Total dose radiation resistant triode and preparation method thereof

Abstract

The invention discloses a total dose radiation resistant triode and a preparation method thereof, and belongs to the technical field of radiation hardening of bipolar devices. According to the preparation method of the total dose radiation resistant triode provided by the invention, an STI (shallow trench isolation) structure above the interface of the base well region and the emitter well region is eliminated and replaced by an oxide layer and polycrystalline silicon double-layer protection structure. As the thickness of the oxide layer is far smaller than that of the STI shallow trench isolation structure, under the same total dose irradiation, the number of oxide layer fixed charges and interface states generated by the oxide layer is greatly reduced, the excess base current of the triode can be effectively reduced, the degree of current gain damage is reduced, and the total dose irradiation resistance of the triode is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of radiation resistance reinforcement of bipolar devices, and particularly relates to a total dose radiation resistant triode and a preparation method thereof. Background Art

[0002] In the existing advanced node technology, such as 0.18μm BCD technology, the more common triode device adopts shallow trench isolation structure. Its preparation process is as follows: Figure 1-Figure 3 As shown, firstly, a second conductive type buried layer (2), a second conductive type collector deep well region (3), and a first conductive type base deep well region (6) are formed on a first conductive type semiconductor substrate (1), and then photolithography and STI etching are performed on the upper surfaces of the second conductive type collector deep well region (3) and the first conductive type base deep well region (6), SiO2 or other filling materials are deposited in the trenches, and chemical mechanical polishing is performed to form an STI shallow trench isolation region (11), and then photolithography and doping ion implantation are performed on the surfaces of the second conductive type collector deep well region (3) and the first conductive type base deep well region (6) to form a second conductive type collector well region (4), a second conductive type collector injection region (5), a first conductive type base well region (7), a first conductive type base injection region (8), a second conductive type emitter well region (9), and a second conductive type emitter injection region (10), thereby forming a complete radiation-resistant reinforced bipolar device structure. This transistor device performs poorly in total dose irradiation because the emitter-base junction of the transistor is located just below the STI isolation structure. The total dose irradiation effect forms fixed charges in the oxide layer in the STI isolation structure and generates interface states at the SiO2 / Si interface of the STI, which causes the transistor's excess base current I B increases, the gain factor β decreases.

[0003] Therefore, it is necessary to improve the existing method of preparing triodes to enhance the ability of the triodes to resist total dose radiation. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the existing triode structure, an object of the present invention is to provide a total dose radiation resistant triode and a preparation method thereof.

[0005] The technical solution to achieve the purpose of the present invention is: a total dose radiation resistant triode, comprising a first conductive type substrate, a second conductive type buried layer, and a second conductive type collector deep well region arranged in sequence from bottom to top, a second conductive type collector well region is arranged above the edges of the second conductive type collector well region, a second conductive type collector injection region is arranged above the second conductive type collector well region, a first conductive type base deep well region is arranged above the inside of the second conductive type collector deep well region, a first conductive type base well region is arranged above the edges of the first conductive type base deep well region, a first conductive type base injection region is arranged above the first conductive type base well region, and a first conductive type base injection region is arranged above the first conductive type base well region. A second conductive type emitter well region is arranged above the inside of the conductive type base deep well region, a second conductive type emitter injection region is arranged above the second conductive type emitter well region, a first STI isolation structure is arranged between the first conductive type base injection region and the second conductive type collector injection region, a second STI isolation structure is arranged outside the second conductive type collector injection region and above the edges of the second conductive type collector deep well region, an oxide layer is arranged between the first conductive type base injection region and the second conductive type emitter injection region, the oxide layer covers the first conductive type base well region and the second conductive type emitter well region, and the oxide layer is covered with polysilicon.

