Photoelectric temperature-time coupled phase change memory programming device and method

Abstract

The invention discloses a photoelectric temperature-time coupled phase change memory programming device and method. The device comprises a pump laser system, an electrical test system, a cold and hot temperature control system and control monitoring software, the pump laser system, the electrical test system, the cold and hot temperature control system and the control monitoring software operate cooperatively, under the unified coordination of the control monitoring software, the pump laser system emits laser pulses with specified parameters, the laser pulses cooperate with the displacement platform, gradual crystallization or non-crystallization switching is achieved in a specified laser irradiation area and path, and the laser pulses are emitted by the displacement platform. The cold and hot temperature control system reaches a specified environment temperature at a certain heating rate, and the electrical test system records the electrical response of the phase change memory device in a specified test duration in real time, so that the light-operated electrical test programming operation of the phase change memory device in a specific environment is realized. According to the invention, quantitative control of the product proportion of the crystal to the amorphous in the SET and RESET step-by-step switching process is realized through a light-operated electric measurement mode, and linear continuous and symmetrical change of the switching resistance value is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of programming of phase change memory devices, and in particular to a device and method for programming a phase change memory device coupled with photoelectric temperature and time. Background Art

[0002] The rapid development of network, communication technology, big data, artificial intelligence and other technologies has put forward extremely high requirements for data storage. The "storage and computing separation" architecture of the traditional von Neumann system requires frequent data writing and retrieving from the storage medium during data processing, and the computing speed is gradually unable to meet the demand. In recent years, academia and industry are committed to developing a third type of storage technology, namely "non-volatile storage", in order to achieve fast reading and writing and stable storage of data in the same unit. Among them, phase change storage technology represented by Intel Optane chips has been commercialized and is one of the most mature non-volatile storage technologies.

[0003] Phase change storage technology uses the rapid reversible phase change and huge resistance difference between the amorphous phase and the crystalline phase of the phase change material to switch between the logical values ​​of "0" (RESET state) and "1" (SET state) to erase and write data. There is a huge resistance window of more than 1000 times between the SET and RESET states. It is possible to obtain multiple identifiable resistance values ​​in the same storage unit through the programming method of gradual phase change, thus breaking through binary storage and realizing "multi-value storage" technology and "storage and computing in one" technology. Gradual phase change programming usually includes two methods: cumulative writing (cumulative SET) and iterative erasing (iterative RESET). The former controls the phase change material in the device unit to gradually crystallize by loading a series of electrical pulses with a certain pulse width and amplitude, while the latter controls the phase change material in the device unit to gradually amorphize by loading a series of electrical pulses with a certain pulse width and gradually increasing amplitude. Both methods change the volume ratio of the crystal and amorphous phase change materials in the device unit by adjusting the pulse parameters, thereby achieving continuous changes in resistance values.

[0004] For storage and computing technology, the ideal programming method for a single device unit in a device array requires that it maintains a linear and continuous change in resistance value during the gradual switching between SET and RESET, and the resistance values ​​in the two switching processes have a symmetrical relationship. However, since phase change materials have a large randomness in both the nucleation and crystallization and melt quenching processes, the programming device of the existing phase change memory device and the cumulative writing / iterative erasing programming method cannot achieve quantitative control of the volume ratio of crystal and amorphous in the device unit, resulting in nonlinear changes in resistance values ​​when SET and RESET are gradually switched, and the symmetry between the two is poor. Therefore, it is urgent to develop a new programming device and method that can achieve linear, continuous and symmetrical changes in resistance values ​​in phase change memory devices. Summary of the invention

[0005] In order to overcome the defects of the above-mentioned prior art, the present invention proposes a photoelectric temperature-time coupled phase change memory device programming device and method, which realizes quantitative control of the volume ratio of crystal and amorphous during the gradual switching of SET and RESET by laser precise positioning and quantitative programming switching area, and realizes the linear continuous and symmetrical change of the switching resistance value of the phase change memory device. In addition, the device of the present invention is also coupled with a cold and hot temperature control system and a time control system, which can realize temperature control during the switching process and record the electrical response of the device unit over time in real time.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A photoelectric temperature-time coupled phase change memory device programming device, comprising a pump laser system, an electrical test system, a cold and hot temperature control system and control monitoring software;

[0008] The pump laser system, electrical test system, cold and hot temperature control system and control monitoring software operate in coordination. Under the unified coordination of the control monitoring software, the pump laser system emits laser pulses with specified parameters, and cooperates with the displacement platform to realize the gradual crystallization (SET gradual switching) switching of the phase change storage material or the gradual amorphization switching (RESET gradual switching) under the specified laser irradiation area and path;

