A self-protected electrically controlled thyristor for precise control of transition voltage

Abstract

This invention provides a self-protected electrically controlled thyristor with precise control over the transition voltage. A appropriately deep drooping distorted junction is created below the effective cathode region of the auxiliary thyristor before the amplifying gate, reducing the thickness of the long base region of the auxiliary thyristor and forming a fixed region for the initiation of the forward voltage transition. The transition current in this region is equivalent to the strong gate trigger current already in the amplifying gate region, sufficient to strongly trigger the main thyristor, causing it to enter the safe mode of amplifying gate-cathode perimeter open. This provides the thyristor with self-triggering protection for the forward voltage transition. Precise design of the size and shape of the drooping distorted junction allows for precise control of the device's transition voltage. The fundamental advantage of this invention lies in integrating overvoltage self-protection within the device, eliminating the need for cumbersome external circuit triggering protection, greatly simplifying thyristor application circuits and improving the reliability of power electronic devices.

Description

Technical Field

[0001] This invention belongs to the field of high-power semiconductor device design and manufacturing technology, specifically involving a 4-inch 2500A / 4200V precision-tuned electronically controlled thyristor. Background Technology

[0002] As is well known, a typical electronically controlled thyristor semiconductor chip consists of four layers, three junctions, and three terminals, such as... Figure 1 As shown, thyristors have the following special properties:

[0003] Thyristor semiconductor chips have the ability to block current in the forward direction. When the voltage at the anode A is higher than the voltage at the cathode K, the J2 junction inside the thyristor semiconductor chip is reverse biased. The space charge layer of the J2 junction expands, forming a strong electric field that hinders the flow of majority carriers. Only a very small number of carriers flow through, forming a very small leakage current (a few milliamperes).

[0004] Thyristor semiconductor chips also have the ability to reverse block current. When the anode voltage A is lower than the cathode voltage K, the J1 and J3 junctions inside the thyristor semiconductor chip are reverse biased. Since the concentration on both sides of the J3 junction is very high and the breakdown voltage is very low, the J1 junction plays a major role. The space charge layer of the J1 junction expands, forming a strong electric field that hinders the flow of majority carriers. Only a very small number of minority carriers flow through, forming a very small leakage current (a few milliamperes).

[0005] In addition to the two characteristics mentioned above, thyristors have another invaluable feature called gate-triggered characteristic. When a very small current (tens to hundreds of milliamps) flows from the gate to the cathode, the forward breakover voltage drops until full conduction, allowing hundreds to thousands of amps of current to flow from the anode. The gate provides the ability to control a large amount of power with very little power, making it an ideal high-power switching device.

[0006] However, without a control gate trigger signal, when the forward blocking voltage of a common electronically controlled thyristor is too high, a sudden large current will often appear in the weakest area of ​​the withstand voltage circuit, entering a dangerous local turn-on mode. If the current can spread the entire device in time, the thyristor will not burn out immediately, but the long-term heat accumulation effect will also degrade the thyristor performance; if the current cannot spread in time, the thyristor will burn out immediately. In order to avoid these two failures, the traditional preventive measure is to set a testing control unit (TCU) outside the electronically controlled thyristor, which is called the TCU trigger protection mode. The working process of this mode is as follows: (1) The forward voltage across the thyristor is detected by the TCU unit; (2) It is compared with a set reference voltage value (which is lower than the thyristor turn-on voltage); (3) If the detected value is greater than or equal to the set value, the TCU gives the thyristor gate trigger signal; (4) The thyristor is guided to safely trigger and conduct, so as to effectively protect the thyristor and its main circuit.

[0007] Because the TCU detection, control, and protection unit is entirely external to the thyristor, it requires a large number of electronic components and circuits. Due to the losses and line inductance of these components and circuits, detection and protection are extremely insensitive, often burning out the thyristor and causing the entire device to collapse, resulting in huge losses. Therefore, it not only increases the cost of the device, but also, because the protection trigger control unit requires time to analyze, compare, and trigger at each step, the response is extremely slow, often failing to effectively protect the thyristor, resulting in a decrease in the reliability and stability of the device system. Summary of the Invention

[0008] This invention provides a self-protected electrically controlled thyristor for precise control of the transition voltage, with high detection and protection sensitivity, which solves the shortcomings of existing thyristors such as low utilization efficiency, poor reliability, and high cost.

