Multi-dimensional grid-controlled high-linearity n-face gan-based radio frequency power device and preparation method thereof

Abstract

The application discloses a kind of multi-dimensional grid control high linearity N face GaN base radio frequency power device and preparation method thereof, comprising: substrate, buffer layer, barrier layer and channel layer are sequentially arranged on substrate;Source and drain, located on channel layer, source and drain are spaced apart;Silicon nitride layer, located on channel layer, and located between source and drain, silicon nitride layer includes gate foot area, gate foot area exposes channel layer;Channel array structure, the projection of channel array structure is located in gate foot area, channel array structure includes a plurality of spaced apart etching parts, etching part is formed by etching at least part of channel layer, or by etching channel layer and at least part of barrier layer;Along the direction perpendicular to substrate, the projection of etching part is rectangle or trapezoidal;Gate, cover on channel array structure, and part of silicon nitride layer.The application can provide high-frequency, high linearity N face GaN base Fin / Fin-like HEMT device.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor device technology, specifically relating to a multi-dimensional gate-controlled high linearity N-plane GaN-based radio frequency power device and its fabrication method. Background Technology

[0002] With the advent of the 5G era and the proposal of 6G, the frequency of radio electromagnetic waves used in mobile communication will gradually increase to the terahertz band. With the significant increase in frequency, the numerical transmission rate of 6G may reach 50 times that of 5G, and the latency will be reduced to one-tenth of that of 5G. Moreover, it will be far superior to 5G in terms of network transmission capacity, positioning accuracy, and reliability, and can realize full connectivity of wireless and satellite communication on the Earth's surface, and ultimately achieve the Internet of Everything.

[0003] To achieve a significant increase in information transmission rate and capacity, a reduction in latency, and fully integrated communication between the ground and satellites, GaN-based RF power devices for future 6G are required to have higher operating frequencies while ensuring a certain output power and efficiency. In the existing technology, most research on GaN HEMT RF power devices is based on Ga-plane GaN. For Ga-plane GaN-based HEMT devices, the main methods to increase the device operating frequency include shortening the gate length, using a floating T-gate, ultra-thin barrier, and ohmic regeneration technology. However, the linearity of the device transconductance deteriorates sharply as the gate length decreases.

[0004] Therefore, it is urgent to improve the aforementioned defects in the existing technology. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides a multi-dimensional gate-controlled high-linearity N-plane GaN-based radio frequency power device and its fabrication method. The technical problem to be solved by this invention is achieved through the following technical solution:

[0006] In a first aspect, the present invention provides a multi-dimensional gate-controlled high-linearity N-plane GaN-based radio frequency power device, comprising:

[0007] A substrate, wherein a buffer layer, a barrier layer and a channel layer are sequentially disposed on the substrate;

[0008] The source and drain are located on the channel layer, and the source and drain are arranged alternately.

[0009] A silicon nitride layer is located on the channel layer and between the source and drain. The silicon nitride layer includes a gate pin region that exposes the channel layer.

[0010] The channel array structure is located in the channel layer, or in the channel layer and the barrier layer. Along the direction perpendicular to the substrate, the projection of the channel array structure is located in the gate foot region. The channel array structure includes multiple spaced etched portions. The etched portions are formed by etching away at least a portion of the channel layer, or by etching away the channel layer and at least a portion of the barrier layer. Along the direction perpendicular to the substrate, the projection of the etched portions is rectangular or trapezoidal.

[0011] The gate is covered on the channel array structure and part of the silicon nitride layer.

[0012] Secondly, the present invention also provides a method for fabricating a multidimensional gate-controlled high linearity N-plane GaN-based radio frequency power device, comprising:

[0013] A substrate is provided, and a heterojunction layer is grown on the substrate using an MOCVD device, including the sequential growth of a buffer layer, a barrier layer and a channel layer;

[0014] Electron beam evaporation equipment is used to deposit multilayer metals in the ohmic regions of the source and drain electrodes, and high-temperature annealing is performed in a nitrogen atmosphere at a temperature of 500℃~800℃ for 30s~50s to form the source and drain electrodes.

