Enhanced N-face GaN-based radio frequency power device and preparation method thereof

Abstract

The invention relates to an enhanced N-face GaN-based radio frequency power device and a preparation method thereof, the device comprises an N-face GaN buffer layer, an N-face AlGaN barrier layer, an insertion layer, an N-face GaN channel layer, a groove, an N-face AlGaN cap layer, a source electrode structure, a drain electrode structure and a grid electrode, and the N-face GaN buffer layer, the N-face AlGaN barrier layer, the insertion layer and the N-face GaN channel layer are sequentially arranged from bottom to top; the groove extends from the upper surface of the N-side GaN channel layer to the interior of the N-side GaN channel layer; the N-side AlGaN cap layer extends from the groove to a part of the upper surface of the N-side GaN channel layer, and the part, located in the groove, of the N-side AlGaN cap layer forms a gate groove; the gate is located in the gate groove. According to the device, the control capability of the grid electrode on the 2DEG can be modulated by controlling the thickness of the N-face GaN channel layer and the thickness of the N-face AlGaN cap layer, and the device has better characteristics under higher working frequency.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor technology, and in particular relates to an enhanced N-face GaN-based radio frequency power device and a preparation method thereof. Background Art

[0002] Most GaN high electron mobility transistors (HEMT) devices are depletion type, that is, when the gate electrode is in a zero bias state, the device is in an on state. This means that depletion type devices often require an additional negative power supply to achieve shutdown during application, which increases the complexity of circuit design.

[0003] When zero bias or negative bias is applied to the gate electrode of the enhanced GaN HEMT device, the device is in the off state. There is no need to design an additional negative power supply to turn off the device. This can reduce the power consumption of the power level while simplifying the circuit design and reducing the chip size.

[0004] In the prior art, the methods of enhancing GaN HEMT are all based on Ga-face GaN materials. However, the control capability of enhancing GaN HEMT based on Ga-face GaN materials over two-dimensional electron gas 2DEG is limited by saturation leakage current and is difficult to be further improved. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides an enhanced N-face GaN-based RF power device and a preparation method thereof. The technical problem to be solved by the present invention is achieved by the following technical solutions:

[0006] The first aspect of the present invention provides an enhanced N-face GaN-based radio frequency power device, comprising: an N-face GaN buffer layer, an N-face AlGaN barrier layer, an insertion layer, an N-face GaN channel layer, a trench, an N-face AlGaN cap layer, a source structure, a drain structure and a gate, wherein:

[0007] The N-face GaN buffer layer, the N-face AlGaN barrier layer, the insertion layer and the N-face GaN channel layer are arranged in sequence from bottom to top;

[0008] The groove extends from the upper surface of the N-face GaN channel layer to the interior of the N-face GaN channel layer;

[0009] The N-face AlGaN cap layer extends from the groove to a portion of the upper surface of the N-face GaN channel layer, and a portion of the N-face AlGaN cap layer located in the groove forms a gate groove;

[0010] The source structure is located on one side of the N-face AlGaN cap layer and extends from the upper surface of the N-face GaN channel layer to the lower surface of the N-face AlGaN barrier layer;

[0011] The drain structure is located on the other side of the N-face AlGaN cap layer and extends from the upper surface of the N-face GaN channel layer to the lower surface of the N-face AlGaN barrier layer;

[0012] The gate is located in the gate groove.

[0013] In an achievable manner, it further includes: a substrate layer, a nucleation layer, a device isolation region and a passivation layer, wherein:

[0014] The nucleation layer is located on the lower surface of the N-face GaN buffer layer;

[0015] The substrate layer is located on the lower surface of the nucleation layer;

[0016] The device isolation region extends from the upper surfaces of both ends of the N-face GaN channel layer to the interior of the N-face GaN buffer layer;

[0017] The passivation layer covers the surface of the N-face GaN channel layer, the surface of the N-face AlGaN cap layer, the surface of the source structure, the surface of the drain structure, the surface of the gate and the device isolation region.

[0018] In an achievable manner, the source structure includes: a source doping layer and a source electrode, wherein:

[0019] The source doping layer extends from the upper surface of the N-face GaN channel layer to the lower surface of the N-face AlGaN barrier layer;

[0020] The source electrode is located on the upper surface of the source doping layer.