[0009] The technical solution adopted in this invention is: a self-protected electrically controlled thyristor for precise control of the transition voltage, which, viewed laterally, consists of a central gate, an amplifying gate, an amplifying gate extension segment and an amplifying gate extension branch, a cathode, a mesa, and an anode on the back side; the central gate is located at the very center of the device and is circular; an amplifying gate, which is annular, is provided at the outer end of the central gate; the amplifying gate has amplifying gate extension segment along six directions, and a V-shaped amplifying gate extension branch is connected to the end of each amplifying gate extension segment, with the end being arc-shaped; the amplifying gate extension segment and the amplifying gate extension branch penetrate into the cathode, uniformly dividing the cathode area; a first isolation groove is provided between the central gate and the amplifying gate; a second isolation groove is provided between the amplifying gate, its amplifying gate extension segment, the amplifying gate extension branch, and the cathode; an annular mesa is provided at the outermost end of the device and is connected to the cathode;

[0010] Vertically, it has a four-layer, three-terminal structure. The four layers are N2 layer, P layer, etc. - +P2 layer, N1 layer, P1 layer; the three terminals refer to terminal A, terminal K, and terminal G; the device is symmetrical about the y-axis;

[0011] A P with appropriate width and depth is created in the positive blocking region below the amplification gate. - Layer-depressed circular ring abrupt junction, the P - The layer-down blocking junction is aluminum ion doped with a surface concentration of 1-2 × 10⁻⁶. 21 pcs / cm 3 The width is 2±0.1cm and the depth is 20±5µm; the size of the abrupt junction precisely controls the size of the punch-through channel, which in turn determines the magnitude of the short-circuit current, thereby precisely controlling the level of the breakover voltage.

[0012] Furthermore, the N2 layer is phosphorus-doped at a concentration of 1-2 × 10⁻⁶. 25 pcs / cm3 The depth is 25±2µm; the P1 and P2 layers are doped with the same impurity aluminum element, with a concentration of 4-6×10⁻⁶. 21 pcs / cm 3 The depth is 95±5µm; the N1 layer is a zone-melted high-resistivity silicon single crystal with a resistivity of 500±7%Ω·cm; the concentration is 1-2×10⁻⁶. 19 pcs / cm 3 The thickness is 1250±10µm, and the crystal orientation is... <111> .

[0013] Furthermore, the central gate is a P-shaped circle with a diameter of 4±0.01mm, and its surface is covered with aluminum electrode material.

[0014] Furthermore, the amplification gate consists of two rings, one of which is an N-type ring with an inner diameter of 3.5±0.01cm and an outer diameter of 4.5±0.01cm; the other is a P-type ring with an inner diameter of 4.5±0.01cm and an outer diameter of 5.5±0.01cm; both rings are covered with aluminum electrode material.

[0015] Furthermore, the amplification gate extension segment consists of 6 P-type segments. The width near the amplification gate is 1.0mm ± 0.01mm and is connected to the P-type ring of the amplification gate. The width of the part away from the amplification gate is 0.3mm ± 0.01mm, and the width gradually decreases. At the end of the amplification gate extension segment, it is divided into a V-shaped amplification gate extension branch, and the P-type doping width gradually decreases from 0.3mm ± 0.01mm to 0.2 ± 0.01mm. Aluminum electrode material is covered on the amplification gate extension segment and the amplification gate extension branch and connected to the aluminum electrode material of the amplification gate.

[0016] Furthermore, the cathode 4 is an N-type doped region, with P-type dots of 0.1±0.01mm in diameter evenly distributed on the N-type doped region. It is connected to the P2 layer below the N-type doped region to form a P-type short-circuit channel. The cathode is connected to the amplification gate and its amplification gate extension segment and the outer end of the amplification gate extension branch. The N-type doped region is covered with aluminum electrode material.

[0017] Furthermore, the mesa is a P-shaped ring connected to the P2 layer of the cathode, with a width of 3.5±0.1mm and a depth of 12±1µm.

[0018] Furthermore, the anode is P-type doped and its surface is covered with aluminum electrode material.

[0019] Furthermore, the first isolation groove separates the central gate from the amplification gate, with a width of 0.5±0.01mm and a depth of 7±1µm.

[0020] Furthermore, the second isolation groove separates the amplification gate and its extension segments, the extension branches of the amplification gate, from the cathode, with a width of 0.7±0.01mm and a depth of 21±1µm.