[0015] Using an ion implantation device, a nitrogen ion isolation region is formed by nitrogen ion implantation;

[0016] A silicon nitride layer is deposited between the source and drain using a PECVD device, and the gate pin region is defined using electron beam lithography.

[0017] The silicon nitride layer in the gate pin region was removed using an inductively coupled plasma device and a dry etching method.

[0018] Electron beam lithography is used to define the pattern of the channel array structure. A self-aligned CL-based inductively coupled plasma etching process is used to etch the channel layer or the channel layer and the barrier layer according to the pattern to form the channel array structure. The channel array structure includes multiple spaced etched portions, which are formed by etching away at least part of the channel layer or by etching away the channel layer and at least part of the barrier layer. The projection of the etched portion along the direction perpendicular to the substrate is rectangular or trapezoidal.

[0019] A multilayer metal is deposited in the gate region using an electron beam evaporation device to form the gate.

[0020] The beneficial effects of this invention are:

[0021] This invention provides a multi-dimensional gate-controlled high-linearity N-plane GaN-based RF power device and its fabrication method. Based on Fin and Fin-like structures, it combines the linearity improvement advantage of channel array structures with the inherent advantages of N-plane GaN materials, such as the ease of fabricating devices with high operating frequencies. This allows for the development of high-frequency, high-linearity N-plane GaN-based Fin / Fin-like HEMT devices for future 6G terahertz band communication. In addition to achieving the common characteristics of high frequency and high linearity, the fabricated devices also have their own advantages. Due to the significantly improved gate control capability, the N-plane GaN-based Fin-HEMT device can have a lower knee and is easier to implement enhancement mode. Furthermore, since the etching of the N-plane GaN-based Fin-like HEMT device does not involve the barrier layer, the device can still maintain a large saturation leakage current.

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a multi-dimensional gate-controlled high linearity N-plane GaN-based radio frequency power device provided in an embodiment of the present invention;

[0024] Figure 2 This is another schematic diagram of the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in the embodiments of the present invention;

[0025] Figure 3 This is another schematic diagram of the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in the embodiments of the present invention;

[0026] Figure 4 This is another schematic diagram of the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in the embodiments of the present invention;

[0027] Figure 5 This is another structural schematic diagram of the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in the embodiments of the present invention;

[0028] Figure 6 This is another structural schematic diagram of the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in the embodiments of the present invention;

[0029] Figure 7 This is another structural schematic diagram of the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in the embodiments of the present invention;

[0030] Figure 8 This is another structural schematic diagram of the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in the embodiments of the present invention;

[0031] Figure 9 This is a flowchart of a method for fabricating a multi-dimensional gate-controlled high linearity N-plane GaN-based radio frequency power device provided in an embodiment of the present invention;

[0032] Figure 10 This is a schematic diagram of a multi-dimensional gate-controlled high linearity N-plane GaN-based radio frequency power device provided in an embodiment of the present invention;

[0033] Figure 11 This is a schematic diagram of a multi-dimensional gate-controlled high linearity N-plane GaN-based radio frequency power device provided in an embodiment of the present invention;

[0034] Figure 12 This is a schematic diagram of a multi-dimensional gate-controlled high linearity N-plane GaN-based radio frequency power device provided in an embodiment of the present invention;

[0035] Figure 13 This is a schematic diagram of a multi-dimensional gate-controlled high linearity N-plane GaN-based radio frequency power device provided in an embodiment of the present invention;

[0036] Figure 14 This is a schematic diagram of a multi-dimensional gate-controlled high linearity N-plane GaN-based radio frequency power device provided in an embodiment of the present invention. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0038] Please see Figure 1 As shown, Figure 1 This is a schematic diagram of a multi-dimensional gate-controlled high-linearity N-plane GaN-based radio frequency power device provided in an embodiment of the present invention. Figure 2 This is another schematic diagram of the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in an embodiment of the present invention. Figure 3 This is another schematic diagram of the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in an embodiment of the present invention. Figure 4 This is another schematic diagram of the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in an embodiment of the present invention. The multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided by the present invention includes:

[0039] A substrate, wherein a buffer layer, a barrier layer and a channel layer are sequentially disposed on the substrate;

[0040] The source and drain are located on the channel layer, and the source and drain are arranged alternately.

