A test method for neutron radiation and time-dependent breakdown of a nanometer finfet device in air

Abstract

The application discloses a kind of test methods of nanometer FinFET device atmospheric neutron radiation and time breakdown, including comprehensive effect test device, sample is placed into comprehensive effect test device, atmospheric neutron radiation beam line is applied to sample, voltage and temperature are applied to sample by the comprehensive effect test device;The life time of sample is calculated by experiment, the nanometer FinFET device is tested by time breakdown test in atmospheric neutron radiation environment, to evaluate the comprehensive stress influence of nanometer FinFET device on ground and flight altitude, without separately carrying out two tests to evaluate, more convenient, fast.

Description

Technical Field

[0001] This disclosure relates to the field of breakdown testing technology for nano-FinFET devices, and in particular to a test method for atmospheric neutron radiation and time-dependent breakdown of nano-FinFET devices. Background Technology

[0002] High-energy cosmic rays interact with nitrogen (N) and oxygen (O) in the Earth's atmosphere, producing secondary radiation such as neutrons, protons, electrons, gamma rays, π mesons, and muons. The atmospheric neutron energy spectrum covers the range from eV to GeV. Calculations show that the neutron flux greater than 10 MeV at sea level is approximately 4 × 10⁻³ neutrons / cm² / s, equivalent to one neutron per second on an open human hand. Neutrons, being uncharged, possess extremely strong penetrating power and are widely distributed across the Earth's surface and throughout the atmosphere. However, their flux and energy spectrum are affected by factors such as altitude, solar activity, and latitude / longitude. Atmospheric neutrons bombarding semiconductor devices and integrated circuits trigger single-event effects, which are the most common cause of integrated circuit malfunctions and failures, including memory cell flipping, logic function interruption, latch-up, gate breakdown, and burn-out.

[0003] While the flux of high-energy atmospheric neutron radiation at ground level is relatively low, advanced electronic systems used in ground applications, such as nanoscale integrated circuit chips and high-capacity memory chips, employ the most advanced semiconductor processing technology, such as the three-dimensional FinFET structure technology with feature sizes below 14nm. This technology uses a three-dimensional gate structure with a thin gate oxide layer and a larger channel current, making it more susceptible to the effects of atmospheric neutron single-event radiation. At the same time, it is also more prone to degradation during time breakdown time (TDDB), and the two may have a superimposed effect.

[0004] Existing technologies mainly focus on testing the individual effects of atmospheric neutron single-event effects or TDDB effects on nano-FinFET devices, but there is no method for testing comprehensive effects. Summary of the Invention

[0005] This disclosure provides a test method for atmospheric neutron radiation and time-dependent breakdown of nano-FinFET devices to solve the technical problems recognized by the inventors.

[0006] This disclosure provides a test method for atmospheric neutron radiation and time-dependent breakdown of nano-FinFET devices, including a comprehensive effect test apparatus. The method includes the following steps.

[0007] S1. Place the sample inside the comprehensive effect testing device;

[0008] S2. Apply atmospheric neutron radiation beams to the sample, and apply voltage and temperature to the sample through the comprehensive effect test device;

[0009] S3, judging whether the sample is broken down or not;

[0010] S4, if the sample is broken down, judging whether the total dose of atmospheric neutron irradiation reaches the rated total dose or not, if the total dose of atmospheric neutron irradiation has reached the rated total dose, recording the lifetime; if the total dose of atmospheric neutron irradiation has not reached the rated total dose, calculating the lifetime τ;

[0011] S5, if the sample is not broken down, judging whether the total dose of atmospheric neutron irradiation reaches the rated total dose or not;

[0012] S6, if the total dose of atmospheric neutron irradiation has not reached the rated total dose, returning to step S3;

[0013] S7, if the total dose of atmospheric neutron irradiation has reached the rated total dose, stopping the application of the atmospheric neutron irradiation beam, continuing to maintain the applied voltage and temperature; returning to step S3.

[0014] Preferably, the formula for calculating the lifetime τ in step S4 is: τ=C*Vg n *exp(Ea / kT), wherein τ is the lifetime of TDDB effect (s), C is a proportional constant, Vg is the gate voltage (V), n is the electric field acceleration factor, Ea is the activation energy (eV), k is the Boltzmann constant (8.6174E-5 eV / K), and T is the absolute temperature (K).

[0015] Preferably, the voltage in step S2 is set between the working voltage of the sample and 90% of the breakdown voltage, and the temperature is set between 100°C and 200°C.

