Metal-oxide-semiconductor field effect transistor (MOSFET) epitaxial structure containing hydrogen terminal, preparation method and power device

Abstract

The invention relates to an MOSFET epitaxial structure containing a hydrogen terminal, a preparation method and a power device, in particular to the field of semiconductors, and the MOSFET epitaxial structure containing the hydrogen terminal comprises a buffer layer, an epitaxial layer, a hydrogen terminal layer, a P-N layer, a gate oxide layer and a polycrystalline gate layer which are sequentially arranged on a substrate; and the thickness of the hydrogen terminal layer is 0.5-1 nm. According to the MOSFET epitaxial structure provided by the invention, the specific hydrogen terminal layer is arranged between the epitaxial layer and the gate oxide layer, so that dangling bonds can be effectively reduced, the surface state of SiC can be passivated, the capture of carriers by the surface state is reduced, and the on-resistance is reduced, thereby ensuring the service life of a power device.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductors, and in particular to a MOSFET epitaxial structure with a hydrogen-containing termination, a preparation method and a power device. BACKGROUND

[0002] At present, silicon carbide, as a typical representative of the third generation of semiconductor materials, has superior material properties compared to the previous two generations of semiconductor materials, such as high breakdown field, high thermal conductivity, high electron saturation velocity, and strong radiation resistance, and is more suitable for making high-temperature, high-frequency, and radiation-resistant power devices.

[0003] In recent years, with the development of power device applications, silicon-based devices have gradually been unable to meet application requirements due to their own material limitations, especially in high voltage, high conversion efficiency, and power density, which have made the third generation of semiconductors, including SiC, the preferred material for replacing Si-based devices. SiC power MOSFET, as an important SiC power device, is widely used in power electronic systems due to its simple gate drive circuit, high operating frequency, high power density, and high conversion efficiency.

[0004] CN210805778U discloses a SiC-MOS device structure, which includes a metal drain, a silicon carbide N+ substrate, and a silicon carbide N- epitaxial layer arranged in sequence from bottom to top. The silicon carbide N- epitaxial layer has source trenches on the upper left and upper right sides. The source trenches have a silicon carbide P+ doped region and a silicon carbide P-type doped region from top to bottom below the source trenches. The source trenches are filled with Schottky contact metal. The gate trench has a gate structure inside and on the surface. The first and second mesa structures are composed of the silicon carbide N- epitaxial layer, the silicon carbide P-type doped region, and the silicon carbide N+ source region.

[0005] CN119997582A discloses a 3C-SiC composite epitaxial structure and device structure based on 4H-SiC. The composite epitaxial structure includes a 4H-SiC substrate, an N-type doped epitaxial layer, a P-type doped buried layer, a carrier tunneling region, and a 3C-SiC epitaxial layer. The N-type doped epitaxial layer is arranged on the 4H-SiC substrate. The 3C-SiC epitaxial layer is secondarily epitaxied or bonded to the surface of the N-type doped epitaxial layer. The contact interface layer between the 3C-SiC epitaxial layer and the N-type doped epitaxial layer forms a carrier tunneling region. The P-type doped buried layer is ion implanted in the upper region of the N-type doped epitaxial layer. This structure can effectively solve the problems of limited improvement of interface state density and channel electron mobility, poor conduction capacity of the device, and poor electrical performance and long-term reliability in the prior art of preparing SiC-MOS devices using 4H-SiC as a substrate.

[0006] Although the 4H-SiC MOSFET has made remarkable progress in the research at home and abroad in recent years, there are still problems in the SiO2 / SiC interface quality, wherein the mismatch between the 4H-SiC material and SiO2 causes the dangling bond to be a factor restricting the further improvement of the performance of the 4H-SiC MOSFET. SUMMARY

[0007] In view of the problems in the prior art, the purpose of the present application is to provide a MOSFET epitaxial structure with hydrogen termination, a preparation method and a power device, so as to solve the defect that the mismatch between the 4H-SiC material and SiO2 causes the dangling bond to capture electrons, and with the time extension, the accumulated electrons will form a path to a certain extent, so as to cause the breakdown of the oxide film and lead to the failure of the device.

[0008] In order to achieve the purpose, the present application adopts the following technical solutions:

[0009] In the first aspect, the present application provides a MOSFET epitaxial structure with hydrogen termination, which comprises:

[0010] a buffer layer, an epitaxial layer, a hydrogen termination layer, a P-N layer, a gate oxide layer and a polycrystalline gate layer arranged in sequence on the substrate;

[0011] The thickness of the hydrogen termination layer is 0.5-1nm.

[0012] The MOSFET epitaxial structure provided by the present application can effectively reduce the dangling bond by arranging a specific hydrogen termination layer between the epitaxial layer and the gate oxide layer, can passivate the SiC surface state, reduce the capture of the carriers by the surface state, reduce the on-resistance, and thus ensure the service life of the power device.

[0013] As a preferred technical solution of the present application, the concentration of N-type doping in the buffer layer is 0.7*10 18 -1.3*10 18 / cm 3 .

[0014] Preferably, the thickness of the buffer layer is 0.9-1.1um.

[0015] Preferably, the concentration of N-type doping in the epitaxial layer is 0.7*10 16 -1*10 16 / cm 3 .

[0016] Preferably, the thickness of the epitaxial layer is 5-20um.

[0017] As a preferred technical scheme of the present application, the P-N layer comprises at least one P well region, wherein a P+ doped region and an N doped region are arranged in the P well region, and the N doped region is arranged around the P+ doped region.

[0018] Preferably, the interval between adjacent P well regions is 1.5-3 μm.

[0019] Preferably, the thickness of the P well region is 0.9-1.5 μm.

[0020] Preferably, the width of the P well region is 2-3 μm.

[0021] Preferably, the P type doping concentration of the P well region is 1×10 17 -5×10 17 cm-2. 3

[0022] Preferably, the thickness of the P+ doped region is 0.1-0.3 μm.

[0023] Preferably, the width of the P+ doped region is 0.6-1 μm.

[0024] Preferably, the P type doping concentration of the P+ doped region is 1×10 19 -5×10 19 cm-2. 3

[0025] Preferably, the thickness of the N doped region is 0.1-0.3 μm.

[0026] Preferably, the width of the N doped region is 0.4-0.6 μm.

[0027] Preferably, the N type doping concentration of the N doped region is 5×10 16 -5×10 17 cm-2. 3

[0028] As a preferred technical scheme of the present application, the gate oxide layer comprises a SiO2 layer with a thickness of 50-80 nm.

