiate electromagnetic waves with a predetermined frequency and power.

  When electromagnetic waves are radiated from the measuring device 104, induced electromotive force is generated at both ends of the antenna coil of the TEG on the element substrate 107 by electromagnetic induction. A current in accordance with element characteristics flows through the semiconductor element 106 included in the TEG. This means that the thin film transistors and wirings constituting the semiconductor element 106 provided on the element substrate 107 absorb power depending on the characteristics of the semiconductor element 106. Information on the characteristics of the semiconductor element 106 can be obtained by measuring the amount of power absorbed by the measuring device 104. Since there is a correlation between the characteristics of the semiconductor element 106 and the characteristics of the thin film transistor, it is possible to evaluate and inspect characteristics of a circuit including the thin film transistor included in the semiconductor device.

  A circuit that models the measurement system shown in FIG. 1 will be described with reference to FIG.

As shown in FIG. 2, the measurement device 104 includes a capacitive element having a capacitance C _1, the inductance L _1, a resonance circuit and a coil is connected in series with a parasitic resistance R _1. A current i ₁ and a voltage V are applied to the circuit. On the other hand, the semiconductor element 106 included in the TEG on the element substrate 107 has an antenna coil that has an impedance Z ₂ and can be regarded as having an inductance L ₂ and a parasitic resistance R ₂ . Note that the TEG of the present invention is not provided with a resonance circuit. The antenna coil of the measuring device 104 and the antenna coil 105 of the TEG have a mutual inductance M. In such an antenna coil, an induced electromotive force u ₂ is generated by an electromagnetic wave radiated from the measuring device 104, and a current i ₂ flows.

In the circuit modeled in FIG. 2, the voltage V applied to the resonance circuit of the measuring device 104 is expressed by Equation 1 (Equation 1) under the resonance condition (C ₁ · L ₁ · ω ² = 1). .

Furthermore, since the current i ₂ flowing through the semiconductor element 106 is expressed as in Equation 2 (Equation 2) and the induced electromotive force u ₂ is expressed as in Equation 3 (Equation 3), when these are substituted, the voltage V 2 Equation 4 (Equation 4) is obtained. J represents an imaginary unit.

From Equation 4, it can be seen that the voltage V and current i ₁ generated in the resonance circuit of the measuring apparatus 104 are proportional, and the proportionality coefficient is determined by ω, R ₁ , M, R ₂ , L ₂ , and Z ₂ . When ω, R ₁ , M, R ₂ , and L ₂ are fixed and the impedance Z ₂ of the semiconductor element 106 is changed, the voltage V and the current i ₁ can be represented by a graph as shown in FIG. Recognize. Regions impedance Z ₂ is equal to 0, the area having a certain value, can be divided into regions to be infinite. The region having a certain value has a characteristic that the current i ₁ with respect to the same voltage V increases as the value of the impedance Z ₂ increases.

Since the voltage V and the current i ₁ applied to the antenna coil 103 of the measuring device 104 are measurable quantities, it is possible to obtain information on the impedance Z ₂ of the TEG semiconductor element 106. Based on such a principle, the semiconductor element 106 can be evaluated in a non-contact manner. Since the characteristics of the semiconductor element 106 and the characteristics of the thin film transistor are created in the same process, a correlation can be obtained. Therefore, the characteristics of the thin film transistor can be inspected from the characteristics of the semiconductor element 106, and the characteristics of the circuit and the semiconductor device including the thin film transistor can be inspected.

  Next, a more specific form of the present invention will be described.

FIG. 4, a diode 401 used as a semiconductor element, such as having an impedance Z _2, shows a model circuit diagram of a device substrate provided with a TEG including an antenna coil 402. Note that in FIG. 4, the capacitor 403 is connected in series with the antenna coil 402 and the diode 401, but the capacitor 403 is not necessarily provided. Since the capacitor 403 is provided to adjust the phase component of the signal, the capacitor 403 is not necessarily provided when the adjustment is not necessary. Note that in the case where the capacitor element 403 is provided, the capacitor is included in the impedance in the above formula.

  Next, a method for evaluating the threshold voltage Uth of the diode 401 using the element substrate shown in FIG. 4 will be described.