[0021] The present invention has the following beneficial effects:

[0022] 1. By designing this recessed abrupt junction structure within the electronically controlled thyristor, the excessively high forward voltage causes the space charge layer of the reverse-biased junction to expand and penetrate through the recessed abrupt junction, making the transition start in this region. The punch-through current is equivalent to the gate trigger current that has entered the amplification gate region, causing the auxiliary thyristor to turn on. This rapidly introduces a large anode current and high potential into the aluminum layer on the upper surface of the auxiliary thyristor, which is sufficient to strongly trigger the main thyristor, causing it to enter the safe mode of amplification gate-cathode perimeter opening, thus completing the device's self-protection function design. By precisely designing the dimensions of the recessed abrupt junction, the size of the punch-through channel is precisely controlled, thereby determining the magnitude of the punch-through short-circuit current, which in turn determines the level of the transition voltage.

[0023] 2. The fundamental advantage of the protection function of this invention is that it integrates overvoltage self-protection function inside the device, eliminating the need for cumbersome external circuit triggering protection, greatly simplifying the application circuit of thyristors and improving the reliability of power electronic devices.

[0024] 3. It eliminates a large number of components and circuits such as thyristor assembly isolation detection protection trigger, saving a lot of costs and improving the reliability of the device. Attached Figure Description

[0025] Figure 1 This is a schematic cross-sectional view of an existing electronically controlled thyristor.

[0026] Figure 2 A schematic diagram of the space charge layer expansion when a positive voltage is applied to an existing electronically controlled thyristor.

[0027] Figure 3 This is a schematic diagram of the gate triggering and conduction of an existing electronically controlled thyristor.

[0028] Figure 4 This is a schematic diagram of the thyristor of the present invention.

[0029] Figure 5 for Figure 4 Cross-sectional view along C-C';

[0030] Figure 6 This is a schematic diagram illustrating the precise switching self-protection function of the thyristor of the present invention when a positive voltage is applied.

[0031] The following are the symbols and their meanings: 1. Central gate; 2. Amplifying gate; 3a. Amplifying gate extension segment; 3b. Amplifying gate extension branch; 4. Cathode; 5. Mesa; 6. Anode; 7. First isolation trench; 8. Second isolation trench; 9. Abrupt junction. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0033] According to power semiconductor theory, a specific blocking voltage requires a silicon material with a specific resistivity and the formation of a PN junction of a certain depth in order to form a space charge layer of a specific width to withstand the blocking voltage.

[0034] Figure 1 This is a cross-sectional schematic diagram of an existing electronically controlled thyristor, where: the four layers refer to the P1 layer, N1 layer, P2 layer, and N2 layer; the three terminals refer to the anode terminal A, the cathode terminal K, and the gate terminal G; J1 is the reverse blocking PN junction; J2 is the forward blocking PN junction; J3 is the cathode emitter junction; k is the auxiliary amplification gate; and L is the extension segment of the amplification gate.

[0035] like Figure 2 As shown, according to the thyristor principle, N-type and P-type semiconductors combine to form a PN junction. Due to the difference in electron and hole concentrations at the N-region and P-region boundary, majority carriers from each region diffuse towards the other region, becoming minority carriers. This leaves behind positively and negatively charged but immobile impurity ions on both sides of the interface. These immobile positive and negative charges are called space charges, and the electric field established by the space charges is called the internal electric field or built-in electric field. Its direction opposes the diffusion of majority carriers, while attracting minority carriers from the other region towards its own region; this is the so-called drift motion. Diffusion and drift motion are both interconnected and contradictory, eventually reaching a dynamic equilibrium where the positive and negative space charges reach stable values, forming a stable range of space charges, called the space charge region. When a forward voltage is applied to the thyristor, for junction J2, the applied electric field and the built-in electric field are in the same direction, so the space charge region widens at this location. For junction J1, the applied electric field and the built-in electric field are in opposite directions, so the space charge region shortens at this location. When the avalanche breakdown voltage is applied to junction J2, a switching conduction occurs in the weak region of junction J2, causing a negative resistance effect and forming a strong short-circuit current I. AK The thyristor was burned out.

