Semiconductor device and preparation method thereof, chip and electronic equipment
By adopting the structural design of the first cap layer and the second cap layer in the semiconductor device, using the doping concentration difference and the embedding relationship, the problem of difficult to improve the threshold voltage and reliability in the prior art is solved, and a higher Voltage stability and performance improvements.
Patent Information
- Application Number
- CN202411593248.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-08
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2044-11-08
AI Technical Summary
In high-frequency, high-voltage and high-power applications, the threshold voltage and reliability are difficult to improve simultaneously, and the problem of dynamic on-resistance degradation is more prominent.
A structural design including a first cap layer and a second cap layer, wherein the doping concentration of the first cap layer is less than the second cap layer, the second cap layer is at least partially embedded in the first cap layer, covering its sides, and Close to the substrate surface, use energy bands to differentially regulate two-dimensional electronic gas, reduce impurities diffusion, and improve polarization effect and interface stability.
The threshold voltage and reliability of semiconductor devices are improved, the stability of two-dimensional electronic gas is enhanced, the probability of dynamic on-resistance degradation is reduced, and performance and stability are improved.
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Figure CN119208371A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of semiconductor technology, and in particular to a semiconductor device and a manufacturing method thereof, a chip, and an electronic device. Background Art
[0002] Gallium nitride semiconductor materials are called third-generation semiconductor materials. Compared with the first-generation semiconductor materials represented by silicon, they have higher bandgap width, critical breakdown field strength, and electron saturation drift velocity. They have significant advantages in high frequency, high voltage resistance, high power, and low on-resistance. They can be used as core components in various power conversion systems and have broad prospects in consumer electronics, 5G RF, servers, and telecommunications applications. Summary of the invention
[0003] Embodiments of the present disclosure provide a semiconductor device and a method for manufacturing the same, a chip, and an electronic device, aiming to increase the threshold voltage of the semiconductor device while improving the reliability of the semiconductor device.
[0004] To achieve the above objectives, the embodiments of the present disclosure adopt the following technical solutions: On the one hand, a semiconductor device is provided. The semiconductor device includes a substrate, a barrier layer, a first cap layer, a second cap layer, a source and a drain. The barrier layer is arranged on one side of the substrate. The first cap layer is arranged on the side of the barrier layer away from the substrate. The source and the drain are located on opposite sides of the first cap layer along a first direction, and are both arranged on the side of the barrier layer away from the substrate, and the first direction is parallel to the substrate. The second cap layer is at least partially embedded in the first cap layer, and the first cap layer covers at least part of the side surfaces of the second cap layer on opposite sides along the first direction, and a surface of one side of the second cap layer close to the substrate. Wherein, the first cap layer and the second cap layer both include P-type doped semiconductor materials, and the doping concentration of the first cap layer is less than the doping concentration of the second cap layer.
[0005] The semiconductor device provided by the above-mentioned embodiments of the present disclosure comprises a first cap layer and a second cap layer, wherein the first cap layer is arranged on a side of the barrier layer in the semiconductor device away from the substrate, the second cap layer is at least partially embedded in the first cap layer, the first cap layer covers at least part of the side surfaces of the second cap layer on opposite sides along a first direction (i.e., the arrangement direction of the source and the drain in the semiconductor device), and a surface of one side of the second cap layer close to the substrate, and both the first cap layer and the second cap layer comprise P-type doped semiconductor materials, the doping concentration of the first cap layer is less than the doping concentration of the second cap layer, on the one hand, since the second cap layer is at least partially embedded in the first cap layer, and the first cap layer covers the second cap layer At least part of the side surfaces on the two opposite sides along the first direction, and the surface of one side of the second cap layer close to the substrate, that is, part of the first cap layer is located between the second cap layer and the barrier layer. In the process of forming the second cap layer in the semiconductor device, when the P-type impurities in the second cap layer diffuse, the P-type impurities in the second cap layer will diffuse into the first cap layer first, which can avoid or alleviate the diffusion of the P-type impurities in the second cap layer into the barrier layer, which can reduce the probability of the P-type impurities introducing additional charges and electric fields into the barrier layer and interfering with the polarization effect of the barrier layer, which is beneficial to improving the polarization effect of the barrier layer, and further conducive to enhancing the two-dimensional electron gas (Two-dimensional electron gas, 2DEG) in the semiconductor device, and is beneficial to improving the performance of the semiconductor device, and can also reduce the probability of changes in the characteristics of the connection interface between the first cap layer and the barrier layer (for example, the increase in the density of trap states at the connection interface between the first cap layer and the barrier layer, etc.), and affecting the control ability of the gate layer in the semiconductor device, which is beneficial to reducing the probability of problems such as dynamic on-resistance degradation in the semiconductor device, and further conducive to improving the reliability of the semiconductor device.