FIG. 5A is a graph of voltage-current characteristics (referred to as IV characteristics) of the diode 401, and is difficult to obtain directly without being in contact with the electrodes. On the other hand, FIG. 5B is a graph showing the relationship between the voltage V and the current i ₁ generated in the resonance circuit of the measuring device 104, which is obtained from the non-contact measurement based on the principle described above. Note that a point (V ₀ , I ₀ ) where the graph changes abruptly in FIG. 5B corresponds to the threshold value of the diode 401.

By obtaining the relationship between the IV characteristic of the diode 401 measured in this way and V ₀ and I ₀ of the diode 401, the threshold value Uth of the diode 401 can be evaluated only by non-contact measurement. It becomes. Thus, the threshold value of the diode 401 can be obtained by obtaining the relationship between the IV characteristic of the diode 401 and the V ₀ and I ₀ of the diode 401 according to the present invention.

Practically, it is preferable to perform contact measurement on an element substrate serving as a reference on which an antenna coil and a circuit having the same configuration as the TEG are formed. Thereafter, non-contact measurement can be performed on the element substrate. Using the evaluation of contact to the element substrate as a reference, the same conditions, i.e. by the mutual inductance M, the parasitic resistance R ₂ of the inductance L ₂ and the antenna coil of the antenna coil is measured under certain conditions This is because the relationship between the threshold value Uth of the diode of the TEG and V ₀ or I _{0 in} which non-contact measurement is performed can be obtained.

The threshold voltage Uth can also be calculated using the mutual inductance M, the inductance L _{2 of the} antenna coil, and the parasitic resistance R ₂ from Equation 3 described above. The parasitic resistance R ₂ of the mutual inductance M, the antenna coil inductance L ₂ and the antenna coil can be obtained by the element substrate of the present invention, and a measuring device used. The L ₂ and R ₂ of the antenna coil are determined by the shape and material, and manufacturing variations can be reduced. The mutual inductance can be kept constant by measuring under the same position and measurement environment.

Further, by performing measurements as in the present invention for diodes having various threshold voltages Uth, the relationship between the threshold voltage Uth of the diode and the voltage V ₀ of the measuring device 104 is, for example, as shown in FIG. Can be sought.

Once the relationship between the threshold value Uth of the diode on the reference element substrate and the voltage V ₀ of the measuring device 104 is obtained, the threshold value of the diode can be evaluated only by non-contact measurement. It becomes possible.

  As described above, in the present invention, when obtaining element characteristics to be evaluated (values such as threshold values), it is preferable to separately prepare an element substrate as a reference that can be evaluated by a contact formula. On the other hand, when comparing the element characteristics to be evaluated relatively, for example, when comparing the threshold values of a plurality of elements, or evaluating the aging of a single element, it is not necessary to prepare a reference element substrate. .

  Note that although the case where a diode is used as the semiconductor element 106 has been described in this embodiment, the semiconductor element 106 may be an element such as a transistor, a resistance element, or a light-emitting element. In addition, it is not limited to a single element made of any of these semiconductor elements, and generally, an element having two terminals or a circuit having the element may be used. When the diode, transistor, and light emitting element described above are used, the threshold value is known, and when the resistor element is used, the resistance value is known. As described above, according to the present invention, it is possible to obtain parameters (referred to as element parameters) representing element characteristics such as a threshold value and a resistance value without contact, and as a result, it is possible to evaluate the element characteristics.

  Non-contact measurement is not limited to the method of measuring the voltage V and current i of the measurement device, and generally relates to the amount of power supplied from the measurement device 104 and the amount of power absorption by a circuit or the like provided on the element substrate 107. It suffices if it can be measured. For example, the above-described evaluation can be performed based on the voltage V of the measuring device 104 and the magnetic field strength obtained from a magnetic field prober installed near the antenna coil of the element substrate 107. Such a magnetic field strength can be measured using a spectrum analyzer.

  As described above, the element substrate of the present invention makes it possible to evaluate semiconductor element characteristics in a non-contact manner. As a result, even when it is difficult to perform measurement by bringing a needle into contact with the electrode pad, it is possible to perform element characteristic evaluation efficiently and with high reliability. In addition, electrostatic breakdown of the evaluation element can be suppressed, and highly reliable element characteristic evaluation can be performed.

(Embodiment 2)
An evaluation mode of the element substrate of the present invention, which is different from the first embodiment, will be described.