[0021] In an achievable manner, the drain structure includes: a drain doping layer and a drain electrode, wherein:

[0022] The drain doping layer extends from the upper surface of the N-face GaN channel layer to the lower surface of the N-face AlGaN barrier layer;

[0023] The drain electrode is located on the upper surface of the drain doping layer.

[0024] In an achievable manner, the thickness of the source doping layer is greater than the sum of the thicknesses of the N-face AlGaN barrier layer, the insertion layer and the N-face GaN channel layer;

[0025] The thickness of the drain doping layer is greater than the sum of the thicknesses of the N-face AlGaN barrier layer, the insertion layer and the N-face GaN channel layer.

[0026] In one achievable manner, the materials of the source doping layer and the drain doping layer both include N-type doped GaN;

[0027] The doping concentration of the source doping layer and the drain doping layer is 5e19-5e20cm -3 .

[0028] In one achievable manner, the gate is a T-type gate;

[0029] A portion of the gate is located in the gate groove, and another portion extends to a portion of the surface of the N-face AlGaN cap layer located on the upper surface of the N-face GaN channel layer.

[0030] In one achievable manner, a Si ion doping region is provided at the interface between the N-face GaN buffer layer and the N-face AlGaN barrier layer.

[0031] In one achievable manner, the materials of the nucleation layer and the insertion layer both include AlN;

[0032] The material of the passivation layer includes SiN.

[0033] The second aspect of the present invention provides a method for preparing an enhanced N-face GaN-based RF power device, which is used to prepare the enhanced N-face GaN-based RF power device provided by the first aspect of the present invention, comprising the following steps:

[0034] S1: preparing an N-face GaN buffer layer, an N-face AlGaN barrier layer, an insertion layer and an N-face GaN channel layer arranged in sequence from bottom to top;

[0035] S2: etching the upper surface of the N-face GaN channel layer to form a groove extending from the upper surface of the N-face GaN channel layer to the inside of the N-face GaN channel layer;

[0036] S3: preparing an N-face AlGaN cap layer in the trench and on a portion of the upper surface of the N-face GaN channel layer; a portion of the N-face AlGaN cap layer located in the trench forms a gate trench;

[0037] S4: preparing a source structure extending from the upper surface of the N-face GaN channel layer to the lower surface of the N-face AlGaN barrier layer on one side of the N-face AlGaN cap layer;

[0038] S5: preparing a drain structure extending from the upper surface of the N-face GaN channel layer to the lower surface of the N-face AlGaN barrier layer on the other side of the N-face AlGaN cap layer;

[0039] S6: preparing a gate in the gate groove.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The invention discloses an enhanced N-face GaN-based radio frequency power device, which forms an N-face GaN / AlGaN heterojunction through an N-face AlGaN barrier layer and an N-face GaN channel layer, and forms an enhanced device by arranging an N-face AlGaN cap layer on the lower surface of the gate. The device can modulate the control ability of the gate over 2DEG by controlling the thickness of the N-face GaN channel layer and the thickness of the N-face AlGaN cap layer, and does not affect the saturation leakage current of the device while improving the gate control ability. The device has better characteristics at a higher operating frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic structural diagram of an enhanced N-face GaN-based RF power device provided by an embodiment of the present invention;

[0043] Figure 2a to Figure 2c It is a schematic diagram of the principle of a depletion-mode Ga-face GaN-based device, a depletion-mode N-face GaN-based device, and an enhancement-mode N-face GaN-based device;

[0044] Figure 3 It is a schematic structural diagram of another enhanced N-face GaN-based RF power device provided by an embodiment of the present invention;

[0045] Figure 4a to Figure 4i It is a schematic diagram of the steps of a method for preparing an enhanced N-face GaN-based RF power device provided in an embodiment of the present invention.

[0046] Reference numerals:

[0047] 1: substrate layer; 2: nucleation layer; 3: N-side GaN buffer layer; 4: N-side AlGaN barrier layer; 5: insertion layer; 6: N-side GaN channel layer; 7: N-side AlGaN cap layer; 8: source doping layer; 9: drain doping layer; 10: source electrode; 11: drain electrode; 12: gate; 13: passivation layer; 14: Si ion doping region. DETAILED DESCRIPTION

[0048] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0049] Embodiment 1

[0050] See also Figure 1 , Figure 1 It is a schematic structural diagram of an enhanced N-face GaN-based RF power device provided in an embodiment of the present invention.

