A carbon-based device single-particle effect pulsed laser test system and equivalent LET value calculation method

Abstract

The application belongs to the technical field of space radiation, and discloses a carbon-based device single-particle effect pulsed laser test system and an equivalent LET value calculation method, which can be used for guiding the carbon-based device single-particle effect pulsed laser test. The system is composed of a pulsed laser, a probe test platform, a power supply system, a control system and a high-frequency oscilloscope. The equivalent method based on the system is based on the structural characteristics of the carbon-based device, and the equivalent LET value is obtained through the characteristics of the front laser irradiation, that is, LET = 1.0210 4 The application has important significance for guiding the pulsed laser test of the carbon-based device.

Description

Technical Field

[0001] This invention belongs to the field of space radiation technology, specifically relating to a single-event effect pulsed laser testing system for carbon-based devices and a method for calculating the equivalent LET value. Background Technology

[0002] Carbon nanotubes (CNTs) are quasi-one-dimensional lattice structure devices with excellent electrical properties, good chemical stability, and high mechanical strength, making them promising candidates for next-generation semiconductor channel materials in integrated circuits and driving the future development of electronics. Furthermore, carbon nanotubes possess strong carbon-carbon covalent bonds, nanoscale cross-sectional area, and low atomic number, making them a promising candidate for developing next-generation ultra-radiation-resistant integrated circuit technology.

[0003] Single-event effects (SEE) are one of the key radiation damage effects in space applications of devices, and SEE testing is the technical foundation for SEE resistance performance and SEE resistance design. Pulsed laser testing technology is a common technique for evaluating SEE in devices. For carbon-based devices, a pulsed laser testing system and an equivalent method for pulsed laser LET values ​​are fundamental for conducting pulsed laser SEE testing on carbon-based devices. Therefore, there is an urgent need for an equivalent method and system for pulsed laser LET values ​​of carbon nanotube devices for SEE. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a single-event effect pulsed laser testing system for carbon-based devices and a method for calculating the equivalent LET value, which can be used to guide single-event effect pulsed laser experiments on carbon-based devices.

[0005] To achieve the above objectives, the present invention provides the following solution: A single-event effect pulsed laser testing system for carbon-based devices, the system comprising: a pulsed laser, a probe testing platform, a power supply system, a control system, and a high-frequency oscilloscope; The pulsed laser is used as an irradiation source for single-event effects to induce single-event effects in carbon-based devices. The probe testing platform is used to place the carbon-based device and cooperate with the pulsed laser to induce the single-event effect in the carbon-based device. The power supply system is used to supply power to the carbon-based device; The control system is used to induce the single-event effect in the carbon-based device by controlling the probe testing platform, the pulsed laser, and the power supply system. The high-frequency oscilloscope is used to acquire the single-event effect signal.

[0006] Preferably, the probe testing platform consists of an objective lens, a CCD camera, a three-dimensional moving stage, a probe station, a vacuum pump, and a T-type biaser; The probe station is disposed at the upper end of the three-dimensional moving platform and is used to fix the carbon-based device; The three-dimensional moving stage is used to move the carbon-based device; The T-type bias is disposed at one end of the probe station and is used to power the carbon-based device, as well as to isolate DC signals and acquire high-frequency signals; The vacuum pump is connected to the probe station and is used for vacuum adsorption of semiconductor test devices; The objective lens is positioned above the probe stage and is used to focus the laser light from the pulsed laser onto the surface of the carbon-based device. The CCD camera is positioned directly above the objective lens to capture the focusing effect, and based on the focusing effect, the objective lens is adjusted to focus the laser onto the surface of the carbon-based device.

[0007] This invention also provides a method for calculating the equivalent LET value of a single-event effect pulsed laser for carbon-based devices. The method is implemented using the aforementioned system and includes: Based on the definition of the equivalent LET value of a pulsed laser and the attenuation law of laser intensity with incident depth x, under the linear absorption mechanism, each photon generates an electron-hole pair, thus obtaining the equivalent LET value of a pulsed laser. Value, based on pulsed laser equivalent Value, to obtain the pulsed laser equivalent heavy ion value in the sensitive area of ​​the device. size; For carbon-based devices, a front-side irradiation method is used, based on the reflection and absorption attenuation of pulsed laser energy by each layer of the chip material; By analyzing the laser irradiation process, the effective laser energy for generating single-particle effects in carbon-based devices was determined. ; Based on the effective laser energy, the single-event effect sensitive area of ​​the chip is obtained. value; Based on the typical structure and parameters of carbon nanotubes, the single-particle effect sensitive region of the chip is... The values ​​are simplified to obtain the simplified chip single-event effect sensitive area. value; Based on the carrier conversion efficiency of carbon-based devices, a correction factor is introduced. Ultimately, the single-event effect of carbon-based devices was obtained. .