[0006] On the other hand, since the doping concentration of the first cap layer (i.e., the concentration of P-type impurities in the first cap layer) is less than the doping concentration of the second cap layer (i.e., the concentration of P-type impurities in the second cap layer), that is, the doping concentration of the first cap layer is relatively small, in the process of forming the first cap layer in the semiconductor device, the P-type impurities in the first cap layer may not diffuse or may diffuse in a small amount into the barrier layer, which can further reduce the probability of P-type impurities introducing additional charges and electric fields into the barrier layer and interfering with the polarization effect of the barrier layer, which is beneficial to further improve the polarization effect of the barrier layer, and thus is beneficial to further enhance the two-dimensional electron gas (Two-dimensional electron gas, 2DEG) in the semiconductor device, and is beneficial to further improve the performance of the semiconductor device, and can also further reduce the probability of changes in the characteristics of the connection interface between the first cap layer and the barrier layer (for example, the increase in the trap state density at the connection interface between the first cap layer and the barrier layer, etc.), and affect the control ability of the gate layer G in the semiconductor device, which is beneficial to further reduce the probability of problems such as dynamic on-resistance degradation in the semiconductor device, and thus is beneficial to further improve the reliability of the semiconductor device.
[0007] On the other hand, since the doping concentration of the first cap layer (i.e., the concentration of P-type impurities in the first cap layer) is less than the doping concentration of the second cap layer (i.e., the concentration of P-type impurities in the second cap layer), that is, the doping concentration of the second cap layer is relatively large, there is an energy band difference (e.g., conduction band difference) between the second cap layer and the barrier layer, and the energy band difference (e.g., conduction band difference) between the second cap layer and the barrier layer can be used to regulate the two-dimensional electron gas (2DEG) near the connection interface between the barrier layer and the channel layer, which is conducive to depleting the two-dimensional electron gas (2DEG) below the second cap layer, so that the semiconductor device realizes an enhanced working mode. And due to the depletion effect of the second cap layer in the semiconductor device on the two-dimensional electron gas (2DEG) below the second cap layer, the semiconductor device needs to overcome a higher barrier when it is turned on, which is conducive to increasing the threshold voltage of the semiconductor device.
[0008] In some embodiments, the semiconductor device includes a plurality of the second capping layers, and the plurality of the second capping layers are spaced apart along the first direction.
[0009] In some embodiments, within the first capping layer, the doping concentration gradually decreases in a direction away from the second capping layer.
[0010] In some embodiments, the first capping layer includes a first sublayer and a second sublayer stacked in a thickness direction of the substrate, the first sublayer being closer to the barrier layer than the second sublayer. At least a portion of the second capping layer is disposed in the second sublayer and penetrates the second sublayer in the thickness direction of the substrate. The doping concentration of the first sublayer and the doping concentration of the second sublayer are both less than the doping concentration of the second capping layer.
[0011] In some embodiments, the material of the first sub-layer includes a P-type doped semiconductor material, and the material of the second sub-layer includes a complex and a P-type doped semiconductor material.
[0012] In some embodiments, the second capping layer is doped with magnesium, and the complex in the second sub-layer includes a magnesium hydride complex.
[0013] In some embodiments, a doping concentration of the first sublayer and a doping concentration of the second sublayer are different.
[0014] In some embodiments, the semiconductor device further comprises a gate layer, which is disposed on a side of the first cap layer away from the substrate. The gate layer covers at least a portion of a surface of the first cap layer away from the substrate and a surface of a side of the second cap layer away from the substrate.