Figure 6 shows a model circuit diagram of an element substrate for evaluating the semiconductor device 601 having an impedance Z _2. The TEG provided on the element substrate has a circuit in which an antenna coil 602, a semiconductor element 601, and a capacitor 603 are connected in series, that is, a closed loop circuit. Note that as in FIG. 4, the capacitor 603 is not necessarily provided.

  In the TEG evaluation, it is one of the important purposes to determine whether or not the characteristics of the semiconductor element are within an allowable range in the semiconductor manufacturing process. Here, a method for evaluating whether or not the characteristics of the semiconductor element 601 are within the allowable range using the element substrate shown in FIG. 6 will be described.

  First, the TEG of the reference element substrate is configured to include an antenna coil and a semiconductor element 601 having the same structure as the element substrate shown in FIG. Then, an element substrate on which a plurality of TEGs capable of both contact-type measurement and non-contact-type measurement is formed is prepared. In the case of performing contact measurement, the TEG has a form in which the connection wiring connected to the antenna or the like is exposed. In the case of performing non-contact measurement, the TEG has an antenna mounted form. TEGs each having such a form may be provided on the same element substrate. Of course, you may provide TEG which has such a form on another element board | substrate, respectively. Further, when measurement is performed in a non-contact manner, a flexible substrate can be used as the element substrate.

Using such an element substrate, the mutual inductance M by the contact measurement, measuring the inductance L ₂ and the parasitic resistance R ₂ fixed semiconductor device 601 under the antenna coil. Then, the relationship between the VI characteristic of the semiconductor element 601 and the Vi ₁ curve of the semiconductor element corresponding to the result of the non-contact measurement can be obtained. Further, an allowable range can be obtained by measuring a larger number of TEGs and obtaining a V-i ₁ region of the semiconductor element that falls within the tolerance range.

For example, when the allowable characteristic of the semiconductor element 601 is expressed as a hatched area in FIG. 7A, in the non-contact (V, i ₁ ) plane, as in the hatched area in FIG. Can be represented. This can be obtained because the VI characteristic shown in FIG. 7A obtained by the contact type has a correlation with the VI characteristic shown in FIG. 7B obtained by the non-contact type. Based on the allowable characteristic diagram obtained as shown in FIG. 7B, the semiconductor element 601 can be evaluated in a non-contact manner.

Once the allowable characteristics of the semiconductor element 601 are obtained as a region on the (V, i ₁ ) plane, it is determined whether the characteristics of the semiconductor element are within the allowable range only by non-contact measurement. It becomes possible to evaluate. The allowable characteristic range can be determined based on the specifications of the semiconductor device.

  Note that this embodiment mode can be freely combined with the above embodiment modes.

(Embodiment 3)
In this embodiment, a manufacturing process of a semiconductor device using the evaluation method described in Embodiment 2 will be described.

As shown in FIG. 17A, a semiconductor layer that forms a TEG, a chip, and the like is formed over a glass substrate 701 serving as an element substrate. By forming on a non-flexible substrate such as a glass substrate, the TEG can be inspected in a contact manner. By inspecting the TEG by a contact method, a VI characteristic as shown in FIG. 7A is obtained (S100 in FIG. 17D). Then, an allowable characteristic diagram (Vi- ₁ curve) in the non-contact measurement as shown in FIG. 7B is created (S101 in FIG. 17D).

  Next, as illustrated in FIG. 17B, the glass substrate 701 is peeled off, and a flexible substrate 702 is provided as an element substrate. The TEG 703 on the flexible substrate 702 is inspected in a non-contact manner (S102 in FIG. 17D). Then, it is determined whether or not the element substrate satisfies the permissible characteristic in the permissible characteristic diagram (S103 in FIG. 17D). Any of the element parameters can be used as the allowable characteristic.

  By inspecting the TEG in a non-contact manner, the static characteristic or dynamic characteristic of the TEG can be obtained.

  After that, as shown in FIG. 17C, the element substrate determined to satisfy the allowable characteristics is cut into each chip 704 (S104 in FIG. 17D) and completed (S105 in FIG. 17D). . As described above, a semiconductor device such as a chip can be manufactured.

  At this time, each chip 704 may be inspected (S106 in FIG. 17D). The inspection for each chip can be performed in a non-contact manner in the case of a chip on which an antenna is mounted, and the contact inspection is performed in contact with the antenna connection terminal in the case of a chip without an antenna. be able to.