[0008] Preferably, based on pulsed laser equivalent Value, to obtain the pulsed laser equivalent heavy ion value in the sensitive area of ​​the device. Methods for determining size include: Pulsed laser equivalent The value is: ; Pulsed laser equivalent heavy ion in the sensitive area of ​​the device Size: ; In the formula, λ is the energy required to excite a pair of electron-hole pairs by heavy ions, λ is the pulsed laser wavelength, h is Planck's constant brightness, c is the speed of light, and α is the absorption coefficient of the laser in the semiconductor. The effective pulsed laser energy is the energy that can penetrate the single-event effect sensitive region, ρ is the density of the incident semiconductor material, and d is the thickness of the single-event effect sensitive layer on the chip. The ratio of the energy required to generate an electron-hole pair for heavy ions and pulsed lasers. .

[0009] Preferably, for carbon-based devices, a front-side irradiation method is used, and the methods based on the reflection and absorption attenuation of pulsed laser energy by each layer of the chip material include: Based on the device's structural characteristics, when a laser with an initial energy of E1 irradiates a carbon-based device, reflection and transmission occur on the surface of the carbon-based device. The reflected laser energy is... Transmitted laser energy After entering the carbon-based device and being absorbed, the laser energy reaching the gate dielectric surface is E2. Reflection and transmission occur at this interface, where the reflected laser energy is... The transmitted laser energy is After absorption by the gate dielectric layer, the laser energy reaching the gate metal surface is E3, resulting in complete reflection. The reflected laser energy is... The laser energy, E4, reaches the carbon nanotube layer after absorption by the gate dielectric layer. At this interface, reflection and transmission occur again, with the reflected laser energy being... The transmitted laser energy is .

[0010] Preferably, the effective laser energy for generating single-event effects in carbon-based devices is determined by analyzing the laser irradiation process. The methods include: ; Based on the reflection and transmission process of laser light in materials, let R be the reflectivity of the laser, α be the absorption coefficient, and d be the material thickness, then... ; ; ; ; ; ; ; ; ; ; ; in , and The laser reflectivity, absorption coefficient, and thickness of the first layer material are given. , and The laser reflectivity, absorption coefficient, and thickness of the second layer material are given. The laser reflectivity of the third layer material.

[0011] Preferably, based on the effective laser energy, the single-event effect sensitive area of ​​the chip is obtained. The methods for determining values ​​include: = .

[0012] Preferably, based on the typical structure and parameters of carbon nanotubes, the single-particle effect sensitive region of the chip is... The values ​​are simplified to obtain the simplified chip single-event effect sensitive area. The methods for determining values ​​include: .

[0013] Preferably, a correction factor is introduced based on the carrier conversion efficiency of the carbon-based device. Ultimately, the single-event effect of carbon-based devices was obtained. The methods include: =1.02 10 4 .

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: it proposes a single-event effect pulsed laser testing system for carbon-based devices and a method for calculating the equivalent LET value, which can be used to guide single-event effect pulsed laser tests on carbon-based devices. Attached Figure Description

[0015] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a method for calculating the equivalent LET value of a single-event pulsed laser for a carbon-based device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a single-particle effect pulsed laser testing system for carbon-based devices according to an embodiment of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Example 1 like Figure 2 As shown, the present invention provides a single-event effect pulsed laser testing system for carbon-based devices. The system includes: a pulsed laser, a probe testing platform, a power supply system, a control system, and a high-frequency oscilloscope. Pulsed lasers are used as irradiation sources for single-event effects, inducing single-event effects in carbon-based devices; A probe testing platform is used to place the carbon-based device and, in conjunction with a pulsed laser, induce the carbon-based device to generate a single-event effect. A power supply system for powering carbon-based devices; The control system is used to induce single-event effects in carbon-based devices by controlling the probe test platform, pulsed laser, and power supply system. A high-frequency oscilloscope is used to acquire single-event effect signals.

[0020] In this embodiment, the probe testing platform consists of an objective lens, a CCD camera, a three-dimensional moving stage, a probe station, a vacuum pump, and a T-type biaser. The probe stage is positioned at the upper end of the three-dimensional moving stage for fixing the carbon-based device; A three-dimensional moving stage for moving carbon-based devices; The T-type bias is located at one end of the probe station and is used to power the carbon-based device, as well as to isolate DC signals and acquire high-frequency signals. The vacuum pump is connected to the probe station and is used for vacuum adsorption of semiconductor test devices; The objective lens is positioned above the probe stage to focus the laser light from the pulsed laser onto the surface of the carbon-based device; A CCD camera is positioned directly above the objective lens to capture the focusing effect. Based on the focusing effect, the objective lens is adjusted to focus the laser onto the surface of the carbon-based device.

