CN112649715B - Laser single event effect test method of 3D (three-dimensional) stacked memory - Google Patents
Laser single event effect test method of 3D (three-dimensional) stacked memory Download PDFInfo
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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Abstract
The application discloses a laser single event effect test method of a 3D (three-dimensional) stacked memory. The method aims at a special multilayer structure of the stacked memory, and a corresponding laser single particle damage analysis method is formulated. The method utilizes the sensitive depth of pulse laser incidence penetrating the measured memory and the pulse laser spot diameter of different energy to determine the induced charge quantity, can realize quantitative and positioning irradiation of the internal structure of the measured memory, and can not only obtain the position of an error unit, but also obtain the error type of the error unit; meanwhile, the layer-by-layer calibration test of the single-particle damage effect of the stacked memory can be realized, and reliable data support is provided for radiation damage resistance analysis and reinforcement design of stacked devices.
Description
Technical Field
The application relates to the technical field of space radiation effect testing, in particular to a laser single event effect testing method of a 3D three-dimensional stacked memory.
Background
With the development of microelectronic technology, the feature size of memory integrated circuits is gradually reduced. In advanced integrated circuits, ever decreasing supply voltages, higher and higher operating frequencies, ever decreasing node capacitance, and high-speed increasing chip complexity make the circuit more and more sensitive to environmental impact. When the integrated circuit is impacted by the space high-energy particles, the circuit nodes can be charged and discharged instantaneously, and the internal state of the chip can be destroyed, so that the integrated circuit can be in transient fault, and execution errors or data errors can be caused.
With the continuous shrinking of the nanometer level of the transistor, the integration level inside the chip is higher and the geometric size of the device is smaller. It is becoming more and more difficult to reduce the transistor process size and the length of the chip interconnect lines. In order to further improve the integration level of the device, a three-dimensional stacking packaging mode which is developed from two dimensions to three dimensions becomes an inevitable direction of development. The three-dimensional stacked integrated circuit has the advantages of shorter interconnection line length between chips, smaller outline feature size of the chips, higher packaging density, higher bandwidth, lower power consumption, stronger performance and the like. However, the manner of generating the laser single event effect when the three-dimensional stacked packaged memory device encounters high-energy particle impact is different from that of the traditional two-dimensional packaged memory device, the laser single event effect is possibly generated in each layer, and no specific test method is available for single event failure characterization and failure logic address positioning of the 3D three-dimensional stacked packaged memory device.
Disclosure of Invention
The main purpose of the application is to provide a laser single event effect testing method of a 3D three-dimensional stacked memory, which utilizes the focusing characteristic of a laser to realize single event irradiation testing of the internal structure of a stacked sensor.
In order to achieve the above purpose, the embodiment of the application provides a laser single event effect test method of a 3D stacked memory.
The laser single event effect test method of the 3D stereo stack memory comprises the following steps: placing the memory to be tested, into which data are written, under the irradiation condition of a laboratory simulation source, and performing a single particle irradiation test;
the sensitive depth of the pulse laser incidence penetrating the measured memory and the pulse laser spot diameter are utilized to determine the induced charge quantity, and the charge quantity is compared with the initial data to judge whether the error unit position and the error type single particle are overturned or not and the overturned position.
Optionally, the test method includes a static mode and a dynamic read mode.
Optionally, the testing method in the static mode is as follows:
(1) The system is powered on, and initial data is written into a memory;
(2) Powering up a test system, and preparing for irradiation;
(3) Determining the sensitive position of the storage unit array by using pulse laser before irradiation, and positioning the sensitive position on the surface of the storage unit array for the first time;
(4) Comparing the data after the irradiation is finished, and recording the error positions and the number; if the error number is zero, performing longitudinal positioning of the sensitive position by utilizing Z scanning of the pulse laser, and continuing the next irradiation test; and if the error number is not zero, rewriting the data of the memory cell, and then carrying out the next irradiation test.
Optionally, the test method in the dynamic read mode is as follows:
(1) Writing the initial data into a memory before irradiation;
(2) Determining the sensitive position of the storage unit array by using pulse laser before irradiation, and positioning the sensitive position on the surface of the storage unit array for the first time;
(3) Data comparison is carried out in the irradiation process, and whether the data of the irradiation process is changed relative to initial data is monitored; if the data change and the error number is smaller than a certain determined value N, determining that the data unit is overturned, recording the overturned information, and utilizing the Z scanning of the pulse laser to longitudinally position the sensitive position, and continuing the irradiation test next time.
Optionally, the laser adjustment mode is:
(1) Focusing a measured memory, ensuring that the measured memory is in the field of view of the pulse laser, and determining the pulse width f and the spot diameter d of the pulse laser;
(2) Selecting proper pulse laser initial energy, setting the moving step length of the pulse laser, and performing coarse scanning on a single event effect sensitive area of the whole measured memory to determine a single event effect sensitive area Q;
(3) After the sensitive area Q is determined, the incidence position of the pulse laser is positioned in the area, the incidence energy of the pulse laser is set, the laser is incident to the measured memory, the propagation distance of the laser in the memory is called as the sensitive depth Z, and the relation between the collected charge in the measured memory and the sensitive depth can be obtained.