[0036] Figure 3 This is a schematic diagram of the gate trigger conduction of a conventional electronically controlled thyristor. When a positive voltage is applied to the cathode K through an external circuit at the gate G, the P2N2 junction is in a forward biased state. At this time, the polarity of the thyristor is positive at the bottom and negative at the top, which will force the gate current I to... gThe current flows laterally into the lower end of the cathode and returns to the negative terminal through the short-circuit point and cathode K, forming a closed loop. Due to the lateral resistance of the short base region, the gate current density is maximum near the gate (N2) and minimum further away. As the gate voltage increases, the gate current I... g This also increases the threshold voltage for the P2N2 junction to turn on when the positive bias voltage is reached. This causes the N2 region near the gate to reach the turn-on voltage earliest, thus increasing the anode current I. AK1 The signal is drawn in, causing a strong triggering of the amplification gate L, forming the normal triggering mode of the thyristor, and causing the thyristor to conduct safely.

[0037] This invention discloses a self-protected electrically controlled thyristor for precise control of the transition voltage. It achieves self-protection by designing a dimpled abrupt junction structure below the amplifying gate. By controlling the size and shape of the dimpled abrupt junction, the size of the punch-through channel is controlled, thereby determining the magnitude of the short-circuit current and thus precisely controlling the level of the transition voltage.

[0038] A recessed, distorted annular junction with appropriate width and depth is created in the forward blocking region below the gate k of the original thyristor auxiliary amplification. This narrows the thickness of the long base region N1 at this location. When the forward voltage is too high, the space charge layer of the J2 junction at this location first penetrates the J1 junction, forming a hole current injection channel, equivalent to the gate current I. g Flowing under the amplifying gate, causing N 21 The emission of electrons triggers the opening of the auxiliary amplification gate k, rapidly introducing the large current and high potential of the anode to the extended segment L of the amplification gate, strongly triggering the cathode surface of the thyristor, thus turning on the thyristor and completing the safe conduction of the thyristor.

[0039] Figure 4 , Figure 5 This is a schematic diagram of the present invention, wherein... Figure 4 This is a top view; Figure 5 yes Figure 4 Cross-sectional view along C-C'. Laterally, it consists of a central gate 1, an amplifying gate 2, a cathode 4, a mesa 5, and an anode 6 on the back. The central gate 1 is located at the center of the device and is circular. An amplifying gate 2, which is annular, is located at the outer end of the central gate 1. The amplifying gate 2 has amplifying gate extension segments 3a along six directions, with a V-shaped amplifying gate extension branch 3b connected to the end of each extension segment 3a, the ends of which are arc-shaped. The amplifying gate extension segments 3a and 3b extend into the cathode 4, evenly dividing the cathode 4 region. A first isolation groove 7 is provided between the central gate 1 and the amplifying gate 2. Second isolation grooves 8 are provided between the amplifying gate 2, its extension segments 3a and 3b, and the cathode 4. The outermost end of the device has an annular mesa 5, connected to the cathode 4. Vertically, it has a four-layer, three-terminal structure, with the four layers being the N2 layer, P... -+P2 layer, N1 layer, P1 layer; three terminals refer to anode A terminal, cathode K terminal, and gate G terminal; the device is symmetrical about the y-axis.

[0040] A P with appropriate width and depth is created in the positive blocking region below the amplification gate 2. - Layer-depressed circular ring abrupt junction 9, the P - The layer-depression blocking junction 9 is aluminum ion doped with a surface concentration of 1-2 × 10⁹ / L. 21 pcs / cm 3 The width is 2±0.1cm and the depth is 20±5µm; the size of the abrupt junction 9 precisely controls the size of the punch-through channel, which in turn determines the magnitude of the short-circuit current, thereby precisely controlling the level of the breakover voltage.

[0041] The N2 layer is phosphorus-doped at a concentration of 1-2 × 10⁻⁶. 25 pcs / cm 3 The depth is 25±2µm; the P1 and P2 layers are doped with the same impurity aluminum element, with a concentration of 4-6×10⁻⁶. 21 pcs / cm 3 The depth is 95±5µm; the N1 layer is a zone-melted high-resistivity silicon single crystal with a resistivity of 500±7%Ω·cm; the concentration is 1-2×10⁻⁶. 19 pcs / cm 3 The thickness is 1250±10µm, and the crystal orientation is... <111> .

[0042] The central gate electrode 1 is a P-shaped circle with a diameter of 4±0.01mm and its surface is covered with aluminum electrode material.