  FIG. 17D shows the above process in a flowchart. As shown in FIG. 17D, the element substrate determined to satisfy the allowable characteristics is cut into each chip and completed. As described above, a semiconductor device such as a chip can be manufactured.

  By such an evaluation method using the element substrate of the present invention, a defect of a semiconductor device such as a chip can be inspected for each element substrate. As a result, it is possible to speed up the defect inspection of the semiconductor device.

(Embodiment 4)
The configuration and evaluation mode of the element substrate of the present invention, which is different from the first and second embodiments, will be described.

  The element substrate of the present invention includes a TEG including an antenna coil 804, a capacitor 805, a power supply circuit 801, a transistor 803, and a ring oscillator 802 as shown in FIG. The antenna coil 804, the capacitor 805, and the power supply circuit 801 are connected in series, and the transistor 803 is connected in parallel with the capacitor 805 and the antenna coil 804. The gate electrode of the transistor 803 is connected to the output (Sout) of the ring oscillator 802, one power supply circuit 801 is grounded (GND), and the other is connected to the power supply (VDD) of the ring oscillator 802. The transistor 803 functions as a load modulation transistor for the antenna coil. FIG. 8A illustrates a circuit including a capacitor 805 and a resistor 806 as a typical example of a circuit that performs load modulation at the oscillation frequency of the ring oscillator.

  In such an element substrate, when an induced electromotive force is generated in the antenna coil 804, the power supply circuit 801 generates a power supply voltage and supplies it to the ring oscillator 802. When the ring oscillator 802 receives power supply, the ring oscillator 802 outputs an oscillation signal, and the transistor 803 can be switched by the oscillation signal. And the measuring apparatus 104 can evaluate the oscillation frequency of a ring oscillator by measuring the period when electric power supply changes.

  As a specific evaluation method, for example, the oscillation frequency of the ring oscillator is measured and the relative change is evaluated. The reliability of ring oscillators and power supply circuits can be evaluated by evaluating changes over time under various stress conditions and changes in frequency under various environments.

  Alternatively, a power supply circuit used in an actual wireless chip is employed to measure the oscillation frequency of the ring oscillator. Since there is a correlation between the frequency characteristics of the logic circuit of the wireless chip and the frequency characteristics of the ring oscillator, the characteristics of the wireless chip manufactured in the same process can be evaluated by measuring the oscillation frequency. That is, the capability of the power supply circuit included in the wireless chip can be evaluated by a ring oscillator formed as a TEG.

  Further, by measuring the radiated electromagnetic wave from the ring oscillator 802 using a magnetic field prober and spectrum analyzer, a magnetic field prober and an oscilloscope, the reliability of the ring oscillator and the power supply circuit can be evaluated.

  Further, as shown in the first or second embodiment, a reference element substrate may be prepared even when a ring oscillator is used. The reference element substrate is provided with a ring oscillator that can be measured by a contact type and a ring oscillator that can be measured by a non-contact type. As a result, it is possible to evaluate the dynamic characteristics or static characteristics of the ring oscillator, that is, the relationship between the oscillation frequency and the power supply. Further, as shown in the first or second embodiment, by providing a larger number of ring oscillators, an allowable characteristic range can be determined.

  Note that as long as the above measurement and evaluation can be performed, the transistor 803 may be omitted as illustrated in FIG. The transistor 803 is provided for antenna coil load modulation, and need not be provided if load modulation is unnecessary.

  Note that this embodiment mode can be freely combined with the above embodiment modes.

  A specific example of the power supply circuit 801 used in Embodiment 4 will be described.

  In the power supply circuit illustrated in FIG. 9, a diode 901 and a diode 902 are connected in series, and a capacitor 903 is provided between the output of the diode 901 and the input of the diode 902. The input of the diode 902 is grounded (GND). Such a power supply circuit is a circuit that inputs an AC signal having an amplitude Vin to the input of the diode 901 and outputs a power supply voltage Vout. The input AC signal is rectified by the diode 901 and stabilized by the capacitor 903.

  The power supply circuit shown in FIG. 10 has a configuration in which a regulator 1002 is provided at the subsequent stage of the power supply 1001 corresponding to the power supply circuit shown in FIG. The regulator 1002 is a circuit for keeping the output voltage substantially constant regardless of the input voltage, and a known circuit can be used. The power supply circuit shown in FIG. 10 is preferable in that it can output a stable voltage without depending much on the amplitude Vin of the input AC signal, as shown in FIG.

