A method for measuring the energy and species of heavy ions

Abstract

The present invention relates to a method for measuring the energy and species of heavy ions. The method includes: selecting heavy ion beams with multiple different LET values, performing single event effect calibration on a three-dimensional stacked structure device to obtain the variation relationship of the single event effect cross section with LET; fitting the calibrated data with a Weibull function to obtain the curve of the single event effect cross section of the three-dimensional stacked structure device varying with LET; conducting single event effect tests on the three-dimensional stacked structure device with heavy ions to obtain the stratified single event effect cross sections; determining the LET values corresponding to the single event effect cross sections of each layer based on the calibrated curve, combining the depth of each layer to obtain the variation of the LET value with the incident depth, and determining the energy and species of the heavy ions by comparing the variation relationship of the LET value with the incident depth in the database. The present invention improves the accuracy of heavy ion energy measurement and the reliability of heavy ion species detection, and at the same time solves to a certain extent the problem of the degradation of the performance of heavy ion energy and species detectors over time.

Description

Technical Field

[0001] The present invention relates to the fields of integrated circuits, nuclear science, and space radiation measurement technologies, and particularly relates to a method for measuring the energy and species of heavy ions. Background Art

[0002] When heavy ions are incident on a semiconductor device, they deposit energy and generate a large number of electron-hole pairs. When these electron-hole pairs are collected by the sensitive region of the device, it may cause changes in the internal stored data or functions. Since a single particle can cause this, it is called the single-event effect. Usually, for a specific device in a specific environment, its sensitivity to the single-event effect is determined. The probability of causing a single-event effect inside the device only depends on the incident parameters of the heavy ions, such as energy, species, fluence, and angle, etc. Therefore, whether in the real space radiation environment or in the accelerator simulation test carried out on the ground, the detection of the energy and species of heavy ions is very important.

[0003] Compared with light particles, heavy ions have greater detection difficulty due to their complex reactions with the material medium. The general practice in nuclear physics experiments is to identify the energy of heavy ions by collecting and measuring the electron-hole pairs ionized by heavy ions incident on the detection material. Currently, the commonly used heavy-ion energy detectors are of two types: solid and gas detectors. Their principles are both based on the collection and measurement of ionized electrons in the detector medium, but it is more difficult to identify the species of incident heavy ions. The identification of incident heavy-ion species generally uses the time-of-flight method and the Wien filter method, and is identified by the charge-to-mass ratio.

[0004] Although both solid and gas detectors are based on the collection and measurement of ionized electrons, they have relatively high measurement requirements for collection efficiency and measurement accuracy, and there are also effects such as performance degradation, noise, false counting, and missed counting. Therefore, there are still some inevitable limitations and constraints in some actual application scenarios. And the methods of using the time-of-flight method and Wien filter to identify heavy-ion species also have relatively high requirements for equipment accuracy, and the equipment price is high and requires careful maintenance. Summary of the Invention

[0005] Aiming at the deficiencies of the above-mentioned prior art, the present invention aims to provide a new method for detecting the energy and species of heavy ions to achieve convenient, fast, and real-time identification of the energy and species of heavy ions.

[0006] The present invention provides a method for measuring the energy and species of heavy ions, and the method includes:

[0007] Select multiple heavy-ion beams with different LET values to perform single-event effect calibration on a three-dimensional stacked structure device, and obtain the variation relationship of the single-event effect cross-section with LET;

[0008] Perform Weibull function fitting on the calibrated data to obtain the curve of the single-event effect cross-section of the three-dimensional stacked structure device varying with LET.

[0009] Carry out single-event effect tests on the three-dimensional stacked structure device with heavy ions of the energy and type to be detected, and obtain the single-event effect cross-sections of the heavy ion beams of the energy and type to be detected in the layers of the three-dimensional stacked structure device.

[0010] Based on the curve obtained by the calibrated Weibull function fitting, determine the LET values corresponding to the single-event effect cross-sections of the heavy ions of the energy and type to be detected in each layer of the three-dimensional stacked structure device. Combine the depth of each layer to obtain the variation of the LET values of the heavy ions of the energy and type to be detected with the incident depth. By comparing the variation relationship of the LET values with the incident depth in the database, determine the energy and type of the heavy ions to be detected.

[0011] According to an embodiment of the present invention, the three-dimensional stacked structure device includes at least three layer structures with single-event effects.

[0012] According to an embodiment of the present invention, the three-dimensional stacked structure device is a three-dimensional stacked memory, a three-dimensional stacked digital-to-analog conversion device, or other three-dimensional stacked chips.

[0013] According to an embodiment of the present invention, a single-event effect test system is used to obtain the single-event effect cross-section values of the three-dimensional stacked structure device under different LET parameter conditions.