[0016] Preferably, the irradiation time of the atmospheric neutron irradiation beam in step S2 comprises the following steps,

[0017] S201, when the temperature is unchanged and the voltage is changed, the ratio of the voltage to the lifetime is: wherein t2 and t1 are the lifetimes under the voltage stresses of Vg2 and Vg1 respectively, and n is the voltage acceleration factor;

[0018] S202, taking the lifetime of the sample under the voltage Vg1 as the reference, the atmospheric neutron irradiation dose rate is calculated, and the formula is: wherein and are the atmospheric neutron irradiation dose rates under the voltage stresses of Vg2 and Vg1 respectively, and D is the rated total dose of atmospheric neutron;

[0019] S203, the irradiation time is calculated according to the atmospheric neutron irradiation dose rate and the rated total dose.

[0020] Preferably, the irradiation time calculation of the atmospheric neutron radiation beam in the step S2 comprises the following steps,

[0021] S211, when the voltage is unchanged and the temperature is changed, the ratio of the temperature and the lifetime of the sample is: In the formula, t2, t1 are the lifetime at T2, T1 temperature respectively, and Ea is the temperature activation energy;

[0022] S212, taking the lifetime of the sample at the temperature T1 as the reference, the atmospheric neutron irradiation fluence rate is calculated, and the formula is: In the formula, And T2, T1 temperature atmospheric neutron radiation fluence rate respectively;

[0023] S213, according to the atmospheric neutron irradiation fluence rate and the rated total fluence, the irradiation time is calculated.

[0024] Preferably, the comprehensive effect test device comprises a movable base, a temperature box, a thermostat, an interface panel, a control assembly, a power supply and test equipment and a computer, the surface of the movable base is fixedly connected with a sample placing table, the surface of the sample placing table is placed with a sample, the temperature box is arranged outside the sample placing table, the interface panel is fixedly connected to the side of the temperature box, the interface panel is connected with the control assembly and the power supply and test equipment through wires respectively, the control assembly, the power supply and test equipment are connected with the computer through wires, and the thermostat is arranged on the side of the temperature box.

[0025] Preferably, the control assembly comprises a temperature controller and a display screen, the temperature controller is used to control the temperature of the thermostat, and the display screen is used to display parameters.

[0026] Preferably, the power supply and test equipment comprises a power supply and a high-precision ammeter, the power supply is used to apply voltage to the sample, and the high-precision ammeter is used to test the output current of the sample.

[0027] The beneficial effects of the present disclosure mainly lie in that the present application carries out time-dependent breakdown test on the nano FinFET device in the atmospheric neutron radiation environment, so as to evaluate the comprehensive stress influence of the nano FinFET device on the ground and at the flight height, without the need of separately carrying out two tests for evaluation, which is more convenient and fast.

[0028] It should be understood that both the foregoing general description and the following detailed description are intended for purposes of illustration and description, and are not necessarily limiting of the present disclosure. The accompanying drawings are incorporated in and constitute a part of the specification. Furthermore, the description and drawings are to be construed together with the claims to explain the principles of the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the specific embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings described below are only some embodiments of the present disclosure, and other drawings can also be obtained by those skilled in the art without creative effort based on these drawings.

[0030] Fig. 1 The step block diagram of the comprehensive effect test method of the embodiment of the present disclosure;

[0031] Fig. 2 The structure schematic diagram of the comprehensive effect test device of the embodiment of the present disclosure;

[0032] Figure: 101 - movable base; 1011 - sample placement table; 102 - temperature box; 103 - interface panel; 104 - thermostat; 105 - power supply and test equipment; 106 - control assembly; 107 - computer; 200 - sample. DETAILED DESCRIPTION

[0033] The technical solutions of the present disclosure will be described in detail below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present disclosure, not all the embodiments.

[0034] Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present disclosure.

[0035] In the description of the present disclosure, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present disclosure. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0036] In the description of the present disclosure, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present disclosure can be understood according to the specific circumstances.

[0037] Embodiment

[0038] As Figs. 1-2 shown, the embodiment provides a test method for atmospheric neutron radiation and time-dependent breakdown of a nano FinFET device, comprising a comprehensive effect test device, the method comprising the steps of,

[0039] S1, placing a sample 200 in the comprehensive effect test device;

[0040] In this embodiment, the sample 200 is a nano FinFET device, and the sample 200 is placed in the comprehensive effect test device for testing.

[0041] S2, applying an atmospheric neutron radiation beam line to the sample 200, and applying a voltage and a temperature to the sample 200 through the comprehensive effect test device;

[0042] In this embodiment, an atmospheric neutron radiation beam line is applied externally, and a voltage and a temperature are applied to the sample 200 through the comprehensive effect test device; the test parameters can be changed by inputting the voltage and temperature, so that tests under different parameter conditions can be performed.