[0041] A silicon nitride layer is located on the channel layer and between the source and drain. The silicon nitride layer includes a gate pin region that exposes the channel layer.

[0042] The channel array structure is located in the channel layer, or in the channel layer and the barrier layer. Along the direction perpendicular to the substrate, the projection of the channel array structure is located in the gate foot region. The channel array structure includes multiple spaced etched portions. The etched portions are formed by etching away at least a portion of the channel layer, or by etching away the channel layer and at least a portion of the barrier layer. Along the direction perpendicular to the substrate, the projection of the etched portions is rectangular or trapezoidal.

[0043] The gate is covered on the channel array structure and part of the silicon nitride layer.

[0044] For details, please continue to see Figures 1-4 As shown, the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in this embodiment takes into account the advantages of N-plane gallium nitride (GaN) material, such as its natural back barrier to suppress short-channel effects, short gate-to-channel distance, and ease of control. The operating frequency of the device can be increased by drastically reducing the gate length. Furthermore, considering the natural advantages of N-plane GaN material, such as the ease of forming ohmic contacts to reduce parasitic resistance and improve device frequency characteristics, Fin structures and Fin-like structures that improve the device's gate control capability and transconductance linearity are combined with N-plane GaN material to provide a high-frequency, high linearity N-plane GaN-based Fin / Fin-like HEMT device for future 6G terahertz band communication, ensuring device performance.

[0045] Please continue reading Figure 1 and Figure 2 As shown, in this embodiment, an N-plane GaN-based heterojunction material is used for device fabrication. Specifically, a buffer layer, a barrier layer, and a channel layer are sequentially stacked on a substrate. An electron beam evaporation apparatus is used to deposit a Ti / Al / Ni / Au multilayer metal in the source and drain ohmic regions of the heterojunction material to form the source and drain. A silicon nitride layer is deposited between the source and drain and on the heterojunction material, and the silicon nitride layer in the gate region is etched away. Fin and Fin-like array patterns are defined on the exposed channel layer in the gate region. A channel array structure is formed by etching at least a portion of the channel layer, or by etching the channel layer and at least a portion of the barrier layer. Then, an electron beam evaporation apparatus is used to deposit a Ni / Au multilayer metal in the gate region to form the gate. It should be noted that the etched portion in the channel array structure provided in this embodiment can be of a regular shape or an irregular shape; that is, along the direction perpendicular to the substrate, the projection of the etched portion is rectangular or trapezoidal.

[0046] In this embodiment, based on Fin and Fin-like structures, combining the linearity improvement advantage of channel array structures with the inherent advantages of N-plane GaN materials, such as the ease of fabricating high-frequency devices, a high-frequency, high-linearity N-plane GaN-based Fin / Fin-like HEMT device for future 6G terahertz band communication can be developed. Furthermore, in addition to achieving the common characteristics of high frequency and high linearity, the fabricated devices also possess their own individual advantages, such as: [See...] Figure 1 As shown, N-plane GaN-based Fin-HEMT devices exhibit significantly improved gate control capabilities, resulting in lower knees and easier enhancement-mode implementation; please refer to [link to relevant documentation]. Figure 2 As shown, N-plane GaN-based Fin-like HEMT devices can still maintain a large saturation leakage current because the etching does not involve the barrier layer.

[0047] In this embodiment, the linearity of the HEMT device can be represented by the transconductance parameter (gm). Generally, the flatter the curve formed by the transconductance parameter, the better the linearity of the HEMT device. In this embodiment, the linearity is controlled by adjusting the distribution of the two-dimensional electron gas (2DEG) of the HEMT device. The distribution of the two-dimensional electron gas (2DEG) of the HEMT device is adjusted by changing the structure of the HEMT device, that is, by introducing a variety of channel array structures. In this way, the linearity of the HEMT device can be effectively adjusted.