[0021] Example 2 like Figure 1 As shown, this invention relates to a method for calculating the equivalent LET value of a single-event effect pulsed laser on a carbon-based device, which can be used to guide single-event effect pulsed laser experiments on carbon-based devices. The method is implemented using the system described in Example 1, and the method includes: (1) According to the definition of the equivalent LET value of pulsed laser Given the attenuation law of laser intensity with incident depth x, under the linear absorption mechanism, each photon generates an electron-hole pair, then the pulsed laser is equivalent to... The value is: ; Therefore, the pulsed laser equivalent heavy ion in the sensitive region of the device Size: ; In the formula λ is the energy required to excite a pair of electron-hole pairs by heavy ions, λ is the pulsed laser wavelength, h is Planck's constant brightness, c is the speed of light, and α is the absorption coefficient of the laser in the semiconductor. The effective pulsed laser energy is the energy that can penetrate the single-event effect sensitive region, ρ is the density of the incident semiconductor material, and d is the thickness of the single-event effect sensitive layer on the chip. The ratio of the energy required to generate an electron-hole pair for heavy ions and pulsed lasers. ; (2) For carbon-based devices, the main method is front-side irradiation. Based on the reflection and absorption attenuation of pulsed laser energy by each layer of the chip material, and according to the structural characteristics of the device, when the laser with an initial energy of E1 is irradiated onto the carbon-based device, reflection and transmission occur on the surface of the carbon-based device (the reflected laser energy is E1', and the transmitted laser energy is E1''). After entering the carbon-based device, the laser energy that reaches the surface of the gate dielectric after absorption is E2, and reflection and transmission occur at this interface (the reflected laser energy is E2', and the transmitted laser energy is E2''). After absorption by the gate dielectric layer, the laser energy that reaches the gate metal surface is E3, and complete reflection occurs (the reflected laser energy is E3'). After absorption by the gate dielectric layer again, the laser energy that reaches the carbon nanotube layer is E4, and reflection and transmission occur again at this interface (the reflected laser energy is E4', and the transmitted laser energy is E4'').

[0022] (3) By analyzing the laser irradiation process, the effective laser energy that generates single-event effect in carbon-based devices. Its formula is ; Based on the reflection and transmission process of laser light in materials, let R be the reflectivity of the laser, α be the absorption coefficient, and d be the material thickness, then... ; ; ; ; ; ; ; ; ; ; .

[0023] in , and The laser reflectivity, absorption coefficient, and thickness of the first layer material are given. , and The laser reflectivity, absorption coefficient, and thickness of the second layer material are given. The laser reflectivity of the third layer material.

[0024] (4) Introduce the effective laser energy to obtain the chip's single-event effect sensitive area. The value is: = ; (5) The above formula is simplified by referring to the typical structure and parameters of carbon nanotubes to obtain the chip single-event effect sensitive area. The value is: ; (6) Taking into account the carrier conversion efficiency of carbon-based devices, the above formula is modified by introducing a correction factor. Ultimately, the single-event effect of carbon-based devices was obtained. for: =1.02 10 4 ; The wavelength λ of the pulsed laser is 1064 nm; The common gate dielectric material for the chip is HfO2; The gate metal material of the chip is commonly Pd; α is the light absorption coefficient of carbon nanotubes, which is 2.4 for a 1064nm wavelength laser. 10 5 cm -1 ; ρ is the density of carbon, with a typical value of 1.3 g / cm³. 3 ; R1 is the reflectivity of the carbon nanotube, with a typical value of 0.28; The The ratio of the energy required to generate an electron-hole pair for heavy ions and pulsed lasers in carbon-based devices, typically 11.11; The This is a correction factor for carbon-based devices, with a typical value of 0.11%. The laser energy Its unit is nJ; The equivalent LET value Its unit is MeV·cm 2 / mg.

