CN-122028697-A - Metal clamp and transverse local carrier life control method

Abstract

The invention relates to the technical field of semiconductors and discloses a metal clamp and a transverse local carrier life control method, wherein the metal clamp comprises a bracket for accommodating a power device; and a metal baffle plate positioned in the bracket and forming an accommodating space between the metal baffle plate and the bracket, wherein the metal baffle plate comprises a step baffle plate, the height of a plurality of steps in the step baffle plate is determined by the target irradiation amount of a corresponding area in the power device, and the steps are non-obtuse steps. According to the invention, on the basis of not changing the structure of the power device, the irradiation dose of the transmitted metal is regulated and controlled through the stepped metal baffle plate, so that the minority carrier service life in different areas of the power device is finely designed, the difference of turn-off speeds of different areas of the power device is realized, the turn-off inconsistency caused by parasitic impedance is counteracted, and the turn-off current sharing and turn-off capability improvement are realized.

Inventors

• WANG YAOHUA
• Yuan Guangan
• WU JINPENG
• ZENG RONG
• WEI XIAOGUANG
• JIAO QIANQIAN
• LI SONGWEI
• YAN SU

Assignees

• 北京怀柔实验室
• 清华大学

Dates

Publication Date

20260512

Application Date

20260414

Claims (14)

1. 1. A metal clip, the metal clip comprising: Bracket and The metal baffle is positioned in the bracket, an accommodating space is formed between the metal baffle and the bracket, the accommodating space is used for accommodating the power device, the metal baffle comprises a step baffle, the heights of a plurality of steps in the step baffle are determined by the target irradiation amount of corresponding areas in the power device, and the steps are non-obtuse steps.
2. 2. The metal clip of claim 1, wherein the metal bezel is positively engaged with the bracket.
3. 3. The metal clip of claim 2, wherein the bottom of the stepped baffle is fully mated with the power device.
4. 4. The metal clip of claim 1, wherein the metal retainer further comprises a first locating structure provided at a bottom of the stepped retainer, The metal fixture further comprises a base plate, wherein the base plate is positioned between the metal baffle and the power device, the base plate comprises a positioning plate and a second positioning structure, and the first positioning structure is matched with the second positioning structure.
5. 5. The metal clip of claim 4, wherein the bottom of the locating plate is fully mated with the power device.
6. 6. The metal clip of claim 4, wherein the outer diameter of the metal bezel is a distance from the inner diameter of the bracket that is equal to or greater than a radial dimension of a protective structure of an edge junction termination of the power device.
7. 7. The metal clip of claim 4, wherein the first locating feature is a locating pin and the second locating feature is a locating slot.
8. 8. The metal fixture of claim 4, wherein the step guard comprises a plurality of metal plates of different sizes, any two adjacent metal plates are positioned by positioning pins on the lower surface of the upper metal plate and positioning grooves on the upper surface of the lower metal plate, and the steps of the metal plates are non-obtuse steps.
9. 9. The metal clip of claim 8, wherein the location of the locating pin and the locating slot corresponds to the same location on the highest step in the stepped baffle.
10. 10. The metal clip of claim 1, wherein the bracket is a hollow structure and an inner diameter of the bracket is greater than or equal to an inner diameter of a protective structure of an edge junction termination of the power device and less than an outer diameter of the protective structure.
11. 11. The metal clip of claim 10, further comprising a tray for supporting the power device.
12. 12. The metal clip of claim 11, wherein the bottom of the tray is flush with the bottom of the bracket and the tray is polystyrene.
13. 13. The metal clip of any one of claims 1-12, wherein in the case where the power device is a GCT device, a highest step in the stepped baffle corresponds to a gate ring of the GCT device, and a step in the stepped baffle corresponding to a first cathode ring region of the GCT device is higher than a step corresponding to a second cathode ring region of the GCT device, wherein the first cathode ring region is closer to the gate ring than the second cathode ring region.
14. 14. A lateral localized carrier lifetime control method for a power device, the lateral localized carrier lifetime control method comprising: acquiring the position of a gate contact ring of the power device to be irradiated; Selecting a metal jig according to any one of claims 1 to 13 to position the power device in the accommodation space based on the position of the gate contact ring, wherein the thickness of each step of the stepped baffle is inversely proportional to the distance of the step from the gate contact ring; and irradiating the positioned power device, so that each area of the power device is irradiated with different doses.

