CN114883398A - Gallium nitride device and switching power supply product with same - Google Patents

Abstract

The present invention provides a gallium nitride device and a switching power supply product having the same. The gallium nitride device includes: a substrate; a transition layer disposed on one side of the substrate; and a transition layer disposed on the transition layer away from the substrate a buffer layer on the bottom side; a channel layer arranged on the side of the buffer layer away from the transition layer; a potential barrier layer arranged on the side of the channel layer away from the buffer layer; arranged on the potential barrier a first passivation layer on the side away from the channel layer; a single-layer thin-film field plate disposed on the side of the first passivation layer away from the barrier layer; disposed on the single-layer thin-film field plate away from a second passivation layer on one side of the first passivation layer. Therefore, a single-layer thin film field plate is arranged between the first passivation layer and the second passivation layer, which can better adjust the electric field distribution and avoid the electric field being concentrated on the edge of the gate or the edge region of the metal field plate; and the above The structured gallium nitride device can also reduce the cost in processing and reduce the processing cycle.

Description

Gallium nitride devices and switching power supply products with the same

technical field

The present invention relates to the technical field of microelectronics, and in particular, to a gallium nitride device and a switching power supply product having the same.

Background technique

The third-generation semiconductor materials represented by GaN have many excellent properties, such as wide band gap, high voltage resistance, high temperature resistance, high electron saturation velocity, radiation resistance and so on. Not only that, the interface of the AlGaN/GaN heterojunction structure can generate a high concentration of two-dimensional electron gas, and a channel structure with very low on-resistance can be fabricated. These characteristics make GaN materials have better performance parameters than first-generation semiconductor materials such as Si. For example, the Baliga FOM of GaN (a figure of merit that measures the high-power characteristics of materials) is more than 800 times that of Si materials, and GaN device theory 100 times higher switching speeds than Si-based devices can be achieved. Despite these advantages of GaN materials, there are still some problems in practical use of GaN devices. For example, how to optimize the electric field distribution on the surface of the device, how to improve the electron concentration of the conductive channel, how to optimize the current collapse effect of the device, and how to improve the reliability of the device, etc.

Therefore, the current GaN devices still need further improvement.

SUMMARY OF THE INVENTION

The present invention aims to solve one of the technical problems in the related art at least to a certain extent. Therefore, an object of the present invention is to provide a gallium nitride device and a switching power supply product having the same, the gallium nitride device can modulate electric field distribution, has short processing cycle and low cost.

In one aspect of the present invention, a gallium nitride device is proposed, the gallium nitride device includes: a substrate; a transition layer, the transition layer is located on one side of the substrate; a buffer layer, the buffer layer is provided on the side of the transition layer away from the substrate; the channel layer, the channel layer is arranged on the side of the buffer layer away from the transition layer; the barrier layer, the barrier layer is arranged on the side of the buffer layer away from the transition layer; a side of the channel layer away from the buffer layer; a first passivation layer, the first passivation layer is arranged on the side of the barrier layer away from the channel layer; a single-layer thin film field plate, so The single-layer thin film field plate is disposed on the side of the first passivation layer away from the potential barrier layer; the second passivation layer is disposed on the single-layer thin film field plate away from the one side of the first passivation layer. Therefore, a single-layer thin-film field plate is arranged between the first passivation layer and the second passivation layer, which can better adjust the electric field distribution and avoid the electric field being concentrated at the gate edge or the edge region of the metal field plate; and the above The structured gallium nitride device can also reduce the cost in processing and reduce the processing cycle.

According to some embodiments of the present invention, the single-layer thin-film field plate mainly includes a high-resistance material, and the resistivity of the high-resistance material is 10 ⁷ -10 ¹¹ Ω·cm.

According to some embodiments of the present invention, the thickness of the single-layer thin film field plate is 150 nm˜1000 nm.

According to some embodiments of the present invention, the material for forming the single-layer thin film field plate is selected from at least one of SIPOS, AlN, and Ga ₂ O ₃ .