[0015] The semiconductor device provided by the above-mentioned embodiments of the present disclosure, when the semiconductor device includes a first cap layer and a second cap layer, by making the gate layer in the semiconductor device be arranged on the side of the first cap layer away from the substrate, and the gate layer covers at least a portion of the surface of the first cap layer on the side away from the substrate, and a surface of the second cap layer on the side away from the substrate, that is, the second cap layer is not arranged between a partial area in the gate layer and the first cap layer. In the state where the semiconductor device is turned on (that is, the gate layer in the semiconductor device is under a forward voltage bias), part of the two-dimensional electron gas (2DEG) in the semiconductor device can pass through the first cap layer and be collected by a partial area in the gate layer and between the first cap layer where the second cap layer is not arranged, without passing through the second cap layer.
[0016] On the one hand, since the doping concentration of the first capping layer (i.e., the concentration of P-type impurities in the first capping layer) is less than the doping concentration of the second capping layer (i.e., the concentration of P-type impurities in the second capping layer), that is, the doping concentration of the first capping layer is relatively small, there are fewer electron traps in the first capping layer, which is beneficial to reducing the probability of electrons in the two-dimensional electron gas (2DEG) being captured by electron traps during transmission, and further beneficial to maintaining the concentration of the two-dimensional electron gas (2DEG) near the connection interface between the barrier layer and the channel layer, so that the concentration of the two-dimensional electron gas (2DEG) is more stable, thereby avoiding or reducing the probability of a positive drift of the threshold voltage due to the capture of electrons by electron traps during transmission, which is beneficial to improving the stability of the threshold voltage of the semiconductor device.
[0017] On the other hand, since the doping concentration of the first capping layer (i.e., the concentration of P-type impurities in the first capping layer) is relatively small, there is an approximately uniformly distributed electric field in the first capping layer, which is beneficial for accelerating electrons in the first capping layer and smoothly transitioning to the interface between the first capping layer and the gate layer, which can reduce the scattering and energy loss of electrons during the transmission process, and thus is beneficial for improving the performance stability of semiconductor devices.
[0018] On the other hand, since the doping concentration of the first cap layer (i.e., the concentration of P-type impurities in the first cap layer) is less than the doping concentration of the second cap layer (i.e., the concentration of P-type impurities in the second cap layer), that is, the doping concentration of the second cap layer is relatively large, there is an energy band difference (e.g., conduction band difference) between the second cap layer and the barrier layer, and the energy band difference (e.g., conduction band difference) between the second cap layer and the barrier layer can be used to regulate the two-dimensional electron gas (2DEG) near the connection interface between the barrier layer and the channel layer, which is conducive to depleting the two-dimensional electron gas (2DEG) below the second cap layer, so that the semiconductor device realizes an enhanced working mode. And due to the depletion effect of the second cap layer in the semiconductor device on the two-dimensional electron gas (2DEG) below the second cap layer, the semiconductor device needs to overcome a higher potential barrier when it is turned on, which is conducive to increasing the threshold voltage of the semiconductor device.
[0019] In summary, in the case where the semiconductor device includes a first cap layer and a second cap layer, by providing the gate layer in the semiconductor device on the side of the first cap layer away from the substrate, and the gate layer covers at least a portion of the surface of the first cap layer on the side away from the substrate, and the surface of the second cap layer on the side away from the substrate, the threshold voltage of the semiconductor device can be increased while improving the stability of the threshold voltage of the semiconductor device and the performance stability of the semiconductor device.
[0020] In some embodiments, a dimension of the gate layer along the first direction is smaller than or equal to a dimension of the first capping layer along the first direction.
[0021] In some embodiments, in an orthographic projection onto the substrate, along the first direction, the gate layer is located within a boundary range of the first capping layer and has a distance between the gate layer and a boundary of the first capping layer.
[0022] In some embodiments, a dimension of the second capping layer along a second direction is the same as a dimension of the first capping layer along the second direction, the second direction is perpendicular to the first direction, and the second direction is parallel to the substrate.
[0023] In some embodiments, the doping concentration of the first capping layer is less than or equal to 5×10 17 cm -3 .
[0024] In some embodiments, the doping concentration of the second capping layer is greater than or equal to 5×10 18 cm -3 , and less than or equal to 10×10 19 cm -3 .