[0029] Preferably, the thickness of the polycrystalline gate layer is 0.2-1 μm.

[0030] Preferably, the P type doping concentration of the polycrystalline gate layer is 1×10 18 -2×10 20 cm-2. 3

[0031] In a second aspect, the present application provides a preparation method of a MOSFET epitaxial structure with hydrogen-containing termination, which comprises: ​​​​

[0032] The buffer layer growth, the epitaxial layer growth, the hydrogen terminal formation, the P well region formation, the annealing, the P+ doped region formation, the N doped region formation, the gate oxide layer growth and the polycrystal gate growth are sequentially performed on the substrate.

[0033] Preferably, the flow rate of the carrier gas used in the buffer layer growth is 100-800 slm.

[0034] Preferably, the flow rate of the silicon source gas used in the buffer layer growth is 300-600 sccm.

[0035] Preferably, the flow rate of the carbon source gas used in the buffer layer growth is 200-500 sccm.

[0036] Preferably, the flow rate of the N-type dopant used in the buffer layer growth is 80-120 sccm.

[0037] Preferably, the growth temperature in the buffer layer growth is 1580-1680 ℃.

[0038] Preferably, the growth pressure in the buffer layer growth is 50-100 mbar.

[0039] Preferably, the flow rate of the carrier gas used in the epitaxial layer growth is 100-800 slm.

[0040] Preferably, the flow rate of the silicon source gas used in the epitaxial layer growth is 300-600 sccm.

[0041] Preferably, the flow rate of the carbon source gas used in the epitaxial layer growth is 200-500 sccm.

[0042] Preferably, the flow rate of the N-type dopant used in the epitaxial layer growth is 20-60 sccm.

[0043] Preferably, the growth temperature in the epitaxial layer growth is 1580-1680 ℃.

[0044] Preferably, the growth pressure in the epitaxial layer growth is 50-500 mbar.

[0045] Preferably, the hydrogen terminal formation comprises: performing plasma treatment on the epitaxial layer obtained by the epitaxial layer growth by using hydrogen plasma.

[0046] Preferably, the pressure of the reaction cavity in the plasma treatment is controlled to be 10-25 Pa.

[0047] Preferably, the flow rate of the hydrogen gas in the plasma treatment is 5-15 sccm.

[0048] Preferably, the forming the P-well region comprises: ion implantation on the epitaxial layer to obtain the P-well region.

[0049] Preferably, the annealing temperature is 1600-1850℃.

[0050] Preferably, the annealing time is 3-10min.

[0051] As a preferred technical solution of the present application, the forming the P+ doped region comprises: ion implantation on the P-well region after annealing to obtain the P+ doped region.

[0052] Preferably, the forming the N doped region comprises: ion implantation on the P+ doped region obtained in the forming the P+ doped region to obtain the N doped region.

[0053] Preferably, the gate oxide layer is grown by plasma enhanced chemical vapor deposition.

[0054] Preferably, the polycrystalline gate layer is grown by low pressure chemical vapor deposition.

[0055] In a third aspect, the present application provides a power device, comprising: the MOSFET epitaxial structure with hydrogen termination according to the first aspect or the MOSFET epitaxial structure obtained by the preparation method according to the first aspect.

[0056] Compared with the prior art, the present application has the following beneficial effects:

[0057] In the present application, by designing a specific hydrogen termination layer in the epitaxial structure, the dangling bonds can be effectively passivated, the surface states of SiC can be passivated, the carrier trapping of the surface states can be reduced, and the on-resistance can be reduced. The on-resistance of the obtained epitaxial structure is ≤15.53mΩ when applied. BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 is a schematic diagram of the MOSFET epitaxial structure with hydrogen termination provided by an embodiment of the present application.

[0059] In the figure: 100 is a substrate, 200 is a buffer layer, 300 is an epitaxial layer, 400 is a hydrogen termination layer, 510 is a P-well region, 520 is a P+ doped region, 530 is an N doped region, 600 is a gate oxide layer, and 700 is a polycrystalline gate layer.

[0060] The present application will be further described in detail below. However, the following examples are only simple examples of the present application and do not represent or limit the protection scope of the present application. The protection scope of the present application is subject to the claims. DETAILED DESCRIPTION

[0061] To better illustrate the present invention and facilitate understanding of the technical solutions of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0062] 1. This embodiment provides a MOSFET epitaxial structure containing hydrogen terminals, such as Figure 1 As shown, the hydrogen-terminated MOSFET epitaxial structure includes:

[0063] The buffer layer 200 , the epitaxial layer 300 , the hydrogen termination layer 400 , the PN layer, the gate oxide layer 600 and the polycrystalline gate layer 700 are sequentially disposed on the substrate 100 .

[0064] In the present invention, the substrate 100 refers to a commonly used substrate in the art, such as a 4H-SiC substrate with a 4° deflection toward the <11-20> direction.

[0065] The concentration of N-type doping in the buffer layer 200 is 0.7×10 18 -1.3×10 18 pieces / cm 3 , for example, it can be 0.7×10 18 pieces / cm 3 , 0.75×10 18 pieces / cm 3 , 0.8×10 18 pieces / cm 3 , 0.85×10 18 pieces / cm 3 , 0.9×10 18 pieces / cm 3 , 0.95×10 18 pieces / cm 3 , 1×10 18 pieces / cm 3 , 1.05×10 18 pieces / cm 3 , 1.1×10 18 pieces / cm 3 , 1.15×10 18 pieces / cm 3 , 1.2×10 18 pieces / cm 3 , 1.25×10 18 pieces / cm 3 or 1.3 × 10 18 pieces / cm 3 The above values ​​are not limited to the listed values, and other values ​​not listed in the range also meet the requirements.

[0066] The thickness of the buffer layer 200 is 0.9-1.1 μm, for example, 0.9 μm, 0.92 μm, 0.94 μm, 0.96 μm, 0.98 μm, 1 μm, 1.02 μm, 1.04 μm, 1.06 μm, 1.08 μm or 1.1 μm, etc., but not limited to the listed values, other values not listed in the range are also required.

[0067] The concentration of N-type doping in the epitaxial layer 300 is 0.7*10 16 -1*10 16 6 / cm 3 , for example, 0.7*10 16 6 / cm 3 , 0.75*10 16 6 / cm 3 , 0.8*10 16 6 / cm 3 , 0.85*10 16 6 / cm 3 , 0.9*10 16 6 / cm 3 , 0.95*10 16 6 / cm 3 or 1*10 16 6 / cm 3 , etc., but not limited to the listed values, other values not listed in the range are also required.

