Gallium nitride and MOS power modules for robot digital control units

Abstract

This invention relates to the field of gallium nitride (GaN) technology and discloses a GaN and MOS power module for a robot digital control unit, comprising a substrate, a front GaN structure, and a back GaN structure. The front GaN structure and the back GaN structure are located on opposite sides of the substrate, with an intermediate dielectric deposited between them. The front GaN structure includes a front buffer layer, a front GaN layer, a front aluminum gallium nitride layer, a front source electrode, a front gate electrode, a front P-type GaN layer, and a front drain electrode. This invention achieves normally-off operation through the front enhancement-mode GaN structure to improve system safety, and utilizes the back depletion-mode structure to provide high current drive capability. Simultaneously, the integrated capacitor structure formed by the front electrode, intermediate dielectric, and back electrode effectively absorbs voltage spikes and suppresses electromagnetic interference, thus enabling this power module to combine high-speed switching, low loss, and high reliability in a robot digital control unit.

Description

Technical Field

[0001] This invention relates to the field of gallium nitride technology, and more particularly to a gallium nitride and MOS power module for a robot digital control unit. Background Technology

[0002] In robot digital control units, power modules need to simultaneously achieve low conduction loss, high current drive capability, and good electromagnetic compatibility under high-frequency switching conditions.

[0003] However, existing technologies mostly use a single type of silicon-based or gallium nitride power device, which makes it difficult to meet the conflicting requirements of enhancement-mode normally-off operation and depletion-mode high current output. Furthermore, they lack effective means to suppress voltage spikes and electromagnetic interference, resulting in insufficient reliability, energy efficiency, and integration of the system under high power density conditions. Summary of the Invention

[0004] This invention provides a gallium nitride and MOS power module for robot digital control units to solve existing technical problems, thereby addressing the difficulty of existing power modules in simultaneously achieving normally-off safety, high-current drive, low switching losses, and electromagnetic interference suppression.

[0005] To solve the above-mentioned technical problems, according to one aspect of the present invention, more specifically, a gallium nitride and MOS power module for a robot digital control unit, comprising a substrate, a front gallium nitride structure and a back gallium nitride structure, wherein the front gallium nitride structure and the back gallium nitride structure are respectively located on both sides of the substrate, and an intermediate dielectric is deposited between the front gallium nitride structure and the back gallium nitride structure. The front gallium nitride structure includes a front buffer layer, a front gallium nitride layer, a front aluminum gallium nitride layer, a front source, a front gate, a front P-type gallium nitride layer, and a front drain. The back gallium nitride structure includes a back buffer layer, a back gallium nitride layer, a back aluminum gallium nitride layer, a back drain, a back gate, and a back source. The front source of the front gallium nitride structure and the back drain of the back gallium nitride structure are both located on the left side, and the front drain of the front gallium nitride structure and the back source of the back gallium nitride structure are both located on the right side. A cover dielectric is deposited on the right side of the front gallium nitride structure and the back gallium nitride structure and above the substrate. A front electrode and a back electrode are deposited on both sides of the right side of the middle dielectric above the cover dielectric, respectively. The front electrode, the middle dielectric, and the back electrode form a capacitor structure. The front electrode is in direct contact with the front drain, and the back electrode is in direct contact with the back source.

[0006] Furthermore, the front buffer layer, the front gallium nitride layer, and the front aluminum gallium nitride layer are arranged sequentially from bottom to top; The front source and front drain are located on the left and right sides of the front aluminum gallium nitride layer, respectively; the front gate is located on the side closer to the front source.

[0007] Furthermore, the back buffer layer, the back gallium nitride layer, and the back aluminum gallium nitride layer are arranged sequentially from bottom to top; The back source and back drain are located on the left and right sides of the back aluminum gallium nitride layer, respectively; the back gate is located on the side closer to the back source.

[0008] Furthermore, the front P-type gallium nitride layer is located above the surface of the front aluminum gallium nitride layer, and the front P-type gallium nitride layer is located below the front gate.