[0048] In this embodiment, for HEMT devices, the gate length (Lg) needs to be shortened to increase the device's operating frequency. Shortening the gate length leads to a short-channel effect, meaning that the reduced gate length weakens the gate's control over the etched portion. The aspect ratio Lg / L of the device measures the gate's control over the etched portion, where Lg is the gate length and L is the distance from the bottom of the gate to the etched portion. Therefore, the distance L between the gate and the etched portion needs to be adjusted. Both Ga-side and N-side HEMT devices require shortening the gate length while reasonably reducing L to ensure gate control capability. However, in Ga-side HEMTs, L is mainly the barrier layer. Reducing L by thinning the barrier layer significantly impacts the reduction in saturation current and the increase in gate leakage current. In the invented N-side HEMT device, L is mainly the channel layer. L can be reduced by adjusting the thickness of the channel layer, giving the N-side HEMT device the advantage of easily adjustable distance between the gate and the etched portion. In this embodiment, the AlGaN barrier layer of the N-side HEMT device is below the channel layer. The AlGaN bandgap is relatively large, which can effectively block electrons from entering the substrate and can act as a back barrier. In this embodiment, the source and drain electrodes of the Ga-side material are in direct contact with AlGaN. The large bandgap of AlGaN results in a large barrier height when in contact with the metal. In contrast, the source and drain electrodes of the N-side material are in direct contact with GaN. The bandgap of GaN is smaller than that of AlGaN, resulting in a smaller barrier height. This facilitates the formation of ohmic contacts, reduces parasitic resistance, and improves the frequency characteristics of the device, among other natural advantages.

[0049] In this embodiment, the inherent advantages of Fin structure and Fin-like structure with N-plane GaN material are combined to fabricate N-plane GaN-based Fin / Fin-like HEMT devices, thereby improving the linearity of N-plane GaN-based HEMT devices to meet the application needs of the future 6GW band communication field.

[0050] It should be noted that the substrate material is SiC, Si, or sapphire; the buffer layer is gallium nitride (GaN), which can be composed of Fe or C-doped high-resistivity GaN and Si-doped n-type GaN from bottom to top; the barrier layer material is AlGaN, InAlN, or AlN; and the channel layer material is unintentionally doped gallium nitride (GaN).

[0051] It should be noted that, Figure 1 The embodiment shown is only a schematic diagram illustrating the etching of the channel array structure to the barrier layer, and does not represent the actual size; Figure 2 The embodiments shown are only schematic diagrams illustrating the etching of the channel array structure to the channel layer and do not represent actual dimensions; Figure 3 and Figure 4 The embodiments shown are only schematic representations of the positional relationships between the layers and do not represent their actual dimensions.

[0052] In an optional embodiment of the present invention, please continue to refer to Figure 3 and Figure 4 As shown, the projection of the etched portion along the direction perpendicular to the substrate is rectangular; the size of the etched portion near the source is the same as the size of the etched portion near the drain.

[0053] Please continue reading Figure 5 and Figure 6 As shown, Figure 5 This is another structural schematic diagram of the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in an embodiment of the present invention. Figure 6 This is another structural schematic diagram of the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in an embodiment of the present invention. In an optional embodiment of the present invention, the projection of the etched portion along the direction perpendicular to the substrate is trapezoidal; the size of the etched portion near the source is larger than the size of the etched portion near the drain.

[0054] Specifically, the channel array structure provided in this embodiment is convergent, with a smaller width on the side of the gate near the drain, which can further reduce the knee voltage and allow electrons to reach saturation faster.

[0055] It should be noted that, Figure 5 The embodiments shown are only schematic illustrations of the channel array structure etched on the barrier layer and do not represent its actual size; Figure 6 The embodiments shown are only schematic representations of the channel array structure etched into the channel layer and do not represent the actual size of the device.