[0006] A method for preparing a total dose radiation resistant triode comprises the following steps:

[0007] The first step: providing a first conductive type substrate silicon wafer, performing photolithography and doping ion implantation on the upper surface thereof, and annealing to form a second conductive type buried layer; growing a second conductive type collector deep well region on the upper surface of the second conductive type buried layer; performing photolithography and doping ion implantation on the upper surface of the second conductive type collector deep well region, and annealing to form a first conductive type base deep well region;

[0008] Step 2: growing an oxide layer and depositing a SiN layer on the upper surfaces of the second conductive type collector deep well region and the first conductive type base deep well region, performing active area photolithography, performing STI etching, forming STI grooves, depositing SiO2 or other filling materials in the STI grooves, performing electrode isolation, and then performing chemical mechanical polishing to form a first STI shallow trench isolation region and a second STI shallow trench isolation region;

[0009] Step 3: performing photolithography and doping ion implantation on the upper surfaces of the second conductivity type collector deep well region and the first conductivity type base deep well region to form a second conductivity type collector well region, a first conductivity type base well region, and a second conductivity type emitter well region;

[0010] Step 4: growing a thin oxide layer on the upper surfaces of the second conductivity type collector well region, the first conductivity type base well region, and the second conductivity type emitter well region, depositing polysilicon on the surface of the thin oxide layer, photolithography and etching the polysilicon, and forming an oxide layer and polysilicon double-layer protection structure above the interface between the first conductivity type base well region and the second conductivity type emitter well region;

[0011] Step 5: Perform photolithography and doping ion implantation on the upper surfaces of the second conductivity type collector well region, the first conductivity type base well region, and the second conductivity type emitter well region to form a second conductivity type collector injection region, a first conductivity type base injection region, and a second conductivity type emitter injection region to form a complete total-dose radiation-resistant triode structure.

[0012] Compared with the prior art, the significant advantages of the present invention are: the preparation method of the total dose radiation resistant triode of the present invention is used to form the triode, and the STI shallow trench isolation structure above the interface between the base well region and the emitter well region is eliminated, and replaced by an oxide layer and a polysilicon double-layer structure; because the thickness of the oxide layer is much smaller than the thickness of the STI shallow trench isolation structure, under the same total dose irradiation, the number of oxide layer fixed charges and interface states generated by the oxide layer is greatly reduced, which can effectively reduce the excess base current of the triode and reduce the degree of current gain damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1-Figure 3 This is a flow chart of the triode device preparation method that is more commonly used in existing advanced node processes.

[0014] Figure 1 The schematic diagram of the structural cross-section is that photolithography and dopant ion implantation are performed on a first conductive type substrate silicon wafer 1, and annealing is performed to form a second conductive type buried layer 2; photolithography and dopant ion implantation are performed on the upper surface of the second conductive type buried layer 2, and annealing is performed to form a second conductive type collector deep well region 3; photolithography and dopant ion implantation are performed on the upper surface of the second conductive type collector deep well region 3 to form a first conductive type base deep well region 6.

[0015] Figure 2 The schematic diagram of the cross-section of the structure is that an oxide layer is grown on the upper surface of the second conductive type collector deep well region 3 and the first conductive type base deep well region 6, a SiN layer is deposited, active area lithography is performed, STI etching is performed, STI grooves are formed, SiO2 or other filling materials are deposited in the STI grooves, electrode isolation is performed, and then chemical mechanical polishing is performed to form an STI shallow trench isolation region 11.

[0016] Figure 3Surface photolithography and doping ion implantation are performed on the second conductivity type collector deep well region 3 and the first conductivity type base deep well region 6 to form a second conductivity type collector well region 4, a second conductivity type collector injection region 5, a first conductivity type base well region 7, a first conductivity type base injection region 8, a second conductivity type emitter well region 9, and a second conductivity type emitter injection region 10, forming a schematic diagram of a complete anti-irradiation hardened bipolar device structure.

[0017] Figure 4-Figure 8 It is a cross-sectional view of the process of the method for preparing the total dose radiation resistant triode of the present invention.

