WO2014086011A1 - Rb-igbt manufacturing method - Google Patents

Abstract

An RB-IGBT manufacturing method, comprising: providing a lightly doped layer; employing a transmutation doping process to form an RB-IGBT terminal structure; and performing annealing treatment. The terminal structure has a distinct doped area in the lightly doped layer and slight transverse diffusion, thus saving the RB-IGBT terminal footprint and reducing RB-IGBT manufacturing costs.

Description

 RB-IGBT manufacturing method

Technical field

 The present invention relates to the field of semiconductor manufacturing technology, and more particularly to a method of fabricating an RB-IGBT. Background technique

 RB-IGBT (Reverse Blocking-Insulated Gate Bipolar Transistor) is a new type of power semiconductor device with reverse blocking capability. It is a new type of power semiconductor device with reverse blocking capability. , the reverse can withstand the voltage.

 The existing RB-IGBT is fabricated by taking an N-channel RB-IGBT as an example:

 Extending a thickness of the N- epitaxial layer on the P+ substrate;

 A P-type impurity is implanted into the N- epitaxial layer through a mask having a RB-IGBT termination structure, and after a long annealing, a P+ extension junction is formed, and the junction depth is larger than the N- epitaxial layer, and the P+ extension region and the P+ liner are formed. Bottom connection, forming a continuous P+ region, obtaining a terminal structure of the RB-IGBT;

 A front side structure and a back side structure of the RB-IGBT are formed.

 However, in the existing RB-IGBT fabrication method, since the lateral diffusion distance of the P+ region is large, the terminal structure occupies a relatively large area of the RB-IGBT, thereby increasing the fabrication cost of the RB-IGBT. Summary of the invention

To solve the above technical problem, an embodiment of the present invention provides a method for fabricating an RB-IGBT to reduce the manufacturing cost of the RB-IGBT. Replacement page (Article 26) The manufacturing method of the RB-IGBT includes:

 Providing a lightly doped layer; forming a terminal structure of the RB-IGBT by a enthalpy doping process; annealing treatment.

 Preferably, the process of forming the termination structure of the RB-IGBT by a enthalpy doping process comprises: performing a particle ray on the lightly doped layer by using a mask having a RB-IGBT termination structure pattern as a mask The terminal structure of the RB-IGBT is formed.

 Preferably, the lightly doped layer is P-type lightly doped. The lightly doped layer is made of silicon, or silicon carbide, or gallium arsenide, or indium antimonide. The process of performing particle irradiation on the lightly doped layer comprises: providing a neutron source to form a neutron beam; performing particle irradiation on the lightly doped layer by using the neutron beam to initiate a nuclear reaction, An N-type impurity is formed in the lightly doped layer. The mask is made of a neutron absorber.

 Preferably, the lightly doped layer is N-type lightly doped. The lightly doped layer is made of silicon, or germanium, or silicon carbide, or diamond, or gallium arsenide, or indium antimonide. The process of performing particle irradiation on the lightly doped layer comprises: providing a photon source to form a high energy photon beam; irradiating the lightly doped layer with the high energy photon beam to induce a nuclear reaction, in the light A P-type impurity is formed in the doped layer.

 The high energy photon beam has an energy of 17.5 MeV to 22.5 MeV, and the mask is made of a high energy photon absorber.

 Preferably, the material of the lightly doped layer is germanium, and the material of the mask is made of a neutron absorber. The process of performing particle irradiation on the lightly doped layer comprises: providing a neutron source to form a neutron beam; performing particle irradiation on the lightly doped layer by using the neutron beam to initiate a nuclear reaction, A P-type impurity is formed in the lightly doped layer.

 Preferably, the annealing treatment has an annealing temperature of 800 ° C to 900 ° C.

Preferably, the RB-IGBT termination structure shares an annealing process with the front structure of the RB-IGBT, or the RB-IGBT termination structure shares an annealing process with the back surface structure of the RB-IGBT. Replacement page (Article 26) An RB-IGBT, the termination structure of the RB-IGBT is fabricated by the above method. Compared with the prior art, the foregoing technical solution has the following advantages: The technical solution provided by the embodiment of the present invention first provides a lightly doped layer, and then forms a terminal structure of the RB-IGBT through a enthalpy doping process. Since the enthalpy doping process is the terminal structure of the RB-IGBT formed by the nuclear reaction, and the particle beam used has a strong penetrating ability, and the path of the particles in the lightly doped layer is almost straight, thus the lightly doped layer A uniform doping profile is formed in the inside, the doped region is distinct, and the lateral diffusion is small, so that a very narrow column-type doped region can be formed, which saves the area occupied by the terminal of the RB-IGBT and reduces the RB-IGBT. Production costs.

