Two-dimensional semiconductor material impurity online detection system

Abstract

The utility model relates to the technical field of semiconductor detection, and aims to provide a two-dimensional semiconductor material impurity online detection system which comprises a main analysis target chamber and a sample replacement target chamber, the sample injection system comprises a magnetic coupling transmission rod connected with the sample change target chamber and a manipulator connected with the main analysis target chamber; the sample processing system comprises a laser annealing device and a sample rack positioned in the main analysis target chamber; the Ar + ion gun system is connected with the main analysis target chamber; the flight time detector is connected with the main analysis target chamber; the data acquisition system comprises a nuclear electronics system and is used for converting detected signals into electric signals and transmitting the electric signals to a computer. Through the cooperation of the main analysis target chamber, the sample changing target chamber, the sample injection system, the sample processing system, the Ar + ion gun system, the flight time detector and the nuclear electronics system, the dynamic data acquisition and analysis are realized, and the problem that the impurity H element of the two-dimensional semiconductor material cannot be nondestructively detected by the conventional surface analysis method is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor detection, in particular to an on-line detection system for impurities in two-dimensional semiconductor materials. Background Art

[0002] In recent years, with the continuous improvement of the requirements for the integration and performance of microelectronic devices in various fields, the development of new high-performance functional devices based on two-dimensional semiconductor materials has become an important link and a key direction to break through the current technical bottleneck. Due to its advantages such as atomic-level thickness, flat surface without dangling bonds, no surface states, high intrinsic carrier mobility, rich energy band structure, and excellent mechanical flexibility, two-dimensional semiconductor materials are widely used in field-effect transistors (FETs), integrated circuits, and nanoelectronic devices with special functions such as sensors and memristors.

[0003] Although two-dimensional semiconductor materials have broad performance in electronic and optoelectronic applications, the fabrication of reliable nano-devices based on two-dimensional semiconductor materials faces many challenges, including the synthesis and characterization of two-dimensional semiconductor materials, device fabrication and integration, etc. For example, two-dimensional semiconductors with atomic-level thickness are extremely sensitive to the process environment, and it is inevitable to introduce impurity elements (chemical doping, uncontrollable intrinsic and extrinsic defects generated by the reaction of the two-dimensional surface with air and moisture, etc.), especially hydrogen element, during the synthesis of two-dimensional semiconductor materials, device fabrication and integration. The presence of impurity hydrogen element will greatly affect the performance of the device to a large extent. Therefore, the characterization of impurity hydrogen element is particularly important. The existing non-destructive element analysis methods for two-dimensional semiconductor materials mainly include Energy Dispersive Spectrometer (EDS) and X-Ray Photoelectron Spectroscopy (XPS). However, EDS can only analyze elements from 4Be to 92U and later, and cannot be used to analyze ultra-light elements (H, He, and Li); XPS can analyze all elements except H and He, and can detect impurities existing on the surface of the sample from 1 to 12 nm. Therefore, they cannot detect impurity hydrogen element. In addition to the above methods, Secondary Ion Mass Spectroscopy (SIMS) can theoretically detect all elements and their isotopes on the periodic table, but it has defects such as matrix effect, difficult quantitative analysis, and difficult spectral identification when the sample composition is complex. Therefore, developing a simple on-line detection device for impurity hydrogen element in two-dimensional semiconductor materials is an important problem that needs to be solved urgently at present. Summary of the Utility Model

[0004] The purpose of the utility model is to provide an online detection system for impurities in two-dimensional semiconductor materials to solve the problems raised in the above-mentioned background technology.

[0005] The technical solution adopted by the utility model is as follows:

[0006] A two-dimensional semiconductor material impurity online detection system, comprising a main analysis target chamber: the main analysis target chamber is used for impurity detection and sample annealing of two-dimensional semiconductor materials; a sample changing target chamber: the sample changing target chamber is connected to the main analysis target chamber and is used to quickly change samples without destroying the vacuum condition of the main analysis target chamber; a sample injection system: the sample injection system comprises a magnetic coupling transmission rod connected to the sample changing target chamber and a manipulator connected to the main analysis target chamber; a sample processing system: the sample processing system comprises a four-dimensional joystick connected to the main analysis target chamber, a sample rack located in the main analysis target chamber and connected to the four-dimensional joystick, and a laser annealing device located at an observation window on the main analysis target chamber; Ar + Ion gun system: the Ar + The ion gun system includes an Ar + Ion gun; time-of-flight detector: the time-of-flight detector is connected to the main analysis target chamber and is used to measure the flight time spectrum of scattered particles and recoil particles; data acquisition system: the data acquisition system includes a nuclear electronics system, which is used to convert the signal detected by the time-of-flight detector into an electrical signal and transmit it to a computer.