[0018] Figure 4 The schematic diagram of the structural cross-section is as follows: photolithography and dopant ion implantation are performed on a first conductive type substrate silicon wafer 110, and annealing is performed to form a second conductive type buried layer 120; photolithography and dopant ion implantation are performed on the upper surface of the second conductive type buried layer 120, and annealing is performed to form a second conductive type collector deep well region 130; photolithography and dopant ion implantation are performed on the upper surface of the second conductive type collector deep well region 130 to form a first conductive type base deep well region 160.

[0019] Figure 5 The schematic diagram of the cross-sectional structure is that an oxide layer is grown on the upper surface of the second conductive type collector deep well region 130 and the first conductive type base deep well region 160, a SiN layer is deposited, active area lithography is performed, STI etching is performed, STI grooves are formed, SiO2 or other filling materials are deposited in the STI grooves, electrode isolation is performed, and then chemical mechanical polishing is performed to form STI shallow trench isolation regions 210 and 220.

[0020] Figure 6 It is a schematic diagram of the structural cross-section after photolithography and doping ion implantation are performed on the upper surfaces of the second conductive type collector deep well region 130 and the first conductive type base deep well region 160 to form the second conductive type collector well region 140, the first conductive type base well region 170, and the second conductive type emitter well region 190.

[0021] Figure 7 A thin oxide layer is grown on the upper surfaces of the second conductive type collector well region 140, the first conductive type base well region 170, and the second conductive type emitter well region 190, polysilicon is deposited on the surface of the thin oxide layer, and the polysilicon is photolithographically and etched to form a double-layer protection structure of an oxide layer 230 and polysilicon 240 above the interface between the first conductive type base well region 170 and the second conductive type emitter well region 190. This is a schematic diagram of the structural cross-section.

[0022] Figure 8The upper surfaces of the second conductive type collector well region 140, the first conductive type base well region 170, and the second conductive type emitter well region 190 are photolithographically processed and doped ions are implanted to form a second conductive type collector injection region 150, a first conductive type base injection region 180, and a second conductive type emitter injection region 200, and finally a complete schematic cross-sectional diagram of a total-dose radiation-resistant triode structure is formed.

[0023] Fig. 9 The present invention is a simplified flow chart of the method for preparing the total dose radiation resistant triode.

[0024] Description of labels:

[0025] 1: Traditional triode first conductivity type substrate

[0026] 2: The second conductive type buried layer of the traditional triode

[0027] 3: Traditional triode second conductivity type collector deep well region

[0028] 4: The second conductivity type collector well region of the traditional triode

[0029] 5: The second conductivity type collector injection region of the traditional triode

[0030] 6: Traditional triode first conductivity type base deep well region

[0031] 7: The first conductivity type base well region of the traditional triode

[0032] 8: Traditional triode first conductivity type base injection region

[0033] 9: The second conductivity type emitter well region of the traditional triode

[0034] 10: The second conductivity type emitter injection region of the traditional triode

[0035] 11: Traditional triode shallow trench isolation structure

[0036] 110: The first conductive type substrate of the triode of the present invention

[0037] 120: The second conductive type buried layer of the transistor of the present invention

[0038] 130: The second conductivity type collector deep well region of the triode of the present invention

[0039] 140: The collector well region of the second conductivity type of the transistor of the present invention

[0040] 150: The collector injection region of the second conductivity type of the transistor of the present invention

[0041] 160: The first conductivity type base deep well region of the triode of the present invention

[0042] 170: The first conductivity type base well region of the triode of the present invention

[0043] 180: The first conductivity type base injection region of the triode of the present invention

[0044] 190: The second conductivity type emitter well region of the transistor of the present invention

[0045] 200: The second conductivity type emitter injection region of the transistor of the present invention

[0046] 210: Shallow trench isolation structure between base injection region and emitter injection region of transistor of the present invention

[0047] 220: Shallow trench isolation structure outside the transistor collector injection region of the present invention

[0048] 230: Thin oxide layer above the emitter-base junction of the triode of the present invention

[0049] 240: Polysilicon above the emitter-base junction of the triode of the present invention DETAILED DESCRIPTION

[0050] The following is a further detailed description of a method for preparing a total dose radiation resistant triode proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer according to the following description and claims. It should be noted that the drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0051] Figure 1-Figure 3 This is a flow chart of the triode device preparation method that is more commonly used in existing advanced node processes.