[0051] The embodiment provides an enhanced N-face GaN-based RF power device, comprising: an N-face GaN buffer layer 3, an N-face AlGaN barrier layer 4, an insertion layer 5, an N-face GaN channel layer 6, a groove, an N-face AlGaN cap layer 7, a source structure, a drain structure and a gate 12. Among them, the N-face GaN buffer layer 3, the N-face AlGaN barrier layer 4, the insertion layer 5 and the N-face GaN channel layer 6 are arranged in sequence from bottom to top. The groove extends from the upper surface of the N-face GaN channel layer 6 to the inside of the N-face GaN channel layer 6. The N-face AlGaN cap layer 7 extends from the groove to a portion of the upper surface of the N-face GaN channel layer 6, and the portion of the N-face AlGaN cap layer 7 located in the groove forms a gate groove. The source structure is located on one side of the N-face AlGaN cap layer 7, and extends from the upper surface of the N-face GaN channel layer 6 to the lower surface of the N-face AlGaN barrier layer 4. The drain structure is located on the other side of the N-face AlGaN cap layer 7, and extends from the upper surface of the N-face GaN channel layer 6 to the lower surface of the N-face AlGaN barrier layer 4. The gate 12 is located in the gate groove.

[0052] Specifically, the crystal direction index of Ga-face (gallium-face) GaN is

[0001] , and the crystal direction index of N-face (nitrogen-face) GaN is

[0001] . Figure 2a and Figure 2b , Figure 2a This is a schematic diagram of the principle of a depletion-mode Ga-face GaN-based device. Figure 2b This is a schematic diagram of the principle of a depletion-type N-face GaN-based device. The polarization directions of the Ga-face material and the N-face material (spontaneous polarization P sp and piezoelectric polarization P pe ), therefore, the polarization directions of the Ga-face AlGaN / GaN heterojunction formed by the Ga-face material and the N-face GaN / AlGaN heterojunction formed by the N-face material are also opposite. Since the polarization direction is always from negative charge to positive charge, and 2DEG is formed by the accumulation of electrons attracted by positive charge, the 2DEG in the Ga-face AlGaN / GaN heterojunction is located below the AlGaN layer, while the 2DEG in the N-face GaN / AlGaN heterojunction is located above the AlGaN layer. Therefore, if the thickness of the AlGaN layer of the depletion-type Ga-face GaN-based device is too thick, it will affect the gate control capability of the device. However, since the saturation leakage current of the device is affected by the thickness of the AlGaN layer, if the thickness of the AlGaN layer is too thin, it will affect the saturation leakage current of the device. On the other hand, the depletion-type N-face GaN-based device can be directly thinned by the GaN layer above the AlGaN layer without changing the thickness of the AlGaN layer. Therefore, the gate control capability of the depletion-type N-face GaN-based device is improved without being affected by the saturation leakage current. For further information, please refer to Figure 2c , Figure 2cIt is a schematic diagram of the principle of an enhancement-mode N-face GaN-based device. A layer of N-face AlGaN cap is prepared on the lower surface of the gate electrode of a depletion-mode N-face GaN-based device, which can generate a net negative polarization charge at the AlGaN cap / GaN channel interface. This layer of net negative polarization charge can raise the energy band under the gate electrode, causing the 2DEG in the region under the gate to be depleted and eventually forming an enhancement-mode device.

[0053] In this embodiment, the N-face AlGaN barrier layer 4 and the N-face GaN channel layer 6 form an N-face GaN / AlGaN heterojunction, and the 2DEG of the N-face GaN / AlGaN heterojunction is located in the lower surface layer of the N-face GaN channel layer 6, that is, located above the N-face AlGaN barrier layer 4. Figure 1 The dotted line in the middle is 2DEG, the insertion layer 5 is used to increase the concentration of the device 2DEG, the grooves set in the N-face GaN channel layer 6 are used to further improve the gate control ability of the gate 12, and the N-face AlGaN cap layer 7 is used to deplete the 2DEG in the region under the gate to form an enhancement-mode device, and the threshold voltage of the enhancement-mode device can be modulated by controlling the thickness of the N-face AlGaN cap layer 7 and the content of the Al component in the N-face AlGaN cap layer 7. Since the saturation leakage current of the device is mainly affected by the N-face AlGaN barrier layer 4, the enhanced N-face GaN-based RF power device provided in this embodiment can directly modulate the control ability of the gate 12 on 2DEG by changing the thickness of the N-face GaN channel layer 6 and the thickness of the N-face AlGaN cap layer 7, and does not affect the saturation leakage current of the device. The enhanced N-face GaN-based RF power device provided in this embodiment can well balance the relationship between the improvement of the gate control ability and the saturation leakage current level.

