Atmospheric continuous wafer proton irradiation device for manufacturing high-performance power chip

Abstract

The invention relates to an under-atmosphere continuous wafer proton irradiation device for manufacturing high-performance power chips, which comprises two stock bin assemblies and an irradiation assembly arranged between the two stock bin assemblies, and the stock bin assemblies are provided with material trays capable of moving in the vertical direction and the horizontal direction; the irradiation assembly comprises an irradiation tray moving platform; an X-direction unpowered chip tray conveying roller group and a Y-direction fine adjustment servo module are arranged on the irradiation tray moving platform; an air cooling beam scanning window is arranged above the X-direction unpowered chip tray conveying roller group, and a scanning box is arranged above the air cooling beam scanning window; and a beam monitor is arranged below the irradiation tray moving platform. According to the invention, continuous proton irradiation of a power chip wafer can be realized in an atmospheric environment, batch continuous wafer proton irradiation is realized through the design of the double bins, the irradiation production efficiency is effectively improved, and thus better economic benefits are achieved.

Description

Technical Field

[0001] The invention belongs to the field of chip technology, and in particular relates to an atmospheric continuous wafer proton irradiation device for manufacturing high-performance power chips. Background Art

[0002] At present, with the rapid development of electric vehicles, high-speed rail transit, ultra-high voltage flexible direct current transmission, new energy power generation and other fields, the demand for high-end power chips is increasing. According to statistics, 93% of the high-end power chips represented by IGBT (Insulated Gate Bipolar Transistor) needed by China in 2020 need to be imported. Due to the lack of deep proton irradiation production process, the performance of domestic IGBT and other power chips cannot be compared with imported chips. The fast recovery diodes (FRD chips) currently produced in China cannot achieve performance with a softness factor of more than 2 due to the lack of deep proton irradiation process, and cannot be used in conjunction with IGBT chips in fields such as electric vehicles. Summary of the invention

[0003] The purpose of the present invention is to provide a continuous wafer proton irradiation device under atmosphere for manufacturing high-performance power chips in order to solve the above-mentioned problems.

[0004] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0005] A continuous wafer proton irradiation device under atmosphere for manufacturing high-performance power chips, comprising two silo assemblies and an irradiation assembly arranged between the two silo assemblies, wherein a material tray movable in vertical and horizontal directions is arranged on the silo assemblies;

[0006] The irradiation assembly includes an irradiation tray moving platform, on which an X-direction non-powered chip tray conveying roller group and a Y-direction fine-tuning servo module for driving the tray to move in the X-direction and the Y-direction on the horizontal plane are arranged; an air-cooled beam scanning window is arranged above the X-direction non-powered chip tray conveying roller group, and a scanning box is arranged above the air-cooled beam scanning window; a beam monitor is arranged below the irradiation tray moving platform, and the scanning box, the air-cooled beam scanning window and the beam monitor are located on the same vertical line.

[0007] As a further optimization solution of the present invention, the two silo components are respectively a left silo and a right silo;

[0008] The left material bin comprises a left material bin fixed grid, a left material bin support is arranged at the bottom side of the left material bin fixed grid, a left material bin sheet storage grid is arranged on the left material bin fixed grid, the material tray is divided into a left material tray and a right material tray, and a plurality of the left material trays are placed on the left material bin sheet storage grid; a left material bin tray push rod is arranged on the left material bin fixed grid, and the left material bin tray push rod is used to push the left material tray on the left material bin sheet storage grid onto the X-direction non-powered chip tray conveying roller group, or to pull the left material tray on the X-direction non-powered chip tray conveying roller group back to the left material bin sheet storage grid;

[0009] The right material bin includes a right material bin fixed frame, a right material bin support is arranged on the bottom side of the right material bin fixed frame, a right material bin film storage frame is arranged on the right material bin fixed frame, and a plurality of right material trays are placed on the right material bin film storage frame; a right material bin tray push rod is arranged on the right material bin fixed frame, and the right material bin tray push rod is used to push the right material tray on the right material bin film storage frame onto the X-direction non-powered chip tray conveying roller group, or to pull the right material tray on the X-direction non-powered chip tray conveying roller group back to the right material bin film storage frame.

[0010] As a further optimization scheme of the present invention, the left silo fixed grid and the right silo fixed grid are both provided with grid lifting drive motors, which are respectively used to drive the left silo storage grid and the right silo storage grid to move vertically.

[0011] As a further optimization scheme of the present invention, a left silo position monitor for checking the placement position of the left material tray is provided on the left silo fixed grid; a right silo position monitor for checking the placement position of the right material tray is provided on the right silo fixed grid.

[0012] As a further optimization solution of the present invention, a beam position monitor for detecting the position of the beam output from the air-cooled beam scanning window is provided on the left silo fixed grid.

[0013] As a further optimization solution of the present invention, an irradiation tray moving platform position monitor for monitoring the position of the X-axis non-powered chip tray conveying roller group is provided on the right silo fixed grid.

[0014] As a further optimization solution of the present invention, a support for the XY-direction moving platform of the irradiation tray is provided on the bottom side of the moving platform of the irradiation tray for supporting the irradiation tray.

