Longitudinal Light-Controlled Unit and Semiconductor Voltage-Resistant Unit Composite Device and Fabrication Method Thereof

Abstract

The present invention provides a composite device of a longitudinal light control unit and a semiconductor voltage withstand unit and a manufacturing method thereof. The formation of the voltage withstand unit in the composite device is obtained by jointly constructing an n-epitaxial layer, an n+-epitaxial layer and a substrate layer; the formation of the electronic control unit is to perform Si ion implantation on the n+-epitaxial layer to form an n++-epitaxial layer, and the n++-epitaxial layer and an ohmic metal form a source electrode; on both sides of the n++-epitaxial layer and the n+-epitaxial layer, a gate dielectric / P+ region, a gate metal and an interlayer dielectric are sequentially provided; the formation of the light control unit is to construct a trench structure from the surface of the n+-epitaxial layer towards the substrate layer to form a P-type thin film layer. The P-type thin film layer and the n+-epitaxial layer form a PN junction to form a local depletion region, and a light control electrode is provided on the inner wall side of the P-type thin film layer. The present invention replaces the traditional silicon-based material with a wide-bandgap semiconductor voltage withstand material and innovates the structure, fundamentally improving the physical limit of the light control power device, so that the corresponding light control power device can stably operate at higher temperatures, higher voltages and more severe environments.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and particularly relates to a composite device of a longitudinal light control unit and a semiconductor voltage withstand unit and a manufacturing method thereof. Background Art

[0002] In today's power electronic applications with higher power density and lower power consumption requirements, the Ga2O3 material has greater research significance and broader market application prospects. Contrary to the ease of n-type doping, there has been no report of successful p-type doping in Ga2O3 yet, which limits the application of Ga2O3 in bipolar power devices compared with materials that can be bipolar-doped.

[0003] There are three factors that make it almost impossible to achieve hole-conducting p-type Ga2O3: First, it is difficult to find acceptor impurities with a small activation energy; second, theoretically calculated, the maximum valence band dispersion of Ga2O3 is small and the effective mass is very large, resulting in free holes almost becoming a local distribution of small μ; finally, it has been specifically predicted for Ga2O3 theoretically that due to local lattice distortion, the local self-trapping energy of free holes in the volume is very large, which leads to the formation of small polarons, undoubtedly prohibiting the effective conduction of holes.

[0004] In the existing technology, taking the Ga2O3 material as an example, there is currently no instance of integrating a control unit and a voltage withstand unit of a wide-bandgap semiconductor material with a light control unit on the same wafer substrate. The existing instances are silicon-based light control devices, and there are two problems in their technology:

[0005] First, silicon material is used as the voltage withstand unit of the entire device. Currently developed silicon-based high-voltage devices such as IGBT (Insulated Gate Bipolar Transistor), VDMOS (Vertical Double Diffused Metal Oxide Semiconductor), and GTO (Thyristor) have almost reached the physical limit of silicon-based materials, and it is very difficult to further improve their voltage withstand.

[0006] Second, since the light control units of silicon-based light control devices all work near the surface of the electrode metal material, and silicon material itself is opaque, when the light control unit starts to work, the depth of light entering from the surface of the silicon-based device is very thin and cannot reach the position of the voltage withstand layer of the silicon-based device. At this time, the electron-hole pairs generated by light are instantaneously recombined with the existing majority carriers in the neutral region near the surface and will not generate a large current to turn on the device, so the purpose of light control cannot be achieved.

[0007] Based on this, the present invention provides a new composite device of a longitudinal light control unit and a semiconductor voltage withstand unit and a manufacturing method thereof. Summary of the Invention

[0008] Based on the above description, the present invention provides a composite device and device structure of a longitudinal light control unit and a semiconductor voltage withstand unit to solve the problems in the prior art that silicon-based high-voltage devices have almost reached the physical limit of silicon-based materials, the depth of light irradiated from the surface of silicon-based devices is very thin and cannot reach the position of the voltage withstand layer of silicon-based devices, and the purpose of light control cannot be achieved.