[0054] In this embodiment, the enhanced N-face GaN-based RF power device also includes: a substrate layer 1, a nucleation layer 2, a device isolation region and a passivation layer 13. Among them, the nucleation layer 2 is located on the lower surface of the N-face GaN buffer layer 3. The substrate layer 1 is located on the lower surface of the nucleation layer 2. The device isolation region extends from the upper surfaces of both ends of the N-face GaN channel layer 6 to the inside of the N-face GaN buffer layer 3. The passivation layer 13 covers the surface of the N-face GaN channel layer 6, the surface of the N-face AlGaN cap layer 7, the surface of the source structure, the surface of the drain structure, the surface of the gate 12 and the device isolation region.

[0055] Specifically, the materials of the nucleation layer 2 and the insertion layer 5 both include AlN. The material of the passivation layer 13 includes SiN. The substrate layer 1, the nucleation layer 2, the N-face GaN buffer layer 3, the N-face AlGaN barrier layer 4, the insertion layer 5 and the N-face GaN channel layer 6 are arranged in sequence from bottom to top. The device isolation region is a step region formed by etching, which is used to form device isolation. The passivation layer 13 covers the surface of the device.

[0056] In this embodiment, the source structure includes: a source doping layer 8 and a source electrode 10, wherein the source doping layer 8 extends from the upper surface of the N-face GaN channel layer 6 to the lower surface of the N-face AlGaN barrier layer 4. The source electrode 10 is located on the upper surface of the source doping layer 8. The drain structure includes: a drain doping layer 9 and a drain electrode 11, wherein the drain doping layer 9 extends from the upper surface of the N-face GaN channel layer 6 to the lower surface of the N-face AlGaN barrier layer 4. The drain electrode 11 is located on the upper surface of the drain doping layer 9. The gate 12 is a T-type gate. A portion of the gate 12 is located in the gate groove, and the other portion extends to a portion of the surface of the N-face AlGaN cap layer 7 located on the upper surface of the N-face GaN channel layer 6.

[0057] In this embodiment, the thickness of the source doping layer 8 is greater than the sum of the thicknesses of the N-face AlGaN barrier layer 4, the insertion layer 5 and the N-face GaN channel layer 6, and the thickness of the drain doping layer 9 is greater than the sum of the thicknesses of the N-face AlGaN barrier layer 4, the insertion layer 5 and the N-face GaN channel layer 6, that is, the upper surface of the source doping layer 8 and the upper surface of the drain doping layer 9 are both higher than the upper surface of the N-face GaN channel layer 6. The materials of the source doping layer 8 and the drain doping layer 9 both include N (Negative) type doped GaN, and the doping concentrations of the source doping layer 8 and the drain doping layer 9 are 5e19-5e20cm -3 The source doping layer 8 and the drain doping layer 9 at least extend to the lower surface of the N-face AlGaN barrier layer 4, that is, the source doping layer 8 and the drain doping layer 9 at least penetrate the N-face GaN / AlGaN heterojunction, and the source doping layer 8 and the drain doping layer 9 can selectively extend to the inside of the N-face GaN buffer layer 3 according to actual needs.

[0058] See also Figure 3 In one achievable manner, a Si ion doping region 14 is provided at the interface between the N-face GaN buffer layer 3 and the N-face AlGaN barrier layer 4. It should be understood that the Si ion doping region 14 is formed on the upper surface of the N-face GaN buffer layer 3 and / or the lower surface of the N-face AlGaN barrier layer 4 by ion implantation. The Si ion doping region 14 can suppress the two-dimensional hole gas of the device. Exemplarily, the doping concentration of the Si ion doping region 14 is 1e18 to 9e18 cm -3 .

[0059] In this embodiment, the thickness of the N-face AlGaN barrier layer 4 is 20-30nm, the thickness of the N-face GaN channel layer 6 is 3-10nm, and the distance between the bottom of the groove and the lower surface of the N-face GaN channel layer 6 is 3-4nm. The thickness of the N-face AlGaN cap layer 7 is 2-5nm. The materials of the source electrode 10 and the drain electrode 11 are both Ti / Au / Ni / Au laminated metals, with thicknesses of 20nm / 100nm / 10nm / 50nm, respectively. The material of the gate 12 is Ni / Au / Ni laminated metal, with thicknesses of 30nm / 300nm / 30nm, respectively.