[0015] As a further optimization scheme of the present invention, a scanning box bracket is arranged above the X-axis non-powered chip tray conveying roller group, the scanning box is arranged on the scanning box bracket, and the scanning box includes a scanning box upper section and a scanning box lower section; the scanning box upper section, the scanning box lower section and the scanning box bracket are all in a vacuum state.

[0016] As a further optimization scheme of the present invention, a tray picking module is provided on the X-axis non-powered chip tray conveying roller group, and both sides of the tray picking module are provided with electromagnet modules for alternately grabbing the trays in the two silo assemblies.

[0017] As a further optimization solution of the present invention, the distances from the two silo assemblies to the proton beam position are both greater than the length of the material tray.

[0018] The beneficial effects of the present invention are:

[0019] The present invention can realize continuous proton irradiation of power chip wafers in an atmospheric environment. Through a double-bin design, it focuses on realizing batch continuous wafer proton irradiation, effectively improving irradiation production efficiency, thereby achieving better economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 It is a schematic diagram of the combined structure of the material tray taking module and the electromagnet module of the present invention;

[0022] Figure 3 It is a classification diagram of power semiconductor devices;

[0023] Figure 4 This is a schematic diagram of the parallel connection of the IGBT chip and the FRD chip;

[0024] Figure 5 It is a structural diagram of a PIN structure FRD;

[0025] Figure 6 It is a schematic diagram of the reverse recovery current and voltage waveform of FRD;

[0026] Figure 7 This is a diagram of the manufacturing process of chips such as IGBT and FRD.

[0027] In the figure: 1. Left silo fixed grid; 2. Beam position monitor; 3. Left silo position monitor; 4. Left silo tray push rod; 5. Left silo film storage grid; 6. Left silo support; 7. Scanning box upper section; 8. Scanning box lower section; 9. Air-cooled beam scanning window; 10. Scanning box bracket; 11. Tray material taking module; 12. Electromagnet module; 13. Right silo; 14. Left silo; 15. X-axis non-powered chip tray conveying roller group; 16. Y-axis fine-tuning servo module; 17. Irradiation tray moving platform; 18. Beam monitor; 19. Irradiation tray XY moving platform support; 20. Irradiation tray moving platform position monitor; 21. Right silo position monitor; 22. Right silo fixed grid; 23. Right silo tray push rod; 24. Right silo film storage grid; 25. Right silo support; 26. Grid lifting drive motor. DETAILED DESCRIPTION

[0028] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0029] With the rapid development of my country's economy, power electronics technology has become an indispensable technology to promote national development, and is also an important supporting technology for the development of various high-tech technologies in the national economy. Modern power electronics technology is widely used in scientific research, industry, electricity, transportation systems, electronic communications, computer fields and new energy systems in the national economy due to its high efficiency, energy saving and strong practicality. In addition, it is also widely used in household appliances such as lighting and other fields.

[0030] Power electronic devices, also known as power semiconductor devices, are high-power electronic devices mainly used in power equipment power conversion and control circuits. The core and foundation of power electronic technology is power semiconductor devices, and the main problem that power electronic technology needs to solve is how to use power semiconductor devices to achieve high-efficiency transmission and conversion of electric energy and precise control during the process, so as to achieve effective use of electric energy.

[0031] In the 1950s, power electronic devices were mainly mercury arc thyristors and high-power electron tubes. Thyristors developed in the 1960s were widely used in power electronic circuits because of their reliable operation, long life, small size and fast switching speed. In the early 1970s, they gradually replaced mercury arc thyristors. In the 1980s, the switching current of ordinary thyristors reached thousands of amperes, and the forward and reverse working voltages they could withstand reached thousands of volts. On this basis, in order to meet the needs of the development of power electronic technology, a series of derivative devices such as gate turn-off thyristors, bidirectional thyristors, photo-controlled thyristors, reverse conducting thyristors, as well as new power electronic devices such as unipolar MOS power field effect transistors, bipolar power transistors, electrostatic induction thyristors, functional combination modules and power integrated circuits have been developed. Each generation of power semiconductor products has also continuously broken through the original technical bottlenecks in practice, and derived many specifications and models to adapt to different downstream products. The emergence of new technologies and new products has broadened the application scope of existing products and technologies and adapted to the needs of more terminal products. However, each generation of products has irreplaceable advantages in parameters such as frequency, power, and switching speed. The emergence of a new generation of products and new technologies cannot replace the original products and technologies, and a pattern of coexistence of multiple generations of power semiconductor discrete device products has been formed in the market.

[0032] Various power electronic devices have two working characteristics: conduction and blocking. Various types of power semiconductor devices are classified as follows: Figure 3 As shown. In addition to overvoltage and overcurrent protection devices, power devices can be divided into three categories according to their working characteristics: the first category - uncontrollable power devices, that is, power diodes, are two-terminal (cathode and anode) devices, whose device current is determined by the volt-ampere characteristics. Except for changing the voltage applied between the two terminals, its anode current cannot be controlled; the second category - semi-controlled power devices, that is, ordinary thyristors, are three-terminal devices, whose gate signals can control the conduction of the components, but cannot control their shutdown; the third category - fully controlled power devices, that is, devices such as turn-off thyristors and power transistors, whose gate signals can control both the conduction and shutdown of the devices. The latter two types of devices are flexible to control, simple in circuit, and fast in switching speed. They are widely used in rectification, inversion, and chopping circuits, and are core components in power electronic devices such as motor speed regulation, generator excitation, induction heating, electroplating, electrolytic power supply, and direct power transmission. The devices composed of these devices are not only small in size and reliable in operation, but also have obvious energy-saving effects (generally saving 10% to 40% of electricity).