[0025] In some embodiments, at least one of the source and the drain contacts a side surface of the first capping layer.
[0026] In some embodiments, at least one of the source and the drain and the first capping layer have a distance in the first direction.
[0027] In some embodiments, the first capping layer further covers a surface of the second capping layer that is away from the substrate.
[0028] In some embodiments, a portion of the second capping layer is embedded in the first capping layer, and the rest of the second capping layer is covered by the gate layer.
[0029] In another aspect, a method for preparing a semiconductor device is provided. The method for preparing a semiconductor device comprises the following steps: A barrier layer is formed on one side of the substrate.
[0030] A first cap layer and a second cap layer are formed on a side of the barrier layer away from the substrate. The second cap layer is at least partially embedded in the first cap layer, and the first cap layer covers at least part of the side surfaces of the second cap layer on two opposite sides along a first direction, and a side surface of the second cap layer close to the substrate, and the first direction is parallel to the substrate.
[0031] A source electrode and a drain electrode are formed. The source electrode and the drain electrode are located on opposite sides of the first cap layer along the first direction, and are both arranged on a side of the barrier layer away from the substrate.
[0032] The first capping layer and the second capping layer both include P-type doped semiconductor materials, and the doping concentration of the first capping layer is less than the doping concentration of the second capping layer.
[0033] In some embodiments, forming a first cap layer and a second cap layer on a side of the barrier layer away from the substrate comprises the following steps: A first initial capping layer is formed on a side of the barrier layer away from the substrate.
[0034] A partial area of the first initial capping layer is doped with a P-type material to form a second capping layer.
[0035] The first initial capping layer in the region where the source electrode is to be formed and the region where the drain electrode is to be formed is removed to form a first capping layer.
[0036] In some embodiments, forming a first cap layer and a second cap layer on a side of the barrier layer away from the substrate comprises the following steps: A first initial capping layer and a second initial capping layer are sequentially formed on a side of the barrier layer away from the substrate, wherein the doping concentration of the second initial capping layer is greater than the doping concentration of the first initial capping layer.
[0037] A partial area of the second initial capping layer is processed so that the partial area of the second initial capping layer forms a third capping layer, and the remaining area of the second initial capping layer forms the second capping layer, and the doping concentration of the third capping layer is less than the doping concentration of the second capping layer.
[0038] The first initial capping layer and the third capping layer in the source region to be formed and the drain region to be formed are removed, and the remaining first initial capping layer and the third capping layer form the first capping layer.
[0039] In some embodiments, the processing of a partial area of the second initial capping layer so that the partial area of the second initial capping layer forms a third capping layer comprises the following steps: A partial area of the second initial capping layer is hydrogenated to allow hydrogen atoms to react with P-type impurities in the second initial capping layer to form a complex, thereby reducing the doping concentration of the partial area of the second initial capping layer to form a third capping layer.
[0040] In another aspect, a chip is provided, wherein the chip includes the semiconductor device described in any one of the above embodiments.
[0041] In another aspect, an electronic device is provided, wherein the electronic device comprises a circuit board and the chip as described above, wherein the chip is electrically connected to the circuit board.
[0042] It can be understood that the beneficial effects that can be achieved by the semiconductor device manufacturing method, chip and electronic device provided by the above embodiments of the present disclosure can refer to the beneficial effects of the semiconductor device mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS
[0043] In order to more clearly illustrate the technical solutions in the present disclosure, the following briefly introduces the drawings required to be used in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can also be obtained based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams, and are not limitations on the actual size of the product involved in the embodiments of the present disclosure, the actual process of the method, the actual timing of the signal, etc.