[0060] The enhanced N-face GaN-based RF power device provided in this embodiment forms an N-face GaN / AlGaN heterojunction through the N-face AlGaN barrier layer 4 and the N-face GaN channel layer 6, and forms an enhanced device by setting the N-face AlGaN cap layer 7 on the lower surface of the gate 12. The device can modulate the control ability of the gate 12 on 2DEG by controlling the thickness of the N-face GaN channel layer 6 and the thickness of the N-face AlGaN cap layer 7, and does not affect the saturation leakage current of the device. The device has better characteristics at higher operating frequencies. The enhanced N-face GaN-based RF power device provided in this embodiment is realized based on the polarization modulation effect, which effectively improves the operating frequency of the device while obtaining an enhanced device. The device has broad application prospects in future 6G and other higher frequency band communication fields.

[0061] Embodiment 2

[0062] See also Figure 4a to Figure 4i , Figure 4a to Figure 4i It is a schematic diagram of the steps of a method for preparing an enhanced N-face GaN-based RF power device provided in an embodiment of the present invention.

[0063] The present embodiment provides a method for preparing an enhanced N-face GaN-based RF power device, which is used to prepare the enhanced N-face GaN-based RF power device provided in the first embodiment of the present invention, and comprises the following steps:

[0064] S1: preparing an N-face GaN buffer layer 3, an N-face AlGaN barrier layer 4, an insertion layer 5 and an N-face GaN channel layer 6 arranged in sequence from bottom to top.

[0065] Specifically, see Figure 4a, step S1 includes: using metal organic chemical vapor deposition MOCVD equipment to sequentially grow a nucleation layer 2, an N-face GaN buffer layer 3, an N-face AlGaN barrier layer 4, an insertion layer 5 and an N-face GaN channel layer 6 from bottom to top on the upper surface of the substrate layer 1, wherein the N-face AlGaN barrier layer 4 and the N-face GaN channel layer 6 form an N-face heterojunction. Exemplarily, the thickness of the N-face AlGaN barrier layer 4 is 20 to 30 nm, and the thickness of the N-face GaN channel layer 6 is 3 to 10 nm. A 2 to 3 nm thick Si ion doping region 14 is also formed at the interface between the N-face GaN buffer layer 3 and the N-face AlGaN barrier layer 4, and the doping concentration of the Si ion doping region 14 is 1e18 to 9e18 cm -3 In this embodiment, the Si ion doping region 14 is formed by delta doping technology.

[0066] S2 : etching the upper surface of the N-face GaN channel layer 6 to form a trench extending from the upper surface of the N-face GaN channel layer 6 to the inside of the N-face GaN channel layer 6 .

[0067] Specifically, see Figure 4b , electron beam lithography is used to define the gate foot region, and BCl3 / Cl2 is used to etch the N-face GaN channel layer 6 to form a groove extending from the upper surface of the N-face GaN channel layer 6 to the inside of the N-face GaN channel layer 6. In this embodiment, the groove is located in the middle of the N-face GaN channel layer 6, and the distance between the bottom of the groove and the lower surface of the N-face GaN channel layer 6 is 3-4 nm.

[0068] S3: preparing an N-face AlGaN cap layer 7 in the trench and on a portion of the upper surface of the N-face GaN channel layer 6; the portion of the N-face AlGaN cap layer 7 located in the trench forms a gate trench.

[0069] Specifically, see Figure 4c , the N-face AlGaN cap layer 7 is selectively regrown in the trench and on a portion of the upper surface of the N-face GaN channel layer 6 by plasma assisted molecular beam epitaxy (PAMBE) technology. The N-face AlGaN cap layer 7 in the trench covers the side surface and the bottom of the trench to form a gate trench. In this embodiment, the thickness of the N-face AlGaN cap layer 7 is 2 to 5 nm.

[0070] S4: preparing a source structure extending from the upper surface of the N-face GaN channel layer 6 to the lower surface of the N-face AlGaN barrier layer 4 on one side of the N-face AlGaN cap layer 7 .

[0071] S5 : preparing a drain structure extending from the upper surface of the N-face GaN channel layer 6 to the lower surface of the N-face AlGaN barrier layer 4 on the other side of the N-face AlGaN cap layer 7 .