[0033] High-voltage and high-power semiconductor devices mainly refer to high-power electronic devices used in power conversion and power control circuits, that is, fully controllable power devices with self-shutdown capabilities including GTO, IGBT, MOSFET, etc.

[0034] Since the beginning of the 21st century, new energy represented by large-scale wind power generation and solar power generation has become the key development direction of my country's future energy structure adjustment, while traditional AC and DC transmission technologies have been unable to meet the urgent needs of large-scale wind power and solar power generation to be safely and reliably connected to the power grid. Flexible AC and high-voltage DC transmission based on high-voltage and high-power power electronics technology is one of the core technologies for the future smart grid to achieve safe and efficient access to the power grid for various large-scale new energy sources.

[0035] Among the new generation of high-voltage and high-power turn-off semiconductor devices, IGBT devices have become the preferred devices in high-power power electronics technology due to their superior gate controllability, low on-state loss, and rapid improvement in voltage and current parameters. IGBT can achieve energy conservation and emission reduction, improve the efficiency of power utilization, and has good environmental protection benefits. It is recognized as the most representative product of the third revolution in power electronics technology and is the inevitable direction of future application development.

[0036] In high-voltage and high-current circuits, the switch devices mainly use power semiconductor devices GTO, MOSFET, and IGBT with self-shutdown capability. Taking IGBT as an example, in actual applications, it appears in the form of IGBT modules, such as Figure 4 As shown in the figure, a power diode needs to be connected in parallel with the IGBT inside the IGBT module. It is mainly used to pass the excess current in the circuit load, form a loop with the load, reduce the storage and disappearance time of the charge on the capacitor in the switching device, and weaken the high voltage induced by the parasitic inductance caused by the reverse load current. This is beneficial to delay the aging of the switching device and increase the service life of the device.

[0037] The parallel diode in a general low-power switch is usually called a freewheeling diode (FWD). This type of diode usually has a large current, high voltage, and a reverse recovery time of more than 1μs. Most of them use a diffused punch-through structure and electron irradiation process. The current ranges from tens of amperes to thousands of amperes, and the voltage ranges from hundreds to less than 3000V. The reverse recovery characteristics are usually relatively hard. The structures mainly include a circular structure and a square structure, among which the large-area circular structure has more advantages. With the development of power electronics technology, the switching speed of modern IGBT and MOSFET devices is very fast. The diode is mainly developing in the direction of low voltage drop, high withstand voltage, and fast soft recovery. General power diodes can no longer meet the performance requirements of modern IGBT and other power devices, and how to improve the performance of fast recovery diodes has attracted much attention.

[0038] Fast Recovery Diode (FRD) is a semiconductor diode with good switching characteristics and short reverse recovery time. Since PIN diodes can withstand high voltage, they are widely used in high voltage fields. Figure 5 As shown in the figure, its microscopic electron concentration program gradient distribution is similar to that of a general PN junction diode. The characteristics of FRD are that the N region near the PN junction has a low doping concentration and a very narrow width W. On both sides of it, namely the adjacent P region and N region, the doping concentration is very high, so a high resistance region is formed near the width W.

[0039] During forward conduction, holes are injected from the P+ region into the W region, and electrons are injected from the n+ region into the W region. They are first stored in the equivalent high-resistance region (W region), and then recombine after a certain period of time until they recombine with each other according to their lifetime, forming a stable current and a stable forward voltage drop.

[0040] When reverse voltage is applied, before the PIN diode is broken down, the holes on one side of the P region are attracted by the negative end of the external voltage and leave the high resistance region. Similarly, the electrons in the N region are attracted by the positive end of the external voltage and leave the high resistance region. This effect widens the space charge region inside the material, and the high resistance region (N-) widens faster. As the reverse voltage increases, the space charge of the N-layer continues to widen. When the reverse bias voltage increases to a certain value, the entire N-layer becomes a space charge region, showing a high resistance region penetration state. At the same time, the electric field strength of the P+N-junction quickly reaches the "critical electric field". We call the reverse bias voltage at both ends of the P+N-junction at this time the "breakdown voltage".

[0041] Figure 6 The reverse recovery current and voltage waveform diagram of FRD. When conducting forward current, all PIN diodes will inject a large number of carriers from the anode and cathode, and the hole carriers injected from the anode will store charge in the form of minority carriers in the base region. The minority carrier injection causes the base region to produce a conductivity modulation effect, making the forward on-state voltage drop Vf very low, which is the biggest advantage of PIN diodes and bipolar devices.