[0043] S3, determining whether the sample 200 is broken down;

[0044] In this embodiment, whether the sample 200 is broken down is determined by detecting the change in current output by the sample 200.

[0045] S4, if the sample 200 is broken down, determining whether the total neutron irradiation dose reaches the rated total dose, if the total neutron irradiation dose has reached the rated total dose, recording the lifetime time; if the total neutron irradiation dose has not reached the rated total dose, calculating the lifetime time τ;

[0046] In this embodiment, if the sample 200 is broken down, it is necessary to determine whether the total atmospheric neutron irradiation dose reaches the rated total dose, the rated total dose can be calculated according to the irradiation time and the atmospheric neutron irradiation dose rate, the rated total dose is pre-set, and the atmospheric neutron irradiation dose rate will vary due to changes in voltage and temperature. Therefore, by calculating the atmospheric neutron irradiation dose rate, it can be deduced how long the irradiation time can reach the rated total dose, and according to the irradiation time, it can be determined whether the rated total dose is reached. If the rated total dose is reached, the lifetime time τ is recorded, and the conclusion is drawn; if the rated total dose is not reached, the lifetime time τ needs to be calculated.

[0047] S5, if the sample 200 is not broken down, calculating whether the total neutron irradiation dose reaches the rated total dose;

[0048] S6, if the total neutron irradiation dose has not reached the rated total dose, return to step S2;

[0049] In this embodiment, if the sample 200 is not broken down and the total neutron irradiation dose has not reached the rated total dose, continue to apply the atmospheric neutron radiation beam line and voltage and temperature to the sample 200 until the sample 200 is broken down or the total neutron irradiation dose reaches the rated total dose. If the total neutron irradiation dose reaches the rated total dose before the sample 200 is broken down, go to step S7. If the sample 200 is broken down before the total neutron irradiation dose reaches the rated total dose, calculate the lifetime τ, which is consistent with steps S2-S4.

[0050] S7, if the total neutron irradiation dose reaches the rated total dose, stop applying the atmospheric neutron radiation beam line and continue to apply the voltage and temperature; return to step S3.

[0051] In this embodiment, if the total neutron irradiation dose reaches the rated total dose before the sample 200 is broken down, the atmospheric neutron radiation beam line is no longer applied, but the voltage and temperature are still applied. After the sample 200 is broken down, the lifetime τ is recorded.

[0052] Further, the calculation formula of the lifetime τ in step S4 is: τ = C * Vg n *exp(Ea / kT), where τ is the lifetime of the TDDB effect (s), C is the proportionality constant, Vg is the gate voltage (V), n is the electric field acceleration coefficient, Ea is the activation energy (eV), k is the Boltzmann constant (8.6174E-5 eV / K), and T is the absolute temperature (K).

[0053] Regarding the setting of voltage and temperature in the test, the voltage in step S2 is set between the working voltage of the sample 200 and 90% of the breakdown voltage, and the temperature is set between 100°C and 200°C. In this embodiment, the voltage setting of the breakdown test cannot be lower than the working voltage, otherwise the acceleration effect cannot be achieved and the test time is too long. The voltage setting of the breakdown test cannot be higher than 90% of the breakdown voltage, otherwise the sample 200 is easily broken down and the breakdown is caused by over-stress breakdown due to high voltage, rather than time-dependent breakdown. The temperature setting of the breakdown test is between 100°C and 200°C. If the temperature is too low, the temperature acceleration coefficient is too low and the test time is too long. If the temperature is too high, thermal failure is easily caused rather than time-dependent breakdown failure. The time-dependent breakdown test needs to be tested under 3 temperature conditions and 3 voltage conditions. The temperature and voltage stress should be in an arithmetic progression relationship. For example, the temperature can be selected as 100°C, 125°C and 150°C, and the voltage stress can be selected as 2V, 2.5V and 3V, etc.

[0054] Regarding the setting of the atmospheric neutron irradiation conditions in the experiment, because the time of each time-dependent breakdown test is inconsistent, the total fluence of the atmospheric neutron radiation to which the sample 200 is subjected in the atmospheric neutron radiation and time-dependent breakdown combined stress test differs, and normalization processing of the fluence rate of the atmospheric neutron radiation test is required to make the total fluence of the atmospheric neutron radiation to which each chip is subjected the same.