[0044] Figure 1 is a schematic structural diagram of an electronic device according to some embodiments; Figure 2 A schematic cross-sectional view of a chip according to some embodiments Figure 1 ; Figure 3 A schematic cross-sectional view of a chip according to some embodiments Figure 2 ; Figure 4 A cross-sectional view of a semiconductor device according to some embodiments Figure 1 ; Figure 5 A cross-sectional view of a semiconductor device according to some embodiments Figure 2 ; Figure 6 A cross-sectional view of a semiconductor device according to some embodiments Figure 3 ; Figure 7 A cross-sectional view of a semiconductor device according to some embodiments Figure 4 ; Figure 8 FIG. 1 is a top view of a first capping layer and a second capping layer in a semiconductor device according to some embodiments. Figure 1 ; Fig. 9 FIG. 1 is a top view of a first capping layer and a second capping layer in a semiconductor device according to some embodiments. Figure 2 ; Fig.10 A cross-sectional view of a semiconductor device according to some embodiments Figure 5 ; Fig.11 A cross-sectional view of a semiconductor device according to some embodiments Figure 6 ; Fig.12 A cross-sectional view of a semiconductor device according to some embodiments Figure 7 ; Fig.13 A cross-sectional view of a semiconductor device according to some embodiments Figure 8 ; Fig.14 is a schematic top view of a first cap layer and a gate layer in a semiconductor device according to some embodiments; Fig.15 A cross-sectional view of a semiconductor device according to some embodiments Figure 9 ; Fig.16 A cross-sectional view of a semiconductor device according to some embodiments Figure 10 ; Fig.17 A process for preparing a semiconductor device according to some embodiments Figure 1 ; Fig.18 A process for preparing a semiconductor device according to some embodiments Figure 2 ; Fig.19 for Fig.17 and Fig.18 A schematic structural diagram of a semiconductor device corresponding to step S1 in the flowchart of the method for preparing a semiconductor device in FIG. 1 ; Fig. 20 for Fig.17 and Fig.18 A schematic structural diagram of a semiconductor device corresponding to step S2 in the flowchart of the method for preparing a semiconductor device in FIG. 1 ; Fig.21 for Fig.17 and Fig.18 A schematic structural diagram of a semiconductor device corresponding to step S3 in the flowchart of the method for preparing a semiconductor device in FIG. 1 ; Fig. 22 for Fig.17 A schematic structural diagram of a semiconductor device corresponding to step S21 in the flowchart of the method for preparing a semiconductor device in FIG. Fig.23 for Fig.17A schematic structural diagram of a semiconductor device corresponding to step S22 in the flowchart of the method for preparing a semiconductor device in FIG. 1 ; Fig.24 for Fig.17 A schematic structural diagram of a semiconductor device corresponding to step S23 in the flowchart of the method for preparing a semiconductor device in FIG. 1 ; Fig.25 for Fig.18 A schematic structural diagram of a semiconductor device corresponding to step S21 in the flowchart of the method for preparing a semiconductor device in FIG. Fig.26 for Fig.18 A schematic structural diagram of a semiconductor device corresponding to step S22 in the flowchart of the method for preparing a semiconductor device in FIG. 1 ; Fig. 27 for Fig.18 A schematic structural diagram of a semiconductor device corresponding to step S23 in the flowchart of the method for preparing a semiconductor device in FIG. 1 ; Fig.28 for Fig.17 and Fig.18 A schematic structural diagram of a semiconductor device corresponding to step S4 in the flowchart of the method for preparing a semiconductor device in FIG. Fig.29 for Fig.17 and Fig.18 A schematic structural diagram of a semiconductor device corresponding to step S5 in the flowchart of the method for preparing a semiconductor device in FIG.
[0045] Reference numerals: 1000-electronic device; 100-chip; 200-circuit board; 10-semiconductor device; 1-substrate; 2-buffer layer; 31-first insertion layer; 32-second insertion layer; 4-channel layer; 5-barrier layer; 61-first capping layer; 62-second capping layer; 63-third capping layer; 64-fourth capping layer; 611-first sublayer; 612-second sublayer; 61a-first initial capping layer; 62a-second initial capping layer; 7-passivation layer; G-gate layer; S-source; D-drain; Sa-source region to be formed; Da-drain region to be formed. DETAILED DESCRIPTION
[0046] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present disclosure.
[0047] In the description of the present disclosure, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present disclosure.
[0048] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as an open, inclusive meaning, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "exemplarily" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.
[0049] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.
[0050] When describing some embodiments, the expressions "coupled" and "connected" and their derivatives may be used. For example, when describing some embodiments, the term "connected" may be used to indicate that two or more components are in direct physical or electrical contact with each other. For another example, when describing some embodiments, the term "coupled" may be used to indicate that two or more components are in direct physical or electrical contact. However, the term "coupled" may also refer to two or more components that are not in direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents of this document.