DRAWINGS

 1 is a flow chart of manufacturing an RB-IGBT according to an embodiment of the present invention;

 FIG. 2 to FIG. 4 are schematic diagrams showing a doping process of a RB-IGBT terminal structure according to another embodiment of the present invention; FIG.

 FIG. 5 is a schematic diagram of another RB-IGBT terminal structure doping flow according to another embodiment of the present invention; FIG.

 FIG. 6 is a schematic structural diagram of an RB-IGBT according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION As described in the background section, in the prior art, since the lateral diffusion distance of the P+ region is large, the terminal structure occupies a relatively large area of the RB-IGBT, thereby increasing the manufacturing cost of the RB-IGBT. The inventors have found that the prior art generally adopts an RB-IGBT termination structure formed by an ion implantation or diffusion process. Since the junction depth of the RB-IGBT terminal is large, and is limited by the conventional conventional processes, the formation depth is formed. Large RB-IGBT termination structure, inevitably, RB-IGBT termination structure replacement page (Article 26) The lateral diffusion distance is also large, so that the terminal structure occupies a relatively large area of the RB-IGBT, thereby increasing the manufacturing cost of the RB-IGBT. However, if the doped region formed by the nuclear reaction can precisely control the doped region, a RB-IGBT terminal structure having a large junction depth and a narrow lateral direction can be obtained.

 Based on the above research, the embodiment of the present invention provides a method for fabricating an RB-IGBT, and the method includes the following steps:

 Providing a lightly doped layer;

 The termination structure of the RB-IGBT is formed by a enthalpy doping process. According to the technical solution provided by the embodiments of the present invention, since the enthalpy doping process is a terminal structure of the RB-IGBT formed by a nuclear reaction, and the particle beam used has a penetrating ability, and the particles are in the lightly doped layer. The path is almost straight, so a nearly uniform doping profile is formed in the lightly doped layer, the doped region is distinct, and the lateral diffusion is small, so that a very narrow column-type doped region can be formed, saving

The area occupied by the terminals of the RB-IGBT reduces the manufacturing cost of the RB-IGBT. The above described objects, features and advantages of the present invention will become more apparent from the aspects of the appended claims. Specific details are set forth in the following description in order to provide a thorough understanding of the invention. However, the present invention can be implemented in a variety of other ways than those described herein, and those skilled in the art can make similar promotion without departing from the spirit of the invention. The invention is therefore not limited by the specific embodiments disclosed below. Embodiment 1:

 This embodiment discloses a method for fabricating an RB-IGBT. As shown in FIG. 1 , the method includes: providing a lightly doped layer, wherein the lightly doped layer is N-type lightly doped or P-type lightly doped, and the method is The material is silicon, or tantalum, or silicon carbide, or diamond, or gallium rubide, or indium antimonide, which can be used in semiconductor device fabrication.

The termination structure of the RB-IGBT is formed by a enthalpy doping process. Replacement page (Article 26) The process of forming the terminal structure of the RB-IGBT by a enthalpy doping process includes:

 Performing particle irradiation on the lightly doped layer by using a mask having a RB-IGBT terminal structure pattern as a mask, and forming a terminal structure of the RB-IGBT by reacting the implanted particles with a nuclear reaction of atoms in the lightly doped layer ;

 Annealing treatment restores electrical properties of the lightly doped layer, wherein the annealing temperature of the annealing treatment is 800 ° C to 900 ° C.

 Since the enthalpy doping process is the terminal structure of the RB-IGBT formed by the nuclear reaction, and the particle beam used has a strong penetrating ability, and the path of the particles in the lightly doped layer is almost straight, thus the lightly doped layer A uniform doping profile is formed in the inside, the doped region is distinct, and the lateral diffusion is small, so that a very narrow column-type doped region can be formed, which saves the area occupied by the terminal of the RB-IGBT and reduces the RB-IGBT. Production costs.