[0042] However, when a reverse voltage is suddenly applied to a diode that is conducting, since there are a large number of minority carriers stored in the base region when conducting, these minority carriers need to be completely extracted or neutralized before turning off. This process takes a certain amount of time, and the time used for this process is defined as the reverse recovery time trr. The reverse recovery process severely limits the high-frequency characteristics of the device and needs to be minimized or eliminated. The ideal FRD that people hope for has the advantages of good switching characteristics, short reverse recovery time, large forward current, small size, easy installation, safety and reliability, light weight, and easy to carry. The shorter reverse recovery time also obtains a smaller forward voltage drop to reduce the turn-on loss. However, the root cause of the reverse recovery process is the injection of minority carriers. Minority carrier injection can obtain a smaller forward voltage drop, but the reverse recovery process is inevitable. How to balance the relationship between the two and improve the performance of FRD is still a core problem that needs to be solved urgently.

[0043] FRD is a semiconductor product segment. Typical FRD manufacturing processes include: Figure 7 As shown in the figure, the contradictory relationship between conduction loss and switching frequency in FRD can be improved by controlling the anode emission efficiency and lifetime control technology on silicon-based devices to reasonably adjust the diode structure design.

[0044] At present, there are mainly the following methods to control the minority carrier lifetime in FRD:

[0045] ①Heavy metal doping

[0046] It refers to the diffusion of heavy metal impurities such as gold and platinum into silicon, with the aim of introducing recombination centers to reduce the minority carrier lifetime and thus reduce the reverse recovery time of the device.

[0047] ②Electron irradiation

[0048] It uses electron irradiation to generate induced defects inside the semiconductor as recombination centers to achieve the purpose of controlling the minority carrier lifetime. The finished product is placed in an irradiation field and bombarded with high-energy electrons. The electrons entering the semiconductor collide with silicon atoms to produce basic defects such as gaps and holes. Basic defects interact with silicon atoms or defects to produce secondary defects. These defects are extremely unstable and will gradually disappear completely through annealing at 200-300℃. Electron irradiation mainly forms oxygen vacancies, phosphorus vacancies, and divacancy defects, and correspondingly forms various deep energy level recombination centers in the silicon band gap. The characteristic of electron radiation is that the minority carrier lifetime can be accurately controlled by adjusting the electron injection dose, so that the different requirements of the device electrical parameters for the minority carrier lifetime can be well coordinated, and it can be carried out after the device is manufactured, making the manufacturing process simple and flexible. At present, the electron irradiation energy is selected between 0.5-15MeV. Electrons in this energy range can completely penetrate the device and form evenly distributed induced defects throughout the device. However, the induced defects caused by electron irradiation are unstable and will degenerate and disappear at lower temperatures. Therefore, the long-term stability of devices made by electron irradiation is poor. The carrier lifetime in the depletion region is determined by deep energy level defects. Therefore, compared with platinum-diffused devices, the leakage current of devices made by electron irradiation is relatively large and has not yet been widely used.

[0049] ③ Proton irradiation

[0050] Proton irradiation is currently the only technology that can achieve local lifetime control. The so-called light ions mainly refer to H+ and He2+. Proton irradiation is similar to electron irradiation, both of which use the induced defects generated by irradiation as recombination centers to control the minority carrier lifetime. The mass of light ions is larger than that of electrons, so the injection range is shorter. If the range of light ions is smaller than the axial size of the device, a defect peak with a much higher defect concentration than other positions will be formed at the end of the range (i.e., a high-concentration recombination center area). The defect density between the irradiated surface and the defect peak is only 10% to 20% of the defect peak, which is called defect tailing. The position of the defect peak can be controlled by the irradiation energy. Compared with traditional lifetime control technology, the position of the defect peak formed by proton irradiation provides new design freedom for optimizing device performance. In addition to the irradiation energy, the design of the irradiation process also includes accurately selecting the irradiation dose. However, only one proton irradiation of the device can only obtain a defect peak with a fixed width, so it is impossible to form an arbitrary recombination center concentration distribution. In order to obtain greater design freedom, the device can be irradiated multiple times to form an arbitrary recombination center concentration distribution.

[0051] Pt-doped overall lifetime control FRD is mostly used in IGBT modules with a voltage level of 600-1700V. Electron irradiation overall lifetime control FRD is mostly used in IGBT modules with a voltage level of 600-1200V. H+ or He2+ high energy injection local lifetime control FRD is used in IGBT modules with a voltage level greater than 2500V. Due to the excellent performance of H+ or He2+ high energy injection local lifetime control FRD, some companies have launched 1200V and 1700V FRD made using this technology in recent years, but the price is relatively high. The most advanced FRD technology in the world is proton irradiation and proton irradiation + platinum expansion local lifetime control technology. FRD requires a large softness factor S to improve reliability. Electron irradiation global lifetime control introduces recombination centers to the entire FRD chip and reduces the carrier lifetime, but it has no effect on improving softness. The chip softness factors obtained by several mainstream irradiation methods are as follows: ① PIN structure + electron irradiation method softness factor 0.5-0.6; ② double diffusion double base region + electron irradiation method softness factor greater than 1.0; ③ proton irradiation + platinum extraction method softness factor > 2.0.