[0009] The technical solution of the present invention to solve the above technical problems is as follows:

[0010] In the first aspect, the present invention provides a composite device of a longitudinal light control unit and a semiconductor voltage withstand unit, including: a substrate layer, an n-epitaxial layer, an n+-epitaxial layer, an n++-epitaxial layer, a voltage withstand unit, an electric control unit, and a light control unit;

[0011] The n-epitaxial layer and the n+-epitaxial layer are sequentially stacked on the substrate layer from bottom to top;

[0012] The formation of the voltage withstand unit is jointly constructed by the n-epitaxial layer, the n+-epitaxial layer, and the substrate layer; the electric control unit and the light control unit are respectively arranged on the voltage withstand unit;

[0013] Among them, the formation of the electric control unit is to perform Si ion implantation on the n+-epitaxial layer to form the n++-epitaxial layer, and the n++-epitaxial layer forms a source electrode with ohmic metal; on both sides of the n++-epitaxial layer and the n+-epitaxial layer, a gate dielectric / P+ region, a gate metal, and an interlayer dielectric are sequentially arranged;

[0014] The formation of the light control unit is to construct a trench structure in the n+-epitaxial layer from the surface towards the substrate layer, and form a P-type thin film layer through a sputtering and stripping process. The P-type thin film layer and the n+-epitaxial layer form a PN junction to form a local depletion region, and a light control electrode is arranged on the inner wall side of the P-type thin film layer.

[0015] Based on the above technical solution, the present invention can also be improved as follows.

[0016] Further, the material of the substrate layer is an N-type high-resistance or high-purity semi-insulating semiconductor material, or a P-type or quasi-P-type material.

[0017] Further, the composite device further includes a drain electrode;

[0018] The drain electrode is arranged at the bottom of the substrate layer.

[0019] Further, the P-type thin film layer is a transparent material.

[0020] Further, a transparent metal layer is arranged on the inner wall side of the P-type thin film layer.

[0021] Further, the groove structure is a multi-stage groove, a regular groove or an irregular groove.

[0022] Further, the electronic control unit is provided with one of a Fin structure, a JFET structure, a GAA structure, a MOS structure, a BJT structure, a PN structure, a PIN structure, a heterojunction PN structure, an IGBT structure, a GTO structure and an SJ structure.

[0023] Further, the n-epitaxial layer is one or any combination of Ga2O3, AlN, BN, SiC, GaN, diamond wide bandgap semiconductor materials.

[0024] Second, the present invention also provides a manufacturing method for manufacturing the composite device of the longitudinal light control unit and the semiconductor voltage withstand unit as described in the first aspect, which is characterized by including the following steps:

[0025] S1: Construct a current channel layer on the surface of the substrate layer and the n-epitaxial wafer, and sequentially form an n+ epitaxial layer and an n++ epitaxial layer by ion implantation;

[0026] S2: Etch the n+ epitaxial layer and the n++ epitaxial layer;

[0027] S3: Grow a gate dielectric layer and a gate metal sequentially at the etched edge;

[0028] S4: Use a photoresist planarization process to expose the top gate metal;

[0029] S5: Etch the gate metal and the gate dielectric sequentially on the structure after photoresist planarization, and perform a degluing process after etching;

[0030] S6: Grow an interlayer dielectric, and then perform an interlayer dielectric etching to open holes;

[0031] S7: Selectively and locally deposit a source metal by evaporation and stripping, and then anneal to form an ohmic contact, and the manufacturing of the electronic control unit is completed;

[0032] S8: Protect the electronic control unit by coating photoresist, and only expose and perform corresponding etching on the light control unit; etch the n+ epitaxial layer and the n++ epitaxial layer, and at the same time use a sidewall process to obtain a groove structure;

[0033] S9: Use a sputtering process to grow a transparent thin P-type material on the surface of the groove structure to form a P-type thin film layer;

[0034] S10: Evaporate a transparent metal on the P-type thin film layer, and the transparent P-type thin film layer forms a light control electrode; an ohmic contact is formed after annealing the transparent metal and the transparent P-type thin film layer; flip the device, evaporate a metal on the substrate layer, and also form an ohmic contact after annealing to manufacture a drain electrode, thus obtaining the device.