[0051] “At least one of A, B, and C” has the same meaning as “at least one of A, B, or C” and both include the following combinations of A, B, and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B, and C.
[0052] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.
[0053] The use of "adapted to" or "configured to" herein is meant to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.
[0054] Additionally, the use of “based on” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values may, in practice, be based on additional conditions or values beyond those stated.
[0055] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of variation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).
[0056] In the context of the present disclosure, the meanings of “on,” “over,” and “over” should be interpreted in the broadest manner, so that “on” means not only “directly on something,” but also includes the meaning of “on something” with intervening features or layers therebetween, and “over” or “above” means not only “above” or “over” something, but also includes the meaning of “above” or “over” something without intervening features or layers therebetween (i.e., directly on something).
[0057] The words "exemplary" or "for example" are used herein to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a specific way.
[0058] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are conceivable. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but include shape deviations due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device, and are not intended to limit the scope of the exemplary embodiments.
[0059] For the convenience of the following description, an XYZ coordinate system is established. The third direction Z is the thickness direction of the substrate, the XY plane is perpendicular to the third direction Z, and the first direction X intersects the second direction Y. For example, the first direction X and the second direction Y are perpendicular to each other.
[0060] like Figure 1 As shown, an embodiment of the present application provides an electronic device 1000. The electronic device 1000 may include communication equipment (e.g., satellite communication equipment, wireless television receiver, etc.), radar equipment (e.g., millimeter wave radar, weather radar, etc.), radio navigation equipment (e.g., GPS receiver, etc.), etc. The embodiment of the present application does not impose any special restrictions on the specific form of the above electronic device 1000.
[0061] In some embodiments, please refer to Figure 1 , the electronic device 1000 includes a chip 100 and a circuit board 200. The chip 100 and the circuit board 200 are electrically connected.
[0062] Exemplarily, the circuit board 200 in the electronic device 1000 may include a printed circuit board (PCB) or the like.
[0063] For example, the circuit board 200 in the electronic device 1000 may include a plurality of conductive layers. The plurality of conductive layers in the circuit board 200 may be separated from each other by a dielectric layer.
[0064] The chip 100 is described in detail below.
[0065] In some embodiments, Figure 2 and Figure 3 As shown, Figure 2 and Figure 3 1 and 2 are schematic cross-sectional views of a chip 100 according to some embodiments. The chip 100 includes a semiconductor device 10 .
[0066] Exemplarily, the chip 100 may include a processor chip. For example, the processor chip may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.
[0067] The semiconductor device 10 is described in detail below.
[0068] In some embodiments, please refer to Figure 2 and Figure 3 , a semiconductor device 10 may include a substrate 1 .
[0069] By way of example, the material of the substrate 1 in the semiconductor device 10 may include one of silicon (Si), silicon carbide (SiC), sapphire, and the like.
[0070] In some embodiments, please refer to Figure 2 and Figure 3 The semiconductor device 10 may further include a buffer layer 2. The buffer layer 2 may be disposed on one side of the substrate 1.
[0071] By setting a buffer layer 2 in the semiconductor device 10, and the buffer layer 2 is set on one side of the substrate 1, other film layer structures set on the side of the buffer layer 2 in the semiconductor device 10 away from the substrate 1 can be bonded, and the substrate 1 can be protected to prevent the substrate 1 from being invaded by some metal ions.
[0072] For example, the material of the buffer layer 2 in the semiconductor device 10 may include a plurality of nitride Al x In y Ga (1-x-y) At least one of N, (0≤x, y≤1).
[0073] For example, the material of the buffer layer 2 in the semiconductor device 10 may include a plurality of nitride Al x In y Ga (1-x-y) N, one of (0≤x,y≤1).
[0074] For another example, the material of the buffer layer 2 in the semiconductor device 10 may include a plurality of nitride Al x In y Ga (1-x-y) Multiple (greater than or equal to two) of N, (0≤x, y≤1).
[0075] For example, the buffer layer 2 in the semiconductor device 10 can be formed by a process such as Metal-organic Chemical Vapor Deposition (MOCVD), Molecular Beam Epitaxy (MBE) or Physical Vapor Deposition (PVD).