[0052] Figure 1 The schematic diagram of the structural cross-section is that photolithography and dopant ion implantation are performed on a first conductive type substrate silicon wafer 1, and annealing is performed to form a second conductive type buried layer 2; photolithography and dopant ion implantation are performed on the upper surface of the second conductive type buried layer 2, and annealing is performed to form a second conductive type collector deep well region 3; photolithography and dopant ion implantation are performed on the upper surface of the second conductive type collector deep well region 3 to form a first conductive type base deep well region 6.

[0053] Figure 2 The schematic diagram of the cross-section of the structure is that an oxide layer is grown on the upper surface of the second conductive type collector deep well region 3 and the first conductive type base deep well region 6, a SiN layer is deposited, active area lithography is performed, STI etching is performed, STI grooves are formed, SiO2 or other filling materials are deposited in the STI grooves, electrode isolation is performed, and then chemical mechanical polishing is performed to form an STI shallow trench isolation region 11.

[0054] Figure 3Surface photolithography and doping ion implantation are performed on the second conductivity type collector deep well region 3 and the first conductivity type base deep well region 6 to form a second conductivity type collector well region 4, a second conductivity type collector injection region 5, a first conductivity type base well region 7, a first conductivity type base injection region 8, a second conductivity type emitter well region 9, and a second conductivity type emitter injection region 10, forming a schematic diagram of a complete anti-irradiation hardened bipolar device structure.

[0055] Figure 4-Figure 8 It is a cross-sectional view of the process of the method for preparing the total dose radiation resistant triode of the present invention.

[0056] like Figure 8 As shown, a total dose radiation resistant triode comprises a first conductive type substrate 110, a second conductive type buried layer 120, and a second conductive type collector deep well region 130 arranged in sequence from bottom to top, a second conductive type collector well region 140 is arranged above the edges of the second conductive type collector well region 130, a second conductive type collector injection region 150 is arranged above the second conductive type collector well region 140, a first conductive type base deep well region 160 is arranged above the second conductive type collector deep well region 130, a first conductive type base well region 170 is arranged above the edges of the first conductive type base deep well region 160, a first conductive type base injection region 180 is arranged above the first conductive type base well region 170, and a first conductive type base deep well region 160 is arranged inside the first conductive type base deep well region 160. A second conductive type emitter well region 190 is arranged above the second conductive type emitter well region 190, a second conductive type emitter injection region 200 is arranged above the second conductive type emitter well region 190, an STI isolation structure 210 is arranged between the first conductive type base injection region 180 and the second conductive type collector injection region 150, an STI isolation structure 220 is arranged outside the second conductive type collector injection region 150 and above the edges of the second conductive type collector deep well region 130, an oxide layer 230 is arranged between the first conductive type base injection region 180 and the second conductive type emitter injection region 200, the oxide layer 230 covers the first conductive type base well region 170 and the second conductive type emitter well region 190, and the oxide layer 230 is covered with polysilicon 240.

[0057] Furthermore, the second conductivity type collector injection region 150 is located inside the second conductivity type collector well region 140 , the former has a smaller area than the latter, and a higher concentration than the latter;

[0058] The first conductivity type base injection region 180 is located inside the first conductivity type base well region 170 , the former has a smaller area than the latter and a higher concentration than the latter;

[0059] The second conductive type emitter injection region 200 is located inside the second conductive type emitter well region 190 , and the former has a smaller area than the latter and a higher concentration than the latter.

[0060] Furthermore, the edge of the second conductive type collector injection region 150 is tangent to the STI structure, the outer edge of the first conductive type base injection region 180 is tangent to the STI structure, the inner edge of the first conductive type base injection region 180 is tangent to the oxide layer 230 , and the edge of the second conductive type emitter injection region 200 is tangent to the oxide layer 230 .