[0009] Furthermore, the back-deposited P-type gallium nitride layer is deposited inside the back aluminum gallium nitride layer, and the back-deposited P-type gallium nitride layer is in direct contact with the back gate.

[0010] Furthermore, the front P-type gallium nitride layer includes a front-deposited P-type gallium nitride layer, which is deposited inside the front aluminum gallium nitride layer and is in direct contact with the front gate.

[0011] Furthermore, the back-deposited P-type gallium nitride layer also includes a back P-type gallium nitride layer, wherein the back P-type gallium nitride layer is located above the surface of the back aluminum gallium nitride layer.

[0012] Furthermore, a heavily doped drain layer is formed inside the front aluminum gallium nitride layer and below the front drain electrode; a heavily doped active electrode layer is formed inside the back aluminum gallium nitride layer and below the back source electrode.

[0013] Furthermore, both the drain heavy doping layer and the source heavy doping layer are formed by carbon-iron co-doping.

[0014] The present invention provides a gallium nitride and MOS power module for a robot digital control unit. Compared with the prior art, the advantages achieved by this method are as follows: 1. This invention achieves normally-off operation through a front-enhanced gallium nitride structure to improve system safety, and utilizes a back-depleted structure to provide high current drive capability. At the same time, it effectively absorbs voltage spikes and suppresses electromagnetic interference through an integrated capacitor structure composed of the front electrode, intermediate dielectric and back electrode. Thus, this power module in the robot digital control unit has high-speed switching, low loss and high reliability.

[0015] 2. This invention replaces the front P-type gallium nitride layer with a front-deposited P-type gallium nitride layer deposited inside the front aluminum gallium nitride layer to form a front depletion-mode device, thereby obtaining a lower on-resistance to adapt to high-frequency, high-current scenarios. At the same time, it replaces the back-deposited P-type gallium nitride layer with a back P-type gallium nitride layer located above the surface of the back aluminum gallium nitride layer to form a back enhancement-mode device, providing safe normally-off characteristics and simplifying gate drive control. The complementary configuration of the two significantly improves the module's adaptability to different drive strategies, energy efficiency, and process integration.

[0016] 3. This invention uses a heavily doped drain layer formed by co-doping carbon and iron, and introduces a heavily doped source layer formed by co-doping carbon and iron below the back source electrode, thereby significantly reducing ohmic contact resistance and interface loss, improving carrier injection and collection efficiency, and thus enhancing current output capability and switching speed. At the same time, the co-doping carbon and iron method gives the heavily doped layer excellent thermal stability, enabling the module to maintain low resistance characteristics even in high-temperature operating environments, effectively enhancing the long-term reliability and anti-degradation capability of high power density systems in robot digital control units. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 In the diagram, A is a schematic diagram of the front gallium nitride structure in Example 1; B is a schematic diagram of the back gallium nitride structure in Example 1. Figure 3 In Example 2, A is a schematic diagram of the front gallium nitride structure; B is a schematic diagram of the back gallium nitride structure. Figure 4 In Example 3, A is a schematic diagram of the front gallium nitride structure; B is a schematic diagram of the back gallium nitride structure.

[0018] In the figure: 1. Substrate; 2. Front gallium nitride structure; 3. Intermediate dielectric; 4. Back gallium nitride structure; 5. Cover dielectric; 6. Front electrode; 7. Back electrode; 201. Front buffer layer; 202. Front gallium nitride layer; 203. Front aluminum gallium nitride layer; 204. Front source; 205. Front gate; 206. Front P-type gallium nitride layer; 207. Front drain; 208. Drain heavily doped layer; 2061. Front deposited P-type gallium nitride layer; 401. Back buffer layer; 402. Back gallium nitride layer; 403. Back aluminum gallium nitride layer; 404. Back drain; 405. Back gate; 406. Back source; 407. Back deposited P-type gallium nitride layer; 408. Source heavily doped layer; 4071. Back P-type gallium nitride layer. Detailed Implementation