[0068] The thickness of the epitaxial layer 300 is 5-20 μm, for example, 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm or 20 μm, etc., but not limited to the listed values, other values not listed in the range are also required.

[0069] The thickness of the hydrogen terminal layer 400 is 0.5-1 nm, for example, 0.5 nm, 0.6 nm, 0.7 nm, 0.8 nm, 0.9 nm or 1 nm, etc., but not limited to the listed values, other values not listed in the range are also required.

[0070] The P-N layer includes at least one P-well region 510, the P-well region 510 is provided with a P+ doped region 520 and an N doped region 530, and the N doped region 530 is arranged around the P+ doped region 520.

[0071] Among them, the spacing between adjacent P-well regions 510 is 1.5-2μm, for example, it can be 1.5μm, 1.55μm, 1.6μm, 1.65μm, 1.7μm, 1.75μm, 1.8μm, 1.85μm, 1.9μm, 1.95μm or 2μm, etc., but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0072] Among them, the thickness of the P-well region 510 is 0.9-1.5μm, for example, it can be 0.9μm, 0.95μm, 1μm, 1.05μm, 1.1μm, 1.15μm, 1.2μm, 1.25μm, 1.3μm, 1.35μm, 1.4μm, 1.45μm or 1.5μm, etc., but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0073] Among them, the width of the P-well region is 2-3μm, for example, it can be 2μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm, 2.5μm, 2.6μm, 2.7μm, 2.8μm, 2.9μm or 3μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0074] The concentration of P-type doping in the P-well region 510 is 1×10 17 -5×10 17 pieces / cm 3 , for example, it can be 1×10 17 pieces / cm 3 , 1.5×10 17 pieces / cm 3 , 2×10 17 pieces / cm 3 , 2.5×10 17 pieces / cm 3 , 3×10 17 pieces / cm 3 , 3.5×10 17 pieces / cm 3 , 4×10 17 pieces / cm 3 , 4.5×10 17 pieces / cm 3 or 5×10 17 pieces / cm 3 The above values ​​are not limited to the listed values, and other values ​​not listed in the range also meet the requirements.

[0075] Among them, the thickness of the P+ doping region 520 is 0.1-0.3μm, for example, it can be 0.1μm, 0.12μm, 0.14μm, 0.16μm, 0.18μm, 0.2μm, 0.22μm, 0.24μm, 0.26μm, 0.28μm or 0.3μm, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0076] Among them, the width of the P+ doping region is 0.6-1μm, for example, it can be 0.6μm, 0.65μm, 0.7μm, 0.75μm, 0.8μm, 0.85μm, 0.9μm, 0.95μm or 1μm, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0077] The P-type doping concentration of the P+ doping region 520 is 1×10 19 -5×10 19 pieces / cm 3 , for example, it can be 1×10 19 pieces / cm 3 , 1.5×10 19 pieces / cm 3 , 2×10 19 pieces / cm 3 , 2.5×10 19 pieces / cm 3 , 3×10 19 pieces / cm 3 , 3.5×10 19 pieces / cm 3 , 4×10 19 pieces / cm 3 , 4.5×10 19 pieces / cm 3 or 5×10 19 pieces / cm 3 The above values ​​are not limited to the listed values, and other values ​​not listed in the range also meet the requirements.

[0078] Among them, the thickness of the N-doped region 530 is 0.1-0.3μm, for example, it can be 0.1μm, 0.12μm, 0.14μm, 0.16μm, 0.18μm, 0.2μm, 0.22μm, 0.24μm, 0.26μm, 0.28μm or 0.3μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0079] Among them, the width of the N-doped region 530 is 0.4-0.6μm, for example, it can be 0.4μm, 0.42μm, 0.44μm, 0.46μm, 0.48μm, 0.5μm, 0.52μm, 0.54μm, 0.56μm, 0.58μm or 0.6μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0080] In the present invention, the width of the N-doped region 530 refers to the width of the bandwidth surrounding the P+-doped region 520 .

[0081] The N-type doping concentration of the N-doped region 530 is 5×10 16 -5×10 17 pieces / cm 3 , for example, it can be 5×10 16 pieces / cm 3 , 10×10 16 pieces / cm 3 , 15×10 16 pieces / cm 3 , 20×10 16 pieces / cm 3 , 25×10 16 pieces / cm 3 , 30×10 16 pieces / cm 3 , 35×10 16 pieces / cm 3 , 40×10 16 pieces / cm 3 , 45×10 16 pieces / cm 3 or 50×10 16 pieces / cm 3 The above values ​​are not limited to the listed values, and other values ​​not listed in the range also meet the requirements.

[0082] The gate oxide layer 600 includes a SiO2 layer with a thickness of 50-80 nm, for example, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm or 80 nm, but is not limited to the listed values. Other values ​​not listed within the range also meet the requirements.

[0083] The thickness of the polycrystalline gate layer 700 is 0.2-1 μm, for example, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm or 1 μm, but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0084] The P-type doping concentration of the polycrystalline gate layer 700 is 1×1018 -2 x 10 20 cm-2 3 , for example, can be 1 x 10 18 cm-2 3 , 2 x 10 18 cm-2 3 , 4 x 10 18 cm-2 3 , 6 x 10 18 cm-2 3 , 8 x 10 18 cm-2 3 , 10 x 10 18 cm-2 3 , 20 x 10 18 cm-2 3 , 40 x 10 18 cm-2 3 , 60 x 10 18 cm-2 3 , 80 x 10 18 cm-2 3 , 100 x 10 18 cm-2 3 , 120 x 10 18 cm-2 3 , 140 x 10 18 cm-2 3 , 160 x 10 18 cm-2 3 , 180 x 10 18 cm-2 3 , or 200 x 10 18 cm-2 3 , but are not limited to the listed values, and other unlisted values within the range are acceptable.

[0085] In the present application, the hydrogen-terminated MOSFET epitaxial structure further comprises a drain and a source, which are designed according to conventional requirements in the field, and are exemplarily as follows: the drain is a film layer of titanium layer / nickel layer / silver layer deposited in sequence, and the corresponding thickness of each layer is as follows: titanium layer: 0.05-0.15 μm, nickel layer: 0.2-0.4 μm, and silver layer: 0.5-1.5 μm; and the source is an aluminum layer / titanium layer deposited in sequence, and the corresponding thickness of each layer is as follows: aluminum layer: 100-300 nm, and titanium layer: 30-100 nm.