According to some embodiments of the present invention, the mass percentage content of the high-resistance material in the single-layer thin-film field plate is 20% to 100%.

According to some embodiments of the present invention, the orthographic projection of the single-layer thin-film field plate on the substrate is the same as the orthographic projection of the barrier layer on the substrate.

According to some embodiments of the present invention, the gallium nitride device further includes: a source electrode, the source electrode being in contact with the channel layer through a first through hole, the first through hole passing through the second passivation layer, the single-layer thin film field plate, the first passivation layer and the barrier layer, and extend to the channel layer; a drain, the drain is connected to the channel through a second through hole layer contact, the second through hole penetrates through the second passivation layer, the single-layer thin film field plate, the first passivation layer and the barrier layer, and extends to the channel layer; gate The gate electrode is arranged in a third through hole, and the third through hole penetrates the second passivation layer and the single-layer thin film field plate.

According to some embodiments of the present invention, the second passivation layer is disposed overlying the edge side of the single-layer thin film field plate, the edge side of the first passivation layer, the edge side of the barrier layer and all the edge side of the channel layer.

In another aspect of the present invention, a switching power supply product is provided, including the aforementioned gallium nitride device. Therefore, the switching power supply product has all the features and advantages of the aforementioned gallium nitride device, which will not be repeated here. In general, at least it has the advantages of more uniform electric field distribution and lower cost.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

FIG. 1 shows a schematic structural diagram of a gallium nitride device according to an embodiment of the present invention.

Reference number:

100: substrate; 200: transition layer; 300: buffer layer; 400: channel layer; 500: barrier layer; 600: first passivation layer; 700: single-layer thin film field plate; 800: second passivation layer ; 10: source; 20: drain; 30: gate.

Detailed ways

Embodiments of the present invention are described in detail below. The embodiments described below are exemplary, only for explaining the present invention, and should not be construed as limiting the present invention. If no specific technique or condition is indicated in the examples, the technique or condition described in the literature in the field or the product specification is used. The reagents or instruments used without the manufacturer's indication are conventional products that can be obtained from the market.

In one aspect of the present invention, referring to FIG. 1 , a gallium nitride device is proposed, including a substrate 100 , a transition layer 200 located on one side of the substrate 100 , and a buffer layer disposed on the side of the transition layer 200 away from the substrate 100 . 300, the channel layer 400 arranged on the side of the buffer layer 300 away from the transition layer 200, the barrier layer 500 arranged on the side of the channel layer 400 away from the buffer layer 300, arranged on the side of the barrier layer 500 away from the channel layer 400 The first passivation layer 600, the single-layer thin film field plate 700 disposed on the side of the first passivation layer 600 away from the barrier layer 500 is disposed on the second side of the single-layer thin film field plate 700 away from the first passivation layer 600 Passivation layer 800 . Therefore, only one single-layer thin-film field plate 700 is arranged between the first passivation layer 600 and the second passivation layer 800 , that is, the electric field distribution can be better adjusted and the electric field can be prevented from being concentrated on the edge of the gate 30 or the metal field The edge area of the board; and the gallium nitride device with the above structure can also reduce the cost and reduce the processing cycle during processing.

In the related art, it is necessary to arrange multiple layers in the gallium nitride device in order to improve the electric field distribution, and the arrangement of multiple layers increases the number of photolithography and etching, due to the high cost of photoresist and developer. , the setting of multi-film layers will inevitably prolong the production cycle and increase the production cost. In this application, only one single-layer thin-film field plate 700 is provided in the gallium nitride device, which can achieve the effect of modulating the electric field distribution with multiple film layers, not only The processing cycle is shortened, and the production cost is also reduced.

当在漏极20施加关断高压时，即可使单层薄膜场板700层的电场均匀分布。According to some embodiments of the present invention, the single-layer thin film field plate 700 mainly includes a high-resistance material, and the resistivity of the high-resistance material is 10 ⁷ -10 ¹¹ Ω·cm. Therefore, when a voltage is applied across the single-layer thin-film field plate 700, the potential of the field plate is uniformly distributed with the resistance. Since the single-layer thin-film field plate 700 has a uniform resistivity, according to

When the turn-off high voltage is applied to the drain electrode 20, the electric field of the single-layer thin film field plate 700 can be uniformly distributed.