 The manufacturing method of the RB-IGBT further includes:

 A front side structure and a back side structure of the RB-IGBT are formed.

Embodiment 2:

 This embodiment discloses another method for fabricating an RB-IGBT, including:

 Providing a lightly doped layer, the lightly doped layer is P-type lightly doped, and the material is preferably silicon, or silicon carbide, or gallium arsenide, or indium antimonide, and the lightly doped layer may be A P-type lightly doped substrate can also be formed by an epitaxial process on an N-type heavily doped substrate.

 The lightly doped layer is subjected to particle irradiation using a mask having a RB-IGBT termination structure pattern as a mask to form a terminal structure of the RB-IGBT.

Specifically, the process of performing particle irradiation on the lightly doped layer comprises: Step S1 l, providing a neutron source to form a neutron beam. Replacement page (Article 26) Since free neutrons are unstable, they can decay into protons emitting electrons and anti-electric neutrinos. The average lifetime is only 15 minutes and cannot be stored for a long time. Therefore, it needs to be supplied by appropriate sources. The neutron source has the following three types:

1. Radioactive isotope neutron source. The radioisotope neutron source comprises: (α, η) neutron source, which utilizes a nuclear reaction 9Be+a→12C+n+5.701 MeV, which will emit ²³⁸ Pu, ²²⁶ Ra of a-ray or

^24, Am is mixed with metal tantalum powder in a certain proportion and then pressed into a small cylinder and sealed in a metal shell; (γ, n) neutron source, which uses gamma rays emitted from the nuclear reaction to generate neutrons, There are ²⁴ Na-Be sources, ¹²⁴ Sb-Be sources, etc. The radioactive isotope neutron source has a small volume, is simple to prepare, and is convenient to use.

 2. Accelerator neutron source. The accelerator neutron source bombards an appropriate target nucleus by charged particles accelerated by an accelerator, and generates neutrons through a nuclear reaction. The most commonly used nuclear reactions are (d, n), (p, n), and (γ, η), etc. The intensity is much larger than that of the radioisotope neutron source, and single-energy neutrons can be obtained over a wide energy region. Moreover, the accelerator can be pulsed neutron source after pulse modulation.

 3. Reactor neutron source. The reactor neutron source generates a large number of neutrons using a nuclear fission reactor. The reactor is the strongest source of thermal neutrons. By opening a hole in the wall of the reactor, 4 bar neutrons are extracted, and the resulting neutron energy is continuously distributed, very close to the Maxwell distribution. Take certain measures to obtain a neutron beam of various energies.

 In order to achieve local doping, the neutron direction of the neutron beam generated by the neutron source needs to be parallel to each other, i.e., a neutron beam resembling parallel light (at least also having a certain degree of parallelism).

Step S12: irradiating the lightly doped layer with the neutron beam to initiate a nuclear reaction, and forming an N-type impurity in the lightly doped layer. The above method uses neutron irradiation to dope the material. Since the distribution of isotopic atoms in the crystal is very uniform, and the penetration depth of neutrons in the semiconductor material is very large (about the replacement page (Rule 26) 100 cm), so the light-doped layer is irradiated with particles by the neutron beam, and the doping by the enthalpy of the element is very uniform, which is useful for the fabrication of high-power semiconductor devices and radiation detectors. .

 Further, for a lightly doped layer made of silicon, after irradiation with a neutron beam, an N-type impurity can be formed by initiating a nuclear reaction. That is, after the silicon 30 absorbs a neutron, it becomes silicon 31, and a photon is released, and after a half life of 2.6 h, an electron is released and becomes phosphorus 31. The specific nuclear reaction is:

·(", ) · ¹ ' ^Β ― Ρ

 The stable enthalpy produced by this reaction is the donor element to be incorporated into the bismuth silicon.

The radon concentration N _D (unit: cm- ³ ) reached after irradiation can be calculated by the following formula:

N _D = Ν^ ₀ σ Χ

Where, N _Si3 . Is the abundance of ^3Q Si in silicon (unit: cm- ³ ); σ is the radiation capture cross section of Si atom for thermal neutrons (σ=0.11 target); ψ is the irradiation dose of thermal neutron (unit: η· ² ); t is the irradiation time (unit: s).