[0072] Specifically, step S5 includes:

[0073] S501: Please see Figure 4d , the source ohmic regrowth region and the drain ohmic regrowth region are respectively defined by photolithography on the upper surface of the N-face GaN channel layer 6 on both sides of the N-face AlGaN cap layer 7, and then the source ohmic regrowth region and the drain ohmic regrowth region are etched by dry etching using inductively coupled plasma ICP etching equipment and SiO2 as a hard mask to form a source groove and a drain groove. In this embodiment, the source groove and the drain groove are extended from the upper surface of the N-face GaN channel layer 6 to the lower surface of the N-face AlGaN barrier layer 4.

[0074] S502: Please see Figure 4e , a PAMBE device is used to selectively grow an N-type heavily doped GaN layer in the source groove and the drain groove at low temperature to form a source doping layer 8 and a drain doping layer 9. In this embodiment, the upper surface of the source doping layer 8 and the upper surface of the drain doping layer 9 are both higher than the upper surface of the N-face GaN channel layer 6, and the doping concentration of the source doping layer 8 and the drain doping layer 9 is 5e19-5e20cm -3 .

[0075] S503: Please see Figure 4f , etching is performed at both ends of the N-face GaN channel layer 6 using a Cl2-based reactive ion etching (RIE) device to form a device isolation region extending from the upper surface of the N-face GaN channel layer 6 to the inside of the N-face GaN buffer layer 3.

[0076] S504: Please see Figure 4g , source metal and drain metal are deposited on the upper surfaces of the source doping layer 8 and the drain doping layer 9 respectively by electron beam evaporation equipment to form a source electrode 10 and a drain electrode 11. In this embodiment, the source metal and the drain metal are both Ti / Au / Ni / Au laminated metals with thicknesses of 20nm / 100nm / 10nm / 50nm respectively.

[0077] S6: preparing a gate 12 in the gate groove.

[0078] Specifically, see Figure 4h , a gate metal is evaporated on the upper surface of the gate groove and a portion of the N-face AlGaN cap layer 7 located on the upper surface of the N-face GaN channel layer 6, and then stripped to form a gate 12. In this embodiment, the gate metal is made of Ni / Au / Ni laminated metal with thicknesses of 30nm / 300nm / 30nm, respectively.

[0079] In this embodiment, after step S6, the following steps are further included:

[0080] S7: See Figure 4iBy using plasma enhanced chemical vapor deposition (PECVD) technology, 20 nm thick SiN is deposited on the surface of the N-face GaN channel layer 6, the surface of the N-face AlGaN cap layer 7, the surface of the source structure, the surface of the drain structure, the surface of the gate 12 and the device isolation region as a passivation layer 13.

[0081] The method for preparing an enhanced N-face GaN-based RF power device provided in the present embodiment forms an N-face GaN / AlGaN heterojunction through an N-face AlGaN barrier layer 4 and an N-face GaN channel layer 6, and forms an enhanced device by preparing an N-face AlGaN cap layer 7 in the groove. The device prepared by the preparation method provided in the present embodiment can modulate the control ability of the gate over 2DEG by controlling the thickness of the N-face GaN channel layer 6 and the thickness of the N-face AlGaN cap layer 7, thereby improving the gate control ability without affecting the saturation leakage current of the device. The device prepared by the preparation method provided in the present embodiment has better characteristics at higher operating frequencies.

[0082] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. An enhanced N-face GaN-based RF power device, characterized in that: include: N-face GaN buffer layer (3), N-face AlGaN barrier layer (4), insertion layer (5), N-face GaN channel layer (6), trench, N-face AlGaN cap layer (7), source structure, drain structure and gate (12), wherein: The N-face GaN buffer layer (3), the N-face AlGaN barrier layer (4), the insertion layer (5) and the N-face GaN channel layer (6) are arranged in sequence from bottom to top; The groove extends from the upper surface of the N-face GaN channel layer (6) to the interior of the N-face GaN channel layer (6); The N-face AlGaN cap layer (7) extends from the groove to a portion of the upper surface of the N-face GaN channel layer (6), and a portion of the N-face AlGaN cap layer (7) located in the groove forms a gate groove; The source structure is located on one side of the N-face AlGaN cap layer (7), and extends from the upper surface of the N-face GaN channel layer (6) to the lower surface of the N-face AlGaN barrier layer (4); The drain structure is located on the other side of the N-face AlGaN cap layer (7), and extends from the upper surface of the N-face GaN channel layer (6) to the lower surface of the N-face AlGaN barrier layer (4); The gate (12) is located in the gate groove.