[0043] The amplification gate 2 consists of two rings. One ring is an N-type ring with an inner diameter of 3.5±0.01cm and an outer diameter of 4.5±0.01cm. The other ring is a P-type ring with an inner diameter of 4.5±0.01cm and an outer diameter of 5.5±0.01cm. Both rings are covered with aluminum electrode material.

[0044] The aforementioned gate extension segment 3a consists of 6 P-type segments. The width of the segment near the gate 2 is 1.0mm ± 0.01mm, and it is connected to the P-type ring of the gate 2. The width of the segment further away from the gate 2 is 0.3mm ± 0.01mm, and the width gradually decreases. At the end of the gate extension segment 3a, it is divided into a V-shaped gate extension branch 3b, and the width of the P-type doping gradually decreases from 0.3mm ± 0.01mm to 0.2 ± 0.01mm, and the end is arc-shaped. Aluminum electrode material is covered on the gate extension segment 3a and the gate extension branch 3b, and it is connected to the aluminum electrode material of the gate 2.

[0045] The cathode 4 is an N-type doped region, with P-type dots of 0.1±0.01 mm in diameter evenly distributed on the N-type doped region. It is connected to the P2 layer below the N-type doped region to form a P-type short-circuit channel. The cathode 4 is connected to the amplification gate 2 and the outer ends of its amplification gate extension segment 3a and amplification gate extension branch 3b. The N-type doped region is covered with aluminum electrode material.

[0046] The mesa 5 is a P-shaped ring connected to the P2 layer of the cathode 4, with a width of 3.5±0.1mm and a depth of 12±1µm.

[0047] The anode 6 is P-type doped and its surface is covered with aluminum electrode material.

[0048] The first isolation groove 7 separates the central gate 1 from the amplification gate 2, with a width of 0.5±0.01mm and a depth of 7±1µm.

[0049] The second isolation groove 8 separates the amplifying gate 2 and its amplifying gate extension segment 3a and amplifying gate extension branch 3b from the cathode 4. The width is 0.7±0.01mm and the depth is 21±1µm.

[0050] in Figure 6 for Figure 5 The diagram illustrates self-protection conduction under forward voltage application. When a forward voltage is applied to the device (i.e., forward bias at the anode and reverse bias at the cathode), junction J2 is in a reverse bias state. Due to the external electric field, holes in region P2 diffuse into region N1, and electrons in region N1 diffuse into region P2, forming a space charge layer. As the applied forward voltage increases, the space charge layer widens. Due to the presence of abrupt junction 9, it will first connect with the forward bias junction J1 at abrupt junction 9, thus transferring the anode current I... AK1 This triggers the amplifying gate 2, establishing the normal triggering mode for the thyristor and causing it to conduct. This demonstrates that a self-protection function is integrated within the chip. By precisely controlling the size and shape of the dipped junction 9, the size of the punch-through channel is precisely controlled, thus determining the short-circuit current I. AK1 The size of the voltage is adjusted to precisely control the transition voltage.

[0051] This invention requires only one photolithography process before the traditional thyristor doping process, using selective aluminum ion implantation and a drive-through process to form P. - The doping region is sufficient; subsequent processes follow the traditional thyristor manufacturing process without any changes.

Claims

1. A self-protected electrically controlled thyristor for precise control of transition voltage, characterized in that: From a transverse perspective, it consists of a central gate (1), an amplifying gate (2), an amplifying gate extension segment (3a), an amplifying gate extension branch (3b), a cathode (4), a mesa (5), and an anode (6) on the back side; the central gate (1) is located at the very center of the device and is circular; the outer end of the central gate (1) is provided with an amplifying gate (2), which is annular; the amplifying gate (2) is provided with amplifying gate extension segments (3a) in six directions, and a V-shaped amplifying gate is connected to the end of each amplifying gate extension segment (3a). The pole extension branch (3b) has an arc-shaped end; the amplification gate extension segment (3a) and the amplification gate extension branch (3b) penetrate into the cathode (4) and evenly divide the cathode (4) area; a first isolation groove (7) is provided between the central gate (1) and the amplification gate (2); a second isolation groove (8) is provided between the amplification gate (2) and its amplification gate extension segment (3a) and the amplification gate extension branch (3b) and the cathode (4); the outermost end of the device is provided with an annular mesa (5) connected to the cathode (4); Vertically, it has a four-layer, three-terminal structure. The four layers are N2 layer, P layer, etc. - +P2 layer, N1 layer, P1 layer; three terminals refer to anode A terminal, cathode K terminal, and gate G terminal; the device is symmetrical about the y-axis; A P is created in the positive blocking region below the amplification gate (2). - Layer-depressed circular abrupt junction (9), the P - The layer-depressed circular abrupt junction (9) is aluminum ion doped with a surface concentration of 1-2×10⁻⁶. 21 pcs / cm 3 The width is 2±0.1cm and the depth is 20±5µm; the size of the recessed circular abrupt junction (9) precisely controls the size of the through-channel, thereby determining the size of the short-circuit current and thus precisely controlling the transition voltage.