[0056] In an optional embodiment of the present invention, please continue to refer to Figure 7 and Figure 8 As shown, Figure 7 This is another structural schematic diagram of the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in an embodiment of the present invention. Figure 8 This is another structural schematic diagram of the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in the embodiment of the present invention. Along the direction perpendicular to the substrate, the projection of the etched portion is trapezoidal; the size of the etched portion near the source is smaller than the size of the etched portion near the drain.

[0057] Specifically, the channel array structure provided in this embodiment is divergent, which can weaken the electric field on the side of the gate near the drain, thus helping to reduce gate leakage current and weaken current collapse.

[0058] It should be noted that, Figure 7 The embodiments shown are only schematic illustrations of the channel array structure etched on the barrier layer and do not represent its actual size; Figure 8The embodiments shown are only schematic illustrations of the channel array structure etched into the channel layer and do not represent its actual size.

[0059] In an optional embodiment of the present invention, the etched portion is formed by etching away at least a portion of the channel layer. Along a direction perpendicular to the substrate, the etched portion extends from the surface of the channel layer near the silicon nitride side to the channel layer, and the depth of the etched portion does not exceed the heterojunction interface, wherein the heterojunction interface is the contact surface between the barrier layer and the channel layer.

[0060] Specifically, in the N-plane GaN-based Fin-like HEMT device provided in this embodiment, the etched portion extends from the surface of the channel layer near the silicon nitride side to the channel layer along a direction perpendicular to the substrate, and the depth of the etched portion does not exceed the heterojunction interface. Since the etching does not involve the barrier layer, the device can maintain a large saturation leakage current. Electrons can also pass through the etched portion, resulting in less damage to the device's saturation leakage current.

[0061] In an optional embodiment of the present invention, the etched portion is formed by etching away the channel layer and at least part of the barrier layer. Along a direction perpendicular to the substrate, the etched portion extends from the surface of the channel layer near the silicon nitride side to the barrier layer, and the depth of the etched portion exceeds the heterojunction interface, wherein the heterojunction interface is the contact surface between the barrier layer and the channel layer.

[0062] Specifically, in this embodiment, the N-plane GaN-based Fin-HEMT device has an etched portion extending from the surface of the channel layer near the silicon nitride side to the barrier layer, and the depth of the etched portion exceeds the heterojunction interface. This results in a low knee voltage and ease of achieving enhancement mode. Conventional HEMT devices have one-dimensional control over the etched portion of the gate, which can only be controlled from above. However, the Fin-HEMT device has three-dimensional control over the etched portion of the gate, greatly increasing the gate control capability. Conventional HEMT devices are depletion-mode, meaning the device is on when no gate voltage is applied. In contrast, Fin-HEMT devices are easy to achieve enhancement mode, meaning the device is off when no gate voltage is applied. Due to the large number of etched portions in the Fin structure, some areas have no carriers passing through. As the Fin width decreases, the number of electrons below the gate is reduced, making the Fin structure easier to achieve enhancement mode. In the electric field near the drain of the Fin structure, electrons easily reach saturation velocity when the drain voltage is high, resulting in a low knee voltage.

[0063] It should be noted that in HEMT devices, the source is grounded and the drain is subjected to a high voltage. The device is turned on and off by controlling the gate voltage. That is, different voltages are applied to the gate, and the carrier concentration below the gate changes. When the carrier concentration below the gate decreases to a certain level, the device is turned off.

[0064] In an optional embodiment of the present invention, the size of the gate foot region is 80nm to 200nm along the gate length direction.

[0065] In an optional embodiment of the present invention, please continue to refer to Figure 3 and Figure 4 As shown, it also includes nitrogen ion implantation regions, located on the side of the source away from the drain and on the side of the drain away from the source, respectively. The nitrogen ion implantation regions are used to achieve device isolation.

[0066] Specifically, in this embodiment, nitrogen ion implantation regions are formed on both sides of the device to serve as isolation, prevent adjacent devices from affecting each other, and ensure the normal and effective operation of the device.