[0009] When the device is in the RESET state, the phase change memory film in the device is in the amorphous phase, and a laser pulse with specified parameters is used to irradiate a specified area of ​​the film to make it gradually crystallize, which is the SET step-by-step switching; when the device is in the SET state, the phase change memory film in the device is in the crystalline phase, and a laser pulse with specified parameters is used to irradiate a specified area of ​​the film to make it gradually amorphous, which is the RESET step-by-step switching; the above two operations can be switched to each other at any time;

[0010] At the same time, the hot and cold temperature control systems reach the specified ambient temperature at a certain heating rate and keep the temperature for a certain period of time. The electrical test system records the electrical response of the phase change memory device at the specified test time in real time, thereby realizing the "light-controlled electrical measurement" programming operation of the phase change memory device under specific conditions.

[0011] The pump laser system is used to adjust the beam spot size, power, and pulse width parameters of the laser pulse, and to provide a light source for the phase change region and acquire a microscopic image in real time;

[0012] The electrical testing system is used to monitor the electrical signal response of the phase change memory device in real time;

[0013] The hot and cold temperature control system is used to accurately control the ambient temperature during the test as well as the temperature change and insulation time parameters;

[0014] The control monitoring software is used to integrate all editable control parameters in the entire programming device, including laser pulse parameters, electrical test parameters, displacement platform parameters and temperature control parameters.

[0015] The pump laser system includes a laser control and focusing module, an illumination module, and a camera module; the laser control and focusing module is used to emit laser pulses and adjust pulse parameters and laser beam spot size; the illumination module is used to provide a visible light source for the phase change memory device, the illumination direction is consistent with the laser illumination direction, and cooperates with the camera module to monitor the microscopic image of the phase change area in real time.

[0016] The laser control and focusing module includes a signal generator and a laser controller. After being emitted by the laser, the laser passes through the polarization-maintaining single-mode optical fiber, a laser collimator, an optical path calibration unit, a beam expansion unit, a dichroic mirror, and an objective lens in sequence;

[0017] The output ends of the signal generator and the laser controller are connected to the input end of the laser respectively, wherein the signal generator is used to adjust the waveform, pulse width and amplitude parameters of the laser pulse; the laser controller is used to control the on and off of the laser; and the laser is used to generate a laser beam of a specific wavelength band;

[0018] The polarization-maintaining single-mode optical fiber is used to connect the laser and the laser collimator, wherein the polarization-maintaining single-mode optical fiber is used for low-loss laser transmission; the laser collimator is used to convert the laser transmitted by the polarization-maintaining single-mode optical fiber into collimated spatial light;

[0019] The laser beam output by the laser collimator will sequentially pass through an optical path calibration unit, a beam expansion unit, a dichroic mirror and an objective lens that are interconnected; wherein the optical path calibration unit is used to adjust the direction of the laser to ensure that the laser is finally incident vertically on the sample surface; the beam expansion unit uses a double convex lens for imaging to adjust the size of the laser beam spot before it is incident on the objective lens; the dichroic mirror is used to reflect more than about 85% of the laser transmitted from the beam expansion unit to the objective lens, and the objective lens is used to finally focus the laser beam into the phase change memory device; the illumination module includes a fourth convex lens, a beam splitter, a dichroic mirror and an objective lens that are sequentially arranged starting from the LED light source;

[0020] The LED light source provides LED illumination light, which is used to provide an illumination light source for microscopic observation of the sample. The illumination point light source output from the LED light source is first transmitted to the convex lens, which is used to diverge the illumination point light source into parallel light. The beam splitter is located between the convex lens and the dichroic mirror, wherein the beam splitter reflects the parallel light to the dichroic mirror on the one hand, and transmits the reflected light generated by the phase change memory device to the camera on the other hand; the dichroic mirror allows the illumination light to be transmitted to the objective lens, and the objective lens is used to focus the illumination parallel light onto the phase change memory device;

[0021] The camera module comprises an objective lens, a dichroic mirror, a beam splitter, a third convex lens and a CMOS camera which are arranged in sequence based on the reflected light of the phase change memory device.

[0022] The electrical test system includes a source meter and a probe, wherein the source meter provides a voltage and current measurement source for the phase change memory device, and tests and records the electrical response signal (including but not limited to resistance value, current value, etc.) of the phase change memory device before and after laser programming. The probe is used to connect the sample and the source meter. The electrical test system can measure the electrical response of the phase change memory device in real time, and can also be coupled with a time parameter to test the electrical response of the phase change memory device before and after laser programming within a certain time range.