[0019] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Example 1 like Figure 1 - Figure 2 As shown, according to one aspect of the present invention, a gallium nitride and MOS power module for a robot digital control unit is provided, comprising a substrate 1, a front gallium nitride structure 2, and a back gallium nitride structure 4, the front gallium nitride structure 2 and the back gallium nitride structure 4 being located on opposite sides of the substrate 1, with an intermediate dielectric 3 deposited between the front gallium nitride structure 2 and the back gallium nitride structure 4; the front gallium nitride structure 2 includes a front buffer layer 201, a front gallium nitride layer 202, a front aluminum gallium nitride layer 203, a front source 204, a front gate 205, a front p-type gallium nitride layer 206, and a front drain 207; the back gallium nitride structure 4 includes a back buffer layer 401, a back gallium nitride layer 402, a back aluminum gallium nitride layer 403, and a back... The structure includes a drain 404, a back gate 405, and a back source 406. The front source 204 of the front gallium nitride structure 2 and the back drain 404 of the back gallium nitride structure 4 are both located on the left side, while the front drain 207 of the front gallium nitride structure 2 and the back source 406 of the back gallium nitride structure 4 are both located on the right side. A covering dielectric 5 is deposited on the right side of the front gallium nitride structure 2 and the back gallium nitride structure 4, above the substrate layer 1. A front electrode 6 and a back electrode 7 are deposited on both sides of the right side of the intermediate dielectric 3 above the covering dielectric 5. The front electrode 6, the intermediate dielectric 3, and the back electrode 7 form a capacitor structure. The front electrode 6 is in direct contact with the front drain 207, and the back electrode 7 is in direct contact with the back source 406.

[0021] The front buffer layer 201, front gallium nitride layer 202, and front aluminum gallium nitride layer 203 are arranged sequentially from bottom to top; the front source 204 and front drain 207 are located on the left and right sides of the front aluminum gallium nitride layer 203, respectively; the front gate 205 is located on the side closer to the front source 204. The back buffer layer 401, back gallium nitride layer 402, and back aluminum gallium nitride layer 403 are arranged sequentially from bottom to top; the back source 406 and back drain 404 are located on the left and right sides of the back aluminum gallium nitride layer 403, respectively; the back gate 405 is located on the side closer to the back source 406.

[0022] In this embodiment, the front P-type gallium nitride layer 206 is located above the surface of the front aluminum gallium nitride layer 203 and below the front gate 205. The back-deposited P-type gallium nitride layer 407 is deposited inside the back aluminum gallium nitride layer 403 and is in direct contact with the back gate 405.

[0023] By employing a heterogeneous integration structure of "front enhancement-mode + back depletion-mode", the front P-type gallium nitride layer 206 is located above the surface of the front aluminum gallium nitride layer 203 and below the front gate 205, forming an enhancement-mode gallium nitride high electron mobility transistor; while the back-deposited P-type gallium nitride layer 407 is deposited inside the back aluminum gallium nitride layer 403 and directly contacts the back gate 405, forming a depletion-mode device. Through a symmetrical layout of the front source 204 and back drain 404 on the same side, and the front drain 207 and back source 406 on the same side, combined with a capacitor structure formed by the front electrode 6, intermediate dielectric 3, and back electrode 7, compact electrical coupling between the front gallium nitride structure 2 and the back gallium nitride structure 4 is achieved.

[0024] On the one hand, the front-enhanced structure enables normally-off operation, improving system safety; on the other hand, the back-depleted structure provides high current drive capability, suitable for the high-speed, low-loss requirements of power switches in robot digital control units. Furthermore, the integrated capacitor structure (front electrode 6, intermediate dielectric 3, back electrode 7) effectively absorbs voltage spikes, suppresses electromagnetic interference, and enhances the stability and reliability of the module under high-frequency switching conditions.