[0061] Furthermore, the second conductivity type collector deep well region 130, the second conductivity type collector well region 140, and the second conductivity type collector injection region 150 together constitute a collector structure;

[0062] The first conductivity type base deep well region 160 , the first conductivity type base well region 170 , and the first conductivity type base injection region 180 together constitute a base structure;

[0063] The second conductivity type emitter well region 190 and the first conductivity type emitter injection region 200 together constitute an emitter structure.

[0064] Furthermore, the second conductive type collector well region 140 is not in direct contact with the first conductive type base well region 170; the first conductive type base well region 170 is in direct contact with the second conductive type emitter well region 190 or there is a certain distance between them. The existence of the distance means that the area of ​​170 is small, and it is sufficient to ensure that 160 can be connected to 180 through 170, and finally connect the potential. At this time, 170 and 190 are separated by 160.

[0065] When the first conductive type base well region 170 and the second conductive type emitter well region 190 are tangent to each other, the tangent surface is located below the oxide layer 230; when there is a certain distance between the first conductive type base well region 170 and the second conductive type emitter well region 190, the two edges of the first conductive type base well region 170 and the second conductive type emitter well region 190 that are close to each other are both located below the oxide layer 230.

[0066] Furthermore, when the first conductivity type doped impurities in the device are acceptor type, the second conductivity type doped impurities are donor type; when the first conductivity type doped impurities are donor type, the second conductivity type doped impurities are acceptor type.

[0067] Furthermore, the polysilicon 240 and the oxide layer 230 have the same shape.

[0068] Further, one of the first conductive type base well region 170 and the second conductive type emitter well region 190 can be omitted according to requirements, but both cannot be omitted at the same time.

[0069] If the first conductive type base well region 170 is omitted and the second conductive type emitter well region 190 is retained, the edge of the second conductive type emitter well region 190 should be below the inside of the oxide layer 230;

[0070] If the second conductivity type emitter well region 190 is omitted and the first conductivity type base well region 170 is retained, the inner edge of the first conductivity type base well region 170 should be below the inside of the oxide layer 230 .

[0071] Furthermore, the second conductive type buried layer 120 may be omitted as required.

[0072] When the second conductive type buried layer 120 exists, the first conductive type base deep well region 160 may be in direct contact with the second conductive type buried layer 120 .

[0073] like Figures 4 to 8 , Fig. 9 As shown, the present invention provides a method for preparing a total dose radiation resistant triode, the method comprising the following steps:

[0074] The first step is to provide a first conductive type substrate silicon wafer 110, perform photolithography and dopant ion implantation on the upper surface thereof, and perform annealing to form a second conductive type buried layer 120; perform photolithography and dopant ion implantation on the upper surface of the second conductive type buried layer 120, and perform annealing to form a second conductive type collector deep well region 130; perform photolithography and dopant ion implantation on the upper surface of the second conductive type collector deep well region 130, and perform annealing to form a first conductive type base deep well region 160, such as Figure 4 As shown;

[0075] Step 2: grow an oxide layer and deposit a SiN layer on the upper surface of the second conductive type collector deep well region 130 and the first conductive type base deep well region 160, perform active area photolithography, perform STI etching, form STI grooves, deposit SiO2 or other filling materials in the STI grooves, perform electrode isolation, and then perform chemical mechanical polishing to form STI shallow trench isolation regions 210 and 220, as shown in FIG. Figure 5 As shown;

[0076] The first STI shallow trench isolation structure 210 is only located at the junction of the second conductive type collector deep well region 130 and the first conductive type base deep well region 160; the second STI shallow trench isolation structure 220 is located at the periphery of the second conductive type collector deep well region 130; and there is no STI shallow trench isolation structure inside the first conductive type base deep well region 160;

[0077] Step 3: Perform photolithography and doping ion implantation on the upper surfaces of the second conductive type collector deep well region 130 and the first conductive type base deep well region 160 to form a second conductive type collector well region 140, a first conductive type base well region 170, and a second conductive type emitter well region 190, such as Figure 6 shown.