[0023] The hot and cold temperature control system includes a temperature controller and a temperature control probe station, wherein the temperature controller is used to accurately control the programmed ambient temperature, set a constant temperature for testing or change the temperature in real time for testing;

[0024] The temperature-controlled probe station is used to connect the test probes for electrical response testing, and is connected to the temperature controller to control the temperature of the test environment and the temperature change rate. The high temperature environment can be achieved by a heater, and the low temperature environment can be achieved with the help of liquid nitrogen or liquid helium. The probe station can also introduce different gas atmospheres according to the test environment requirements, including but not limited to air, nitrogen, argon, oxygen, and vacuum atmosphere.

[0025] The control and monitoring software includes a laser control module, a signal generator control module, a displacement platform control module, a temperature control probe station control module, an electrical performance monitoring module, and a camera monitoring module;

[0026] Among them, the laser control module realizes the switching and power control of the laser; the signal generator control module sets the signal generator to emit pulses and sets the parameters of waveform, pulse width and amplitude; the displacement platform control module is used to adjust the relative position of the phase change memory device and the laser, so as to control the irradiation path and area of ​​the laser. The irradiation path is programmed to be perpendicular to the electrode direction or parallel to the electrode direction or any path according to the actual test needs. The irradiation area is switched point by point or in a jumpy manner by changing the displacement step length, and the amorphous area is gradually crystallized (SET step-by-step switching) or the crystal area is gradually amorphized (RESET step-by-step switching), and the volume ratio of the crystal and amorphous in the effective phase change area inside the phase change memory device is quantitatively changed, and finally the quantitative volume of the phase change material and the specific area are realized. The precise programming of the adjustable displacement platform (XYZ displacement platform, XY displacement platform) can be carried out in the X, Y, and Z axis directions with high precision displacement, and can realize single-step displacement of a set distance and continuous displacement of a set speed; the temperature control probe station control module is used to control the set temperature and temperature change speed parameters of the temperature controller 21; the electrical performance monitoring module is used to monitor and record the electrical response of the device unit during the SET / RESET step-by-step switching process, such as the linear change of the resistance value continuously increasing or decreasing, and the symmetrical change of increasing first and then decreasing or decreasing first and then increasing, and can adjust the parameters of the test time in real time, including but not limited to the resistance-temperature curve (RT curve), the resistance-time curve (Rt curve), the volt-ampere characteristic curve (IV curve), the voltage-current curve (VI curve), etc. The camera monitoring module can monitor and record the microscopic image of the device unit in real time.

[0027] A method for programming a phase change memory device coupled with photoelectric temperature and time, which couples four parameters of light, electricity, temperature and time through important components such as laser control and focusing module, displacement platform control module, temperature control probe station control module, and electrical performance monitoring module;

[0028] Use the laser control and focusing module to generate laser pulses with specific parameters, combine with the displacement platform control module to adjust the relative position of the device and the laser, and use the optical signal to control the phase change material in the device to perform quantitative SET and RESET step-by-step switching;

[0029] The electrical performance monitoring module is used to measure the linear, continuous and symmetrical changes of the resistance value during the device switching process in real time. At the same time, the electrical signal response process within a certain period of time can be recorded by setting the monitoring time. The temperature control probe station control module is used to set the test temperature of the phase change memory device to examine the response of the phase change memory device to electrical signals such as resistance value under different temperature environments.

[0030] The programming device and the programming method cooperate together to realize quantitative controllable programming of linear continuous and symmetrical change of resistance value in phase change memory device.

[0031] In the laser control and focusing module, the polarization-maintaining single-mode optical fiber, the laser, the laser collimator, the optical path calibration unit, the beam expansion unit, the dichroic mirror and the objective lens are modulated to directly act on the phase change material in the phase change memory device. The laser spot size and the irradiation area are regulated by using the pump laser system in the programming device. The Joule heat excited by the laser when irradiating the phase change material is used to induce the material to undergo a crystallization or amorphization phase change, thereby quantifying the volume ratio of the crystal to the amorphous in the programming device unit. The parameters involved in the above operation are as follows:

[0032] The beam spot diameter ranges from 0.5 to 3 μm, the irradiation area ranges from 5 to 200 μm in length and 5 to 200 μm in width, the amorphization programming parameters are power 100 to 150 mW and pulse width 5 to 80 ns, the crystallization programming parameters are power 20 to 100 mW and pulse width 30 to 500 ns, and the volume ratio of crystal to amorphous ranges from 0% to 100%;

[0033] By combining the laser control and focusing module in the pump laser system with the displacement platform control module in the control monitoring software, the laser pulse can be controlled to precisely position and erase the programmed area, thereby obtaining the crystal and amorphous volume ratio (100% to 0%) corresponding to the previous switching process.