[0025] Example 2 like Figure 3 As shown, according to one aspect of the present invention, a gallium nitride and MOS power module for a robot digital control unit is provided, including a front P-type gallium nitride layer 206 comprising a front-deposited P-type gallium nitride layer 2061, wherein the front-deposited P-type gallium nitride layer 2061 is deposited inside a front aluminum gallium nitride layer 203, and the front-deposited P-type gallium nitride layer 2061 is in direct contact with a front gate 205. A back-deposited P-type gallium nitride layer 407 further includes a back P-type gallium nitride layer 4071, wherein the back P-type gallium nitride layer 4071 is located above the surface of the back aluminum gallium nitride layer 403.

[0026] The front P-type gallium nitride layer 206 is replaced with a front-deposited P-type gallium nitride layer 2061, which is deposited inside the front aluminum gallium nitride layer 203 and directly contacts the front gate 205, thereby forming a depletion-mode front gallium nitride structure. Simultaneously, the back-deposited P-type gallium nitride layer 407 is replaced with a back P-type gallium nitride layer 4071, located above the surface of the back aluminum gallium nitride layer 403, forming an enhancement-mode back gallium nitride structure. This "front depletion + back enhancement" structural configuration implements power control logic complementary to the previous embodiment, expanding the module's adaptability under different driving strategies.

[0027] Front-depletion devices achieve lower on-resistance, making them suitable for high-frequency, high-current applications; back-enhancing devices provide safe normally-off characteristics, facilitating gate drive control. The combination of these two technologies allows the module in a robot's digital control unit to meet both the requirements of rapid response and the need for system safety and energy efficiency. Furthermore, adjustments to the deposition method simplify process compatibility and improve integration.

[0028] Example 3 like Figure 4 As shown, according to one aspect of the present invention, a gallium nitride and MOS power module for a robot digital control unit is provided, including a front P-type gallium nitride layer 206 comprising a front-deposited P-type gallium nitride layer 2061, wherein the front-deposited P-type gallium nitride layer 2061 is deposited inside a front aluminum gallium nitride layer 203, and the front-deposited P-type gallium nitride layer 2061 is in direct contact with a front gate 205. A back-deposited P-type gallium nitride layer 407 further includes a back P-type gallium nitride layer 4071, wherein the back P-type gallium nitride layer 4071 is located above the surface of the back aluminum gallium nitride layer 403.

[0029] A heavily doped drain layer 208 is formed inside the front gallium aluminum nitride layer 203 and below the front drain 207 through doping; a heavily doped active layer 408 is formed inside the back gallium aluminum nitride layer 403 and below the back source 406 through doping. Both the heavily doped drain layer 208 and the heavily doped source layer 408 are formed by co-doping with carbon and iron.

[0030] Building upon Example 2, a heavily doped drain layer 208 and a heavily doped source layer 408 are further introduced, located below the front drain 207 and the back source 406, respectively, and formed through carbon-iron co-doping. This innovation significantly reduces the ohmic contact resistance between the front gallium nitride structure 2 and the back gallium nitride structure 4, improving the injection and collection efficiency of charge carriers in the drain and source regions, thereby enhancing the overall module's current output capability and switching speed.

[0031] The advantages of this design are as follows: the heavily doped layers (208, 408) effectively reduce contact resistance and interface losses, making it particularly suitable for the stringent requirements of high power density and high energy efficiency in robot digital control units. Simultaneously, the carbon-iron co-doping method exhibits excellent thermal stability, maintaining low resistance characteristics under high-temperature operating conditions, enhancing the module's long-term reliability and degradation resistance, and providing a superior power integration solution for high-performance robot control systems.