[0086] Secondly, the present application provides a preparation method of the hydrogen-terminated MOSFET epitaxial structure, and the preparation method comprises:

[0087] The buffer layer is grown, the epitaxial layer is grown, a hydrogen terminal is formed, a P well region is formed, annealing is performed, a P+ doping region is formed, an N doping region is formed, a gate oxide layer is grown, and a polycrystalline gate is grown.

[0088] Wherein, the MOSFET epitaxial structure containing hydrogen terminal is as follows: Figure 1 As shown, it includes: a buffer layer 200 , an epitaxial layer 300 , a hydrogen termination layer 400 , a PN layer, a gate oxide layer 600 and a polycrystalline gate layer 700 which are sequentially arranged on a substrate 100 .

[0089] The concentration of N-type doping in the buffer layer 200 is 0.7×10 18 -1.3×10 18 pieces / cm 3 , for example, it can be 0.7×10 18 pieces / cm 3 , 0.75×10 18 pieces / cm 3 , 0.8×10 18 pieces / cm 3 , 0.85×10 18 pieces / cm 3 , 0.9×10 18 pieces / cm 3 , 0.95×10 18 pieces / cm 3 , 1×10 18 pieces / cm 3 , 1.05×10 18 pieces / cm 3 , 1.1×10 18 pieces / cm 3 , 1.15×10 18 pieces / cm 3 , 1.2×10 18 pieces / cm 3 , 1.25×10 18 pieces / cm 3 or 1.3 × 10 18 pieces / cm 3 The above values ​​are not limited to the listed values, and other values ​​not listed in the range also meet the requirements.

[0090] Among them, the thickness of the buffer layer 200 is 0.9-1.1μm, for example, it can be 0.9μm, 0.92μm, 0.94μm, 0.96μm, 0.98μm, 1μm, 1.02μm, 1.04μm, 1.06μm, 1.08μm or 1.1μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0091] The concentration of N-type doping in the epitaxial layer 300 is 0.7×10 16 -1×10 16 pieces / cm 3 , for example, it can be 0.7×10 16 pieces / cm 3 , 0.75×10 16 pieces / cm 3 , 0.8×10 16 pieces / cm 3 , 0.85×10 16 pieces / cm 3 , 0.9×10 16 pieces / cm 3 , 0.95×10 16 pieces / cm 3 or 1×10 16 pieces / cm 3 The above values ​​are not limited to the listed values, and other values ​​not listed in the range also meet the requirements.

[0092] The thickness of the epitaxial layer 300 is 5-20 μm, for example, 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm or 20 μm, but is not limited to the listed values. Other values ​​not listed within the range also meet the requirements.

[0093] The thickness of the hydrogen termination layer 400 is 0.5-1 nm, for example, 0.5 nm, 0.6 nm, 0.7 nm, 0.8 nm, 0.9 nm or 1 nm, but is not limited to the listed values. Other values ​​not listed within the range also meet the requirements.

[0094] The PN layer includes at least one P-well region 510 . A P+ doping region 520 and an N-doping region 530 are provided in the P-well region 510 . The N-doping region 530 is provided around the P+ doping region 520 .

[0095] Among them, the spacing between adjacent P-well regions 510 is 1.5-2μm, for example, it can be 1.5μm, 1.55μm, 1.6μm, 1.65μm, 1.7μm, 1.75μm, 1.8μm, 1.85μm, 1.9μm, 1.95μm or 2μm, etc., but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0096] Among them, the thickness of the P-well region 510 is 0.9-1.5μm, for example, it can be 0.9μm, 0.95μm, 1μm, 1.05μm, 1.1μm, 1.15μm, 1.2μm, 1.25μm, 1.3μm, 1.35μm, 1.4μm, 1.45μm or 1.5μm, etc., but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0097] Among them, the width of the P-well region is 2-3μm, for example, it can be 2μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm, 2.5μm, 2.6μm, 2.7μm, 2.8μm, 2.9μm or 3μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0098] The concentration of P-type doping in the P-well region 510 is 1×10 17 -5×10 17 pieces / cm 3 , for example, it can be 1×10 17 pieces / cm 3 , 1.5×10 17 pieces / cm 3 , 2×10 17 pieces / cm 3 , 2.5×10 17 pieces / cm 3 , 3×10 17 pieces / cm 3 , 3.5×10 17 pieces / cm 3 , 4×10 17 pieces / cm 3 , 4.5×10 17 pieces / cm 3 or 5×10 17 pieces / cm 3 The above values ​​are not limited to the listed values, and other values ​​not listed in the range also meet the requirements.

[0099] Among them, the thickness of the P+ doping region 520 is 0.1-0.3μm, for example, it can be 0.1μm, 0.12μm, 0.14μm, 0.16μm, 0.18μm, 0.2μm, 0.22μm, 0.24μm, 0.26μm, 0.28μm or 0.3μm, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0100] Among them, the width of the P+ doping region is 0.6-1μm, for example, it can be 0.6μm, 0.65μm, 0.7μm, 0.75μm, 0.8μm, 0.85μm, 0.9μm, 0.95μm or 1μm, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0101] The P-type doping concentration of the P+ doping region 520 is 1×10 19 -5×10 19 pieces / cm 3 , for example, it can be 1×10 19 pieces / cm 3 , 1.5×10 19 pieces / cm 3 , 2×10 19 pieces / cm 3 , 2.5×10 19 pieces / cm 3 , 3×10 19 pieces / cm 3 , 3.5×10 19 pieces / cm 3 , 4×10 19 pieces / cm 3 , 4.5×10 19 pieces / cm 3 or 5×10 19 pieces / cm 3 The above values ​​are not limited to the listed values, and other values ​​not listed in the range also meet the requirements.

[0102] Among them, the thickness of the N-doped region 530 is 0.1-0.3μm, for example, it can be 0.1μm, 0.12μm, 0.14μm, 0.16μm, 0.18μm, 0.2μm, 0.22μm, 0.24μm, 0.26μm, 0.28μm or 0.3μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0103] Among them, the width of the N-doped region 530 is 0.4-0.6μm, for example, it can be 0.4μm, 0.42μm, 0.44μm, 0.46μm, 0.48μm, 0.5μm, 0.52μm, 0.54μm, 0.56μm, 0.58μm or 0.6μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0104] In the present invention, the width of the N-doped region 530 refers to the width of the bandwidth surrounding the P+-doped region 520 .