[0034] Since there is a huge difference in resistance between the crystal and amorphous phase change material, the conductivity of the device unit will show certain differences under different crystal-amorphous volume ratios. By using the electrical testing system in the above-mentioned programming device to measure the device resistance value under different crystal-amorphous volume ratios, a linear, continuous and symmetrical resistance value programming result can be obtained.

[0035] In the programming method, the size of the phase change material region irradiated by the laser can be designed according to the requirements of programming accuracy. By combining the laser control and focusing module in the pump laser system and the displacement platform control module in the control monitoring software, the laser beam spot size, irradiation time and irradiation path are jointly adjusted. By changing the switching time and switching volume of gradual crystallization or amorphization, the step size and slope of the linear change of the crystal and amorphous volume ratio in the effective phase change region are quantitatively controlled, so that the number of identifiable logical states in a single phase change storage unit can be controllably programmed.

[0036] The electrical test system can measure the electrical response of the phase change memory device in real time, and can also be coupled with the time parameter to test the electrical response of the phase change memory device within a certain time range; the electrical response includes but is not limited to the resistance-temperature curve (RT curve), the resistance-time curve (Rt curve), the volt-ampere characteristic curve (IV curve), and the voltage-current curve (VI curve). The hot and cold temperature control system can be set to a constant temperature for testing, or it can be set to a real-time variable temperature for testing, wherein the temperature control probe station 17 can be introduced into different gas atmospheres according to the test environment requirements, including but not limited to air, nitrogen, argon, oxygen, vacuum and other atmospheres.

[0037] Beneficial effects of the present invention:

[0038] The novel programming device and method for phase change memory devices provided by the present invention is a "light-controlled electrical measurement" method, which can accurately control the volume of the material undergoing phase change by adjusting the laser beam spot size and the irradiated area, quantitatively program the volume ratio of the phase change material crystal and amorphous, and realize linear and continuous resistance value programming; by accurately positioning and erasing the programmed area, the crystal and amorphous volume ratio corresponding to the previous switching process is obtained, thereby realizing symmetrical resistance value programming.

[0039] The device and method provided by the present invention can arbitrarily adjust the waveform, pulse width, power and other parameters of the laser pulse through the signal generator in the laser control and focusing module to realize the crystallization or amorphization switching of the phase change material; use the beam expansion unit to adjust the laser beam spot size to change the irradiation area of ​​a single laser pulse; use the lighting module and the camera module to realize the micro-region morphology observation before and after the laser switching of the phase change material; use the displacement platform control module to accurately locate the target area of ​​laser irradiation and automatically program the laser irradiation path, the displacement direction and displacement step of the path can directly affect the step length and slope of the linear change of the resistance value; use the temperature control probe station control module to provide an adjustable external environment temperature for device testing; use the electrical performance monitoring module to monitor the electrical response of the phase change device unit under the action of the laser pulse in real time, and realize the quantitative and controllable programming of the number of identifiable logical states in a single phase change storage unit.

[0040] The device and method provided by the present invention couple multiple physical parameters such as laser irradiation, programming temperature and programming time, and can effectively test the performance indicators of phase change memory device units under multiple physical fields, providing a reliable evaluation basis for the performance preview of device arrays.

[0041] In the device and method provided by the present invention, each system and module can be linked by software, and automatic programming test can be performed after calibration is completed and programming conditions are set. In addition, the system has good compatibility and can further develop and expand new functions and modules according to different programming test requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a structural schematic diagram of the photoelectric temperature-time coupling test device involved in the present invention.

[0043] Figure 2 A partial schematic diagram of the gradual switching of phase change materials in a device unit induced by a laser pulse. DETAILED DESCRIPTION

[0044] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0045] A phase change memory device coupled with photoelectric temperature and time, such as Figure 1 As shown, it includes pump laser system, electrical test system, hot and cold temperature control system and control monitoring software.