[0007] The main analysis target chamber is a spherical target chamber, and the sample changing target chamber is a vertically placed cylindrical target chamber. The main analysis target chamber and the sample changing target chamber are respectively connected to a vacuum pump group, which is used to generate and maintain vacuum in the main analysis target chamber and the sample changing target chamber.

[0008] A manual gate valve is installed between the main analysis target chamber and the sample change target chamber.

[0009] The magnetic coupling transmission rod and the manipulator are both horizontally installed on the equatorial plane of the main analysis target chamber, and the angle between the magnetic coupling transmission rod and the manipulator is 90°.

[0010] The four-dimensional joystick is vertically installed on the top of the upper hemisphere of the main analysis target room and is perpendicular to the equatorial plane of the main analysis target room.

[0011] The sample rack is located at the center of the main analysis target chamber, the middle of the sample rack is a hollow structure, a sample holder for carrying samples is arranged on the front of the sample rack, and the top of the sample rack is connected to the bottom of the four-dimensional joystick.

[0012] The laser annealing device consists of a laser located at the observation window. The high-power laser beam generated by the laser is used to locally heat the two-dimensional semiconductor material sample to eliminate or reduce the defects of the sample.

[0013] The said Ar + ion gun is a multi-functional ion gun using argon as the working gas, and is used to emit Ar + ion beam current.

[0014] The included angle between the said Ar + ion gun and the sample holder is 10°, and the included angle between the Ar + ion gun and the time-of-flight detector is 20°.

[0015] The said time-of-flight detector is a metal anode microchannel plate detector.

[0016] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present utility model are as follows:

[0017] 1) Through the cooperation among the main analysis target chamber, the sample-changing target chamber, the sample introduction system, the sample processing system, the Ar+ ion gun system, the time-of-flight detector and the nuclear electronics system, the functions of dynamic data acquisition and analysis are realized, and the problem that the existing conventional surface analysis methods cannot nondestructively detect the impurity H element in the two-dimensional semiconductor material is solved;

[0018] 2) By making the low-energy Ar + ion beam incident on the two-dimensional semiconductor material at a small angle, the damage caused by the Ar + ion beam penetrating through the two-dimensional semiconductor material is avoided, and at the same time, the influence of the matrix effect on the impurity detection of the two-dimensional semiconductor material is reduced; and through the accurate collection of information from the surface particles by the time-of-flight detector, the detection of the impurity elements in the two-dimensional semiconductor material, especially the detection of the H element, is realized, which has the advantages of low cost, easy operation, high efficiency, high detection sensitivity, etc. Description of the Drawings

[0019] Figure 1 is the overall structural schematic diagram of the embodiment of the present utility model.

[0020] Figure 2 is the schematic diagram of the working principle of the embodiment of the present utility model.

[0021] Figure 3 is the schematic diagram of the time-of-flight spectrum of the 3keV-Ar + sputtering on the Si(100) surface in the embodiment of the present utility model, where S represents the scattered particles and DR represents the recoil particles.

[0022] Figure reference numbers and names: sample-changing target chamber 1, main analysis target chamber 2, sample rack 3, computer 4, nuclear electronics system 5, time-of-flight detector 6, observation window 7, manipulator 8, Ar + ion gun 9, gate valve 10, magnetic coupling transfer rod 11. Detailed implementation manners

[0023] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. The components of the embodiments of the present utility model usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present utility model provided in the accompanying drawings is not intended to limit the scope of the claimed present utility model, but merely represents the selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts fall within the scope of protection of the present utility model.

[0025] As Figure 1 shown, an on-line impurity detection system for two-dimensional semiconductor materials according to the present utility model includes a sample-changing target chamber 1, a main analysis target chamber 2, a sample introduction system, a sample processing system, an Ar + ion gun system, a time-of-flight detector 6, a nuclear electronics system 5 and a computer 4.

[0026] The main analysis target chamber 2 is a spherical target chamber for impurity detection and sample annealing treatment of two-dimensional semiconductor materials. The main analysis target chamber 2 is connected to a vacuum pump set to generate and maintain a vacuum in the main analysis target chamber 2, and the vacuum can reach 3×10 -8 Pa.

[0027] The sample-changing target chamber 1 is a vertically placed cylindrical target chamber for quickly changing samples without destroying the vacuum condition of the main analysis target chamber 2. The sample-changing target chamber 1 is connected to a vacuum pump set to generate and maintain a vacuum in the sample-changing target chamber 1, and the vacuum can reach 10 -8 Pa; the sample-changing target chamber 1 is communicated with the main analysis target chamber 2, and a manual gate valve is installed between the main analysis target chamber 2 and the sample-changing target chamber 1. When sample changing is not required, the two target chambers can be separated by closing this gate valve, so that the two vacuum chambers are independent of each other and do not affect each other.