[0052] Experiments have shown that the combination of multiple proton irradiation + electron irradiation + heavy metal doping can achieve better device performance than single proton irradiation. However, the cost of multiple irradiation is very high, which greatly limits its application. Therefore, combining global lifetime control of electron irradiation and local lifetime control of light ion implantation can take into account both reverse recovery time and softness.

[0053] In the medium and high power field (voltage 1200V-6500V), IGBT is the mainstream product on the market. IGBT devices (including high power modules and intelligent power modules) have covered voltages of 300V-6500kV and currents of 2A-3600A. In the medium and low power field (below 900V), power MOSFET is the most widely used power electronic device, and it is also the device with the largest market capacity and the fastest demand growth. Among them, new structure devices represented by super junction are an important direction for the development of this device.

[0054] In the future, with the development of emerging industries such as mobile smart terminals, 5G networks, and the Internet of Things, new semiconductor discrete devices will continue to emerge. While replacing existing market applications, they will continue to explore emerging application areas. At the same time, in order to enable existing semiconductor discrete devices to adapt to the rapid changes in market demand, it is necessary to adopt new technologies, develop new application materials, continue to optimize and improve structural design, manufacturing processes and packaging technologies, etc., to improve the performance of devices. In addition, the development trend of miniaturization and intelligence of downstream electronic information products will inevitably require that key components such as semiconductor discrete devices embedded therein be as small, miniaturized and multifunctional as possible. In order to meet the requirements of overall assembly efficiency and improve the reliability and stability of overall performance, semiconductor discrete devices will tend to be miniaturized, modularized in assembly, and systematic in function.

[0055] Example 1

[0056] like Figure 1 As shown, a continuous wafer proton irradiation device under atmosphere for manufacturing high-performance power chips comprises two silo assemblies and an irradiation assembly arranged between the two silo assemblies, wherein a material tray movable in vertical and horizontal directions is arranged on the silo assemblies;

[0057] The irradiation assembly includes an irradiation tray moving platform 17, on which an X-direction non-powered chip tray conveying roller group 15 and a Y-direction fine-tuning servo module 16 for driving the tray to move in the X and Y directions on a horizontal plane are provided; an air-cooled beam scanning window 9 is provided above the X-direction non-powered chip tray conveying roller group 15, and a scanning box is provided above the air-cooled beam scanning window 9; a beam monitor 18 is provided below the irradiation tray moving platform 17, and the scanning box, the air-cooled beam scanning window 9 and the beam monitor 18 are located on the same vertical line.

[0058] The two silo components are respectively a left silo and a right silo;

[0059] The left material bin comprises a left material bin fixed grid 1, a left material bin support 6 is arranged at the bottom side of the left material bin fixed grid 1, a left material bin sheet storage grid 5 is arranged on the left material bin fixed grid 1, the material tray is divided into a left material tray 14 and a right material tray 13, and a plurality of the left material trays 14 are placed on the left material bin sheet storage grid 5; a left material bin tray push rod 4 is arranged on the left material bin fixed grid 1, and the left material bin tray push rod 4 is used to push the left material tray 14 on the left material bin sheet storage grid 5 onto the X-direction non-powered chip tray conveying roller group 15, or to pull the left material tray 14 on the X-direction non-powered chip tray conveying roller group 15 back to the left material bin sheet storage grid 5;

[0060] The right material bin includes a right material bin fixed frame 22, a right material bin support 25 is arranged on the bottom side of the right material bin fixed frame 22, a right material bin film storage frame 24 is arranged on the right material bin fixed frame 22, and a plurality of right material trays 13 are placed on the right material bin film storage frame 24; a right material bin tray push rod 23 is arranged on the right material bin fixed frame 22, and the right material bin tray push rod 23 is used to push the right material tray 13 on the right material bin film storage frame 24 onto the X-direction non-powered chip tray conveying roller group 15, or to pull the right material tray 13 on the X-direction non-powered chip tray conveying roller group 15 back to the right material bin film storage frame 24.

[0061] The left silo fixed grid 1 and the right silo fixed grid 22 are both provided with a grid lifting drive motor 26, which is used to drive the left silo sheet storage grid 5 and the right silo sheet storage grid 24 to move in the vertical direction respectively.

[0062] The left silo fixed grid 1 is provided with a left silo position monitor 3 for checking the placement position of the left material tray 14 ; the right silo fixed grid 22 is provided with a right silo position monitor 21 for checking the placement position of the right material tray 13 .

[0063] The left silo fixed grid 1 is provided with a beam position monitor 2 for detecting the position of the beam output from the air-cooled beam scanning window 9 .

[0064] The right silo fixed grid 22 is provided with an irradiation tray moving platform position monitor 20 for monitoring the position of the X-axis non-powered chip tray conveying roller group 15 .

[0065] The bottom side of the irradiation tray moving platform 17 is provided with an XY moving platform support 19 for supporting the irradiation tray.

[0066] A scanning box bracket 10 is arranged above the X-axis non-powered chip tray conveying roller group 15, and the scanning box is arranged on the scanning box bracket 10. The scanning box includes a scanning box upper section 7 and a scanning box lower section 8; the scanning box upper section 7, the scanning box lower section 8 and the scanning box bracket 10 are all in a vacuum state.