[0046] The pump laser system, electrical test system, cold and hot temperature control system and control monitoring software operate in coordination. Under the unified coordination of the control monitoring software, the pump laser system emits laser pulses with specified parameters, and cooperates with the displacement platform to realize the gradual crystallization (SET gradual switching) switching of the phase change storage material or the gradual amorphization switching (RESET gradual switching) under the specified laser irradiation area and path;

[0047] When the device is in the RESET state, the phase change memory film in the device is in the amorphous phase, and a laser pulse with specified parameters is used to irradiate a specified area of ​​the film to make it gradually crystallize, which is the SET step-by-step switching; when the device is in the SET state, the phase change memory film in the device is in the crystalline phase, and a laser pulse with specified parameters is used to irradiate a specified area of ​​the film to make it gradually amorphous, which is the RESET step-by-step switching; the above two operations can be switched to each other at any time;

[0048] At the same time, the hot and cold temperature control systems reach the specified ambient temperature at a certain heating rate and keep the temperature for a certain period of time. The electrical test system records the electrical response of the phase change memory device at the specified test time in real time, thereby realizing the "light-controlled electrical measurement" programming operation of the phase change memory device under specific conditions.

[0049] The pump laser system includes a laser control and focusing module, an illumination module, a camera module, and a displacement platform, which are used to emit laser signals to control the switching of phase change materials in the device. The laser control and focusing module includes a signal generator 1, a laser controller 2, a laser 3, a polarization-maintaining single-mode optical fiber 4, a laser collimator 5, an optical path calibration unit 6, a first reflector 61, a second reflector 62, a beam expansion unit 7, a first convex lens 71, a second convex lens 72, a dichroic mirror 13, and an objective lens 14; the illumination module includes an LED light source 12, a fourth convex lens 11, a beam splitter 10, a dichroic mirror 13, and an objective lens 14; the camera module includes a camera 8, a third convex lens 9, a beam splitter 10, a dichroic mirror 13, and an objective lens 14; and the displacement platform includes an XYZ axis displacement platform 18 and an XY axis displacement platform 19.

[0050] The electrical test system includes a probe 16 and a source meter 20, which are used to connect device units to form an electrical loop and provide electrical signals such as current or voltage to test the electrical response of the device.

[0051] The hot and cold temperature control system includes a temperature control probe station 17 and a temperature controller 21, which are used to control the temperature during the programming process.

[0052] The control and monitoring software relies on the computer 22 to realize the control and signal monitoring of the test device, including the laser control module, the signal generator control module, the displacement platform control module, the temperature control probe station control module, the electrical performance monitoring module, and the camera monitoring module. Through the linkage of the software to each system and module, the automated test is realized, and the electrical response process of the phase change memory device changing over time is recorded in real time. The signal generator control module can set the signal generator to emit pulses, and set parameters such as waveform, pulse width, and amplitude. The displacement platform control module is used to adjust the relative position of the device unit and the laser, realize the precise programming of the quantitative volume and the phase change material in a specific area, and can adjust the displacement platform to perform high-precision displacement in the X, Y, and Z axis directions, and can realize single-step displacement of a set distance and continuous displacement of a set speed. The temperature control probe station control module is used to control the set temperature, temperature change speed and other parameters of the temperature controller. The electrical performance monitoring module is used to monitor and record the electrical response of the device unit, including but not limited to the resistance-temperature curve (RT curve), resistance-time curve (Rt curve), volt-ampere characteristic curve (IV curve), voltage-current curve (VI curve), etc., and can adjust parameters such as test time in real time. The single test duration ranges from 0.1s to 10h. The camera monitoring module can monitor and record the microscopic image of the device unit in real time.

[0053] Figure 2 A partial schematic diagram of the gradual switching of phase change materials in a device unit induced by a laser pulse.

[0054] The boxed area in the figure is the effective phase change area, the circular area is the area where the phase change has occurred after laser irradiation, and the rest of the area in the box is the area without laser irradiation. Different programming operations can be achieved by adjusting laser parameters such as power and pulse width, such as writing (corresponding to crystallization) or erasing (corresponding to amorphization), where the amorphization parameters are power 100-150mW, pulse width 5-80ns, and crystallization parameters are power 20-100mW, pulse width 30-500ns; by adjusting the laser beam spot size (diameter 0.5-3μm) and irradiation area (length: 5-200μm; width: 5-200μm), the volume of the material undergoing phase change can be precisely controlled, thereby quantitatively programming the crystalline and amorphous in the device unit. The volume ratio of the phase change area (0% to 100%) can be adjusted to realize linear and continuous resistance programming; by controlling the laser pulse to precisely position and erase the programmed area, the volume ratio of the crystal and amorphous (100% to 0%) corresponding to the previous switching process can be obtained to realize symmetrical resistance programming; by jointly adjusting the effective phase change area size and a variety of laser parameters (such as beam spot size, irradiation range, power, pulse width, etc.), the step size and slope of the linear change of the volume ratio of the crystal and amorphous can be adjusted, thereby realizing the controllable programming of the number of identifiable logical states in a single phase change storage unit. The optical and electrical performance responses of the phase change material under the temperature field are obtained by adjusting the operating environment temperature of the device. The temperature control range is -200 to 200℃, the heating or cooling rate is 0.1℃ / min to 1000℃ / min, and the holding time is 0.1s to 10h.