[0028] The sample injection system includes a magnetic coupling transfer rod 11 connected to the sample changing target chamber 1 and a manipulator 8 connected to the main analysis target chamber 2. The magnetic coupling transfer rod 11 and the manipulator 8 are both horizontally installed in the equatorial plane of the main analysis target chamber 2, and the angle between the magnetic coupling transfer rod 11 and the manipulator 8 is 90°. The magnetic coupling transfer rod 11 is used to transfer the sample in the sample changing target chamber 1 to the main analysis target chamber 2, and then the manipulator 8 installs the sample on the sample holder 3. Among them, both the magnetic coupling transfer rod 11 and the manipulator 8 are off-the-shelf products available on the market.

[0029] The sample processing system includes a four-dimensional joystick connected to the main analysis target chamber 2, a sample holder 3 located inside the main analysis target chamber 2 and connected to the four-dimensional joystick, and a laser annealing device located at the observation window 7 of the main analysis target chamber 2; the four-dimensional joystick is vertically installed at the top of the upper hemisphere of the main analysis target chamber 2 and is perpendicular to the equatorial plane of the main analysis target chamber 2; the sample holder 3 is located at the center of the main analysis target chamber 2, and the middle of the sample holder 3 is a hollow structure. A sample tray for carrying the sample is provided on the front of the sample holder 3, and the top of the sample holder 3 is connected to the bottom of the four-dimensional joystick; the laser annealing device consists of a laser located at the observation window 7, and the high-power laser beam generated by the laser is used to locally heat the two-dimensional semiconductor material sample to eliminate or reduce the defects of the sample. It should be noted that during actual use, the sample can also be heated, annealed, and cleaned by installing an electron beam bombardment annealing device on the back of the sample holder 3. Among them, the four-dimensional joystick, the laser annealing device, and the electron beam bombardment annealing device are also off-the-shelf products available on the market.

[0030] Ar + The ion gun system includes an Ar + ion gun 9 connected to the main analysis target chamber 2. + The ion gun 9 is a multi-functional ion gun, using argon as the working gas to provide pulsed ion beams. + The angle between the ion gun 9 and the sample holder 3 is 10°. + The angle between the ion gun 9 and the time-of-flight detector 6 is 20°. + The ion gun 9 uses the multi-functional ion gun product developed by our school, and its patent publication numbers are CN104091741 B and CN219393323U.

[0031] The time-of-flight detector 6 is connected to the main analysis target chamber 2, and its core component is a metal anode microchannel plate detector, which is used to measure the time-of-flight spectra of scattered particles and recoil particles.

[0032] The data acquisition system includes a nuclear electronics system 5 and a computer 4. The nuclear electronics system 5 is a conventional nuclear electronics system for signal reading, which is used to convert the signals detected by the time-of-flight detector 6 into electrical signals and transmit them to the computer 4.

[0033] The working principle of the utility model is as follows Figure 2 As shown, Ar + Ion gun 9 generates pulsed Ar + The ion beam enters the time-of-flight detector 6 after sputtering the sample surface. The output pulse signal of the time-of-flight detector 6 is transmitted to the computer 4 through the nuclear electronics system 5 for data analysis and processing.

[0034] The method of using the utility model comprises the following specific steps:

[0035] Step S1: using a magnetic coupling transfer rod to transfer a sample holder with a sample from the sample changing target chamber to the main analysis target chamber, and then using a manipulator to install the sample holder on the sample rack;

[0036] Step S2: Use the four-dimensional joystick to adjust the position of the sample holder so that the Ar + The ion beam sputtered the sample surface at an incident angle of 10°;

[0037] Step S3: using a time-of-flight detector to measure the time-of-flight spectra of scattered particles and recoil particles;

[0038] Step S4: Perform data analysis. In order to determine the surface impurity components, the type of surface impurity elements can be determined using a calibrated mass spectrum. In addition, the area (or peak height) corresponding to different element peaks in the time-of-flight scattering recoil spectrum can reflect the relative content of the element on the surface;

[0039] Step S5: annealing the sample. Then, repeat steps S2-S4 to perform comparative analysis.