  The TEG of the present invention can be applied even when performing measurement by contact. And the electrostatic breakdown is less likely to occur when the number of electrode pads to be brought into contact is small. Further, in a chip having flexibility, contact measurement with a large number of electrode pads is difficult, but contact measurement may be possible with a small number of electrode pads.

  In such a case, an element substrate provided with a TEG as shown in the model circuit diagrams of FIGS. 12 and 13 may be used. The TEG illustrated in FIG. 12 includes a capacitor 1204, an antenna coil 1203, a transistor 1202, a ring oscillator 1201, and two power supply pads 1205 and 1206. A power supply voltage is supplied from the power supply pads 1205 and 1206. The power (VDD) and GND of the ring oscillator 1201 are connected to power pads 1205 and 1206, respectively. Such a TEG is called a ring oscillator evaluation circuit, and the ring oscillator evaluation circuit can be expressed as a circuit capable of measuring the oscillation frequency wirelessly.

  Since the element substrate having such a ring oscillator evaluation circuit can measure both the input power supply voltage and the oscillation frequency, the characteristics of the ring oscillator 1201 can be accurately evaluated. As a result, the characteristics of the circuit formed from the thin film transistor can be accurately evaluated.

  As a configuration for reducing the number of electrode pads, as shown in FIG. 13, a configuration in which two electrode pads 1302 and 1303 are shared and a plurality of ring oscillator evaluation circuits 1301 (1) to 1301 (n) are connected in parallel. There is also. The characteristic evaluation accuracy can be improved by connecting a plurality of ring oscillator evaluation circuits.

  Note that this embodiment can be freely combined with the above embodiment or replaced with the TEG of the above embodiment.

  In this example, a result of measuring an element substrate having a ring oscillator evaluation circuit using a spectrum analyzer is shown.

  As shown in FIG. 14, the spectrum analyzer antenna coil 144 is inserted between a pair of bases 140 supported by the spacer 141. A picoprobe needle 142 is brought into contact with an evaluation element substrate 143 having a ring oscillator evaluation circuit arranged on one base, and a measurement frequency is output to a connected oscilloscope. The ring oscillator was arranged in 51 stages, the channel width of the n-type thin film transistor was 10 μm, the channel width of the p-type thin film transistor was 20 μm, the channel length of both thin film transistors was 1 μm, and the thickness of the gate insulating film was 40 nm. The n-type thin film transistor has an LDD structure, and the p-type thin film transistor has a single drain structure.

FIG. 15 shows the measurement result of the oscillation frequency of the ring oscillator using an oscilloscope.
FIG. 16 shows the measurement result of the oscillation frequency of the ring oscillator by the spectrum analyzer.
Since the waveform shown in FIG. 15 and the waveform shown in FIG. 16 substantially match, it can be seen that the oscillation frequency of the ring oscillator evaluation circuit can be measured in a non-contact manner by a spectrum analyzer using a non-contact antenna.

Block diagram comprising the element substrate and measuring apparatus of the present invention The circuit diagram explaining the evaluation principle of the semiconductor element of this invention The graph explaining the evaluation method of the semiconductor element characteristic of this invention Circuit diagram formed on the element substrate of the present invention The graph explaining the evaluation method of the semiconductor element of this invention Circuit diagram formed on the element substrate of the present invention The graph explaining the evaluation method of the semiconductor element of this invention Circuit diagram formed on the element substrate of the present invention Circuit diagram of power supply circuit formed on element substrate of the present invention Circuit diagram of power supply circuit formed on element substrate of the present invention Characteristic curve of power supply circuit formed on element substrate of the present invention Circuit diagram formed on the element substrate of the present invention Circuit diagram formed on the element substrate of the present invention Measurement model with spectrum analyzer Measurement results of oscillation frequency of ring oscillator using oscilloscope Measurement results of ring oscillator oscillation frequency using spectrum analyzer FIG. 6 is a diagram showing a method for manufacturing a semiconductor device using the evaluation method of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Control circuit 102 Radio wave interface 103 Antenna coil 104 Measuring apparatus 105 Antenna coil 106 Semiconductor element 107 Element board 140 Base 141 Spacer 142 Pico probe needle 143 Evaluation element board 144 Spectrum analyzer antenna coil 401 Diode 402 Antenna coil 403 Capacitance element 601 Semiconductor Element 602 Antenna coil 603 Capacitor element 701 Glass substrate 702 Flexible substrate 801 Power supply circuit 802 Ring oscillator 803 Transistor 804 Antenna coil 805 Capacitor element 901 Diode 902 Diode 903 Capacitor element 1001 Power supply 1002 Regulator 1201 Ring oscillator 1202 Transistor 1203 Antenna coil 1204 Capacitor Element 1205 Power supply pad 1301 Phosphorus Oscillator evaluation circuit 1302 electrode pad