2. The enhanced N-face GaN-based RF power device according to claim 1, characterized in that: Also includes: A substrate layer (1), a nucleation layer (2), a device isolation region and a passivation layer (13), wherein: The nucleation layer (2) is located on the lower surface of the N-face GaN buffer layer (3); The substrate layer (1) is located on the lower surface of the nucleation layer (2); The device isolation region extends from the upper surfaces of both ends of the N-face GaN channel layer (6) to the interior of the N-face GaN buffer layer (3); The passivation layer (13) covers the surface of the N-face GaN channel layer (6), the surface of the N-face AlGaN cap layer (7), the surface of the source structure, the surface of the drain structure, the surface of the gate (12) and the device isolation region.

3. The enhanced N-face GaN-based RF power device according to claim 1, characterized in that: The source structure comprises: a source doping layer (8) and a source electrode (10), wherein: The source doping layer (8) extends from the upper surface of the N-face GaN channel layer (6) to the lower surface of the N-face AlGaN barrier layer (4); The source electrode (10) is located on the upper surface of the source doping layer (8).

4. The enhanced N-face GaN-based RF power device according to claim 3, characterized in that: The drain structure comprises: a drain doping layer (9) and a drain electrode (11), wherein: The drain doping layer (9) extends from the upper surface of the N-face GaN channel layer (6) to the lower surface of the N-face AlGaN barrier layer (4); The drain electrode (11) is located on the upper surface of the drain doping layer (9).

5. The enhanced N-face GaN-based RF power device according to claim 4, characterized in that: The thickness of the source doping layer (8) is greater than the sum of the thicknesses of the N-face AlGaN barrier layer (4), the insertion layer (5) and the N-face GaN channel layer (6); The thickness of the drain doping layer (9) is greater than the sum of the thicknesses of the N-face AlGaN barrier layer (4), the insertion layer (5) and the N-face GaN channel layer (6).

6. The enhanced N-face GaN-based RF power device according to claim 4, characterized in that: The materials of the source doping layer (8) and the drain doping layer (9) both include N-type doped GaN; The doping concentration of the source doping layer (8) and the drain doping layer (9) is 5e19-5e20cm -3 .

7. The enhanced N-face GaN-based RF power device according to claim 1, characterized in that: The gate (12) is a T-type gate; A portion of the gate (12) is located in the gate groove, and another portion extends to a portion of the surface of the N-face AlGaN cap layer (7) located on the upper surface of the N-face GaN channel layer (6).

8. The enhanced N-face GaN-based RF power device according to claim 1, characterized in that: A Si ion doping region (14) is provided at the interface between the N-face GaN buffer layer (3) and the N-face AlGaN barrier layer (4).

9. The enhanced N-face GaN-based RF power device according to claim 2, characterized in that: The materials of the nucleation layer (2) and the insertion layer (5) both include AlN; The material of the passivation layer (13) includes SiN.

10. A method for preparing an enhanced N-face GaN-based radio frequency power device, characterized in that: The method for preparing the enhanced N-face GaN-based radio frequency power device according to any one of claims 1 to 9 comprises the following steps: S1: preparing an N-face GaN buffer layer (3), an N-face AlGaN barrier layer (4), an insertion layer (5) and an N-face GaN channel layer (6) arranged in sequence from bottom to top; S2: etching the upper surface of the N-face GaN channel layer (6) to form a groove extending from the upper surface of the N-face GaN channel layer (6) to the inside of the N-face GaN channel layer (6); S3: preparing an N-face AlGaN cap layer (7) in the groove and on a portion of the upper surface of the N-face GaN channel layer (6); the portion of the N-face AlGaN cap layer (7) located in the groove forms a gate groove; S4: preparing a source structure extending from the upper surface of the N-face GaN channel layer (6) to the lower surface of the N-face AlGaN barrier layer (4) on one side of the N-face AlGaN cap layer (7); S5: preparing a drain structure extending from the upper surface of the N-face GaN channel layer (6) to the lower surface of the N-face AlGaN barrier layer (4) on the other side of the N-face AlGaN cap layer (7); S6: preparing a gate (12) in the gate groove.

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