[0078] Among them, the second conductive type collector well region 140 is located at the periphery of the second conductive type collector deep well region 130, between the first STI shallow trench isolation structure 210 and the second STI shallow trench isolation structure 220; the first conductive type base well region 170 and the second conductive type emitter well region 190 are located above the inside of the first conductive type base deep well region 160; the first conductive type base well region 170 is located at the periphery of the first conductive type base deep well region 160, inside the first STI shallow trench isolation structure 210; the second conductive type emitter well region 190 is located at the center above the first conductive type base deep well region 160; the edges of the first conductive type base well region 170 and the second conductive type emitter well region 190 are tangent;

[0079] Step 4: grow a thin oxide layer on the upper surfaces of the second conductive type collector well region 140, the first conductive type base well region 170, and the second conductive type emitter well region 190, deposit polysilicon on the surface of the thin oxide layer, perform photolithography and etching on the polysilicon, and form a double-layer protection structure of an oxide layer 230 and polysilicon 240 above the interface between the first conductive type base well region 170 and the second conductive type emitter well region 190, such as Figure 7 shown.

[0080] Step 5: Photolithography and doping ion implantation are performed on the upper surfaces of the second conductive type collector well region 140, the first conductive type base well region 170, and the second conductive type emitter well region 190, and annealing is performed to form the second conductive type collector implantation region 150, the first conductive type base implantation region 180, and the second conductive type emitter implantation region 200, and finally a complete total dose radiation resistant triode structure is formed, such as Figure 8 shown.

[0081] The total-dose radiation-resistant reinforced triode prepared by the above method has effectively improved total-dose radiation resistance and can effectively solve the problem of current gain decrease after total-dose radiation.

[0082] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A total dose radiation resistant triode, characterized in that: The invention comprises a first conductive type substrate (110), a second conductive type buried layer (120), and a second conductive type collector deep well region (130) which are sequentially arranged from bottom to top; a second conductive type collector well region (140) is arranged above the edges of the second conductive type collector well region (130); a second conductive type collector injection region (150) is arranged above the second conductive type collector well region (140); a first conductive type base deep well region (160) is arranged above the inside of the second conductive type collector deep well region (130); a first conductive type base well region (170) is arranged above the edges of the first conductive type base deep well region (160); a first conductive type base injection region (180) is arranged above the first conductive type base well region (170); a second conductive type base deep well region (160) is arranged above the inside of the first conductive type base deep well region (160); An emitter well region (190) is provided, a second conductive type emitter injection region (200) is arranged above the second conductive type emitter well region (190), a first STI isolation structure (210) is arranged between the first conductive type base injection region (180) and the second conductive type collector injection region (150), a second STI isolation structure (220) is arranged outside the second conductive type collector injection region (150) and above the edges of the second conductive type collector deep well region (130), an oxide layer (230) is arranged between the first conductive type base injection region (180) and the second conductive type emitter injection region (200), the oxide layer (230) covers the first conductive type base well region (170) and the second conductive type emitter well region (190), and polysilicon (240) is covered above the oxide layer (230).

2. The total dose radiation resistant triode according to claim 1, characterized in that: The second conductive type collector injection region (150) is located inside the second conductive type collector well region (140), the former has a smaller area than the latter, and a higher concentration than the latter; The first conductive type base injection region (180) is located inside the first conductive type base well region (170), the former has a smaller area than the latter, and a higher concentration than the latter; The second conductive type emitter injection region (200) is located inside the second conductive type emitter well region (190), the former having a smaller area than the latter and a higher concentration than the latter.

3. The total dose radiation resistant triode according to claim 1, characterized in that: The edge of the second conductive type collector injection region (150) is tangent to the STI structure, the outer edge of the first conductive type base injection region (180) is tangent to the STI structure, the inner edge of the first conductive type base injection region (180) is tangent to the oxide layer (230), and the edge of the second conductive type emitter injection region (200) is tangent to the oxide layer (230).