2. The self-protected electrically controlled thyristor for precise control of the transition voltage as described in claim 1, characterized in that: The N2 layer is phosphorus-doped at a concentration of 1-2 × 10⁻⁶. 25 pcs / cm 3 The depth is 25±2µm; the P1 and P2 layers are doped with the same impurity aluminum element, with a concentration of 4-6×10⁻⁶. 21 pcs / cm 3 The depth is 95±5µm; the N1 layer is a zone-melted high-resistivity silicon single crystal with a resistivity of 500±7%Ω·cm; the concentration is 1-2×10⁻⁶. 19 pcs / cm 3 The thickness is 1250±10µm, and the crystal orientation is... <111> .

3. The self-protected electrically controlled thyristor for precise control of the transition voltage as described in claim 1, characterized in that: The central gate electrode (1) is a P-shaped circle with a diameter of 4±0.01mm, and its surface is covered with aluminum electrode material.

4. A self-protected electrically controlled thyristor for precise control of transition voltage as described in claim 1, characterized in that: The amplification gate (2) consists of two rings. One ring is an N-type ring with an inner diameter of 3.5±0.01cm and an outer diameter of 4.5±0.01cm. The other ring is a P-type ring with an inner diameter of 4.5±0.01cm and an outer diameter of 5.5±0.01cm. The two rings are covered with aluminum electrode material.

5. A self-protected electrically controlled thyristor for precise control of transition voltage as described in claim 1, characterized in that: The amplification gate extension segment (3a) consists of 6 P-type segments. The width of the segment near the amplification gate (2) is 1.0 mm ± 0.01 mm and is connected to the P-type ring of the amplification gate (2). The width of the segment away from the amplification gate (2) is 0.3 mm ± 0.01 mm and gradually decreases. At the end of the amplification gate extension segment (3a), it is divided into a V-shaped amplification gate extension branch (3b). The width of the P-type doping gradually decreases from 0.3 mm ± 0.01 mm to 0.2 ± 0.01 mm. The amplification gate extension segment (3a) and the amplification gate extension branch (3b) are covered with aluminum electrode material and connected to the aluminum electrode material of the amplification gate (2).

6. A self-protected electrically controlled thyristor for precise control of transition voltage as described in claim 1, characterized in that: The cathode (4) is an N-type doped region. P-type dots with a diameter of 0.1±0.01 mm are uniformly distributed on the N-type doped region. It is connected to the P2 layer below the N-type doped region to form a P-type short-circuit channel. The cathode (4) is connected to the amplification gate (2) and the outer ends of its amplification gate extension segment (3a) and amplification gate extension branch (3b). The N-type doped region is covered with aluminum electrode material.

7. A self-protected electrically controlled thyristor for precise control of transition voltage as described in claim 1, characterized in that: The platform (5) is a P-shaped ring connected to the P2 layer of the cathode K, with a width of 3.5±0.1mm and a depth of 12±1µm.

8. A self-protected electrically controlled thyristor for precise control of transition voltage as described in claim 1, characterized in that: The first isolation groove (7) separates the central gate (1) from the amplification gate (2), with a width of 0.5±0.01mm and a depth of 7±1µm.

9. A self-protected electrically controlled thyristor for precise control of transition voltage as described in claim 1, characterized in that: The second isolation groove (8) separates the amplifying gate (2) and its amplifying gate extension segment (3a), amplifying gate extension branch (3b) from the cathode (4), with a width of 0.7±0.01mm and a depth of 21±1µm.

10. A self-protected electrically controlled thyristor for precise control of transition voltage as described in claim 1, characterized in that: The anode (6) is P-type doped and its surface is covered with aluminum electrode material.

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