[0025] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for calculating the equivalent LET value of a single-event effect pulsed laser on a carbon-based device, the method being implemented using a single-event effect pulsed laser testing system for carbon-based devices, characterized in that... The system includes: a pulsed laser, a probe testing platform, a power supply system, a control system, and a high-frequency oscilloscope; The pulsed laser is used as an irradiation source for single-event effects to induce single-event effects in carbon-based devices. The probe testing platform is used to place the carbon-based device and cooperate with the pulsed laser to induce the single-event effect in the carbon-based device. The power supply system is used to supply power to the carbon-based device; The control system is used to induce the single-event effect in the carbon-based device by controlling the probe testing platform, the pulsed laser, and the power supply system. The high-frequency oscilloscope is used to acquire the single-event effect signal; The method includes: Based on the definition of the equivalent LET value of a pulsed laser and the attenuation law of laser intensity with incident depth x, under the linear absorption mechanism, each photon generates an electron-hole pair, thus obtaining the equivalent LET value of a pulsed laser. Value, based on pulsed laser equivalent Value, to obtain the pulsed laser equivalent heavy ion value in the sensitive area of ​​the device. size; For carbon-based devices, a front-side irradiation method is used, based on the reflection and absorption attenuation of pulsed laser energy by each layer of the chip material; By analyzing the laser irradiation process, the effective laser energy for generating single-particle effects in carbon-based devices was determined. ; Based on the effective laser energy, the single-event effect sensitive area of ​​the chip is obtained. value; Based on the typical structure and parameters of carbon nanotubes, the single-particle effect sensitive region of the chip is... The values ​​are simplified to obtain the simplified chip single-event effect sensitive area. value; Based on the carrier conversion efficiency of carbon-based devices, a correction factor is introduced. Ultimately, the single-event effect of carbon-based devices was obtained. ; For carbon-based devices, a front-side irradiation method is used, and the methods based on the reflection and absorption attenuation of pulsed laser energy by each layer of the chip include: Based on the device's structural characteristics, when a laser with an initial energy of E1 irradiates a carbon-based device, reflection and transmission occur on the surface of the carbon-based device. The reflected laser energy is... Transmitted laser energy After entering the carbon-based device and being absorbed, the laser energy reaching the gate dielectric surface is E2. Reflection and transmission occur at this interface, where the reflected laser energy is... The transmitted laser energy is After absorption by the gate dielectric layer, the laser energy reaching the gate metal surface is E3, resulting in complete reflection. The reflected laser energy is... The laser energy, E4, reaches the carbon nanotube layer after absorption by the gate dielectric layer. At this interface, reflection and transmission occur again, with the reflected laser energy being... The transmitted laser energy is ; By analyzing the laser irradiation process, the effective laser energy for generating single-particle effects in carbon-based devices was determined. The methods include: ； Based on the reflection and transmission process of laser light in materials, let R be the reflectivity of the laser, α be the absorption coefficient, and d be the material thickness, then... in , and The laser reflectivity, absorption coefficient, and thickness of the first layer material are given. , and The laser reflectivity, absorption coefficient, and thickness of the second layer material are given. The laser reflectivity of the third layer material; Based on the carrier conversion efficiency of carbon-based devices, a correction factor is introduced. Ultimately, the single-event effect of carbon-based devices was obtained. The methods include: ； Where ρ is the density of the incident semiconductor material. The ratio of the energy required to generate an electron-hole pair for heavy ions and pulsed lasers. , λ is the energy required to excite a pair of electron-hole pairs with heavy ions, h is the Planck constant, and c is the speed of light.

2. The method according to claim 1, characterized in that, The probe testing platform consists of an objective lens, a CCD camera, a three-dimensional moving stage, a probe station, a vacuum pump, and a T-type biaser. The probe station is disposed at the upper end of the three-dimensional moving platform and is used to fix the carbon-based device; The three-dimensional moving stage is used to move the carbon-based device; The T-type bias is disposed at one end of the probe station and is used to power the carbon-based device, as well as to isolate DC signals and acquire high-frequency signals; The vacuum pump is connected to the probe station and is used for vacuum adsorption of semiconductor test devices; The objective lens is positioned above the probe stage and is used to focus the laser light from the pulsed laser onto the surface of the carbon-based device. The CCD camera is positioned directly above the objective lens to capture the focusing effect, and based on the focusing effect, the objective lens is adjusted to focus the laser onto the surface of the carbon-based device.

3. The method according to claim 1, characterized in that, Based on pulsed laser equivalent Value, to obtain the pulsed laser equivalent heavy ion value in the sensitive area of ​​the device. Methods for determining size include: Pulsed laser equivalent The value is: ； Pulsed laser equivalent heavy ion in the sensitive area of ​​the device Size: ； In the formula, λ is the energy required to excite a pair of electron-hole pairs by heavy ions, λ is the pulsed laser wavelength, h is Planck's constant brightness, c is the speed of light, and α is the absorption coefficient of the laser in the semiconductor. The effective pulsed laser energy is the energy that can penetrate the single-event effect sensitive region, ρ is the density of the incident semiconductor material, and d is the thickness of the single-event effect sensitive layer on the chip. The ratio of the energy required to generate an electron-hole pair for heavy ions and pulsed lasers. .

4. The method according to claim 1, characterized in that, Based on the effective laser energy, the single-event effect sensitive area of ​​the chip is obtained. The methods for determining values ​​include: 。 5. The method according to claim 4, characterized in that, Based on the typical structure and parameters of carbon nanotubes, the single-particle effect sensitive region of the chip is... The values ​​are simplified to obtain the simplified chip single-event effect sensitive area. The methods for determining values ​​include: 。

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