[0014] According to an embodiment of the present invention, the single-event effect test system is used to write, read, test, and compare the stored data inside the device in real time or offline.

[0015] According to an embodiment of the present invention, when performing the calibration, if the dies of each layer of the three-dimensional stacked structure device are the same, only the single-event effect sensitivity of the outermost die is calibrated.

[0016] According to an embodiment of the present invention, if the dies are different, the single-event effect sensitivities of different die layers are calibrated.

[0017] According to an embodiment of the present invention, when performing the calibration, at least obtain the single-event effect threshold, the cross-section data near the inflection point, and the saturation region of the three-dimensional stacked structure device.

[0018] According to an embodiment of the present invention, when using a three-dimensional stacked structure device, a device with a higher single-event sensitivity is used to detect the energy and type of heavy ions with a lower atomic number.

[0019] According to an embodiment of the present invention, when using a three-dimensional stacked structure device, a device with a lower single-event sensitivity is used for detecting the energy and type of heavy ions with a higher atomic number.

[0020] The present invention uses a three-dimensional stacked structure device to measure the energy and type of heavy ions. By comparing the single-event effect cross-section between different layers with the calibrated cross-section, the energy and type of the heavy ions incident on the device are finally obtained, improving the accuracy of heavy ion energy measurement and the reliability of heavy ion type detection. At the same time, to a certain extent, problems such as the degradation of the performance of heavy ion energy and type detectors over time are solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flowchart of a method for using a three-dimensional stacked structure device as a heavy ion energy and type detector according to an embodiment of the present invention;

[0022] Figure 2 It is a schematic diagram of the cross-section data and the corresponding LET value calibration of multiple types of heavy ions on one layer according to an embodiment of the present invention;

[0023] Figure 3 For Figure 2 A schematic diagram of the fitting curve of the data;

[0024] Figure 4 It is a schematic diagram of a three-dimensional stacked structure device used for heavy ions whose energy and type need to be detected according to an embodiment of the present invention;

[0025] Figure 5 It is a schematic diagram of the single-event effect cross-section of unknown heavy ions on each layer of the device when conducting a single-event effect test according to an embodiment of the present invention;

[0026] Figure 6 It is a schematic diagram of the LET value corresponding to the single-event effect cross-section of each layer of unknown heavy ions when conducting a single-event effect test according to an embodiment of the present invention;

[0027] Figure 7 It is a schematic diagram of the change of the LET value of heavy ions with the incident depth obtained from the depth of each die of unknown heavy ions when conducting a single-event effect test according to an embodiment of the present invention;

[0028] Figure 8 It is a schematic diagram of the change of the LET value of heavy ions with different types and different initial energies in the database with the incident depth according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The following will describe the preferred embodiments of the present invention in detail with reference to the accompanying drawings, so as to more clearly understand the purpose, features, and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not a limitation on the scope of the present invention, but only to illustrate the essential spirit of the technical solution of the present invention.

[0030] The present invention intends to use a three-dimensional stacked structure device to measure the energy and type of heavy ions, and adopt a technology of comparing the single-event effect cross-section between different layers with the calibrated cross-section to finally obtain the energy and type of the heavy ions incident on the device. The specific method is as follows: When heavy ions are incident on a three-dimensional stacked structure device such as a three-dimensional stacked memory device, they will deposit energy to ionize and generate a large number of electron-hole pairs. After these electron-hole pairs are collected by the device, they may cause changes in the stored data in the sensitive area of the device. For each determined device, under the same device operating parameter conditions and similar test environments, the single-event effect cross-section generated inside the planar two-dimensional device by heavy ions with the same LET (linear energy transfer) is the same, that is, each single-event effect cross-section obtained by testing with different heavy ion incidences corresponds to a LET value. For heavy ions incident on device materials such as semiconductors, their LET values change with the incident depth. Different energy and type heavy ions incident on different positions inside the device may have the same LET value, but the change curve of the LET value of the same type of heavy ion incident on the semiconductor device material with the incident depth is unique. Therefore, if the change curve of the LET of the heavy ions incident on the device with the incident depth can be obtained, the energy and type of the heavy ions can be discriminated. And the three-dimensional stacked structure device just has such an advantage. The die chips are stacked on top of each other layer by layer. Heavy ions with a certain initial energy are incident from the surface of the device, and after passing through multiple die chips, their final energy deposition is completed and they stop or penetrate the entire chip. The energy and LET of each layer of die chips are different, and the LET value when passing through a specific number of layers can be determined by the single-event effect cross-section value of that layer of die chips. In this way, it is very convenient to obtain the change relationship between the LET of the incident heavy ions and the incident depth. After having this change relationship, comparing it with the database can finally determine the energy and type of the incident heavy ions.