Optionally, increasing the incident energy of the pulse laser with 0.1nJ step length in sequence to obtain the curve relationship between the collected charge and the sensitive depth of the measured memory under different energies respectively.
Optionally, according to the curve relation between the collected charges and the sensitive depths of the measured memories under different energies, obtaining the sensitive depth Z corresponding to the peak value of the collected charges under different energies of the pulse laser RPP The sensitive volume length of the measured memory is the sensitive volume length of the measured memory; obtaining the sensitive volume V=d of the measured memory according to the RPP model of the single event effect analysis 2 ·Z RPP 。
In the laser single event effect test method of the 3D stereo stack memory provided by the embodiment of the application, the sensitive depth of the pulse laser incidence penetrating through the tested memory and the pulse laser spot diameter with different energy are utilized to determine the induced charge quantity, so that quantitative and positioning irradiation on the internal structure of the tested memory can be realized, the position of an error unit can be obtained, and the error type of the error unit can be obtained; meanwhile, the layer-by-layer calibration test of the single-particle damage effect of the stacked memory can be realized, and reliable data support is provided for radiation damage resistance analysis and reinforcement design of stacked devices.
Detailed Description
In order that those skilled in the art will better understand the present application, a detailed description of the present application will be provided below, with reference to specific embodiments thereof, wherein it is apparent that the described embodiments are merely some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, shall fall within the scope of the present application.
The application provides a laser single event effect test method of a 3D stereo stack memory, which comprises the following steps: placing the memory to be tested, into which data are written, under the irradiation condition of a laboratory simulation source, and performing a single particle irradiation test; the sensitive depth of the pulse laser incidence penetrating the measured memory and the pulse laser spot diameter are utilized to determine the induced charge quantity, and the charge quantity is compared with the initial data to judge whether the error unit position and the error type single particle are overturned or not and the overturned position.
The method and the device realize single particle irradiation test of the internal structure of the stacked sensor by utilizing the focusing characteristic of the laser. By adopting a method of combining the sensitivity depth of pulse laser incidence penetrating the semiconductor device and the pulse laser spot diameter with different energies, the single event effect sensitivity volume of the semiconductor device is obtained, and the accurate calculation of the collected charges induced by the pulse laser incidence to the semiconductor device is realized.
Because the pulse lasers with different energies are different in penetration paths when entering the semiconductor device, the induced charge amounts are different, the single particle irradiation test of the stacked memory device can be realized by using the memory inversion condition of the pulse laser test device in the test process, and the sensitivity depth of the device is determined.
In this embodiment, the test method includes a static mode and a dynamic read mode; and in each test mode, placing the memory to be tested, into which initial data are written, under the irradiation condition of a laboratory simulation source, and carrying out a single particle irradiation test.
For the memory cell portion of a stacked memory device, the single event effect that may occur is Single Event Upset (SEU) whose statistical principle is: and writing fixed data into the memory, and judging whether the overturn occurs by monitoring whether the data content is consistent with the written content.
Specifically, in this embodiment, the test method in the static mode is as follows:
(1) The system is powered on, and initial data is written into a memory;
(2) Powering up a test system, and preparing for irradiation;
(3) Determining the sensitive position of the storage unit array by using pulse laser before irradiation, and positioning the sensitive position on the surface of the storage unit array for the first time;
(4) Comparing the data after the irradiation is finished, and recording the error positions (namely the addresses of the error storage units) and the number of the error storage units; if the error number is zero, performing longitudinal positioning of the sensitive position by utilizing Z scanning of the pulse laser, and continuing the next irradiation test; and if the error number is not zero, rewriting the data of the memory cell, and then carrying out the next irradiation test.
The test method of the dynamic reading mode comprises the following steps:
(1) Writing the initial data into a memory before irradiation;
(2) Determining the sensitive position of the storage unit array by using pulse laser before irradiation, and positioning the sensitive position on the surface of the storage unit array for the first time;
(3) Data comparison is carried out in the irradiation process, and whether the data of the irradiation process is changed relative to initial data is monitored; if the data change and the error number is smaller than a certain determined value N, determining that the data unit is overturned, recording the overturned information, and utilizing the Z scanning of the pulse laser to longitudinally position the sensitive position, and continuing the irradiation test next time.
In this embodiment, when the inversion judgment is performed, the address where the inversion occurs is counted in a nand logic manner, which is simple and efficient to implement, and not only can the position of the error unit be obtained, but also the error type of the error unit can be obtained.