[0067] like Figure 2 As shown, a tray picking module 11 is provided on the X-axis non-powered chip tray conveying roller group 15, and both sides of the tray picking module 11 are provided with electromagnet modules 12 for alternately grabbing the trays in the two bin assemblies.

[0068] The distances from the two silo assemblies to the proton beam position are both greater than the length of the material tray.

[0069] The double-bin structure design enables single-batch proton irradiation of wafers. The device adopts a double-bin grid structure design. The double bin can hold 2,400 3-inch wafers at a time, with large capacity and high production efficiency. Two irradiation methods, single-disc irradiation and double-disc irradiation, enable continuous proton irradiation of large quantities of wafers. The device can simultaneously grab two irradiation trays, realize two irradiation methods, single tray / each time and double tray / each time, minimize the beam waste rate, and achieve continuous proton irradiation of large quantities of wafers. The X, Y moving platform in the irradiation chamber can achieve uniform irradiation of wafers and improve irradiation quality. The grid-type wafer storage array has a large storage capacity. At the same time, according to the subsequent production capacity needs, the capacity is expandable, which further increases the number of wafers irradiated in a single time and improves production efficiency.

[0070] 5. The transmission structure from the array-type wafer storage rack to the irradiation platform ensures the smooth transmission of the wafer tray and its effective placement.

[0071] The structure of the continuous wafer proton irradiation device under atmosphere is introduced as follows: During the proton beam irradiation process, strong gamma rays and neutron rays will be generated, and the ionizing radiation generated during the irradiation process needs to be shielded. At the same time, the irradiated wafers should be placed in different levels of clean environments according to product requirements. Therefore, the continuous wafer proton irradiation device under atmosphere should be placed in a shielded clean room as a whole. Figure 6 In the figure, the upper section 7 of the scanning box, the lower section 8 of the scanning box and the scanning box bracket 10 are all in a vacuum state, and the beam is output through the air-cooled beam scanning window 9. Before the wafer irradiation starts, the proton beam intensity and beam spot shape are measured by the beam monitor 18. After confirming that the beam state meets the requirements, the wafer irradiation starts. The irradiation tray moving platform 17 is connected to the left silo fixed grid 1 and the right silo fixed grid 22. The tray picking module 11 alternately grabs the irradiation trays of the two silos through the electromagnet modules 12 on both sides to realize batch continuous irradiation. The distance from the silos on both sides to the proton beam position is greater than the length of the irradiation tray. The irradiation tray moving platform 17 uses the X-axis non-powered chip tray conveying roller group 15 and the Y-axis fine-tuning servo module 16 to enable the wafer in the irradiation position to move in both the X and Y directions. The maximum moving speeds in the X and Y directions can reach 600mm / s and 100mm / s respectively. At the same time, the irradiation uniformity is controlled by precisely controlling the moving speeds in both directions, and the speed control accuracy is better than 0.1mm / s.

[0072] Normal irradiation workflow of continuous wafer proton irradiation device under atmosphere:

[0073] 1. Manually place trays containing wafers into the left material storage rack 5 and the right material storage rack 24 one by one, and lock the trays to prevent them from moving;

[0074] 2. After all the pallets are placed in the left material storage rack 5 and the right material storage rack 24 of the storage array, the rack lifting drive motor 26 is started to move the left material storage rack 5 and the right material storage rack 24 up and down to check whether the pallets are placed in the appropriate position. If the pallets are placed correctly, the upper and lower positions of the storage array are reset to zero;

[0075] 3. After the personnel have left and the irradiation room is closed, the grid lifting drive motor 26 is started again to move the left material bin storage grid 5 and the right material bin storage grid 24 up and down, and the left material bin position monitor 3 and the right material bin position monitor 21 are used to check whether the tray is properly placed. If the tray is correctly placed, the storage array is moved up and down to the starting position;

[0076] 4. Start the left silo tray push rod 4 and the right silo tray push rod 23 to push the first wafer from the left silo storage rack 5 and the right silo storage rack 24 to the X-axis non-powered chip tray conveying roller group 15, and then the left silo tray push rod 4 and the right silo tray push rod 23 are retracted;

[0077] 5. The tray picking module 11 grabs the left tray 14 through the left electromagnet module 12 and moves the left tray 14 to the irradiation starting zero position to stand by;

[0078] 6. Turn on the proton beam, lead the beam out of the air-cooled beam scanning window 9, use the beam monitor 18 to receive the beam and measure the beam intensity;

[0079] 7. After confirming that the beam parameters are correct, start the tray taking module 11 to drive the left tray 14 to move under the beam for proton irradiation of the wafer;

[0080] This device can achieve continuous wafer proton irradiation under atmosphere through the following two methods.