[0105] The N-type doping concentration of the N-doped region 530 is 5×1016 -5×10 17 pieces / cm 3 , for example, it can be 5×10 16 pieces / cm 3 , 10×10 16 pieces / cm 3 , 15×10 16 pieces / cm 3 , 20×10 16 pieces / cm 3 , 25×10 16 pieces / cm 3 , 30×10 16 pieces / cm 3 , 35×10 16 pieces / cm 3 , 40×10 16 pieces / cm 3 , 45×10 16 pieces / cm 3 or 50×10 16 pieces / cm 3 The above values ​​are not limited to the listed values, and other values ​​not listed in the range also meet the requirements.

[0106] The gate oxide layer 600 includes a SiO2 layer with a thickness of 50-80 nm, for example, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm or 80 nm, but is not limited to the listed values. Other values ​​not listed within the range also meet the requirements.

[0107] The thickness of the polycrystalline gate layer 700 is 0.2-1 μm, for example, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm or 1 μm, but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0108] The P-type doping concentration of the polycrystalline gate layer 700 is 1×10 18 -2×10 20 pieces / cm 3 , for example, it can be 1×10 18 pieces / cm 3 , 2×10 18 pieces / cm 3 , 4×10 18 pieces / cm 3 , 6×10 18 pieces / cm 3 , 8×10 18 pieces / cm 3 , 10×10 18cm-2 3 cm-2 18 cm-2 3 cm-2 18 cm-2 3 cm-2 18 cm-2 3 cm-2 18 cm-2 3 cm-2 18 cm-2 3 cm-2 18 cm-2 3 cm-2 18 cm-2 3 cm-2 18 cm-2 3 cm-2 18 cm-2 3 cm-2 18 cm-2 3 cm-2 cm-2

[0109] cm-2 cm-2

[0110] cm-2 cm-2

[0111] cm-2 cm-2

[0112] The flow rate of the N-type dopant used in the growth of the buffer layer is 80-120 sccm, for example, it can be 80 sccm, 85 sccm, 90 sccm, 95 sccm, 100 sccm, 105 sccm, 110 sccm, 115 sccm or 120 sccm, etc., but not limited to the listed values, other values not listed in the range are also required.

[0113] The growth temperature in the growth of the buffer layer is 1580-1680℃, for example, it can be 1580℃, 1590℃, 1600℃, 1610℃, 1620℃, 1630℃, 1640℃, 1650℃, 1660℃, 1670℃ or 1680℃, etc., but not limited to the listed values, other values not listed in the range are also required.

[0114] The growth pressure in the growth of the buffer layer is 50-100 mbar, for example, it can be 50 mbar, 55 mbar, 60 mbar, 65 mbar, 70 mbar, 75 mbar, 80 mbar, 85 mbar, 90 mbar, 95 mbar or 100 mbar, etc., but not limited to the listed values, other values not listed in the range are also required.

[0115] The flow rate of the carrier gas used in the growth of the epitaxial layer is 100-800 slm, for example, it can be 100 slm, 150 slm, 200 slm, 250 slm, 300 slm, 350 slm, 400 slm, 450 slm, 500 slm, 550 slm, 600 slm, 650 slm, 700 slm, 750 slm or 800 slm, etc., but not limited to the listed values, other values not listed in the range are also required.

[0116] The flow rate of the silicon source gas used in the growth of the epitaxial layer is 300-600 sccm, for example, it can be 300 sccm, 350 sccm, 400 sccm, 450 sccm, 500 sccm, 550 sccm or 600 sccm, etc., but not limited to the listed values, other values not listed in the range are also required.

[0117] The flow rate of the carbon source gas used in the growth of the epitaxial layer is 200-500 sccm, for example, it can be 200 sccm, 250 sccm, 300 sccm, 350 sccm, 400 sccm, 450 sccm or 500 sccm, etc., but not limited to the listed values, other values not listed in the range are also required.

[0118] Among them, the flow rate of the N-type dopant used in the epitaxial layer growth is 20-60sccm, for example, it can be 20sccm, 25sccm, 30sccm, 35sccm, 40sccm, 45sccm, 50sccm, 55sccm or 60sccm, etc., but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0119] Among them, the growth temperature of the epitaxial layer growth is 1580-1680℃, for example, it can be 1580℃, 1590℃, 1600℃, 1610℃, 1620℃, 1630℃, 1640℃, 1650℃, 1660℃, 1670℃ or 1680℃, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0120] Among them, the growth pressure during the epitaxial layer growth is 50-500 mbar, for example, it can be 50 mbar, 60 mbar, 70 mbar, 80 mbar, 90 mbar, 100 mbar, 200 mbar, 300 mbar, 400 mbar or 500 mbar, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0121] Wherein, forming the hydrogen terminal includes: performing plasma treatment on the epitaxial layer obtained by epitaxial layer growth using hydrogen plasma.

[0122] The pressure of the reaction chamber during the plasma treatment is controlled to be 10-25 Pa, for example, it can be 10 Pa, 11 Pa, 12 Pa, 13 Pa, 14 Pa, 15 Pa, 16 Pa, 17 Pa, 18 Pa, 19 Pa, 20 Pa, 21 Pa, 22 Pa, 23 Pa, 24 Pa or 25 Pa, etc., but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0123] Among them, the flow rate of hydrogen in the plasma treatment is 5-15sccm, for example, it can be 5sccm, 6sccm, 7sccm, 8sccm, 9sccm, 10sccm, 11sccm, 12sccm, 13sccm, 14sccm or 15sccm, etc., but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0124] The forming of the P-well region includes: performing ion implantation on the epitaxial layer obtained by epitaxial layer growth to obtain the P-well region.

[0125] The annealing temperature is 1600-1850℃, for example, 1600℃, 1650℃, 1700℃, 1750℃, 1800℃ or 1850℃, but is not limited to the listed values, and other values not listed in the range are also acceptable.

[0126] The annealing time is 3-10min, for example, 3min, 4min, 5min, 6min, 7min, 8min, 9min or 10min, but is not limited to the listed values, and other values not listed in the range are also acceptable.

[0127] The P+ doped region is formed by ion implantation on the P well region after annealing.

[0128] The N doped region is formed by ion implantation on the P+ doped region obtained by forming the P+ doped region.

[0129] The gate oxide layer is grown by plasma enhanced chemical vapor deposition (PECVD), for example, the related parameters for growing the gate oxide layer are as follows: the flow ratio of the gases introduced into the PECVD is (18-20):(1700-1900) sccm, the radio frequency power is 50-500W, the substrate temperature is usually controlled at 200-400℃, and the chamber pressure is 0.1-10Torr.

[0130] The polycrystalline gate is grown by low pressure chemical vapor deposition (LPCVD), wherein the related control parameters of the LPCVD are reasonably designed according to the conventional requirements in the art, as long as the preparation of the polycrystalline gate of the present application can be ensured.