Claims (26)

A characteristic evaluation element having a closed loop circuit in which an antenna coil and a semiconductor element are electrically connected in series is provided, and a surface of the region in which the closed loop circuit is provided is covered with an insulating film. Element substrate to be used. An element substrate characterized by having a characteristic evaluation element having a closed loop circuit in which an antenna coil and a semiconductor element are electrically connected in series and having flexibility. In claim 1 or claim 2,
2. The element substrate according to claim 1, wherein the semiconductor element is any one of a diode, a transistor, a light emitting element, a resistance element, and a capacitor element. A characteristic evaluation element having a closed loop circuit in which an antenna coil, a capacitor element, and a semiconductor element are electrically connected in series is provided, and a surface of the region where the closed loop circuit is provided is covered with an insulating film An element substrate. An element substrate characterized in that a characteristic evaluation element having a closed loop circuit in which an antenna coil, a capacitor element, and a semiconductor element are electrically connected in series is provided and has flexibility. In claim 4 or claim 5,
The element substrate, wherein the semiconductor element is any one of a diode, a transistor, a light emitting element, and a resistance element. An element for characteristic evaluation having an antenna coil, a power supply circuit, a ring oscillator, and a transistor is provided.
The power supply circuit has a function of supplying a power supply voltage to the ring oscillator;
The antenna coil has the transistor, and is electrically connected to a circuit that performs load modulation at the oscillation frequency of the ring oscillator,
The element substrate, wherein the surface of the region where the power supply circuit, the ring oscillator, and the transistor are provided is covered with an insulating film. An element for characteristic evaluation having an antenna coil, a power supply circuit, a ring oscillator, and a transistor is provided.
The power supply circuit has a function of supplying a power supply voltage to the ring oscillator;
The antenna coil has the transistor, and is electrically connected to a circuit that performs load modulation at the oscillation frequency of the ring oscillator,
An element substrate having flexibility. A characteristic evaluation element having an antenna coil, a ring oscillator, a transistor, and an electrode pad for supplying a power supply voltage to the ring oscillator is provided.
The antenna coil includes the transistor, and a circuit that performs load modulation at an oscillation frequency of the ring oscillator is electrically connected;
An element substrate, wherein a surface of a region where the power supply circuit, the ring oscillator, and the transistor are provided is covered with an insulating film except for a region where the electrode pad is provided . A characteristic evaluation element having an antenna coil, a ring oscillator, a transistor, and an electrode pad for supplying a power supply voltage to the ring oscillator is provided.
The antenna coil includes the transistor, and a circuit that performs load modulation at an oscillation frequency of the ring oscillator is electrically connected;
An element substrate having flexibility. In any one of Claims 7 to 10,
The element substrate having a function of performing load modulation. Radiating electromagnetic waves to the element substrate according to any one of claims 1 to 6,
An inspection method characterized by evaluating characteristics of the semiconductor element by measuring electric power consumed by the element substrate. The element substrate according to any one of claims 1 to 6, using a measuring device capable to <br/> Rukoto radiate electromagnetic waves from the antenna, and radiate the electromagnetic wave,
An inspection method for evaluating characteristics of the semiconductor element by measuring a current or a voltage generated in the antenna. The element substrate according to any one of claims 1 to 6, an electromagnetic wave with a release morphism friendly <br/> ability measurement apparatus from the antenna, the steps of emitting an electromagnetic wave,
Measuring power absorbed by the element substrate by a magnetic field prober;
An inspection method characterized by evaluating the characteristics of the semiconductor element. An inspection method, wherein the static characteristics of a semiconductor element provided on the element substrate are evaluated in a non-contact manner using the inspection method according to claim 12. The element substrate according to any one of claims 7 to 9, an electromagnetic wave with a release morphism friendly <br/> ability measurement apparatus from the antenna, the steps of emitting an electromagnetic wave,
Measuring the current or voltage generated in the antenna;