[0035] Compared with the prior art, the technical solution of the present application has the following beneficial technical effects:

[0036] The composite device of a longitudinal light control unit and a semiconductor breakdown voltage unit, the device structure thereof, and the manufacturing method thereof provided by the present invention have the following beneficial effects compared with the prior art:

[0037] The composite device of a longitudinal light control unit and a semiconductor breakdown voltage unit includes an N-type doped 4H-SiC substrate, an N-type doped epitaxial layer above the 4H-SiC substrate, an N-type doped 3C-SiC epitaxial layer above the N-type epitaxial layer, an epitaxial interface layer naturally formed between the N-type doped epitaxial layer and the 3C-SiC, an N-type doped carrier tunneling region penetrating through part of the epitaxial interface layer, and a P-type doped buried layer below the N-type doped carrier tunneling region.

[0038] (1) A novel gallium oxide photocontrolled high-voltage and high-current power device with direct photon injection into the body region of the breakdown voltage layer of a wide-bandgap semiconductor material is proposed for the first time. This solution solves the problem of the marketization of gallium oxide power device applications in the absence of P-type doping in gallium oxide materials. That is, a power device with ultra-high breakdown voltage and high current is realized only by using n-type gallium oxide material.

[0039] (2) Through the structural design of combining an electronic control unit with a photocontrol unit in a trench composite structure that penetrates deep into the epitaxial body region, photo-generated carriers can penetrate deep into the high-resistance body region with high breakdown voltage inside the device structure, solving the problem that after electron-hole pairs are formed on the material surface by light irradiation and then quickly recombined by the majority carriers in this neutral region, the conduction current is small and the photocontrol is insensitive; at the same time, a high-voltage switching process can be controlled by a low-voltage electronic control unit;

[0040] When the photocontrol unit in the deep epitaxial body region adopts a multi-level trench structure, the multi-level trench-assisted light injection region structure can penetrate deep into the epitaxial breakdown voltage layer and even penetrate the epitaxial layer into the high-resistance substrate layer with high breakdown voltage, so as to realize a photon injection conductance modulation region with a higher total surface area ratio of deep high-light injection, which is beneficial to further reducing the on-resistance when the device is turned on by light irradiation.

[0041] (3) Replacing traditional silicon-based materials with wide-bandgap semiconductor breakdown voltage materials such as gallium oxide and innovating the structural design can fundamentally improve the physical limit of photocontrolled power devices, give full play to the material characteristics, and the manufactured photocontrolled power devices can work stably at higher temperatures, higher voltages, and more severe environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic structural diagram of the composite device of a longitudinal light control unit and a semiconductor breakdown voltage unit provided by Embodiment 1 of the present invention;

[0043] Figure 2Equivalent model diagram of the composite device of the longitudinal light control unit and the semiconductor voltage withstand unit provided in Embodiment 1 of the present invention;

[0044] Figure 3 Schematic principle diagram of the composite device of the longitudinal light control unit and the semiconductor voltage withstand unit provided in Embodiment 1 of the present invention;

[0045] Figure 4 Schematic diagram of the manufacturing process of the composite device of the longitudinal light control unit and the semiconductor voltage withstand unit provided in Embodiment 2 of the present invention;

[0046] Figure 5 Schematic diagram of the structure of the composite device of the longitudinal light control unit and the semiconductor voltage withstand unit provided in Embodiment 3 of the present invention;

[0047] Figure 6 Schematic diagram of the structure of the composite device of the longitudinal light control unit and the semiconductor voltage withstand unit provided in Embodiment 4 of the present invention;

[0048] Figure 7 and Figure 8 Schematic diagram of the structure of the composite device of the longitudinal light control unit and the semiconductor voltage withstand unit provided in Embodiment 5 of the present invention;

[0049] Figure 9 and Figure 10 Schematic diagram of the structure of the composite device of the longitudinal light control unit and the semiconductor voltage withstand unit provided in Embodiment 6 of the present invention;

[0050] In the drawings, the list of components represented by each reference numeral is as follows:

[0051] 1. Substrate layer; 2. n-epitaxial layer; 3. n+-epitaxial layer; 4. n++-epitaxial layer; 5. Voltage withstand unit; 6. Electric control unit; 7. Light control unit; 8. Gate dielectric; 9. P+ region; 10. Gate metal; 11. Interlayer dielectric; 12. Source electrode; 13. P-type thin film layer; 14. Light control electrode; 15. Drain electrode. Detailed implementation manners

[0052] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. Embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0053] The following will further describe in detail the implementation manners of the present invention in conjunction with the drawings and embodiments. The following embodiments are used to illustrate the present invention but cannot be used to limit the scope of the present invention.