[0131] In the present application, the silicon source gas used includes one or a combination of at least two of SiCl4, SiHCl3, SiH2Cl2 or SiH3Cl.

[0132] In the present application, the carbon source gas used includes C2H4 and / or C3H8.

[0133] In the present application, the carrier gas used includes hydrogen.

[0134] In the present application, the N-type dopant used includes nitrogen.

[0135] In the present application, the P-type dopant used includes B dopant, Al dopant or Ga dopant, and other P-type dopants commonly used in the art.

[0136] Thirdly, the present application provides a power device, which comprises the hydrogen-terminated MOSFET epitaxial structure or the MOSFET epitaxial structure obtained by the preparation method.

[0137] Four, in order to illustrate the present application provides a hydrogen-terminated MOSFET epitaxial structure can achieve good results, using the following actual examples are described as follows:

[0138] Embodiment 1

[0139] The present embodiment provides a hydrogen-terminated MOSFET epitaxial structure, the hydrogen-terminated MOSFET epitaxial structure comprises:

[0140] Buffer layer, epitaxial layer, hydrogen terminal layer, P-N layer, gate oxide layer and polycrystalline gate layer are sequentially arranged on the substrate;

[0141] The substrate is a 4H-SiC substrate with a deviation of 4° from the <11-20> direction;

[0142] The concentration of N-type doping in the buffer layer is 1×10 18 cm 3 -1, and the thickness is 1 μm;

[0143] The concentration of N-type doping in the epitaxial layer is 0.85×10 16 cm 3 -1, and the thickness is 10 μm;

[0144] The thickness of the hydrogen terminal layer is 0.8 nm;

[0145] The P-N layer comprises: 2 P-well regions with a spacing of 1.8 μm; the P-well region is provided with a P+ doped region and an N doped region, the N doped region is arranged around the P+ doped region; the thickness of the P-well region is 1.2 μm, the width is 2 μm, the P-type doping concentration is 3×10 17 cm 3 -1; the thickness of the P+ doped region is 0.2 μm, the width is 0.8 μm, the P-type doping concentration is 3×10 19 cm 3 -1; the thickness of the N doped region is 0.2 μm, the width is 0.5 μm, and the N-type doping concentration is 30×10 16 cm 3 -1;

[0146] The gate oxide layer is a SiO2 layer with a thickness of 65 nm;

[0147] The P-type doping concentration of the polycrystalline gate layer is 100×10 18 cm 3 -1, and the thickness is 0.5 μm.

[0148] The preparation process is as follows:

[0149] The buffer layer growth, the epitaxial layer growth, the hydrogen terminal formation, the P well region formation, the annealing, the P+ doped region formation, the N doped region formation, the gate oxide layer growth and the polycrystal gate growth are sequentially performed on the substrate;

[0150] In the growth, the silicon source gas used is SiCl4; the carbon source gas used is C2H4; the carrier gas used is hydrogen; the N-type dopant used is nitrogen; and the P-type dopant used is an aluminum dopant;

[0151] In the buffer layer growth, the flow rate of the carrier gas used is 450 slm, the flow rate of the silicon source gas is 450 sccm, the flow rate of the carbon source gas is 350 sccm, the flow rate of the N-type dopant is 100 sccm, the growth temperature is 1620℃, and the growth pressure is 75 mbar;

[0152] In the epitaxial layer growth, the flow rate of the carrier gas used is 450 slm, the flow rate of the silicon source gas is 450 sccm, the flow rate of the carbon source gas is 350 sccm, the flow rate of the N-type dopant is 40 sccm, the growth temperature is 1620℃, and the growth pressure is 300 mbar;

[0153] The hydrogen terminal formation includes: performing plasma treatment on the epitaxial layer obtained by the epitaxial layer growth by using hydrogen plasma, and the pressure of the reaction cavity is controlled to be 15 Pa and the flow rate of the hydrogen is 10 sccm;

[0154] The P well region formation includes: performing ion implantation on the epitaxial layer obtained by the epitaxial layer growth to obtain the P well region;

[0155] The annealing has a temperature of 1700℃ and a time of 6 min;

[0156] The P+ doped region formation includes: performing ion implantation on the P well region after the annealing to obtain the P+ doped region;

[0157] The N doped region formation includes: performing ion implantation on the P+ doped region obtained by the P+ doped region formation to obtain the N doped region;

[0158] The gate oxide layer growth is performed by plasma enhanced chemical vapor deposition, and the flow rate ratio of the gases introduced is SiH4:N2O 19:1800 sccm, the radio frequency power is 300 W, the substrate temperature is 300℃, and the cavity pressure is 5 Torr;

[0159] The polycrystal gate growth is performed by low pressure chemical vapor deposition.

[0160] Embodiment 2

[0161] The embodiment provides a MOSFET epitaxial structure with a hydrogen terminal, and the MOSFET epitaxial structure with the hydrogen terminal comprises:

[0162] A buffer layer, an epitaxial layer, a hydrogen termination layer, a PN layer, a gate oxide layer and a polycrystalline gate layer are sequentially arranged on the substrate;

[0163] The substrate is a 4H-SiC substrate with a 4° deviation toward the <11-20> direction;

[0164] The concentration of N-type doping in the buffer layer is 0.7×10 18 pieces / cm 3 , thickness is 1.1μm;

[0165] The concentration of N-type doping in the epitaxial layer is 1×10 16 pieces / cm 3 , thickness of 5 μm;

[0166] The thickness of the hydrogen terminal layer is 0.5 nm;

[0167] The PN layer includes: three P-well regions with a spacing of 3 μm; a P+ doping region and an N-doping region are provided in the P-well region, and the N-doping region is provided around the P+ doping region; the thickness of the P-well region is 1.5 μm, the width is 2.5 μm, and the concentration of P-type doping is 5×10 17 pieces / cm 3 The thickness of the P+ doped region is 0.3 μm, the width is 0.6 μm, and the P-type doping concentration is 5×10 19 pieces / cm 3 The thickness of the N-doped region is 0.3 μm, the width is 0.4 μm, and the N-type doping concentration is 5×10 16 pieces / cm 3 ;

[0168] The gate oxide layer is a SiO2 layer with a thickness of 80 nm;

[0169] The P-type doping concentration of the polycrystalline gate layer is 1×10 18 pieces / cm 3 , with a thickness of 0.2μm.