[0031] Among them, the three-dimensional stacked structure device is at least a device including three layers that can calibrate a complete single-event effect sensitivity Weibull curve, and generally can be a three-dimensional stacked memory with single-event effect, a three-dimensional stacked digital-to-analog conversion device, or other three-dimensional stacked chips, etc.

[0032] The technical solutions and effects of the present invention will be further described in detail below with reference to the accompanying drawings:

[0033] Refer to Figure 1 As shown in the flowchart of the method for using a three-dimensional stacked structure device as a heavy ion energy and type detector, the specific implementation steps of this method are as follows:

[0034] Step 1: Select a suitable three-dimensional stacked structure device and configure the relevant single-event effect test system.

[0035] A suitable three-dimensional stacked structure device refers to: the number of stacked layers of the device is sufficient (usually required to be ≥3), the single-particle effect sensitivity of the device is appropriate (devices with high single-particle sensitivity are suitable for the energy and species detection of heavy ions with lower atomic numbers, while devices with low sensitivity are suitable for the energy and species detection of heavy ions with higher atomic numbers), and appropriate means can be taken to obtain the single-particle sensitivity of each internal layer.

[0036] Appropriate means can be used to obtain the single-particle sensitivity of each internal layer. Generally, a device monitoring circuit can be designed, that is, a single-particle effect test system that matches the device. The single-particle effect test system can realize cyclic dynamic monitoring of the storage data or functions inside the device during heavy ion irradiation. If the storage data changes, it is considered that a single-particle flip effect has occurred, and the data is reset and monitoring continues. If the current doubles, it can be determined that a single-particle lock effect has occurred, and the device is restarted and monitored again.

[0037] The so-called supporting single-particle effect test system refers to the chip monitoring system that can write, read, test and compare the internal storage data of the device in real time or offline. Here, the relevant single-particle effect test system is used to operate the device, including internal data operation and power on and off.

[0038] Step 2: Select heavy ion beams with multiple different LET values to calibrate the single particle effect of the device and obtain the relationship between the single particle effect cross section and LET.

[0039] The so-called heavy ion beams with multiple different LET values mainly refer to heavy ions of the same type with different energies, heavy ions of different types with the same energy, or heavy ions of different types with different energies. Generally speaking, the single particle effect cross-section data under different LETs can meet the requirements of Weibull function fitting, mainly in the single particle effect threshold, near the inflection point and saturation region of the device.

[0040] Use the matching single-particle effect test system in step 1 to obtain the single-particle effect cross-section value of the three-dimensional stacked structure device under different LET parameter conditions. If the bare chips in each layer are the same, it is only necessary to calibrate the single-particle effect sensitivity of the topmost bare chip. If there are differences in the bare chips in each layer, it is necessary to calibrate the single-particle effect sensitivity of each layer.

[0041] For example, three different types of heavy ions with six different energies in Table 1 are used for calibration. Different energies have different LET values. Different LET values show different cross-sectional data on the device layer. The cross-sectional data on one layer and the corresponding LET value calibration are as follows: Figure 2 shown.

[0042] Table 1

[0043]

[0044] Step 3: Perform Weibull function fitting on the calibration data to obtain a complete curve of the single-event effect cross-section of the device varying with LET.

[0045] Using the partial single-event effect experimental data obtained in Step 2, perform data fitting using the Weibull function. The achieved effect is that each single-event effect cross-section value of each die layer can correspond to an LET value.

[0046]

[0047] Equation <1> is the Weibull function for fitting single-event effect cross-section data, where A is the saturation value of the single-event effect cross-section of the device, L is the LET value, L0 is the threshold LET that causes the single-event effect of the device, and W and S are the Weibull fitting parameters.

[0048] For Figure 2 the fitting curve of the data is as shown in Figure 3 Figure.

[0049] Step 4: Refer to Figure 4 , Figure 5 , and use heavy ions with the required detection energy and type to conduct single-event effect tests on the three-dimensional stacked structure device to obtain the single-event effect cross-sections of the layers of the three-dimensional stacked structure device under the conditions of unknown energy and type of heavy ion beam.

[0050] Step 5: Refer to Figure 6 , and based on the calibrated Weibull function fitting curve, determine the LET value corresponding to the single-event effect cross-section of each layer of the three-dimensional stacked structure device. Then, combine the depth of each die layer to obtain the variation of the LET value of the heavy ion with unknown energy and type with the incident depth, as shown in Figure 7 Figure. Finally, by comparing with the database curve as shown in Figure 8 Figure, see which section of the curve in Figure 7 fits the curve in Figure 8 . Different curves represent different types, and the variation trends of different LET values on the same curve represent different energy changes. Since there is a peak in this curve, it is possible that the same LET corresponds to two energy values. Therefore, it is necessary to use the three-dimensional stacked structure device to obtain the variation trend of the curve to determine the final energy value. In this way, the energy and type of the heavy ion can be determined, achieving the detection effect of the heavy ion energy and type.