[0054] Embodiment 1

[0055] As Figure 1As shown, this embodiment provides a composite device of a longitudinal light control unit and a semiconductor breakdown voltage unit, including: a substrate layer 1, an n-epitaxial layer 2, an n+-epitaxial layer 3, an n++-epitaxial layer 4, a breakdown voltage unit 5, an electric control unit 6, and a light control unit 7.

[0056] The n-epitaxial layer 2 and the n+-epitaxial layer 3 are sequentially stacked on the substrate layer 1 from bottom to top.

[0057] Among them, the material of the substrate layer 1 is an N-type high-resistance or high-purity semi-insulating semiconductor material, or a P-type or quasi-P-type material.

[0058] The n-epitaxial layer 2 is one or any combination of Ga2O3, AlN, BN, SiC, GaN, diamond wide-bandgap semiconductor materials. In a specific example, the material of the substrate layer 1 is gallium oxide.

[0059] The breakdown voltage unit 5 is formed by jointly constructing the n-epitaxial layer 2, the n+-epitaxial layer 3 and the substrate layer 1; the electric control unit 6 and the light control unit 7 are respectively disposed on the breakdown voltage unit 5. The electric field diagram of the breakdown voltage unit 5 is shown on the left in Figure 1 the following.

[0060] Among them, the electric control unit 6 is formed by performing Si ion implantation on the n+-epitaxial layer 3 to form the n++-epitaxial layer 4, and the n++-epitaxial layer 4 and the ohmic metal form the source electrode 12; on both sides of the n++-epitaxial layer 4 and the n+-epitaxial layer 3, a gate dielectric 8, a gate metal 10 and an interlayer dielectric 11 are sequentially provided.

[0061] The light control unit 7 is formed by constructing a trench structure from the surface of the n+-epitaxial layer 3 towards the substrate layer 1, and forming a P-type thin film layer 13 through a sputtering and stripping process. The P-type thin film layer 13 and the n+-epitaxial layer 3 form a PN junction to form a local depletion region, and a light control electrode 14 is provided on the inner wall side of the P-type thin film layer 13.

[0062] Among them, the P-type thin film layer 13 is a transparent material.

[0063] As Figure 1 shown, the light control electrode 14 on the inner wall side of the P-type thin film layer 13 is a transparent metal layer.

[0064] As Figure 2As shown in the figure, when light irradiates the depletion region in the n-epitaxial layer 2 through the transparent electrode and the transparent p-type material, photons generate electron-hole pairs. Under the conditions of high voltage and high electric field, these electron-hole pairs will not recombine in the depletion region, but are respectively pulled by the high electric field to both poles to form a current, and continue to generate more new electron-hole pairs. As a result, for the epitaxial layer with a large on-resistance, due to the generation of a large number of electron-hole pairs, light injection replaces traditional electrical injection, ultimately reducing the on-resistance and forming a large on-current. In this way, it is possible to control the formation of high-power pulsed current only by controlling the light intensity. When no light is applied, the device can withstand an ultra-high operating voltage through the thick n-epitaxial layer 2, realizing a gallium oxide light-controlled high-voltage and high-current power device.

[0065] Therefore, the setting of the transparent material and the transparent metal can effectively ensure that light can enter the depletion region in the voltage-resistant layer from this area to form a large number of electron-hole pairs. Under the bias of an externally applied high voltage, the electron-hole pairs move towards the source electrode and the gate electrode respectively, forming a high-power current pulse, playing the role of light-controlled high-voltage and high-current.

[0066] Furthermore, as Figure 1 shown, the composite device further includes a drain electrode 15; the drain electrode 15 is provided at the bottom of the substrate layer 1.

[0067] The trench structure is a multi-level trench, a regular trench or an irregular trench.