Description

Metal clamp and transverse local carrier life control method Technical Field The invention relates to the technical field of semiconductors, in particular to a metal clamp and a transverse local carrier life control method. Background IGCT (INTEGRATED GATE Commutated Thyristor ) is a new type of semiconductor switching device that is formed integrally with the GCT (Gate Commutated Thyristor ). The GCT device is a novel power semiconductor device based on a GTO (gate turn-off thyristor) structure, which has not only high blocking capability and low on-state voltage drop as the GTO but also switching performance as the IGBT (Insulate-Gate Bipolar Transistor). That is, the GCT device is a result of the GTO and IGBT complement each other, and is a relatively ideal megawatt, medium and high voltage switching device that is widely used in voltage source type inverters, current source type inverters, choppers, static circuit breakers, and other topology circuits. The GCT device is a whole wafer structure, and is composed of an edge junction termination region 1, an active region 2, and a gate ring region 3 (also referred to as a gate contact ring region for short) (see the top view shown in fig. 1). The edge junction terminal area 1 is arranged around the outermost periphery of the chip and is used for reducing electric field concentration at the edge of the active area and widening the width of a depletion layer so as to improve the breakdown voltage of the device, the gate electrode ring area 3 is arranged between the active areas 2 of the chip (in the middle gate electrode form shown in fig. 1) or at the periphery of the active areas 2 (in the outer gate electrode form shown in fig. 2) and is responsible for the transmission of gate electrode signals, the active areas 2 are arranged inside the chip and are composed of a plurality of cathode rings, each cathode ring is formed by connecting a plurality of GCT units in parallel, and the cathode rings are distributed annularly along the radial direction and are responsible for the through flow of the GCT device. The metal of the gate ring region 3 is connected with the gate metal in the GCT cell, and since the distances between each cathode ring and the gate ring region 3 are different (i.e., the gate parasitic impedances are different), the gate signals transmitted to the cathode rings in the GCT cell are also different, and the cathode rings farther from the gate ring region 3 turn off more slowly, which easily causes current redistribution to cause turn-off failure. At present, the scheme for improving the turn-off capability of the power device is mainly realized by optimizing the structure of the power device, but the process for optimizing the structure of the power device is generally complex, and the cost is relatively high. Disclosure of Invention The invention aims to provide a metal clamp and a transverse local carrier service life control method, which are used for adjusting and controlling irradiation doses of penetrating metal through a stepped metal baffle on the basis of not changing the structure of a power device, so that minority carrier service lives in different areas of the power device are finely designed, further, accurate adjustment and control of turn-off speeds of different areas of the power device are realized, turn-off inconsistency caused by parasitic impedance is counteracted, and turn-off current sharing and turn-off capacity improvement are realized. In order to achieve the above object, a first aspect of the present invention provides a metal fixture, which includes a bracket for accommodating the power device, and a metal baffle plate located in the bracket and forming an accommodating space between the metal baffle plate and the bracket, the metal baffle plate including a stepped baffle plate, wherein a height of a plurality of steps in the stepped baffle plate is determined by a target irradiation amount of a corresponding region in the power device, and the plurality of steps are non-obtuse steps. Preferably, the metal baffle is just clamped with the bracket. Preferably, the bottom of the step baffle is completely attached to the power device. Preferably, the metal baffle plate further comprises a first positioning structure arranged at the bottom of the stepped baffle plate, and the metal clamp further comprises a base plate positioned between the metal baffle plate and the power device, wherein the base plate comprises a positioning plate and a second positioning structure, and the first positioning structure is matched with the second positioning structure. Preferably, the bottom of the locating plate is completely attached to the power device. Preferably, the distance between the outer diameter of the metal baffle plate and the inner diameter of the bracket is equal to or greater than the radial dimension of the protection structure of the edge junction terminal of the power device. Preferably, the first positioning struct