According to some embodiments of the present invention, the thickness of the single-layer thin film field plate 700 is 150 nm˜1000 nm, and specifically, may be 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800nm, 850nm, 900nm and 950nm. Therefore, the single-layer thin-film field plate 700 with the above-mentioned thickness is easy to manufacture, without significantly increasing the overall thickness of the device, and at the same time, it can meet the resistivity requirements of the single-layer thin-film field plate 700 .

According to some embodiments of the present invention, the material for forming the single-layer thin film field plate 700 is selected from at least one of SIPOS, AlN, and Ga ₂ O ₃ . Therefore, the above-mentioned high-resistance materials all have uniform resistivity, and the potential distribution is also linear in theory. When the drain 20 of the gallium nitride device applies a high voltage to turn off, the single-layer thin-film field plate 700 will have a uniform electric field distribution, and then The effect of improving the electric field distribution of the device is achieved. In addition, when the single-layer thin film field plate 700 contains a dopant material, the dopant material may be aluminum, gallium and other materials. In some specific embodiments, the high-resistance material is semi-insulating polysilicon (SIPOS), and the doping material can be at least one of aluminum and gallium; the high-resistance material is AlN, and the doping material can be gallium; the high-resistance material is gallium Insulated polysilicon (SIPOS), the doping material can be at least one of aluminum and gallium; the high resistance material is Ga ₂ O ₃ , and the doping material can be aluminum.

According to some embodiments of the present invention, the mass percentage content of the high-resistance material in the single-layer thin-film field plate 700 is 20% to 100%. Specifically, it can be 30%, 40%, 50%, 60%, 70%, 80%, 90%, and the like. Therefore, the modulation effect of the electric field of the single-layer thin film field plate 700 is better, and the state of the electric field distribution of the device can be optimally improved.

According to some embodiments of the invention, the orthographic projection of the single-layer thin film field plate 700 on the substrate 100 is the same as the orthographic projection of the barrier layer 500 on the substrate 100 . Therefore, the single-layer thin-film field plate 700 can uniformly adjust the electric field near the barrier layer 500 . The inventors found that if the orthographic projection of the single-layer thin-film field plate 700 on the substrate 100 is smaller than the orthographic projection of the barrier layer 500 on the substrate 100, the positions on the barrier layer 500 that are not covered by the single-layer thin-film field plate 700 will be reduced. There is a strong electric field, which causes the local field strength to be too high and the device to break down.

According to some embodiments of the present invention, the gallium nitride device may further include a source electrode 10, a drain electrode 20 and a gate electrode 30, the source electrode 10 is in contact with the channel layer 400 through a first through hole, and the first through hole penetrates the second passivation The passivation layer 800, the single-layer thin film field plate 700, the first passivation layer 600 and the barrier layer 500, and extend to the channel layer 400, the drain electrode 20 is in contact with the channel layer 400 through a second through hole, and the second through hole Passing through the second passivation layer 800 , the single-layer thin film field plate 700 , the first passivation layer 600 and the barrier layer 500 and extending to the channel layer 400 , the gate electrode 30 is disposed in the third through hole, and the third through hole The second passivation layer 800 and the single-layer thin film field plate 700 are penetrated.

According to an embodiment of the present invention, the second passivation layer 800 covers the edge side of the single-layer thin film field plate 700 , the edge side of the first passivation layer 600 , the edge side of the barrier layer 500 and the edge of the channel layer 400 . side. Thus, the single-layer thin film field plate 700 is completely surrounded by the first passivation layer 600 and the second passivation layer 800 to prevent the single-layer thin film field plate 700 from being connected to the conductive layers such as the source electrode 10 , the drain electrode 20 or the gate electrode 30 . Structural contacts affect the performance of GaN devices.