Since the abundance N _Si30 of ^3G Si is fixed in a specific lightly doped layer, and the Si atom is also a certain value for the radiation capture cross section σ of the thermal neutron, by controlling the irradiation dose of the thermal neutron ψ And the irradiation time t can precisely control the doping concentration of impurities in the silicon type silicon. Moreover, the above reaction produces only one element (P), and no compensation due to enthalpy change occurs.

In addition, the distribution of ^3G Si in silicon is naturally uniform, so that the distribution of ³¹ P produced by the enthalpy is uniform, that is, the distribution of impurities in the N-type silicon is uniform.

In addition, in order to avoid the influence of uneven distribution of neutron beam flux, a metal flux homogenizer can be used to obtain a neutron beam with uniform flux distribution. Replacement page (Article 26) For a lightly doped layer made of silicon carbide, similar to silicon, after irradiation with a neutron beam, silicon 30 absorbs a neutron and becomes silicon 31, releasing a photon and then passing a half life of 2.6 h. After releasing an electron, it becomes phosphorus 31, so that donor phosphorus appears in the silicon carbide, and the silicon carbide becomes N-type doped silicon carbide. Since the particle irradiation process is performed using a neutron beam, the mask is made of a neutron absorber to block unwanted particle irradiation. Among them, an effective neutron absorber is a radioisotope that can generate a stable nucleus by absorbing a neutron. For example, 氙135 (half-life of about 9.1 hours) can absorb a neutron that becomes stable 氙136. The 氙135 can be fissioned in the nuclear reactor through the uranium 235, uranium 233 and 钚239 nuclear nucleus, accompanied by the production of iodine 135, which can rapidly decay, emitting a beta particle (high energy electron) and producing 氙135.

 Other major neutron absorbers include the 氦3 isotope, which absorbs neutrons to produce cesium (a heavier isotope of hydrogen); boron 10, which absorbs neutrons, produces lithium and ruthenium nucleus; 钐149 is also a An effective neutron absorber that produces a stable isotope 钐150 after neutron absorption. The neutron absorber may be several or at least one of the above isotopes.

 Other neutron absorbers used in control rods in nuclear reactors include cadmium, lanthanum and rare earth metal lanthanum, which contain several isotopes, some of which are very efficient neutron absorbers.

 These materials can be used as the neutron absorber described in this embodiment, that is, both can be used as the mask. Moreover, by selecting a suitable material and a mask of sufficient thickness, the neutron can be effectively absorbed to achieve the mask effect and achieve local doping.

In addition, for ease of understanding, FIGS. 2 to 4 show a specific process of the above doping. As shown in FIG. 2, the Ν-type lightly doped layer 102 is formed on the Ρ-type heavily doped substrate 101 by an epitaxial process; as shown in FIG. 3, the Ν-type lightly doped layer 102 is covered with an RB-IGBT. The mask 103 of the terminal structure pattern is aligned and then replaced by a neutron beam pair perpendicular to the surface of the 轻-type lightly doped layer 102 in the incident direction (Rule 26) The N-type lightly doped layer 102 is irradiated, and at a portion where the mask 103 is blocked, the neutron beam is absorbed by the mask 103, and the RB-IGBT terminal structure region that is not blocked by the mask 103, the neutron beam The RB-IGBT termination structure 104 can be directly injected into the N-type lightly doped layer 102 to generate a nuclear reaction (for example, Si 嬗 becomes P), and the resulting RB-IGBT termination structure 104 is as shown in FIG.

 And, as shown in FIG. 5, the neutron beam and the oblique implant can also be implanted into the N-type lightly doped layer 202 by changing the incident direction of the neutron beam, in the N-type lightly doped layer. An upper rib-wide narrow RB-IGBT termination structure 204 is formed in 202 to enable the RB-IGBT to withstand greater reverse withstand voltage. Alternatively, in a similar manner, other shapes of RB-IGBT termination structures are formed to accommodate other practical needs.

 It can be seen that the RB-IGBT terminal structure formed in the N-type lightly doped layer by the above method has the same doping distribution, distinct doping regions, and small lateral diffusion, and is a very narrow column or trapezoidal doped region. The area occupied by the terminals of the RB-IGBT is saved, and the manufacturing cost of the RB-IGBT is reduced.