[0055] The present invention is further described below by taking specific embodiments as examples.

[0056] This embodiment takes a germanium antimony tellurium bridge structure phase change memory device as an example, and uses the device and method provided by the present invention to perform single device multi-resistance state programming. The specific process is as follows:

[0057] The effective phase change region in the germanium antimony tellurium bridge structure phase change memory device is 20μm long, 10μm wide and 80nm thick. Start the control monitoring software of computer 22 to ensure that all systems are connected normally. Place the germanium antimony tellurium phase change memory device on the temperature-controlled probe station 17 and connect the probe 16 to the device electrode. Turn on the source meter to preliminarily test the sample resistance to ensure that the probe is in good contact with the sample. According to the sample microscopic image, roughly adjust the XYZ axis displacement platform 18 to move the sample to the center of the field of view and focus clearly, and focus the laser to the smallest spot. Finely adjust the X and Y axis positions of the XY axis displacement platform 19 so that the position where the effective phase change region of the device needs to be irradiated by the laser falls at the laser spot position. Adjust the temperature controller 21, use a heating rate of 10℃ / min to raise the temperature to 100℃, and keep warm for 200 minutes. When the temperature stabilizes to 100℃, use the source meter to collect the initial amorphous resistance value and IV curve of the device. Then set the pulse laser parameters, the irradiated beam spot size is about 1μm, the power is 80mW, and the pulse width is 200ns. The laser irradiates the effective phase change area point by point in a horizontal displacement from right to left, and the irradiated area crystallizes to form a crystalline phase. After the laser irradiates each point, the source meter is used to collect the resistance value and IV curve of the device. The time for collecting the resistance value is 10 seconds, and the time for testing the IV curve is 20 seconds. During the test process, the resistance value of the device increases linearly, and 64 different resistance logic states are obtained. Then reset the pulse laser parameters, the pulse width is 50ns, the power is 120mW, the beam spot size after irradiation is about 1μm, and the laser irradiates the effective phase change area point by point in the same trajectory. The irradiated area is amorphized to form an amorphous phase. After the laser irradiates each point, the source meter is used to collect the resistance value and IV curve of the device. The time for collecting the resistance value is 10 seconds, and the time for testing the IV curve is 20 seconds. During the test process, the resistance value of the device decreases linearly, and about 64 different resistance logic states are obtained, and the resistance value of each logic state basically corresponds to the resistance value during the crystallization process.

[0058] The above embodiments are only for explaining the test device and the test method of the present invention in more detail, and are not intended to limit the present invention, and the protection scope of the present invention should not be limited thereto. Any equivalent replacement of some technical features made by technicians in the technical field on the basis of the present invention is within the protection scope of the present invention.

Claims

1. A photoelectric temperature-time coupled phase change memory device programming device, characterized in that: Including pump laser system, electrical test system, hot and cold temperature control system and control monitoring software; The pump laser system, electrical test system, cold and hot temperature control system and control monitoring software operate in coordination. Under the unified coordination of the control monitoring software, the pump laser system emits laser pulses with specified parameters, and cooperates with the displacement platform to achieve gradual crystallization switching or gradual amorphization switching of the phase change storage material under the specified laser irradiation area and path; When the device is in the RESET state, the phase change memory film in the device is in the amorphous phase, and a laser pulse with specified parameters is used to irradiate a specified area of ​​the film to make it gradually crystallize, which is the SET step-by-step switching; when the device is in the SET state, the phase change memory film in the device is in the crystalline phase, and a laser pulse with specified parameters is used to irradiate a specified area of ​​the film to make it gradually amorphous, which is the RESET step-by-step switching; the above two operations can be switched to each other at any time; At the same time, the hot and cold temperature control system reaches the specified ambient temperature at a certain heating rate and keeps the temperature for a certain period of time. The electrical test system records the electrical response of the phase change memory device at the specified test time in real time, thereby realizing the "light-controlled electrical measurement" programming operation of the phase change memory device under a specific environment.