[0170] The preparation process is as follows:

[0171] On the substrate, a buffer layer is grown, an epitaxial layer is grown, a hydrogen terminal is formed, a P-well region is formed, annealing is performed, a P+ doping region is formed, an N-doping region is formed, a gate oxide layer is grown, and a polycrystalline gate is grown;

[0172] During the growth, the silicon source gas used was SiH3Cl; the carbon source gas used was C2H4; the carrier gas used was hydrogen; the N-type dopant used was nitrogen; and the P-type dopant used was aluminum dopant.

[0173] The flow rate of the carrier gas used in the growth of the buffer layer is 800 slm, the flow rate of the silicon source gas is 300 sccm, the flow rate of the carbon source gas is 500 sccm, the flow rate of the N-type dopant is 80 sccm, the growth temperature is 1680℃, and the growth pressure is 50 mbar;

[0174] The flow rate of the carrier gas used in the growth of the buffer layer is 800 slm, the flow rate of the silicon source gas is 300 sccm, the flow rate of the carbon source gas is 500 sccm, the flow rate of the N-type dopant is 80 sccm, the growth temperature is 1680℃, and the growth pressure is 50 mbar;

[0175] The formation of the hydrogen termination includes: performing plasma treatment on the epitaxial layer obtained by epitaxial growth by using hydrogen plasma, and the pressure of the reaction cavity is controlled to be 10 Pa, and the flow rate of hydrogen is 5 sccm;

[0176] The formation of the P-well region includes: performing ion implantation on the epitaxial layer obtained by epitaxial growth to obtain a P-well region;

[0177] The annealing temperature is 1850℃, and the time is 3 min;

[0178] The formation of the P+ doped region includes: performing ion implantation on the P-well region after annealing to obtain a P+ doped region;

[0179] The formation of the N doped region includes: performing ion implantation on the P+ doped region obtained by forming the P+ doped region to obtain an N doped region;

[0180] The gate oxide layer is grown by plasma enhanced chemical vapor deposition, and the flow rate ratio of the input gas is SiH4:N2O, which is 19:1800 sccm, the radio frequency power is 50 W, the substrate temperature is 400℃, and the cavity pressure is 10 Torr;

[0181] The polycrystalline gate is grown by low pressure chemical vapor deposition.

[0182] Embodiment 3

[0183] The embodiment provides a hydrogen-terminated MOSFET epitaxial structure, which comprises:

[0184] A buffer layer, an epitaxial layer, a hydrogen termination layer, a P-N layer, a gate oxide layer and a polycrystalline gate layer are sequentially arranged on a substrate;

[0185] The substrate is a 4H-SiC substrate deviated by 4° from the <11-20> direction;

[0186] The concentration of N-type doping in the buffer layer is 1.3×10 18 / cm 3 , and the thickness is 0.9 μm;

[0187] The concentration of N-type doping in the epitaxial layer is 0.7*10 16 cm-2, and the thickness is 20um; 3

[0188] The thickness of the hydrogen terminal layer is 1nm;

[0189] The P-N layer comprises: 4 P-well regions with a spacing of 1.5um; the P-well region is provided with a P+ doped region and an N doped region, the N doped region is provided around the P+ doped region; the thickness of the P-well region is 0.9um, the width is 3um, the P-type doping concentration is 1*10 17 cm-2, the thickness of the P+ doped region is 0.1um, the width is 1um, the P-type doping concentration is 1*10 3 cm-2, the thickness of the N doped region is 0.1um, the width is 0.6um, and the N-type doping concentration is 5*10 19 cm-2. 3 17 3

[0190] The gate oxide layer is a SiO2 layer with a thickness of 50nm;

[0191] The P-type doping concentration of the polycrystalline gate layer is 2*10 20 cm-2, and the thickness is 1um. 3

[0192] The preparation process is as follows:

[0193] The buffer layer growth, epitaxial layer growth, hydrogen terminal formation, P-well region formation, annealing, P+ doped region formation, N doped region formation, gate oxide layer growth and polycrystalline gate growth are sequentially performed on the substrate;

[0194] In the growth, the silicon source gas used is SiHCl3; the carbon source gas used is C3H8; the carrier gas used is hydrogen; the N-type dopant used is nitrogen; and the P-type dopant used is an aluminum dopant;

[0195] In the buffer layer growth, the flow rate of the carrier gas used is 100slm, the flow rate of the silicon source gas is 600sccm, the flow rate of the carbon source gas is 200sccm, the flow rate of the N-type dopant is 120sccm, the growth temperature is 1580℃, and the growth pressure is 100mbar;

[0196] In the epitaxial layer growth, the flow rate of the carrier gas used is 100slm, the flow rate of the silicon source gas is 600sccm, the flow rate of the carbon source gas is 200sccm, the flow rate of the N-type dopant is 20sccm, the growth temperature is 1580℃, and the growth pressure is 500mbar;

[0197] ​​​​​The forming of the hydrogen terminal comprises: performing plasma treatment on the epitaxial layer obtained by epitaxial growth of the epitaxial layer by using hydrogen plasma, the pressure of the reaction cavity is controlled to be 25 Pa, and the flow rate of hydrogen is 15 sccm;

[0198] The forming of the P well region comprises: performing ion implantation on the epitaxial layer obtained by epitaxial growth of the epitaxial layer to obtain a P well region;

[0199] The annealing temperature is 1600℃, and the annealing time is 10 min;

[0200] The forming of the P+ doped region comprises: performing ion implantation on the P well region after annealing to obtain a P+ doped region;

[0201] The forming of the N doped region comprises: performing ion implantation on the P+ doped region obtained by forming the P+ doped region to obtain an N doped region;

[0202] The gate oxide layer is grown by plasma enhanced chemical vapor deposition, the flow rate ratio of the input gas is SiH4:N2O 19:1800 sccm, the radio frequency power is 500 W, the substrate temperature is 200℃, and the cavity pressure is 0.1 Torr;

[0203] The polycrystalline gate is grown by low pressure chemical vapor deposition.

[0204] Comparative Example 1

[0205] The difference from Example 1 is only that no hydrogen terminal layer is arranged between the epitaxial layer and the P-N layer.

[0206] Comparative Example 2

[0207] The difference from Example 1 is only that the thickness of the hydrogen terminal layer is 0.2 nm.

[0208] Comparative Example 3

[0209] The difference from Example 1 is only that the thickness of the hydrogen terminal layer is 1.5 nm.

[0210] Example 4

[0211] The difference from Example 1 is only that the plasma used for forming the hydrogen terminal layer is replaced by ammonia plasma, that is, no hydrogen terminal layer is formed.