 In addition, since the above method causes many irradiation defects in the lightly doped layer, the physical properties of the lightly doped layer are significantly changed. In order to restore the electrical properties of the lightly doped layer, it is also required to be annealed, wherein the annealing temperature is preferably 800 ° C to 900 ° C.

 Finally, it is also necessary to form the front and back structures of the RB-IGBT.

Embodiment 3:

 This embodiment discloses another method for fabricating an RB-IGBT, including:

 Providing a lightly doped layer, the lightly doped layer is N-type lightly doped, and the material is preferably silicon, or germanium, or silicon carbide, or diamond, or gallium arsenide, or indium antimonide, and The lightly doped layer may be an N-type lightly doped substrate, or may be formed by an epitaxial process on a P-type heavily doped substrate.

 The lightly doped layer is subjected to particle irradiation using a mask having a RB-IGBT termination structure pattern as a mask to form a terminal structure of the RB-IGBT.

Specifically, the process of irradiating the lightly doped layer with particles includes: replacing the page (Article 26) Step S21: providing a photon source to form a high-energy photon beam.

 Since the high energy photon beam can be generated by bremsstrahlung from an electron linear accelerator, the photon source described in this embodiment is preferably an electron linear accelerator photon source. The energy of the resulting high energy photon beam is 17.5 MeV to 22.5 MeV. Of course, as with the neutron beam requirements, we also need that the direction of motion of the photons in the high-energy photon beam is parallel to each other (at least with a certain degree of parallelism).

 Step S22: Perform particle irradiation on the lightly doped layer by using the high energy photon beam to initiate a nuclear reaction, and form a P-type impurity in the lightly doped layer.

 The above method uses photon irradiation to dope the material.

 Since the high-energy electrons have a small attenuation coefficient in silicon, deep doping of the semiconductor can be achieved. And the distribution of the isotope atoms in the crystal is very uniform, so that the lightly doped layer is irradiated with particles by the high energy photon beam, and the doping by the enthalpy of the element is very uniform.

 Further, for a lightly doped layer made of silicon, after irradiation with a high-energy photon beam, a P-type impurity can be formed by initiating a nuclear reaction.

 That is, after the silicon 30 absorbs a photon, it becomes aluminum 27 and releases a shield. The specific nuclear reaction is:

 Alternatively, silicon 30 absorbs a photon and becomes silicon 27, and releases a neutron. After a half-life of 4.2 s, it releases a positron and turns into aluminum 27. The specific nuclear reaction is:

 The stable A1 generated by this reaction is the donor element to be incorporated into P-type silicon.

Replacement page (Article 26) Among them, although the threshold photon energy of the nuclear reaction is 11.6 MeV, when the photon energy is between 17.5 MeV and 22.5 MeV, the large resonance produces the largest photon capture cross section. Therefore, the energy of the high energy photon beam of this embodiment is 17.5 MeV. ~22.5 MeV, preferably 20 MeV. For a lightly doped layer made of diamond, P-type impurities can also be formed by initiating a nuclear reaction after irradiation with a high-energy photon beam. That is, after carbon 12 absorbs a photon, it becomes boron 11, and releases a proton. The specific nuclear reaction is:

u ₆ c(r, _P ) ⁿ ₅ B or, after carbon 12 absorbs a photon, it becomes carbon 11 and releases a proton. Then carbon 11 releases a positron and becomes boron 11. The specific nuclear reaction is :

 For the lightly doped layer made of silicon carbide, after the irradiation with the high-energy photon beam, the nuclear reaction of the two crystals of silicon and diamond is combined to form P-type impurities. Since the particle irradiation process is carried out using a high energy photon beam, the masking material is made of a photon absorber to block unwanted particle irradiation.

 The high-energy photon absorber includes at least one of a simple substance or a compound of a heavy metal element atom and a substance capable of effectively absorbing photons such as a titanate or a silane coupling agent.

 In addition, similar to the above embodiment, the high-energy photon beam can be obliquely implanted into the N-type lightly doped layer by changing the incident direction of the high-energy photon beam, and the upper width is formed in the N-type lightly doped layer. The narrow RB-IGBT termination structure allows the RB-IGBT to withstand greater reverse withstand voltage. Alternatively, other shapes of RB-IGBT termination structures are formed in a similar manner to accommodate other practical requirements, and will not be described herein.