[0067] Based on the same inventive concept, please refer to Figure 9 As shown, Figure 9 This is a flowchart of a method for fabricating a multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in an embodiment of the present invention. This application also provides a method for fabricating a multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device, used to fabricate the multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device provided in the above embodiments of the present invention. The structural configuration of the device is described above; repeated details will not be repeated. The fabrication method includes:

[0068] S101, please continue to see Figure 10 As shown, Figure 10 This is a schematic diagram of a multi-dimensional gate-controlled high linearity N-plane GaN-based radio frequency power device provided in an embodiment of the present invention. A substrate is provided, and a heterojunction layer is grown on the substrate using an MOCVD device, including the sequential growth of a buffer layer, a barrier layer and a channel layer.

[0069] S102, Please continue to see Figure 11 As shown, Figure 11 This is a schematic diagram of a multi-dimensional gate-controlled high linearity N-plane GaN-based radio frequency power device provided in an embodiment of the present invention. The device uses an electron beam evaporation device to deposit stacked metals in the ohmic regions of the source and drain, and performs high-temperature annealing in a nitrogen atmosphere at a temperature of 500℃~800℃ for a time of 30s~50s to form the source and drain.

[0070] S103, please continue to see Figure 12 As shown, Figure 12 This is a schematic diagram of a multi-dimensional gate-controlled high linearity N-plane GaN-based radio frequency power device provided in an embodiment of the present invention. It uses an ion implantation device to form a nitrogen ion isolation region through nitrogen ion implantation.

[0071] S104, please continue to see Figure 13 As shown, Figure 13This is a schematic diagram of a multi-dimensional gate-controlled high linearity N-plane GaN-based radio frequency power device provided in an embodiment of the present invention. A silicon nitride layer is deposited between the source and drain using a PECVD device, and the gate pin region is defined using electron beam lithography.

[0072] S105, please continue to see Figure 14 As shown, Figure 14 This is a schematic diagram of a multi-dimensional gate-controlled high linearity N-plane GaN-based radio frequency power device provided in an embodiment of the present invention. The silicon nitride layer in the gate foot region is removed by dry etching using an inductively coupled plasma device, i.e., an ICP device.

[0073] S106. Define the channel array structure pattern using electron beam lithography, and use a self-aligned CL-based inductively coupled plasma (ICP) etching process to etch the channel layer or the channel layer and barrier layer according to the pattern to form the channel array structure; wherein, the channel array structure includes multiple spaced etched portions, the etched portions are formed by etching away at least part of the channel layer, or by etching away the channel layer and at least part of the barrier layer; along the direction perpendicular to the substrate, the projection of the etched portion is rectangular or trapezoidal;

[0074] S107, please refer to Figure 3 and Figure 4 As shown, a multilayer metal is deposited in the gate region using an electron beam evaporation apparatus to form the gate.

[0075] In an optional embodiment of the present invention, the gases used for dry etching are CF4 and O2, with a flow rate of 25 sccm for CF4, a flow rate of 5 sccm for O2, a chamber pressure of 5 mTorr, an upper electrode power of 80 W for the ICP, and a lower electrode power of 10 W.