According to the embodiment of the present invention, the specific materials of the above-mentioned structures of the gallium nitride device except the single-layer thin film field plate 700 have no special requirements, and those skilled in the art can flexibly select according to actual needs. In some embodiments, the specific material of the substrate 100 includes but is not limited to silicon, nitride nitride or sapphire, etc., the specific material of the transition layer 200 includes but is not limited to aluminum nitride, and the material of the buffer layer 300 includes but is not limited to nitride Gallium; the material of the channel layer 400 includes but not limited to gallium nitride; the material of the barrier layer 500 includes but not limited to AlGaN, the material of the passivation layer (the first passivation layer 600 and the second passivation layer 800 ) includes but not limited to It is not limited to materials such as silicon oxide, silicon nitride, and silicon oxynitride; the specific materials of the source electrode 10, the drain electrode 20 and the gate electrode 30 include but are not limited to conductive materials such as aluminum and titanium.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " Rear, Left, Right, Vertical, Horizontal, Top, Bottom, Inner, Outer, Clockwise, Counterclockwise, Axial, The orientations or positional relationships indicated by "radial direction", "circumferential direction", etc. are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the indicated devices or elements. It must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

In the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrated; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of the two elements or the interaction relationship between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may be in direct contact between the first and second features, or the first and second features indirectly through an intermediary touch. Also, the first feature being "above", "over" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and variations.

Claims (9)

1. a gallium nitride device, is characterized in that, comprises: substrate; a transition layer, the transition layer is located on one side of the substrate; a buffer layer, the buffer layer is disposed on the side of the transition layer away from the substrate; a channel layer, the channel layer is disposed on the side of the buffer layer away from the transition layer; a barrier layer, the barrier layer is disposed on the side of the channel layer away from the buffer layer; a first passivation layer, the first passivation layer is disposed on the side of the barrier layer away from the channel layer; a single-layer thin-film field plate, the single-layer thin-film field plate is disposed on the side of the first passivation layer away from the potential barrier layer; A second passivation layer, the second passivation layer is disposed on the side of the single-layer thin film field plate away from the first passivation layer. 2 . The gallium nitride device according to claim 1 , wherein the single-layer thin-film field plate mainly comprises a high-resistance material, and the resistivity of the high-resistance material is 10 ⁷ -10 ¹¹ Ω·cm. 3 . 3 . The gallium nitride device according to claim 1 , wherein the thickness of the single-layer thin film field plate is 150 nm˜1000 nm. 4 . 4 . The gallium nitride device according to claim 1 , wherein the material for forming the single-layer thin film field plate is selected from at least one of SIPOS, AlN, and Ga ₂ O ₃ . 5 . The gallium nitride device according to claim 1 , wherein the mass percentage content of the high-resistance material in the single-layer thin-film field plate is 20% to 100%. 6 . 6 . The gallium nitride device according to claim 1 , wherein the orthographic projection of the single-layer thin-film field plate on the substrate is the same as that of the barrier layer on the substrate. 7 . The orthographic projection on the base is the same. 7 . The gallium nitride device according to claim 1 , further comprising: a source electrode, the source electrode is in contact with the channel layer through a first through hole, and the first through hole penetrates the second passivation layer, the single-layer thin film field plate, and the first passivation layer and the barrier layer, and extending to the channel layer; a drain, the drain is in contact with the channel layer through a second through hole, and the second through hole penetrates the second passivation layer, the single-layer thin film field plate, and the first passivation layer and the barrier layer, and extending to the channel layer; and a gate, the gate is disposed in a third through hole, and the third through hole penetrates the second passivation layer and the single-layer thin film field plate. 8 . The gallium nitride device according to claim 1 , wherein the second passivation layer is arranged to cover the edge side of the single-layer thin film field plate, and the first passivation layer The edge side of the ionization layer, the edge side of the barrier layer, and the edge side of the channel layer. 9 . A switching power supply product, characterized in that it has the gallium nitride device according to any one of claims 1 to 8 .

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