[0081] Method 1:

[0082] 8. The tray taking module 11 drives the left tray 14 to pass through the proton beam at a set speed. When it moves to the side close to the right tray 13, the tray taking module 11 grabs the right tray 13 through the electromagnet module on the right, and then moves in the opposite direction at a set speed to the left bin direction;

[0083] 9. After the wafers on the left tray 14 are irradiated, the left tray 14 is transferred back to the left material storage rack 5 and separated from the electromagnet module 12. The tray taking module 11 and the right tray 13 stop waiting;

[0084] 10. Extend the left material bin tray push rod 4 to pull the wafer tray back to the initial position in the left material bin storage rack 5. At the same time, the left material bin tray push rod 4 also returns to the initial position;

[0085] 11. Start the left grid lifting drive motor 26 to align the next wafer tray to be irradiated with the X-direction non-powered chip tray conveying roller group 15;

[0086] 12. Use the left silo tray push rod 4 to push the next tray of wafers to be irradiated onto the X-axis non-powered chip tray conveying roller group 15, and then the left silo tray push rod 4 is retracted;

[0087] 13. The tray picking module 11 grabs the left tray 14 through the electromagnet module on the left, and the tray picking module 11 drives the left and right trays to be irradiated by the proton beam at the same time;

[0088] 14. After the wafers on the right tray 13 are irradiated, the right tray 13 is transferred back to the right material storage rack 24 and separated from the electromagnet module 12. The tray taking module 11 and the left tray 14 stop waiting;

[0089] 15. Extend the right bin tray push rod 23 to pull the wafer tray back to the initial position in the right bin storage rack 24, and the right bin tray push rod 23 also returns to the initial position;

[0090] 16. Start the right side grid lifting drive motor 26 to align the next wafer tray to be irradiated with the X-direction non-powered chip tray conveying roller group 15;

[0091] 17. Use the right silo tray push rod 23 to push the next tray of wafers to be irradiated onto the X-axis non-powered chip tray conveying roller group 15, and then the right silo tray push rod 23 is retracted;

[0092] 18. The tray taking module 11 grabs the right tray 13 through the electromagnet module on the right, and the tray taking module 11 simultaneously drives the left and right trays to be irradiated by the proton beam;

[0093] Method 2:

[0094] 19. The material tray taking module 11 drives the left material tray 14 to pass through the proton beam at a set speed;

[0095] 20. After the wafers on the left tray 14 are irradiated, the left tray 14 is transferred back to the left material storage rack 5 and separated from the electromagnet module 12;

[0096] 21. Extend the left material bin tray push rod 4 to pull the wafer tray back to the initial position in the left material bin storage rack 5. At the same time, the left material bin tray push rod 4 also returns to the initial position;

[0097] 22. Start the left grid lifting drive motor 26 to align the next wafer tray to be irradiated with the X-direction non-powered chip tray conveying roller group 15;

[0098] 23. Use the left silo tray push rod 4 to push the next tray of wafers to be irradiated onto the X-axis non-powered chip tray conveying roller group 15 to wait, and then the left silo tray push rod 4 is retracted;

[0099] 24. While performing steps 21-23, the tray taking module 11 quickly moves to the side of the right material bin position, grabs the right tray 13 on the X-axis non-powered chip tray conveying roller group 15 through the electromagnet module 12, and drives the right tray 13 through the proton beam at a set speed through the tray taking module 11;

[0100] 25. After the wafers on the right tray 13 are irradiated, the right tray 13 is transferred back to the right bin storage rack 24 and separated from the electromagnet module 12. Then the tray fetching module 11 quickly moves to the left bin position, and grabs the left tray 14 on the X-axis non-powered chip tray conveying roller group 15 through the electromagnet module 12, and then repeats steps 19-24.

[0101] 26. The electromagnet module 12 and the Y-axis fine-tuning servo module 16 are linked to complete the wafer irradiation;

[0102] 27. Repeat steps 1 to 25 to complete the irradiation of all wafers;

[0103] 28. After the wafer irradiation is completed, the proton beam is stopped, and the two side frame lifting drive motors 26 are started to return the left material storage sheet frame 5 and the right material storage sheet frame 24 to zero position;

[0104] 29. Manually take out all irradiated wafer trays in the left material storage rack 5 and the right material storage rack 24 one by one;

[0105] 30. Place a new batch of trays loaded with wafers to be irradiated;

[0106] 31. Repeat the above steps to complete the irradiation of a new batch of wafers;

[0107] 32. After all wafers have been irradiated, shut down all control system equipment and enter shutdown mode.

[0108] The present invention provides a continuous wafer proton irradiation device in the atmosphere for manufacturing high-performance power chips. After completing the front processing process, the wafers used to manufacture high-performance IGBT, FRD, FWD, thyristor and other power chips need to be injected with protons at a depth of 20um to 30um on the back, and the fast soft recovery diode (FRD) wafer also needs to be injected with protons at a depth of 90um to 110um. The present invention provides a device for continuous proton irradiation of wafers for manufacturing high-performance power chips in the atmosphere, thereby realizing the production and manufacturing of high-performance power chips.

[0109] The present invention provides an atmospheric continuous wafer proton irradiation device for manufacturing high-performance power chips, which can realize continuous proton irradiation of power chip wafers in an atmospheric environment. Considering that the proton beam passes through the atmosphere during the irradiation process, there is a certain amount of beam energy loss and scattering. Therefore, this device is mainly used for proton irradiation of wafers with energy of 3MeV and above. This device uses a double silo design to focus on batch continuous wafer proton irradiation. A single batch can realize continuous proton irradiation of more than 2,000 wafers, effectively improving the irradiation production efficiency, thereby achieving better economic benefits.