[0055] Specifically, the irradiation time calculation of the atmospheric neutron radiation beamline in the step S2 includes the following steps,

[0056] S201, when the temperature is unchanged and the voltage changes, the ratio of the voltage to the lifetime time is: In the formula, t2 and t1 are the lifetime times under the voltage stress of Vg2 and Vg1 respectively, and n is the voltage acceleration factor; the voltage acceleration factor n can be obtained by performing a time-dependent breakdown test on the sample 200 that has not been irradiated; a separate time-dependent breakdown test belongs to the prior art, and the specific steps and principles thereof will not be described in detail here, and the calculation formula can refer to the calculation formula of the lifetime time τ.

[0057] S202, taking the lifetime time of the sample 200 under the voltage Vg1 as the reference, the atmospheric neutron irradiation fluence rate is calculated, and the formula is: In the formula, and are the atmospheric neutron radiation fluence rates under the voltage stress of Vg2 and Vg1 respectively, and D is the atmospheric neutron rated total fluence; in the case where the voltage is set to Vg1, the atmospheric neutron rated total fluence D is calculated according to the time at which the sample 200 is broken down, and then the atmospheric neutron radiation fluence rate under the voltage stress of Vg2 is calculated according to the mutual relationship

[0058] S203, the irradiation time is calculated according to the atmospheric neutron irradiation fluence rate and the rated total fluence. Finally, the time required for irradiation is calculated by dividing the rated total fluence by the atmospheric neutron irradiation fluence rate.

[0059] Similarly, the irradiation time calculation of the atmospheric neutron radiation beamline in the step S2 includes the following steps,

[0060] S211, when the voltage is unchanged and the temperature changes, the ratio of the temperature to the lifetime time of the sample 200 is: In the formula, t2 and t1 are the lifetime times under the temperature of T2 and T1 respectively, and Ea is the temperature activation energy; Ea can be obtained by performing a time-dependent breakdown test on the sample 200 that has not been irradiated.

[0061] S212, taking the lifetime time of the sample 200 under the temperature T1 as the reference, the atmospheric neutron irradiation fluence rate is calculated, and the formula is: In the formula, and T2, T1 temperature atmospheric neutron radiation fluence rate; atmospheric neutron rated total fluence D is calculated according to the time when the sample 200 is broken down under the condition that the temperature is set to T1, and then the atmospheric neutron radiation fluence rate under the T2 voltage stress is calculated according to the correlation

[0062] S213, the irradiation time is calculated according to the atmospheric neutron irradiation fluence rate and the rated total fluence. Finally, the time required for irradiation is calculated by dividing the rated total fluence by the atmospheric neutron irradiation fluence rate.

[0063] The comprehensive effect test device includes a movable base 101, a temperature box 102, a thermostat 104, an interface panel 103, a control assembly 106, a power supply and test equipment 105, and a computer 107. The surface of the movable base 101 is fixedly connected with a sample placement table 1011. The surface of the sample placement table 1011 is placed with a sample 200. The temperature box 102 is covered outside the sample placement table 1011. The interface panel 103 is fixedly connected to the side of the temperature box 102. The interface panel 103 is connected with the control assembly 106 and the power supply and test equipment 105 through wires, respectively. The control assembly 106, the power supply and test equipment 105, and the computer 107 are connected through wires. The thermostat 104 is arranged on the side of the temperature box 102. The thermostat 104 is electrically connected with the interface panel 103.

[0064] The test device is moved by the movable base 101. When the atmospheric neutron is radiated, the radiation fluence rate is inconsistent according to the type of device and application requirements. The distance between the radiation test source and the radiated sample 200 can be adjusted. Therefore, the existence of the movable base 101 can move the test device to the position required by the radiation field, so as to ensure that the radiation dose rate on the radiated sample 200 meets the requirements. The temperature box 102 is used to apply temperature stress to the radiated and time-broken test sample 200. The temperature box 102 contains a sample placement table 1011 inside, which is used to place the radiated device. The device can also be vertically placed on the sample 200 table, so that the device is perpendicular to the atmospheric neutron radiation beam line. The side of the temperature box 102 is the interface panel 103, which can be connected with the external control assembly 106, the power supply and test equipment 105, and the thermostat 104. The thermostat 104 is used to apply temperature to the temperature box 102, so as to increase the temperature in the temperature box 102 to 200℃ and keep it stable.

[0065] The control assembly 106 comprises a temperature controller and a display screen, wherein the temperature controller is used for controlling the temperature of the thermostat 104, and the display screen is used for displaying parameters.

[0066] The power supply and test equipment 105 comprises a power supply and a high-precision ammeter, wherein the power supply is used for applying voltage to the sample 200, and the high-precision ammeter is used for testing the output current of the sample 200.

[0067] The test data are recorded and analyzed by the computer 107.