4. The total dose radiation resistant triode according to claim 1, characterized in that: The second conductivity type collector deep well region (130), the second conductivity type collector well region (140), and the second conductivity type collector injection region (150) together constitute a collector structure; A first conductive type base deep well region (160), a first conductive type base well region (170), and a first conductive type base injection region (180) together constitute a base structure; The second conductive type emitter well region (190) and the first conductive type emitter injection region (200) together form an emitter structure.

5. The total dose radiation resistant triode according to claim 1, characterized in that: The second conductive type collector well region (140) is not in direct contact with the first conductive type base well region (170); the first conductive type base well region (170) is in direct contact with the second conductive type emitter well region (190) or there is a gap between them.

6. The total dose radiation resistant triode according to claim 5, characterized in that: When the first conductive type base well region (170) and the second conductive type emitter well region (190) are tangent to each other, the tangent plane is located below the oxide layer (230); when there is a spacing between the first conductive type base well region (170) and the second conductive type emitter well region (190), both edges of the first conductive type base well region (170) and the second conductive type emitter well region (190) that are close to each other are located below the oxide layer (230).

7. The total dose radiation resistant triode according to claim 1, characterized in that: When the first conductivity type doped impurity in the device is an acceptor type, the second conductivity type doped impurity is a donor type; when the first conductivity type doped impurity is a donor type, the second conductivity type doped impurity is an acceptor type.

8. The total dose radiation resistant triode according to claim 1, characterized in that: The polysilicon (240) and the oxide layer (230) have the same shape.

9. The method for preparing a total dose radiation resistant triode according to any one of claims 1 to 8, characterized in that: The steps include: The first step is to provide a first conductive type substrate silicon wafer (110), perform photolithography and doping ion implantation on the upper surface thereof, and perform annealing to form a second conductive type buried layer (120); grow a second conductive type collector deep well region (130) on the upper surface of the second conductive type buried layer (120); perform photolithography and doping ion implantation on the upper surface of the second conductive type collector deep well region (130), and perform annealing to form a first conductive type base deep well region (160); Step 2: growing an oxide layer and depositing a SiN layer on the upper surfaces of the second conductive type collector deep well region (130) and the first conductive type base deep well region (160), performing active area photolithography, performing STI etching, forming STI grooves, depositing SiO2 or other filling materials in the STI grooves, performing electrode isolation, and then performing chemical mechanical polishing to form a first STI shallow trench isolation region (210) and a second STI shallow trench isolation region (220); Step three: performing photolithography and doping ion implantation on the upper surfaces of the second conductive type collector deep well region (130) and the first conductive type base deep well region (160) to form a second conductive type collector well region (140), a first conductive type base well region (170), and a second conductive type emitter well region (190); Step 4: growing a thin oxide layer on the upper surfaces of the second conductive type collector well region (140), the first conductive type base well region (170), and the second conductive type emitter well region (190), depositing polysilicon on the surface of the thin oxide layer, photolithography and etching the polysilicon, and forming a double-layer protection structure of an oxide layer (230) and polysilicon (240) above the interface between the first conductive type base well region (170) and the second conductive type emitter well region (190); Step 5: Perform photolithography and doping ion implantation on the upper surfaces of the second conductive type collector well region (140), the first conductive type base well region (170), and the second conductive type emitter well region (190) to form a second conductive type collector implantation region (150), a first conductive type base implantation region (180), and a second conductive type emitter implantation region (200), thereby forming a complete total-dose radiation-resistant triode structure.

10. The method according to claim 9, characterized in that Omitting one of the first conductivity type base well region (170) and the second conductivity type emitter well region (190); If the first conductive type base well region (170) is omitted and the second conductive type emitter well region (190) is retained, the edge of the second conductive type emitter well region (190) must be below the inside of the oxide layer (230); If the second conductivity type emitter well region (190) is omitted and the first conductivity type base well region (170) is retained, the inner edge of the first conductivity type base well region (170) must be below the inside of the oxide layer (230).

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