[0110] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A continuous wafer proton irradiation device under atmosphere for manufacturing high-performance power chips, characterized in that: It comprises two silo assemblies and an irradiation assembly arranged between the two silo assemblies, wherein the silo assemblies are provided with a material tray which can move in the vertical direction and the horizontal direction; The irradiation assembly comprises an irradiation tray moving platform (17), on which an X-direction non-powered chip tray conveying roller group (15) and a Y-direction fine-tuning servo module (16) for driving the tray to move in the X-direction and the Y-direction on a horizontal plane are arranged; an air-cooled beam scanning window (9) is arranged above the X-direction non-powered chip tray conveying roller group (15), and a scanning box is arranged above the air-cooled beam scanning window (9); and a beam monitor (18) is arranged below the irradiation tray moving platform (17), and the scanning box, the air-cooled beam scanning window (9) and the beam monitor (18) are located on the same vertical line.

2. The continuous wafer proton irradiation device for manufacturing high-performance power chips under atmosphere according to claim 1, characterized in that: The two silo components are respectively a left silo and a right silo; The left material bin comprises a left material bin fixed grid (1), a left material bin support (6) is arranged on the bottom side of the left material bin fixed grid (1), a left material bin sheet storage grid (5) is arranged on the left material bin fixed grid (1), the material tray is divided into a left material tray (14) and a right material tray (13), and a plurality of the left material trays (14) are placed on the left material bin sheet storage grid (5); a left material bin tray push rod (4) is arranged on the left material bin fixed grid (1), and the left material bin tray push rod (4) is used to push the left material tray (14) on the left material bin sheet storage grid (5) onto the X-direction non-powered chip tray conveying roller group (15), or to pull the left material tray (14) on the X-direction non-powered chip tray conveying roller group (15) back to the left material bin sheet storage grid (5); The right material bin comprises a right material bin fixed frame (22), a right material bin support (25) is arranged on the bottom side of the right material bin fixed frame (22), a right material bin film storage frame (24) is arranged on the right material bin fixed frame (22), and a plurality of right material trays (13) are placed on the right material bin film storage frame (24); a right material bin tray push rod (23) is arranged on the right material bin fixed frame (22), and the right material bin tray push rod (23) is used to push the right material tray (13) on the right material bin film storage frame (24) onto the X-direction non-powered chip tray conveying roller group (15), or to pull the right material tray (13) on the X-direction non-powered chip tray conveying roller group (15) back to the right material bin film storage frame (24).

3. The continuous wafer proton irradiation device for manufacturing high-performance power chips under atmosphere according to claim 2, characterized in that: The left material bin fixed grid (1) and the right material bin fixed grid (22) are both provided with a grid lifting drive motor (26), which is used to drive the left material bin sheet storage grid (5) and the right material bin sheet storage grid (24) to move in a vertical direction respectively.

4. The continuous wafer proton irradiation device for manufacturing high-performance power chips under atmosphere according to claim 2, characterized in that: The left silo fixed grid (1) is provided with a left silo position monitor (3) for checking the placement position of the left material tray (14); the right silo fixed grid (22) is provided with a right silo position monitor (21) for checking the placement position of the right material tray (13).

5. The continuous wafer proton irradiation device for manufacturing high-performance power chips under atmosphere according to claim 2, characterized in that: The left silo fixed grid (1) is provided with a beam position monitor (2) for detecting the position of the beam output from the air-cooled beam scanning window (9).

6. The continuous wafer proton irradiation device for manufacturing high-performance power chips under atmosphere according to claim 2, characterized in that: The right silo fixed grid (22) is provided with an irradiation tray moving platform position monitor (20) for monitoring the position of the X-direction non-powered chip tray conveying roller group (15).

7. The continuous wafer proton irradiation device for manufacturing high-performance power chips under atmosphere according to claim 1, characterized in that: The bottom side of the irradiation tray moving platform (17) is provided with an irradiation tray XY moving platform support (19) for supporting.

8. The continuous wafer proton irradiation device for manufacturing high-performance power chips under atmosphere according to claim 1, characterized in that: A scanning box bracket (10) is arranged above the X-axis non-powered chip tray conveying roller group (15); the scanning box is arranged on the scanning box bracket (10); the scanning box comprises a scanning box upper section (7) and a scanning box lower section (8); the scanning box upper section (7), the scanning box lower section (8) and the scanning box bracket (10) are all in a vacuum state.

9. The continuous wafer proton irradiation device for manufacturing high-performance power chips under atmosphere according to claim 1, characterized in that: A material tray picking module (11) is arranged on the X-axis non-powered chip tray conveying roller group (15), and both sides of the material tray picking module (11) are provided with electromagnet modules (12) for alternately grabbing material trays in two bin assemblies.

10. The continuous wafer proton irradiation device for manufacturing high-performance power chips under atmosphere according to claim 1, characterized in that: The distances from the two silo assemblies to the proton beam position are both greater than the length of the material tray.

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