[0068] The working principle of the present application is as follows: the sample 200 is placed on the comprehensive test device, the comprehensive test device is placed in the irradiation test room, and the atmospheric neutron radiation beam line is emitted by the irradiation source arranged in the irradiation test room.

[0069] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A test method for atmospheric neutron radiation and time-dependent breakdown of a nano-FinFET device, characterized in that, The method comprises the following steps of: S1, placing a sample in the comprehensive effect test device; S2, applying an atmospheric neutron radiation beam to the sample, and applying voltage and temperature to the sample through the comprehensive effect test device; S3, determining whether the sample is broken down; S4, if the sample is broken down, determining whether the total neutron irradiation dose reaches the rated total dose, and recording the lifetime if the total neutron irradiation dose reaches the rated total dose; If the total neutron irradiation dose does not reach the rated total dose, the lifetime τ is calculated; S5, if the sample is not broken down, determining whether the total neutron irradiation dose reaches the rated total dose; S6, if the total neutron irradiation dose does not reach the rated total dose, returning to step S3; S7, if the total neutron irradiation dose reaches the rated total dose, stopping applying the atmospheric neutron radiation beam and continuing to apply voltage and temperature; returning to step S3.

2. The method of claim 1, wherein the nanometer FinFET device is exposed to neutron radiation in the atmosphere. The formula for calculating the lifetime time τ in the step S4 is: In the formula, τ is the lifetime time of the TDDB effect, C is a proportional constant, Vg is the gate voltage, n is an electric field acceleration coefficient, Ea is an activation energy, k is the Boltzmann constant, and T is the absolute temperature.

3. The method of claim 2, wherein the nanometer FinFET device is exposed to neutron radiation in the atmosphere. The voltage in step S2 is set between 90% of the working voltage of the sample and the breakdown voltage, and the temperature is set between 100℃ and 200℃.

4. The method of claim 3, wherein the nanometer FinFET device is exposed to neutron radiation in the atmosphere. The irradiation time calculation of the atmospheric neutron radiation beam in step S2 comprises the following steps of: S201、When the temperature is unchanged, and the voltage is changed, the ratio of the voltage and the lifetime is: , wherein t2 and t1 are the lifetime under the voltage stress of Vg2 and Vg1 respectively, and n is the voltage acceleration factor. S202. Using the sample lifetime at voltage Vg1 as a benchmark, the atmospheric neutron irradiation flux rate is calculated using the following formula: In the formula and , Vg2 and Vg1 are the atmospheric neutron radiative fluence rates under voltage stress, respectively, and D is the rated total atmospheric neutron fluence; S203, calculating the irradiation time according to the atmospheric neutron irradiation dose rate and the rated total dose.

5. The method of claim 4, wherein the nanometer FinFET device is exposed to neutron radiation in the atmosphere. The irradiation time calculation of the atmospheric neutron radiation beam in step S2 comprises the following steps of: S211、When the voltage is constant, the ratio of temperature and sample lifetime time is: , wherein t2 and t1 are the lifetime times at T2 and T1, respectively, and Ea is the temperature activation energy. S212, based on the lifetime of the sample at temperature T1, the neutron irradiation fluence rate in the atmosphere is calculated, the formula is: , wherein and are the neutron irradiation fluence rates at T2 and T1, respectively. S213, calculating the irradiation time according to the atmospheric neutron irradiation dose rate and the rated total dose.

6. A test method for atmospheric neutron radiation and time-dependent breakdown of a nano-FinFET device according to any one of claims 1-5, characterized in that, The comprehensive effect test device comprises a movable base, a temperature box, a thermostat, an interface panel, a control assembly, a power supply and test equipment, and a computer, a sample placement table is fixedly connected to the surface of the movable base, a sample is placed on the surface of the sample placement table, the temperature box is arranged outside the sample placement table, the interface panel is fixedly connected to the side surface of the temperature box, the interface panel is connected with the control assembly and the power supply and test equipment through wires, the control assembly, the power supply and test equipment are connected with the computer through wires, the thermostat is arranged on the side surface of the temperature box, and the thermostat is electrically connected with the interface panel.

7. The method of claim 6, wherein the nanometer FinFET device is exposed to neutron radiation in the atmosphere. The control assembly comprises a temperature controller and a display screen, the temperature controller is used to control the temperature of the thermostat, and the display screen is used to display parameters.

8. The method of claim 6, wherein the nanometer FinFET device is exposed to neutron radiation in the atmosphere. The power supply and test equipment comprises a power supply and a high-precision ammeter, the power supply is used to apply voltage to the sample, and the high-precision ammeter is used to test the output current of the sample.

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