An inspection method characterized by evaluating characteristics of the ring oscillator. The element substrate according to any one of claims 7 to 9, an electromagnetic wave with a release morphism friendly <br/> ability measurement apparatus from the antenna, the steps of emitting an electromagnetic wave,
Measuring power absorbed by the element substrate by a magnetic field prober;
An inspection method characterized by evaluating characteristics of the ring oscillator. The element substrate according to any one of claims 7 to 9, an electromagnetic wave with a release morphism friendly <br/> ability measurement apparatus from the antenna, the steps of emitting an electromagnetic wave,
Measuring a morphism electromagnetic wave release from the ring oscillator,
An inspection method for evaluating characteristics of the ring oscillator. 19. An inspection method using the inspection method according to claim 16, wherein the dynamic characteristics of the semiconductor element provided on the element substrate is evaluated in a non-contact manner. A method for manufacturing a semiconductor device, comprising: a method for inspecting the element substrate in a non-contact manner using the inspection method according to claim 12. Forming a characteristic evaluation element having a first semiconductor layer and a thin film transistor having a second semiconductor layer on a first substrate;
Perform contact inspection on the element for characteristic evaluation,
Peeling the element for characteristic evaluation and the thin film transistor from the first substrate;
Transferring the element for characteristic evaluation and the thin film transistor on a second substrate;
Evaluating the characteristics of the thin film transistor by performing a non-contact type inspection on the element for characteristic evaluation transferred on the second substrate;
A method for manufacturing a semiconductor device, comprising cutting the second substrate in which characteristics of the thin film transistor satisfy an allowable range. Forming a characteristic evaluation element having a first semiconductor layer and a thin film transistor having a second semiconductor layer on a first substrate;
Perform contact inspection on the element for characteristic evaluation,
Peeling the element for characteristic evaluation and the thin film transistor from the first substrate;
Transferring the element for characteristic evaluation and the thin film transistor on a second substrate;
Evaluating the characteristics of the thin film transistor by performing a non-contact type inspection on the element for characteristic evaluation transferred on the second substrate;
Cutting the second substrate in which the characteristics of the thin film transistor satisfy an allowable range;
A method for manufacturing a semiconductor device, comprising: inspecting a thin film transistor on the cut second substrate. Forming a characteristic evaluation element having a first semiconductor layer and a thin film transistor having a second semiconductor layer on a first substrate;
Perform contact inspection on the element for characteristic evaluation,
By the contact type inspection, the voltage-current characteristic of the element for characteristic evaluation is obtained,
Peeling the element for characteristic evaluation and the thin film transistor from the first substrate;
Transferring the element for characteristic evaluation and the thin film transistor on a second substrate;
Evaluating the characteristics of the thin film transistor by performing a non-contact type inspection on the element for characteristic evaluation transferred on the second substrate;
A method for manufacturing a semiconductor device, comprising: cutting the second substrate in which characteristics of the thin film transistor satisfy an allowable range of the voltage-current characteristics. Forming a characteristic evaluation element having a first semiconductor layer and a thin film transistor having a second semiconductor layer on a first substrate;
Perform contact inspection on the element for characteristic evaluation,
By the contact type inspection, the voltage-current characteristic of the element for characteristic evaluation is obtained,
Peeling the element for characteristic evaluation and the thin film transistor from the first substrate;
Transferring the element for characteristic evaluation and the thin film transistor on a second substrate;
Evaluating the characteristics of the thin film transistor by performing a non-contact type inspection on the element for characteristic evaluation transferred on the second substrate;
Cutting the second substrate where the characteristics of the thin film transistor satisfy the allowable range of the voltage-current characteristics;
A method for manufacturing a semiconductor device, comprising: inspecting a thin film transistor on the cut second substrate. In any one of Claims 21 to 24,
The method for manufacturing a semiconductor device, wherein the first semiconductor layer and the second semiconductor layer are formed over the first substrate in the same step. In any one of Claims 21 to 25,
The method for manufacturing a semiconductor device, wherein the second substrate has flexibility.

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