[0068] In this embodiment, the trench structure is a multi-level trench, and its structure can be but not limited to a two-level trench structure (n≥2). In a specific example, as Figure 1 shown, the multi-level trench can be a two-level trench, which is defined as the first-level trench and the second-level trench in sequence from the surface to the substrate direction.

[0069] The electronic control unit 6 is provided with one of a Fin structure, a JFET structure, a GAA structure, a MOS structure, a BJT structure, a PN structure, a PIN structure, a heterojunction PN structure, an IGBT structure, a GTO structure and an SJ structure. In this embodiment, as Figure 1 shown, the electronic control unit 6 is preferably a Fin structure.

[0070] By using gallium oxide material to design the electronic control unit 6 and the voltage-resistant unit 5 and integrating them with the light control unit 7 through technical means such as structural optimization, the difficulties of voltage resistance and surface recombination encountered by the above-mentioned silicon-based light-controlled devices can be perfectly solved, thus providing a potential possibility for further promoting the marketization of gallium oxide power device applications.

[0071] Embodiment 2

[0072] To facilitate the understanding of the longitudinal light control unit and the semiconductor voltage-resistant unit composite device provided in Embodiment 1, as Figure 4 shown, this embodiment correspondingly provides its preparation method:

[0073] Step S1: Construct a current channel layer on the surface of the substrate layer and the n-epitaxial wafer. The n+-epitaxial layer and the n++-epitaxial layer are sequentially formed by ion implantation.

[0074] Specifically, a current channel layer can be constructed on the surface of the substrate layer and the n-type low-doped gallium oxide semiconductor epitaxial wafer (n--Ga2O3) by ion implantation. The implanted ion source can be, but is not limited to, Si or Sn elements. After ion implantation, annealing activation treatment is required to sequentially form the n+ layer and the n++ layer.

[0075] Step S2: Etch the n+-epitaxial layer and the n++-epitaxial layer.

[0076] Specifically, a mixed gas of BCl3 and Ar is used to etch the gallium oxide epitaxial n++ and n+ layers to etch out the Fin structure, where the width of the Fin structure meets certain conditions, preferably satisfying W Fin <400 nm.

[0077] Step S3: Sequentially grow a gate dielectric layer (such as Al2O3) and a gate metal (such as Ni / Au) at the etched edge.

[0078] Step S4: Use a photoresist planarization process to expose the top gate metal.

[0079] Step S5: Sequentially etch the gate metal and the gate dielectric on the structure after photoresist planarization, and perform a degluing process after etching.

[0080] Step S6: Grow an interlayer dielectric (such as SiO2), and then perform an interlayer dielectric etching to open holes to facilitate the subsequent deposition and growth of the source metal (such as Ti / Au).

[0081] Step S7: Selectively and locally deposit the source metal by evaporation and lift-off, and then anneal to form an ohmic contact, and the production of the electronic control unit is completed.

[0082] Step S8: Protect the electronic control unit by coating with photoresist, and only expose and perform corresponding etching on the right-side light control unit; use a mixed gas of BCl3 and Ar to etch the n+-epitaxial layer and the n++-epitaxial layer, and at the same time use the sidewall process to obtain a trench structure. Here, a two-stage trench is taken as an example, that is, the sidewall process is used at the same time to obtain.

[0083] Step S9: Use a sputtering process to grow a transparent thin P-type material, such as an AZO thin film material (transparent conductive thin film), on the surface of the trench structure, and the concentration of the transparent thin film P-type material is controllable to form a P-type thin film layer.

[0084] Step S10: Evaporate transparent metal on the P-type thin film layer to form a light-controlled electrode on the transparent P-type thin film layer; an ohmic contact is formed after annealing the transparent metal and the transparent P-type thin film layer; flip the device, evaporate metal (which can be Ti / Au) on the substrate layer, and also form an ohmic contact after annealing to fabricate a drain electrode, and finally form a light-controlled high-voltage large-current power device.

[0085] After the above specific steps form a light-controlled high-voltage large-current power device, its schematic diagram is as shown in Figure 3 As shown, it is further introduced here. The gate G voltage is normally applied with a positive voltage to control the conduction of the entire transistor. Electrons reach the drain D from the source S through a high-voltage electric field. However, due to the large thickness of the n--Ga2O3 epitaxial layer in the voltage withstand unit, the on-resistance of the device is extremely large. Even under the condition of applying a high voltage at the D end, the entire current of the device is still small, which is not conducive to cost and safety control.