RB-IGBT termination structure formed in an N-type lightly doped layer by the above method, its doping distribution replacement page (Article 26) Consistently, the doped region is distinct, the lateral diffusion is small, and it is a very narrow column or trapezoidal doped region, which saves the area occupied by the terminal of the RB-IGBT and reduces the manufacturing cost of the RB-IGBT.

 In addition, since the above method also causes many irradiation defects in the lightly doped layer, the physical properties of the lightly doped layer are significantly changed. In order to restore the electrical properties of the lightly doped layer, it is also necessary to anneal it, wherein the annealing temperature is preferably 800 ° C ~ 900 ° C.

 Finally, it is also necessary to form the front and back structures of the RB-IGBT. Embodiment 4:

 This embodiment discloses another method for fabricating an RB-IGBT, including:

 Providing a lightly doped layer, the lightly doped layer is N-type lightly doped, and the material is made of germanium, and the lightly doped layer may be an N-type lightly doped substrate, or may be a P-type The heavily doped village is formed by an epitaxial process.

 The lightly doped layer is subjected to particle irradiation using a mask having a RB-IGBT termination structure pattern as a mask to form a terminal structure of the RB-IGBT.

 Specifically, the process of performing particle irradiation on the lightly doped layer comprises: Step S31: providing a neutron source to form a neutron beam.

 Since free neutrons are unstable, they can decay into protons emitting electrons and anti-electric neutrinos. The average lifetime is only 15 minutes and cannot be stored for a long time. Therefore, it needs to be supplied by appropriate sources. The neutron source is preferably a radioisotope neutron source, or an accelerator neutron source, or a reactor neutron source. In order to achieve local doping, the neutron motion directions in the neutron beam generated by the neutron source need to be parallel to each other, i.e., a neutron beam similar to parallel light (at least also having a certain degree of parallelism).

 Step S32: Perform particle irradiation on the lightly doped layer by using the neutron beam to initiate a nuclear reaction, and form a P-type impurity in the lightly doped layer.

The above method uses photon irradiation to dope the material. Replacement page (Article 26) The above method uses neutron irradiation to dope the material. Since the distribution of isotopic atoms in the crystal is very uniform, and the penetration depth of the neutrons in the crucible is large, the light-doped layer is irradiated with particles by the neutron beam, and the element is transformed. The doping formed is very uniform, which is useful for the fabrication of high power semiconductor devices and radiation detector devices. Since the particle irradiation process is performed using a neutron beam, the mask is made of a neutron absorber to block unwanted particle irradiation.

 Wherein, the neutron absorber comprises: 氙 135, or 氦 3 isotope, or boron 10, or 钐 149, etc., which can effectively absorb neutrons.

 In addition, similar to the above embodiment, the neutron beam may be obliquely implanted into the N-type lightly doped layer by changing the incident direction of the neutron beam, and the upper width is formed in the N-type lightly doped layer. The narrow RB-IGBT termination structure allows the RB-IGBT to withstand greater reverse withstand voltage. Alternatively, in a similar manner, other shapes of RB-IGBT termination structures are formed to accommodate other practical needs, and will not be described herein.

 The RB-IGBT termination structure formed in the N-type lightly doped layer by the above method has the same doping profile, distinct doped regions, and small lateral diffusion, which is a very narrow column or trapezoidal doped region, saving The area occupied by the terminals of the RB-IGBT reduces the manufacturing cost of the RB-IGBT.

 Step S33, annealing treatment to restore electrical properties of the lightly doped layer, wherein the annealing temperature of the annealing treatment is 800 ° C to 900 ° C.

 Finally, it is also necessary to form the front and back structures of the RB-IGBT. Embodiment 5:

 This embodiment discloses another manufacturing method of the RB-IGBT, which is different from the above embodiment in:

 The RB-IGBT termination structure shares an annealing process with the front structure of the RB-IGBT, or the RB-IGBT termination structure shares an annealing process with the back structure of the RB-IGBT.

Replacement page (Article 26) The process of forming the front and back structures of the RB-IGBT includes:

 Forming a well region, an emitter region, a field limiting ring, a field stop ring, a gate and a front metal on the lightly doped layer to complete fabrication of a front side structure of the RB-IGBT;

 A collector region and a back metal are formed on the back surface of the lightly doped layer to complete the fabrication of the back surface structure of the RB-IGBT.