2. The photoelectric temperature-time coupled phase change memory device programming device according to claim 1, characterized in that: The pump laser system is used to adjust the beam spot size, power, and pulse width parameters of the laser pulse, and to provide a light source for the phase change region and acquire a microscopic image in real time; The electrical testing system is used to monitor the electrical signal response of the phase change memory device (15) in real time; The hot and cold temperature control system is used to accurately control the ambient temperature during the test as well as the temperature change and insulation time parameters; The control monitoring software is used to integrate all editable control parameters in the entire programming device, including laser pulse parameters, electrical test parameters, displacement platform parameters and temperature control parameters.

3. The photoelectric temperature-time coupled phase change memory device programming device according to claim 1, characterized in that: The pump laser system comprises a laser control and focusing module, an illumination module and a camera module; the laser control and focusing module is used to emit laser pulses and adjust pulse parameters and laser beam spot size; the illumination module is used to provide a visible light source for the phase change memory device (15), the illumination direction is consistent with the laser illumination direction, and cooperates with the camera module to monitor the microscopic image of the phase change region in real time.

4. The photoelectric temperature-time coupled phase change memory device programming device according to claim 3, characterized in that: The laser control and focusing module comprises a signal generator (1) and a laser controller (2). After being emitted by a laser (3), the laser passes through a polarization-maintaining single-mode optical fiber (4), a laser collimator (5), an optical path calibration unit (6), a beam expansion unit (7), a dichroic mirror (13), and an objective lens (14) in sequence. The output ends of the signal generator (1) and the laser controller (2) are respectively connected to the input end of the laser (3), wherein the signal generator (1) is used to adjust the waveform, pulse width and amplitude parameters of the laser pulse; the laser controller (2) is used to control the on and off of the laser; and the laser (3) is used to generate a laser beam of a specific wavelength band; The polarization-maintaining single-mode optical fiber (4) is used to connect the laser (3) and the laser collimator (5), wherein the polarization-maintaining single-mode optical fiber (4) is used for low-loss laser transmission; the laser collimator (5) is used to convert the laser transmitted by the polarization-maintaining single-mode optical fiber into collimated spatial light; The laser beam output by the laser collimator (5) will sequentially pass through an optical path calibration unit (6), a beam expansion unit (7), a dichroic mirror (13) and an objective lens (14) which are connected to each other; wherein the optical path calibration unit (6) is used to adjust the direction of the laser to ensure that the laser is finally incident on the sample surface vertically; the beam expansion unit (7) uses a double convex lens for imaging to adjust the size of the laser beam spot before it is incident on the objective lens; the dichroic mirror (8) is used to reflect more than about 85% of the laser transmitted from the beam expansion unit (7) to the objective lens (9), and the objective lens (9) is used to finally focus the laser beam into the phase change memory device (15); the lighting module comprises a fourth convex lens (11), a beam splitter (10), a dichroic mirror (13) and an objective lens (14) which are sequentially arranged starting from the LED light source (12); The LED light source (12) provides LED illumination light for providing an illumination light source for microscopic observation of the sample. The illumination point light source output from the LED light source (12) is first transmitted to the convex lens (11) for diverging the illumination point light source into parallel light. The beam splitter (10) is located between the convex lens (11) and the dichroic mirror (13). The beam splitter (10) reflects the parallel light into the dichroic mirror (13) on the one hand, and transmits the reflected light generated by the phase change memory device (15) to the camera module on the other hand. The dichroic mirror (13) allows the illumination light to be transmitted to the objective lens (14), and the objective lens (14) is used to focus the illumination parallel light onto the phase change memory device (15). The camera module comprises an objective lens (14), a dichroic mirror (13), a beam splitter (10), a third convex lens (9), and a CMOS camera (8), which are arranged in sequence based on light reflected by a phase change memory device (15).

5. The optical-electrical-temperature-time coupled phase change memory device programming device according to claim 4, characterized in that: The electrical test system comprises a source meter (20) and a probe (16), wherein the source meter (20) provides a voltage and current measurement source for the phase change memory device (15), tests and records the electrical response signal of the phase change memory device (15) before and after laser programming, and the probe (16) is used to connect the sample and the source meter (20). The electrical test system can measure the electrical response of the phase change memory device (15) in real time, and can also be coupled with a time parameter to test the electrical response of the phase change memory device (15) before and after laser programming within a certain time range; The hot and cold temperature control system comprises a temperature controller (21) and a temperature control probe station (17), wherein the temperature controller (21) is used to accurately control the programmed ambient temperature, set a constant temperature for testing or change the temperature in real time for testing; The temperature-controlled probe station (17) is used to connect the test probe (16) to perform electrical response testing, and is connected to the temperature controller (21) to perform temperature control and temperature change rate control of the test environment. The high temperature environment can be achieved by a heater, and the low temperature environment can be achieved by liquid nitrogen or liquid helium. The probe station (17) can also introduce different gas atmospheres according to the test environment requirements, including but not limited to air, nitrogen, argon, oxygen, and vacuum atmosphere.