[0212] Example 5

[0213] The difference from Example 1 is only that the plasma used for forming the hydrogen terminal layer is replaced by N2O plasma, that is, no hydrogen terminal layer is formed.

[0214] The epitaxial layer structures obtained in the above examples and comparative examples are analyzed for on-resistance performance according to GB / T 14028-2018, and the results are shown in Table 1 below.

[0215] Table 1

[0216] On resistance / mQ Example 1 14.67 Example 2 15.53 Example 3 15.36 Comparative Example 1 23.56 Comparative Example 2 22.62 Comparative Example 3 24.84 Example 4 32.36 Example 5 36.88

[0217] As shown in Table 1, the scheme provided by the application can effectively reduce the dangling bond by setting the specific hydrogen terminal layer between the epitaxial layer and the gate oxide layer, passivate the SiC surface state, reduce the carrier capture of the surface state, reduce the on-resistance, and thus ensure the service life of the power device.

[0218] The above describes the preferred embodiments of the application, but the application is not limited to the specific details in the above embodiments, and various simple modifications can be made to the technical scheme of the application within the technical concept of the application, and these simple modifications all belong to the protection scope of the application.

[0219] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the application will not further describe various possible combinations.

[0220] In addition, various different embodiments of the application can also be combined in any manner, as long as it does not deviate from the idea of the application, and it should also be considered as disclosed by the application.

Claims

1. A hydrogen-terminated MOSFET epitaxial structure, characterized in that: The hydrogen-terminated MOSFET epitaxial structure comprises: A buffer layer, an epitaxial layer, a hydrogen termination layer, a PN layer, a gate oxide layer and a polycrystalline gate layer are sequentially arranged on the substrate; The thickness of the hydrogen termination layer is 0.5-1 nm.

2. The hydrogen-terminated MOSFET epitaxial structure according to claim 1, wherein: The concentration of N-type doping in the buffer layer is 0.7×10 18 -1.3×10 18 pieces / cm 3 ; Preferably, the thickness of the buffer layer is 0.9-1.1 μm; Preferably, the concentration of N-type doping in the epitaxial layer is 0.7×10 16 -1×10 16 pieces / cm 3 ; Preferably, the epitaxial layer has a thickness of 5-20 μm.

3. The hydrogen-terminated MOSFET epitaxial structure according to claim 1 or 2, wherein: The PN layer includes: at least one P-well region, wherein a P+ doping region and an N-doping region are provided in the P-well region, and the N-doping region is provided around the P+ doping region; Preferably, the spacing between adjacent P-well regions is 1.5-3 μm; Preferably, the thickness of the P-well region is 0.9-1.5 μm; Preferably, the width of the P-well region is 2-3 μm; Preferably, the concentration of P-type doping in the P-well region is 1×10 17 -5×10 17 pieces / cm 3 ; Preferably, the thickness of the P+ doped region is 0.1-0.3 μm; Preferably, the width of the P+ doped region is 0.6-1 μm; Preferably, the P-type doping concentration of the P+ doping region is 1×10 19 -5×10 19 pieces / cm 3 ; Preferably, the thickness of the N-doped region is 0.1-0.3 μm; Preferably, the width of the N-doped region is 0.4-0.6 μm; Preferably, the N-type doping concentration of the N-doped region is 5×10 16 -5×10 17 pieces / cm 3 .

4. The hydrogen-terminated MOSFET epitaxial structure according to any one of claims 1 to 3, wherein: The gate oxide layer includes: a SiO2 layer with a thickness of 50-80nm; Preferably, the thickness of the polycrystalline gate layer is 0.2-1 μm; Preferably, the P-type doping concentration of the polycrystalline gate layer is 1×10 18 -2×10 20 pieces / cm 3 .

5. A method for preparing a hydrogen-terminated MOSFET epitaxial structure, characterized in that: The preparation method comprises: The buffer layer is grown, the epitaxial layer is grown, a hydrogen terminal is formed, a P well region is formed, annealing is performed, a P+ doping region is formed, an N doping region is formed, a gate oxide layer is grown, and a polycrystalline gate is grown.

6. The preparation method according to claim 5, wherein The flow rate of the carrier gas used in the growth of the buffer layer is 100-800 slm; Preferably, the flow rate of the silicon source gas used in the growth of the buffer layer is 300-600 sccm; Preferably, the flow rate of the carbon source gas used in the growth of the buffer layer is 200-500 sccm; Preferably, the flow rate of the N-type dopant used in the growth of the buffer layer is 80-120 sccm; Preferably, the growth temperature of the buffer layer is 1580-1680°C; Preferably, the growth pressure during the growth of the buffer layer is 50-100 mbar.

7. The preparation method according to claim 5 or 6, characterized in that The flow rate of the carrier gas used in the epitaxial layer growth is 100-800 slm; Preferably, the flow rate of the silicon source gas used in the epitaxial layer growth is 300-600 sccm; Preferably, the flow rate of the carbon source gas used in the epitaxial layer growth is 200-500 sccm; Preferably, the flow rate of the N-type dopant used in the epitaxial layer growth is 20-60 sccm; Preferably, the growth temperature of the epitaxial layer is 1580-1680°C; Preferably, the growth pressure during the epitaxial layer growth is 50-500 mbar.

8. The preparation method according to any one of claims 5 to 7, characterized in that: The forming of the hydrogen terminal comprises: performing plasma treatment on the epitaxial layer obtained by epitaxial layer growth using hydrogen plasma; Preferably, the pressure of the reaction chamber during the plasma treatment is controlled to be 10-25 Pa; Preferably, the flow rate of hydrogen in the plasma treatment is 5-15 sccm; Preferably, the forming of the P-well region comprises: performing ion implantation on the epitaxial layer obtained by epitaxial layer growth to obtain the P-well region; Preferably, the annealing temperature is 1600-1850°C; Preferably, the annealing time is 3-10 minutes.

9. The preparation method according to any one of claims 5 to 8, characterized in that The forming of the P+ doped region comprises: performing ion implantation on the annealed P well region to obtain the P+ doped region; Preferably, the forming of the N-doped region comprises: performing ion implantation on the P+-doped region obtained by forming the P+-doped region to obtain the N-doped region; Preferably, the gate oxide layer is grown by: plasma enhanced chemical vapor deposition; Preferably, the polycrystalline gate growth method includes: low pressure chemical vapor deposition.

10. A power device, characterized in that: The power device comprises: a hydrogen-terminated MOSFET epitaxial structure according to any one of claims 1 to 4 or a MOSFET epitaxial structure obtained by the preparation method according to any one of claims 5 to 9.

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