 The following is an example in which the RB-IGBT termination structure and the front structure of the RB-IGBT share an annealing process.

 The manufacturing method of the RB-IGBT includes:

 Providing a heavily doped substrate;

 Epitaxially growing a lightly doped layer on the surface of the heavily doped substrate;

 Forming a well region in an active region of the surface of the lightly doped layer while forming a field limiting ring on a periphery of the active region of the surface of the lightly doped layer;

 Forming the RB-IGBT termination structure on the outermost side of the surface of the lightly doped layer;

 Annealing, activating dopant ions in the well region and the field limiting ring, and restoring electrical properties of the lightly doped layer.

 Forming an emitter region, a field stop ring, a gate and a front metal on the lightly doped layer to complete fabrication of a front side structure of the RB-IGBT;

 A collector region and a back metal are formed on the back surface of the lightly doped layer to complete the fabrication of the back surface structure of the RB-IGBT. Wherein the collector region is formed by thinning the heavily doped substrate.

 For example, the RB-IGBT termination structure and the back surface structure of the RB-IGBT share an annealing process, and the manufacturing method of the RB-IGBT includes:

 Providing a lightly doped substrate;

 Forming a well region, an emitter region, a field limiting ring, a field stop ring, a gate and a front metal in an active region of the surface of the lightly doped substrate to complete fabrication of a front structure of the RB-IGBT;

Forming the RB-IGBT termination structure on the outermost side of the surface of the lightly doped substrate; replacement page (Article 26) Thinning the lightly doped substrate and forming a collector region on the back side of the lightly doped substrate by an ion implantation process;

 Annealing activates dopant ions in the collector region and restores electrical properties of the lightly doped substrate. A back metal is formed on the surface of the collector region to complete the fabrication of the back surface structure of the RB-IGBT. In addition, the RB-IGBT termination structure may also share an annealing process in the emitter region, and details are not described herein. The completed RB-IGBT structure is shown in FIG. 6, wherein the collector region 301 is located on the back side of the lightly doped layer 302, and the back metal 300 is located on the back surface of the collector region 301 in the lightly doped layer 302 (the RB-IGBT The edge position of the RB-IGBT terminal structure 303 is disposed in the surface of the lightly doped layer 302 (the active region position of the RB-IGBT) is provided with a well region 304, an emission region 307 and a gate 308, which are light Within the surface of the doped layer 302 (the position H between the active region and the edge of the RB-IGBT is provided with a field limiting ring 305 and a field stop ring 306, in the RB-IGBT termination structure 303, the well region 304, The field limiting ring 305, the field stop ring 306, the emitter region 307, and the gate 308 are covered with a front side metal 309.

Embodiment 6: This embodiment discloses an RB-IGBT, and the terminal structure of the RB-IGBT is fabricated by the method disclosed in the above embodiments.

 Then, the terminal structure of the RB-IGBT formed by the method provided by the embodiment has a distinct doping region, and the concentration can be accurately controlled, and has a uniform doping profile. It should be noted that the irradiation energy of the particles in the various embodiments of the present application is at least capable of initiating a nuclear reaction, and the irradiation dose needs to be pre-calculated according to actual needs. For other semiconductor materials and irradiated particles, ultra-deep junction terminals can be formed by this method as long as the corresponding doping types can be formed, which are not listed here.

Replacement page (Article 26) Moreover, since the irradiation time of some materials or particles is shorter than the time conventionally used for diffusion, the manufacturing method of the RB-IGBT provided by the present application can also improve the production efficiency.

 In addition, it should be noted that since the semiconductor nuclear enthalpy doping has residual radioactivity, after the particle irradiation, the lightly doped layer or the lightly doped substrate needs to be cooled by radiation for a certain period of time before being used as a non-radioactive material. operating.

 The drawings in the present specification are schematic diagrams and do not represent true scales. Moreover, each part of the specification is described in a progressive manner, and each part focuses on the difference from the other parts, and the same similar parts between the parts can be referred to each other. The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but the scope of the invention.