6. The photoelectric temperature-time coupled phase change memory device programming device according to claim 5, characterized in that: The control and monitoring software includes a laser control module, a signal generator control module, a displacement platform control module, a temperature control probe station control module, an electrical performance monitoring module, and a camera monitoring module; The laser control module realizes the switching and power control of the laser; the signal generator control module sets the signal generator (1) to emit pulses and performs parameter settings of waveform, pulse width and amplitude; the displacement platform control module is used to adjust the relative position between the phase change memory device (15) and the laser, thereby controlling the irradiation path and area of ​​the laser. The irradiation path is programmed to be perpendicular to the electrode direction or parallel to the electrode direction or any path according to actual test needs. The irradiation area is switched point by point or in a jumpy manner by changing the displacement step length, gradually crystallizing the amorphous area (SET step-by-step switching) or gradually amorphizing the crystal area (RESET step-by-step switching), quantitatively changing the volume ratio of the crystal to the amorphous area in the effective phase change area inside the phase change memory device (15), and finally realizing the precise programming of the quantitative volume of the phase change material and the specific area. The XYZ-axis displacement platform (18) and the XY-axis displacement platform (19) perform high-precision displacement in the X, Y, and Z-axis directions, and can realize single-step displacement of a set distance and continuous displacement of a set speed; the temperature control probe station control module is used to control the set temperature and temperature change speed parameters of the temperature controller (21); the electrical performance monitoring module is used to monitor and record the electrical responses of the device unit during the SET / RESET step-by-step switching process, such as linear changes in the resistance value continuously increasing or decreasing, and symmetrical changes such as first increasing and then decreasing or first decreasing and then increasing, and can control the parameters of the test time in real time, including but not limited to the resistance-temperature curve (RT curve), the resistance-time curve (Rt curve), the volt-ampere characteristic curve (IV curve), and the voltage-current curve (VI curve); the camera monitoring module monitors and records the microscopic image of the device unit in real time.

7. According to the method for programming a phase change memory device coupled with photoelectric temperature and time according to claim 6, four parameters of light, electricity, temperature and time are coupled through important components such as laser control and focusing module, displacement platform control module, temperature control probe station control module, and electrical performance monitoring module; Use the laser control and focusing module to generate laser pulses with specific parameters, combine with the displacement platform control module to adjust the relative position of the device and the laser, and use the optical signal to control the phase change material in the device to perform quantitative SET and RESET step-by-step switching; An electrical performance monitoring module is used to measure the linear, continuous and symmetrical changes in the resistance value during the switching process of the device in real time, and the electrical signal response process within a certain period of time can be recorded by setting the monitoring time; a temperature control probe station control module is used to set the test temperature of the phase change memory device (15), and the response of the phase change memory device (15) to electrical signals such as resistance value under different temperature environments is examined.

8. According to the method for programming a phase change memory device coupled with photoelectric temperature and time according to claim 7, in the laser control and focusing module, the polarization-maintaining single-mode optical fiber (4), the laser (3), the laser collimator (5), the optical path calibration unit (6), the beam expansion unit (7), the dichroic mirror (13) and the objective lens (14) are modulated to directly act on the phase change material in the phase change memory device (15), and the laser beam spot size and the irradiation area are regulated by using the pump laser system in the programming device, and the Joule heat excited by the laser when irradiating the phase change material is used to induce the material to undergo a crystallization or amorphization phase change, thereby quantifying the volume ratio of the crystal to the amorphous in the programming device unit, and the parameters involved in the above operation are as follows: The beam spot diameter ranges from 0.5 to 3 μm, the irradiation area ranges from 5 to 200 μm in length and 5 to 200 μm in width, the amorphization programming parameters are power 100 to 150 mW and pulse width 5 to 80 ns, the crystallization programming parameters are power 20 to 100 mW and pulse width 30 to 500 ns, and the volume ratio of crystal to amorphous ranges from 0% to 100%; By combining the laser control and focusing module in the pump laser system with the displacement platform control module in the control monitoring software, the laser pulse can be controlled to precisely position and erase the programmed area, thereby obtaining the crystal and amorphous volume ratio (100% to 0%) corresponding to the previous switching process.

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