[0076] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that an article or device comprising a list of elements includes not only those elements but also other elements not expressly listed. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device comprising said element. Terms such as "connected" or "linked" are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect. The orientations or positional relationships indicated by terms such as "upper," "lower," "left," and "right" are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0077] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0078] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A multi-dimensional gate-controlled high-linearity N-plane GaN-based radio frequency power device, characterized in that, include: A substrate, a buffer layer, a barrier layer and a channel layer are sequentially disposed on the substrate, wherein the barrier layer is located between the buffer layer and the channel layer, forming an N-plane GaN-based heterojunction; The source and drain are located on the channel layer and are spaced apart; wherein the metal stack of the source and drain is annealed in a nitrogen atmosphere at 500~800℃ for 30~50s to form an ohmic contact. A silicon nitride layer is located on the channel layer and between the source and the drain. The silicon nitride layer includes a gate pin region that exposes the N-side of the channel layer. A channel array structure is located in the channel layer, or in the channel layer and the barrier layer. Along a direction perpendicular to the substrate, the projection of the channel array structure is located in the gate pin region. The channel array structure includes multiple spaced etched portions, each etched portion formed by etching away at least a portion of the channel layer, or by etching away the channel layer and at least a portion of the barrier layer. Along a direction perpendicular to the substrate, the projection of the etched portion is rectangular or trapezoidal. Along a direction perpendicular to the substrate, the projection of the etched portion is rectangular. The size of the etched portion near the source is the same as the size of the etched portion near the drain. Along a direction perpendicular to the substrate, the projection of the etched portion is trapezoidal. The size of the etched portion near the source is larger than the size of the etched portion near the drain; or, along a direction perpendicular to the substrate, the projection of the etched portion is trapezoidal. The size of the etched portion near the source is smaller than the size of the etched portion near the drain. A gate is covered on the channel array structure and a portion of the silicon nitride layer; Nitrogen ion implantation regions are located on the side of the source electrode away from the drain electrode and on the side of the drain electrode away from the source electrode, respectively, and the nitrogen ion implantation regions are used to achieve device isolation.

2. The multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device according to claim 1, characterized in that, The etched portion is formed by etching away at least a portion of the channel layer. Along a direction perpendicular to the substrate, the etched portion extends from the surface of the channel layer near the silicon nitride side to the channel layer, and the depth of the etched portion does not exceed the heterojunction interface, wherein the heterojunction interface is the contact surface between the barrier layer and the channel layer.

3. The multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device according to claim 1, characterized in that, The etched portion is formed by etching away the channel layer and at least a portion of the barrier layer. Along a direction perpendicular to the substrate, the etched portion extends from the surface of the channel layer near the silicon nitride side to the barrier layer, and the depth of the etched portion exceeds the heterojunction interface, wherein the heterojunction interface is the contact surface between the barrier layer and the channel layer.

4. The multi-dimensional gate-controlled high linearity N-plane GaN-based RF power device according to claim 1, characterized in that, Along the gate length direction, the size of the gate foot region is 80nm~200nm.

5. A method for fabricating a multidimensional gate-controlled high linearity N-plane GaN-based radio frequency power device, used to fabricate the multidimensional gate-controlled high linearity N-plane GaN-based radio frequency power device as described in any one of claims 1 to 4, characterized in that, include: A substrate is provided, and a heterojunction layer is grown on the substrate using an MOCVD apparatus, including the sequential growth of a buffer layer, a barrier layer and a channel layer. Electron beam evaporation equipment is used to deposit multilayer metals in the ohmic regions of the source and drain electrodes, and high-temperature annealing is performed in a nitrogen atmosphere at a temperature of 500℃~800℃ for 30s~50s to form the source and drain electrodes. Using an ion implantation device, a nitrogen ion isolation region is formed by nitrogen ion implantation; A silicon nitride layer is deposited between the source and the drain using a PECVD device, and the gate pin region is defined using electron beam lithography. The silicon nitride layer in the gate pin region was removed using an inductively coupled plasma device and a dry etching method. Electron beam lithography is used to define the pattern of the channel array structure. A self-aligned CL-based inductively coupled plasma etching process is used to etch the channel layer or the channel layer and the barrier layer according to the pattern to form the channel array structure. The channel array structure includes a plurality of spaced etched portions, which are formed by etching away at least a portion of the channel layer, or by etching away the channel layer and at least a portion of the barrier layer. The projection of the etched portion along the direction perpendicular to the substrate is rectangular or trapezoidal. A stacked metal layer is deposited in the gate region using an electron beam evaporation apparatus to form the gate.

6. The method for fabricating a multidimensional gate-controlled high linearity N-plane GaN-based radio frequency power device according to claim 5, characterized in that, The dry etching gases are CF4 and O2, with a CF4 flow rate of 25 sccm and an O2 flow rate of 5 sccm. The chamber pressure is 5 mTorr, the ICP upper electrode power is 80 W, and the lower electrode power is 10 W.

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