[0051] The above steps are not all necessary settings and can be determined according to specific circumstances.

[0052] The present invention adopts the technology of measuring the single-event effect cross-section of test devices, and finally can realize the detection functions of heavy-ion energy and species.

[0053] The present invention adopts a three-dimensional stacked structure device, which improves the accuracy of heavy-ion energy measurement and the reliability of heavy-ion species detection. At the same time, to a certain extent, it solves the problem that the performance of heavy-ion energy and species detectors degrades over time.

[0054] The method of the present invention can not only realize the detection of heavy-ion energy and species, but also give the range of heavy ions (when the heavy-ion range is less than the longitudinal depth of the three-dimensional stacked structure device) and the area of the heavy-ion beam (when the incident heavy-ion beam area is less than the lateral area of the three-dimensional stacked structure device) under appropriate conditions.

[0055] In short, the present invention provides a brand-new detection technology and method for heavy-ion energy and species detection, which can solve some deficiencies existing in current heavy-ion energy and species detectors (such as high requirements for detector collection efficiency and measurement accuracy, performance degradation over time, noise, false counting, and missed counting, etc.) to a certain extent, and improve the accuracy and reliability of heavy-ion energy and species detection.

[0056] It should be noted that in this article, terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the system or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present invention; relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including an..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0057] In addition, in the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] The above embodiments are only used to illustrate the present invention. Among them, the components and devices of the embodiments can all be changed, and each embodiment can be combined or deleted as needed. Not all components in the drawings are necessary to be provided. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments described herein. Any equivalent transformation and improvement made on the basis of the technical solution of the present invention should not be excluded from the protection scope of the present invention.

Claims

1. A method for measuring the energy and species of heavy ions, characterized in that, The method includes: Selecting multiple heavy ion beams with different LET values to perform single event effect calibration on a three-dimensional stacked structure device, and obtaining the variation relationship of the single event effect cross-section with LET; Performing Weibull function fitting on the calibrated data to obtain the curve of the single event effect cross-section of the three-dimensional stacked structure device varying with LET. The fitting formula is: Formula <1> is the Weibull function for fitting the single event effect cross-section data, where A is the saturation value of the single event effect cross-section of the device, L is the LET value, L0 is the threshold LET causing the single event effect of the device, and W and S are the Weibull fitting parameters; Performing single event effect tests on the three-dimensional stacked structure device with heavy ions of the energy and type to be detected, and obtaining the single event effect cross-sections of the heavy ion beams of the energy and type to be detected in the layers of the three-dimensional stacked structure device; Based on the curve fitted by the calibrated Weibull function, determining the LET value corresponding to the single event effect cross-section of the heavy ions of the energy and type to be detected in each layer of the three-dimensional stacked structure device, combining the depth of each layer to obtain the variation of the LET value of the heavy ions of the energy and type to be detected with the incident depth, and determining the energy and type of the heavy ions to be detected by comparing the variation relationship of the LET value with the incident depth in the database; The three-dimensional stacked structure device includes at least three layer structures with single event effects; The three-dimensional stacked structure device is a three-dimensional stacked memory, a three-dimensional stacked digital-to-analog conversion device, or a three-dimensional stacked chip; When performing the calibration, if the dies of each layer of the three-dimensional stacked structure device are the same, only the single event effect sensitivity calibration is performed on the outermost die; If the dies are different, the single event effect sensitivities of different die layers are calibrated.

2. The method for measuring the energy and type of heavy ions according to claim 1, characterized in that, Using a single event effect test system to obtain the single event effect cross-section values of the three-dimensional stacked structure device under different LET parameter conditions.

3. The method for measuring the energy and type of heavy ions according to claim 2, characterized in that, Using the single event effect test system to write, read, test, and compare the stored data inside the device in real time or offline.

4. The method for measuring the energy and type of heavy ions according to claim 1, characterized in that, When performing the calibration, at least obtaining the single event effect threshold, the cross-section data near the inflection point, and the saturation region of the three-dimensional stacked structure device.

5. The method for measuring the energy and species of heavy ions according to claim 1, wherein, When using a three-dimensional stacked structure device, a device with a higher single event sensitivity is used to detect the energy and type of heavy ions with a lower atomic number.

6. The method for measuring the energy and type of heavy ions according to claim 1, characterized in that, When using a three-dimensional stacked structure device, a device with a lower single event sensitivity is used to detect the energy and type of heavy ions with a higher atomic number.

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