[0032] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A gallium nitride and MOS power module for a robot digital control unit, comprising a substrate (1), a front gallium nitride structure (2), and a back gallium nitride structure (4), characterized in that: The front gallium nitride structure (2) and the back gallium nitride structure (4) are located on both sides of the substrate layer (1), and an intermediate medium (3) is deposited between the front gallium nitride structure (2) and the back gallium nitride structure (4). The front gallium nitride structure (2) includes a front buffer layer (201), a front gallium nitride layer (202), a front aluminum gallium nitride layer (203), a front source (204), a front gate (205), a front P-type gallium nitride layer (206), and a front drain (207). The back gallium nitride structure (4) includes a back buffer layer (401), a back gallium nitride layer (402), a back aluminum gallium nitride layer (403), a back drain (404), a back gate (405), a back source (406), and a back deposited P-type gallium nitride layer (407). The front source electrode (204) of the front gallium nitride structure (2) and the back drain electrode (404) of the back gallium nitride structure (4) are both located on the left side, and the front drain electrode (207) of the front gallium nitride structure (2) and the back source electrode (406) of the back gallium nitride structure (4) are both located on the right side. A cover medium (5) is deposited on the right side of the front gallium nitride structure (2) and the back gallium nitride structure (4) and above the substrate layer (1). A front electrode (6) and a back electrode (7) are deposited on both sides of the right side of the cover medium (5) and the intermediate medium (3), respectively. The front electrode (6), the intermediate medium (3) and the back electrode (7) form a capacitor structure. The front electrode (6) is in direct contact with the front drain (207) and the back electrode (7) is in direct contact with the back source (406).

2. The gallium nitride and MOS power module for a robot digital control unit according to claim 1, characterized in that: The front buffer layer (201), the front gallium nitride layer (202), and the front aluminum gallium nitride layer (203) are arranged sequentially from bottom to top; The front source (204) and front drain (207) are located on the left and right sides of the front aluminum gallium nitride layer (203), respectively; the front gate (205) is located on the side closer to the front source (204).

3. The gallium nitride and MOS power module for a robot digital control unit according to claim 1, characterized in that: The back buffer layer (401), the back gallium nitride layer (402), and the back aluminum gallium nitride layer (403) are arranged sequentially from bottom to top; The back source electrode (406) and the back drain electrode (404) are located on the left and right sides of the back aluminum gallium nitride layer (403), respectively; the back gate electrode (405) is located on the side closer to the back source electrode (406).

4. The gallium nitride and MOS power module for a robot digital control unit according to claim 1, characterized in that: The front P-type gallium nitride layer (206) is located above the surface of the front aluminum gallium nitride layer (203), and the front P-type gallium nitride layer (206) is located below the front gate (205).

5. The gallium nitride and MOS power module for a robot digital control unit according to claim 4, characterized in that: The back-deposited P-type gallium nitride layer (407) is deposited inside the back aluminum gallium nitride layer (403), and the back-deposited P-type gallium nitride layer (407) is in direct contact with the back gate (405).

6. The gallium nitride and MOS power module for a robot digital control unit according to claim 1, characterized in that: The front P-type gallium nitride layer (206) includes a front-deposited P-type gallium nitride layer (2061), which is deposited inside the front aluminum gallium nitride layer (203) and is in direct contact with the front gate (205).

7. The gallium nitride and MOS power module for a robot digital control unit according to claim 6, characterized in that: The back-deposited P-type gallium nitride layer (407) also includes a back P-type gallium nitride layer (4071), wherein the back P-type gallium nitride layer (4071) is located above the surface of the back aluminum gallium nitride layer (403).

8. The gallium nitride and MOS power module for a robot digital control unit according to claim 7, characterized in that: The front aluminum gallium nitride layer (203) is doped inside and below the front drain (207) to form a heavily doped drain layer (208); the back aluminum gallium nitride layer (403) is doped inside and below the back source (406) to form a heavily doped active layer (408).

9. The gallium nitride and MOS power module for a robot digital control unit according to claim 8, characterized in that: Both the drain heavy doped layer (208) and the source heavy doped layer (408) are formed by carbon-iron co-doping.

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