[0086] Through the multi-level trench structure in the upper right, a depletion region is formed between the P-type thin film material and the n--Ga2O3 epitaxial layer, and the concentration of the P-type material is controlled to be more than 10 times that of the n--Ga2O3 epitaxial layer. In this way, the width of the depletion region extends a large thickness in the n-type epitaxial layer. When light irradiates the depletion region in the n--Ga2O3 epitaxial layer through the transparent electrode and the transparent P-type material, photons generate electron-hole pairs. Under the conditions of high voltage and high electric field, these electron-hole pairs will not recombine in the depletion region, but are respectively pulled to both poles by the high electric field to form a current, and continue to generate more new electron-hole pairs, making the epitaxial layer with a very large on-resistance, due to the generation of a large number of electron-hole pairs, the light injection replaces the traditional electric injection, and finally the on-resistance is reduced to form a large on-current. In this way, only by controlling the light intensity can a high-power pulsed current be controlled to be formed. When no light is applied, the device withstands an ultra-high operating voltage through the thick n--Ga2O3 epitaxial layer, realizing a gallium oxide light-controlled high-voltage large-current power device.

[0087] Embodiment 3

[0088] Based on Embodiment 1 and Embodiment 2, the difference lies in:

[0089] The Fin structure can also be one or a combination of several structures among the JFET structure, GAA structure, MOS structure, BJT structure, PN structure, PIN structure, heterojunction PN structure, IGBT structure, GTO structure, and SJ structure.

[0090] In this embodiment, the electronic control unit is a JFET structure. Figure 5 The schematic diagram of the electronic control unit is shown. A JFET region is formed through two laterally back-to-back PN junctions, and P+ regions 9 are formed on both sides. By controlling the voltage on the control gate metal 10, the width of the PN junction depletion region is further controlled to pinch off the conductive channel, achieving the effect of switch control.

[0091] Correspondingly, to implement the above JFET structure, after etching out the Fin structure in the above step S2, P+ regions 9-(quasi)P-type regions are formed on both sides of the Fin structure by ion implantation. The implanted ion source can be one or a combination of N and Mg ions.

[0092] For the rest of the same structure, refer to the introduction in Embodiment 1, and details will not be repeated here.

[0093] Embodiment 4

[0094] Based on Embodiments 1 and 2, the differences are as follows:

[0095] The gallium oxide epitaxial layer (n--Ga2O3) in the breakdown voltage unit in Embodiment 1 can also be one or any combination of wide-bandgap semiconductor materials such as AlN, BN, SiC, GaN, diamond, etc., and can also be a combination of any doping concentration and any doping type (P-type and N-type). The vacuum bonding process bonding can be used to construct the composite wafer breakdown voltage layer structure.

[0096] In this embodiment, as Figure 6 shown, the epitaxial layer is a combination of Ga2O3 and GaN. This combination is for using the vacuum bonding process bonding to construct the composite wafer breakdown voltage layer structure by substrate peeling.

[0097] For the rest of the same structure, refer to the introduction in Embodiment 1, and details will not be repeated here.

[0098] Embodiment 5

[0099] Based on Embodiments 1 and 2, the differences are as follows:

[0100] The trench structure in the light control unit can also be various regular or irregular trench structures. In this embodiment, as Figure 7 shown, it is a pentagonal groove; the (quasi)P-type AZO thin film material (transparent thin film material) can also be N-type highly doped AZO (n+-AZO). In this way, an internal built-in graded electric field is formed between this layer of thin film and the underlying n--Ga2O3 breakdown voltage layer. Under this graded electric field, when electrons reach equilibrium, a depletion region will also be generated. Under light illumination, electron-hole pairs will also be generated in this depletion region. At the same time, under an applied high voltage, an avalanche effect will occur, and finally a high-voltage pulse current will be formed.