[0040] Specifically, in the present invention, Ar + Pulsed Ar from ion gun 9 + The energy of the beam is 3keV. The Si(100) sample is placed on the sample holder 3. Its position is adjusted by a four-dimensional joystick so that the beam sputters the sample surface at an incident angle of 5°. + The sample surface is bombarded and elastically collides with the surface impurity elements H, C and O atoms. According to the classical two-body collision model, the energy of the recoil H atom is 252.14 eV, and the corresponding velocity is 2.21×10 5 m / s. The recoil H atom flies 141 cm before arriving at the time-of-flight detector 6. The H atom has the smallest mass and the shortest flight time. By delaying the electrons, the peak corresponding to the H element can be located at the rightmost end of the time-of-flight spectrum. Figure 3As shown, the relative share of the element on the surface can be obtained by the ratio of the count corresponding to the element on the time-of-flight spectrum to the total count. Then, through the correction of the scattering cross-section and the recoil cross-section, an accurate share value can be obtained.

Claims

1. An on-line impurity detection system for two-dimensional semiconductor materials, characterized in that, Comprising: Main analysis target chamber (2): The main analysis target chamber (2) is used for impurity detection and sample annealing treatment of two-dimensional semiconductor materials; Sample-changing target chamber (1): The sample-changing target chamber (1) is connected to the main analysis target chamber (2) and is used for quickly changing samples without destroying the vacuum condition of the main analysis target chamber (2); Sample injection system: The sample injection system includes a magnetic coupling transfer rod (11) connected to the sample-changing target chamber (1) and a manipulator (8) connected to the main analysis target chamber (2); Sample processing system: The sample processing system includes a four-dimensional joystick connected to the main analysis target chamber (2), a sample holder (3) located inside the main analysis target chamber (2) and connected to the four-dimensional joystick, and a laser annealing device located at the observation window (7) of the main analysis target chamber (2); Ar + Ion gun system: The Ar + ion gun system includes an Ar ion gun (9) connected to the main analysis target chamber (2); + ​ Time-of-flight detector (6): The time-of-flight detector (6) is connected to the main analysis target chamber (2) and is used to measure the time-of-flight spectra of scattered particles and recoil particles; Data acquisition system: The data acquisition system includes a nuclear electronics system (5), and the nuclear electronics system (5) is used to convert the signals detected by the time-of-flight detector (6) into electrical signals and transmit them to a computer (4).

2. The on-line impurity detection system for two-dimensional semiconductor materials according to claim 1, characterized in that: The main analysis target chamber (2) is a spherical target chamber, and the sample-changing target chamber (1) is a vertically placed cylindrical target chamber. The main analysis target chamber (2) and the sample-changing target chamber (1) are respectively connected to a vacuum pump group, and the vacuum pump group is used to generate and maintain a vacuum in the main analysis target chamber (2) and the sample-changing target chamber (1).

3. The on-line impurity detection system for two-dimensional semiconductor materials according to claim 2, characterized in that: A manual gate valve is installed between the main analysis target chamber (2) and the sample-changing target chamber (1).

4. The on-line impurity detection system for two-dimensional semiconductor materials according to claim 1, characterized in that: The magnetic coupling transfer rod (11) and the manipulator (8) are both horizontally installed on the equatorial plane of the main analysis target chamber (2), and the included angle between the magnetic coupling transfer rod (11) and the manipulator (8) is 90°.

5. The on-line impurity detection system for two-dimensional semiconductor materials according to claim 1, characterized in that: The four-dimensional joystick is vertically installed at the top of the upper hemisphere of the main analysis target chamber (2) and is perpendicular to the equatorial plane of the main analysis target chamber (2).

6. The on-line impurity detection system for two-dimensional semiconductor materials according to claim 5, characterized in that: The sample holder (3) is located at the center of the sphere of the main analysis target chamber (2). The middle of the sample holder (3) is a hollow structure. A sample tray for carrying samples is provided on the front of the sample holder (3), and the top of the sample holder (3) is connected to the bottom of the four-dimensional joystick.

7. The on-line impurity detection system for two-dimensional semiconductor materials according to claim 1, characterized in that: The laser annealing device consists of a laser located at the observation window (7). The high-power laser beam generated by the laser is used to locally heat the two-dimensional semiconductor material sample to eliminate or reduce the defects of the sample.

8. The on-line impurity detection system for two-dimensional semiconductor materials according to claim 1, characterized in that: The Ar + ion gun (9) is a multi-functional ion gun using argon as the working gas, and is used to emit an Ar + ion beam with a specific energy.

9. The on-line impurity detection system for two-dimensional semiconductor materials according to claim 8, characterized in that: The Ar + ion gun (9) and the sample stage (3) form an angle of 10°, and the Ar + ion gun (9) and the time-of-flight detector (6) form an angle of 20°.

10. The on-line impurity detection system for two-dimensional semiconductor materials according to claim 1, wherein: The time-of-flight detector (6) is a metal anode microchannel plate detector.

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