Specifically, in this embodiment, the laser adjustment mode is:
(1) The tested device is focused, so that the tested device is ensured to be in the field of view of the pulse laser, and the pulse width f and the spot diameter d of the pulse laser are determined;
(2) Selecting proper pulse laser initial energy, setting the moving step length of the pulse laser, and performing coarse scanning on a single event effect sensitive area of the whole device to be tested to determine a single event effect sensitive area Q;
(3) After the sensitive area Q is determined, the incidence position of the pulse laser is positioned on the area; setting the incident energy of the pulse laser to be 0nJ; the pulse laser is incident to the device to be measured, and the propagation distance in the device is called the sensitivity depth and is marked as z; setting a sitting mark of a pulse laser incidence surface position of a device to be tested as z=0 μm;
(4) The pulse laser is incident to the tested device, so that the relation between the Collected Charge (CC) and the sensitive depth Z in the tested device can be obtained under the condition of the pulse laser energy of 0nJ;
(5) Increasing the incident energy of the pulse laser with a step length of 0.1nJ in sequence to respectively obtain the curve relationship between the collected charge of the tested device and the sensitive depth Z under different energies;
(6) From step (5), the sensitive depth Z corresponding to the peak value of the collected charges under different energies of the pulse laser can be obtained RPP I.e. the length of the sensitive volume of the device;
(7) According to the RPP model of single event effect analysis, the pulse laser spot diameter d and the length Z of the sensitive volume of the device can be used for RPP Obtaining the sensitive volume V of the device:
V＝d 2 ·Z RPP
in the embodiment, a lower computer and an upper computer are adopted for testing; the lower computer is responsible for directly controlling the memory and reading data; the upper computer is responsible for monitoring and judging decision. The lower computer checks whether the data in the memory test process are overturned according to the data written into the memory by the upper computer, and counts the error unit information; the upper computer judges the single event effect according to the information transmitted by the lower computer, and controls the power-off and the power-on of the memory. Meanwhile, the lower computer needs to send the collected working current to the upper computer, and the overall judgment of the single event effect of the upper computer is performed.
The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the same, but rather, various modifications and variations may be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.
Claims (5)
1. The laser single event effect test method for the 3D stereo stack memory is characterized by comprising the following steps of: placing the memory to be tested, into which data are written, under the irradiation condition of a laboratory simulation source, and performing a single particle irradiation test;
determining the induced charge quantity by utilizing the sensitive depth of pulse laser incidence penetration of different energy into a measured memory and the pulse laser spot diameter, comparing the induced charge quantity with initial data, and judging whether the position of an error unit and the single event of the error type are overturned or not and the overturned position;
the laser adjusting mode is as follows:
(1) Focusing a measured memory, ensuring that the measured memory is in the field of view of the pulse laser, and determining the pulse width f and the spot diameter d of the pulse laser;
(2) Selecting proper pulse laser initial energy, setting the moving step length of the pulse laser, and performing coarse scanning on a single event effect sensitive area of the whole measured memory to determine a single event effect sensitive area Q;
(3) After a sensitive area Q is determined, the incidence position of pulse laser is positioned in the area, the incidence energy of the pulse laser is set, the laser is incident to a measured memory, the propagation distance in the memory is called a sensitive depth Z, and then the relation between the collected charge in the measured memory and the sensitive depth can be obtained;
increasing the incident energy of the pulse laser with a step length of 0.1nJ in sequence to respectively obtain the curve relationship between the collected charge and the sensitive depth of the measured memory under different energies;
obtaining the sensitive depth Z corresponding to the peak value of the collected charges under different energies of the pulse laser according to the curve relation between the collected charges and the sensitive depth of the measured memory under different energies RPP The sensitive volume length of the measured memory is the sensitive volume length of the measured memory; obtaining the sensitive volume V=d of the measured memory according to the RPP model of the single event effect analysis 2 ·Z RPP 。
2. The method of claim 1, wherein the method of testing includes a static mode and a dynamic read mode.
3. The method for testing the laser single event effect of the 3D stacked memory according to claim 2, wherein the testing method in the static mode is as follows:
(1) The system is powered on, and initial data is written into a memory;
(2) Powering up a test system, and preparing for irradiation;
(3) Determining the sensitive position of the storage unit array by using pulse laser before irradiation, and positioning the sensitive position on the surface of the storage unit array for the first time;
(4) Comparing the data after the irradiation is finished, and recording the error positions and the number; if the error number is zero, performing longitudinal positioning of the sensitive position by utilizing Z scanning of the pulse laser, and continuing the next irradiation test; and if the error number is not zero, rewriting the data of the memory cell, and then carrying out the next irradiation test.
4. The method for testing the laser single event effect of the 3D stacked memory according to claim 2, wherein the method for testing in the dynamic read mode is as follows:
(1) Writing the initial data into a memory before irradiation;
(2) Determining the sensitive position of the storage unit array by using pulse laser before irradiation, and positioning the sensitive position on the surface of the storage unit array for the first time;
(3) Data comparison is carried out in the irradiation process, and whether the data of the irradiation process is changed relative to initial data is monitored; if the data change and the error number is smaller than a certain determined value N, determining that the data unit is overturned, recording the overturned information, and utilizing the Z scanning of the pulse laser to longitudinally position the sensitive position, and continuing the irradiation test next time.
5. The method for testing the laser single event effect of the 3D stacked memory according to claim 1, wherein a lower computer and an upper computer are adopted for testing; the lower computer checks whether the data in the memory test process are overturned according to the data written into the memory by the upper computer, and counts the error unit information; the upper computer judges the single event effect according to the information transmitted by the lower computer, and controls the power-off and the power-on of the memory.
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