[0101] Based on the above pentagonal groove structure, the design of the substrate layer can be to form N-type heavy doping by ion implantation to form a good ohmic contact with the drain electrode, so as to control and optimize the forward conduction characteristics, as Figure 8As shown, the green part under the gate metal of the electronic control unit is the gate dielectric layer, generally a dielectric material such as Al2O3, SiN, or SiO2 with a thickness of 5 - 100 nm; the gray part is a transparent dielectric passivation layer material such as SiO2; optionally, the source electrode can extend a metal field plate to achieve better reverse electric field masking reliability of the electronic control unit.

[0102] In an alternative example, the back surface of the substrate layer is implanted with N+ ions to form good ohmic contact conduction characteristics with the back drain metal.

[0103] For the remaining same structures, refer to the description of Embodiment 1, which will not be elaborated here.

[0104] Embodiment 6

[0105] Based on Embodiment 5, the difference lies in:

[0106] As Figure 9 and Figure 10 shown, based on the above pentagonal groove structure, the design of the substrate layer can be: the substrate layer is P-type or quasi-P-type (such as P-NiO), which forms good contact with the drain electrode and can control the cut-off and conduction of the device from the back surface.

[0107] In an alternative example, the back surface of the substrate forms a PN heterostructure with a P-type oxide, thereby achieving better reverse control turn-off characteristics. The substrate material can be an N-type high-resistance or high-purity semi-insulating semiconductor material, or a P-type or quasi-P-type material, such as a gallium oxide semiconductor material with a thickness of 20 - 500 μm or even thicker. In this way, a high electric field withstand layer can be formed in the entire substrate region during reverse voltage withstand, constructing an ultra-high voltage withstand switch.

[0108] For the remaining same structures, refer to the description of Embodiment 1, which will not be elaborated here.

[0109] In summary, the longitudinal light control unit and semiconductor voltage withstand unit composite devices and corresponding manufacturing methods provided in the above Embodiments 1 to 6 all have the following technical effects:

[0110] First, a novel gallium oxide light-controlled high-voltage and high-current power device that directly injects photons into the internal region of the wide-bandgap semiconductor material voltage withstand layer is proposed for the first time. This solution solves the problem of the marketization of gallium oxide power device applications in the absence of P-type doping in gallium oxide materials. That is, a power device with ultra-high voltage withstand and high current is realized only by applying n-type gallium oxide materials.

[0111] Second, through the structural design of combining an electronic control unit with a light control unit of a deeply epitaxial body region constructed with a trench composite structure, photo-generated carriers can penetrate deep into the high-voltage high-resistance body region inside the device structure, solving the problem that electron-hole pairs formed on the material surface by light irradiation are quickly recombined by the majority carriers in this neutral region, resulting in a small conduction current and insensitive light control. At the same time, a high-voltage switching process can be controlled by a low-voltage electronic control unit.

[0112] When the light control unit of the deeply epitaxial body region adopts a multi-stage trench structure, the multi-stage trench-assisted light injection region structure can penetrate deep into the epitaxial high-voltage layer and even penetrate the epitaxial layer into the high-voltage high-resistance substrate layer, thereby realizing a deeper photon injection conductivity modulation region with a high proportion of the total light injection surface area, which is beneficial to further reducing the on-resistance when the device is turned on by light.

[0113] Third, replacing traditional silicon-based materials with wide-bandgap semiconductor high-voltage-resistant materials such as gallium oxide and innovating the structural design can fundamentally improve the physical limit of the light-controlled power device, give full play to the material characteristics, and the manufactured light-controlled power device can work stably at higher temperatures, higher voltages, and more severe environments, that is, E c- Ga2O3 >E c- Si , T c- Ga2O3 >T c- Si .