Replacement page (Article 26)

Claims

Rights request 1. A method of manufacturing RB-IGBT, characterized by including: providing a lightly doped layer; The terminal structure of the RB-IGBT is formed through a transmutation doping process; Annealing treatment. 2. The manufacturing method of RB-IGBT according to claim 1, characterized in that the process of forming the terminal structure of the RB-IGBT through a transmutation doping process includes: Using a mask with a pattern of the RB-IGBT terminal structure as a mask, the light-mixed layer is subjected to particle irradiation to form the terminal structure of the RB-IGBT. 3. The manufacturing method of RB-IGBT according to claim 2, characterized in that the lightly doped layer is P-type lightly doped. 4. The manufacturing method of RB-IGBT according to claim 3, characterized in that the lightly doped layer is made of silicon, silicon carbide, gallium arsenide, or indium antimonide. 5. The manufacturing method of RB-IGBT according to claim 3, characterized in that the process of particle irradiation of the light hybrid layer includes: Provide a neutron source to form a neutron beam; The neutron beam is used to irradiate the lightly doped layer with particles to trigger a nuclear reaction and form N-type impurities in the lightly doped layer. 6. The manufacturing method of RB-IGBT according to claim 5, characterized in that the neutron source is a radioisotope neutron source, an accelerator neutron source, or a reactor neutron source. 7. The manufacturing method of RB-IGBT according to claim 5, characterized in that the moving directions of neutrons in the neutron beam are parallel to each other. 8. The manufacturing method of RB-IGBT according to claim 5, characterized in that the mask is made of a neutron absorber. 9. The manufacturing method of RB-IGBT according to claim 8, characterized in that, the neutron absorber The collector includes: at least one of xenon 135, or helium 3 isotope, or boron 10, or samarium 149. 10. The manufacturing method of the RB-IGBT according to claim 2, characterized in that the lightly doped layer is N-type lightly doped. 11. The manufacturing method of RB-IGBT according to claim 10, wherein the lightly doped layer is made of silicon, germanium, silicon carbide, diamond, gallium arsenide, or indium antimonide . 12. The manufacturing method of RB-IGBT according to claim 10, characterized in that the process of particle irradiation of the lightly doped layer includes: Provide a photon source to form a high-energy photon beam; The high-energy photon beam is used to irradiate the lightly doped layer with particles, triggering a nuclear reaction, and forming P-type impurities in the lightly doped layer. 13. The manufacturing method of RB-IGBT according to claim 12, characterized in that the photon source is an electron linear accelerator photon source. 14. The manufacturing method of RB-IGBT according to claim 13, characterized in that the energy of the high-energy photon beam is 17.5MeV~22.5MeV. 15. The manufacturing method of RB-IGBT according to claim 13, characterized in that the moving directions of photons in the high-energy photon beam are parallel to each other. 16. The manufacturing method of RB-IGBT according to claim 13, characterized in that the mask is made of a high-energy photon absorber. 17. The manufacturing method of RB-IGBT according to claim 16, characterized in that the high-energy photon absorber includes: at least one of elements or compounds of heavy metal element atoms and titanate or silane coupling agents. 18. The manufacturing method of RB-IGBT according to claim 12, characterized in that the lightly doped layer is made of germanium, and the mask is made of neutron absorber. 19. The manufacturing method of RB-IGBT according to claim 18, characterized in that the process of particle irradiation of the lightly doped layer includes: Provide a neutron source to form a neutron beam; The neutron beam is used to perform particle irradiation on the lightly doped layer, triggering a nuclear reaction, and forming P-type impurities in the lightly doped layer. 20. The manufacturing method of the RB-IGBT according to claim 1, characterized in that the annealing temperature of the annealing treatment is 800°C~900°C. 21. The manufacturing method of the RB-IGBT according to claim 2, further comprising: forming the front structure and the back structure of the RB-IGBT. 22. The manufacturing method of RB-IGBT according to claim 21, characterized in that, the RB-IGBT terminal structure and the front structure of RB-IGBT share an annealing process, or, the RB-IGBT terminal structure and RB -The backside structures of IGBTs share an annealing process. 23. The manufacturing method of RB-IGBT according to claim 21, characterized in that the process of forming the front structure and back structure of the RB-IGBT includes: Form a well region, an emitter region, a field limit ring, a field stop ring, a gate and a front-side metal on the lightly doped layer to complete the production of the front-side structure of the RB-IGBT; A collector region and a back metal are formed on the back side of the lightly doped layer to complete the fabrication of the RB-IGBT back structure. 24. An RB-IGBT, characterized in that the terminal structure of the RB-IGBT is made by the method described in claim 1.