[0114] In the description of this specification, the description with reference to terms such as "specific examples" or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments or equivalently replace some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite device of a longitudinal light control unit and a wide-bandgap semiconductor breakdown voltage unit, characterized in that, Including: A substrate layer, an n-epitaxial layer, an n+-epitaxial layer, an n++-epitaxial layer, a breakdown voltage unit, an electronic control unit, and an optical control unit; The n-epitaxial layer and the n+-epitaxial layer are sequentially stacked on the substrate layer from bottom to top; the material of the substrate layer is Ga2O3 material; The formation of the breakdown voltage unit is obtained by jointly constructing the n-epitaxial layer, the n+-epitaxial layer, and the substrate layer; the electronic control unit and the optical control unit are respectively disposed on the breakdown voltage unit; Wherein, the formation of the electronic control unit is to perform Si ion implantation on the n+-epitaxial layer to form the n++-epitaxial layer, and the n++-epitaxial layer and the ohmic metal form a source electrode; on both sides of the n++-epitaxial layer and the n+-epitaxial layer, a gate dielectric / P+ region, a gate metal, and an interlayer dielectric are sequentially provided; The formation of the optical control unit is to construct a trench structure in the n+-epitaxial layer from the surface towards the substrate layer, and form a P-type thin film layer through a sputtering and stripping process. The P-type thin film layer and the n+-epitaxial layer form a PN junction to form a local depletion region, and an optical control electrode is provided on the inner wall side of the P-type thin film layer.

2. The longitudinal light control unit and wide bandgap semiconductor withstand voltage unit composite device according to claim 1, characterized in that The material of the substrate layer is an N-type high-resistance or high-purity semi-insulating semiconductor material, or a P-type or quasi-P-type material.

3. The longitudinal light control unit and wide-bandgap semiconductor breakdown voltage unit composite device according to claim 2, characterized in that, The composite device further includes a drain electrode; The drain electrode is disposed at the bottom of the substrate layer.

4. The longitudinal light control unit and wide bandgap semiconductor breakdown voltage unit composite device according to claim 1, characterized in that The P-type thin film layer is a transparent material.

5. The longitudinal light control unit and wide bandgap semiconductor withstand voltage unit composite device according to claim 1, characterized in that, The optical control electrode is a transparent metal layer.

6. The longitudinal light control unit and wide-bandgap semiconductor withstand voltage unit composite device according to claim 1, characterized in that, The trench structure is a multi-stage trench, a regular trench, or an irregular trench.

7. The longitudinal light control unit and wide bandgap semiconductor voltage withstand unit composite device according to claim 1, characterized in that, The electronic control unit is provided with one of a Fin structure, a JFET structure, a GAA structure, a MOS structure, a BJT structure, a PN structure, a PIN structure, a heterojunction PN structure, an IGBT structure, a GTO structure, and an SJ structure.

8. The longitudinal light control unit and wide bandgap semiconductor withstand voltage unit composite device according to claim 1, characterized in that, The n-epitaxial layer is one or any combination of Ga2O3, AlN, BN, SiC, GaN, diamond wide-bandgap semiconductor materials.

9. A manufacturing method for manufacturing a composite device of a longitudinal light control unit and a wide-bandgap semiconductor voltage withstand unit as described in any one of claims 1 to 8, characterized in that, Including the following steps: S1: Construct a current channel layer on the surface of the substrate layer and the n-epitaxial wafer, and sequentially form the n+-epitaxial layer and the n++-epitaxial layer by ion implantation; the material of the substrate layer is Ga2O3 material; S2: Etch the n+-epitaxial layer and the n++-epitaxial layer; S3: Grow a gate dielectric layer and a gate metal on the edge of the etch; S4: Use a photoresist planarization process to expose the top gate metal; S5: Etch the gate metal and the gate dielectric on the structure after photoresist planarization, and perform a degluing process after etching; S6: Grow an interlayer dielectric, and then perform an interlayer dielectric etching and opening; S7: Selectively and locally deposit a source metal by evaporation and stripping, and then anneal to form an ohmic contact, and the production of the electronic control unit is completed; S8: Protect the electronic control unit by coating the photoresist, and only expose and perform corresponding etching on the optical control unit; Etch the n+-epitaxial layer and the n++-epitaxial layer, and at the same time use a sidewall process to obtain a trench structure; S9: Use a sputtering process to grow a transparent thin P-type material on the surface of the trench structure to form a P-type thin film layer; S10: Evaporate a transparent metal on the P-type thin film layer, and the transparent P-type thin film layer forms an optical control electrode; An ohmic contact is formed after annealing the transparent metal and the transparent P-type thin film layer; Flip the device, evaporate metal on the substrate layer, and an ohmic contact is also formed after annealing to fabricate the drain electrode, thus obtaining the device.

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