[0076] Exemplarily, the buffer layer 2 in the semiconductor device 10 may be a single-layer structure, that is, along the third direction (ie, the thickness direction of the substrate 1 ) Z, the buffer layer 2 includes a film layer structure.
[0077] Alternatively, the buffer layer 2 in the semiconductor device 10 may be a multi-layer (greater than or equal to two layers) structure. That is, along the third direction (ie, the thickness direction of the substrate 1) Z, the buffer layer 2 includes a multi-layer (greater than or equal to two layers) film structure.
[0078] For example, please refer to Figure 3 The semiconductor device 10 may further include a first insertion layer 31. The first insertion layer 31 in the semiconductor device 10 may be disposed between the substrate 1 and a buffer layer 2 in the semiconductor device 10.
[0079] The material of the first insertion layer 31 in the semiconductor device 10 may include aluminum nitride (AIN) or the like.
[0080] By setting the first insertion layer 31 between the substrate 1 and the buffer layer 2 in the semiconductor device 10, on the one hand, when the lattice constant between the substrate 1 and the buffer layer 2 in the semiconductor device 10 does not match or the thermal expansion coefficient is different, the first insertion layer 31 can alleviate the stress caused by the lattice constant mismatch or the thermal expansion coefficient difference between the substrate 1 and the buffer layer 2 in the semiconductor device 10, avoid the stress caused by the lattice constant mismatch or the thermal expansion coefficient difference between the substrate 1 and the buffer layer 2 in the semiconductor device 10 from affecting the performance of the semiconductor device 10, which is beneficial to improving the performance of the semiconductor device 10.
[0081] On the other hand, the first insertion layer 31 in the semiconductor device 10 can improve the interface characteristics between the substrate 1 and the buffer layer 2 in the semiconductor device 10, reduce the interface defects between the substrate 1 and the buffer layer 2 in the semiconductor device 10, and help improve the stability and reliability of the semiconductor device 10.
[0082] On the other hand, the material of the substrate 1 in the semiconductor device 10 includes silicon (Si) and silicon carbide (SiC), and the material of the buffer layer 2 in the semiconductor device 10 includes a plurality of nitride Al x In y Ga (1-x-y) In the case of at least one of N, (0≤x, y≤1), the first insertion layer 31 arranged between the substrate 1 and the buffer layer 2 in the semiconductor device 10 can prevent the silicon (Si) element in the substrate 1 and the gallium (Ga) element in the buffer layer 2 from undergoing a back-etching or regrowth etch reaction at high temperature, thereby avoiding damage to the substrate 1 and the buffer layer 2 in the semiconductor device 10, which is beneficial to improving the yield of the semiconductor device 10 and further improving the stability and reliability of the semiconductor device 10.
[0083] In some embodiments, please refer to Figure 2 and Figure 3 The semiconductor device 10 may further include a channel layer 4 . The channel layer 4 may be disposed on one side of the substrate 1 in the semiconductor device 10 .
[0084] For example, please refer to Figure 2 and Figure 3 In the case where the semiconductor device 10 includes a buffer layer 2 , the channel layer 4 in the semiconductor device 10 may be disposed on a side of the buffer layer 2 away from the substrate 1 .
[0085] By way of example, the material of the channel layer 4 in the semiconductor device 10 may include gallium nitride (GaN).
[0086] Exemplarily, the channel layer 4 in the semiconductor device 10 can be formed by processes such as Metal-organic Chemical Vapor Deposition (MOCVD), Molecular Beam Epitaxy (MBE), or Physical Vapor Deposition (PVD).
[0087] In some embodiments, referring further to Figure 2 and Figure 3 , the semiconductor device 10 may further include a barrier layer 5. The barrier layer 5 is disposed on one side of the substrate 1 within the semiconductor device 10.
[0088] Exemplarily, the material of the barrier layer 5 in the semiconductor device 10 may include nitrides of various different components, such as Al x In y Ga (1-x-y) N, at least one of (0 < x ≤ 1, 0 ≤ y ≤ 1).
[0089] For example, the material of the barrier layer 5 in the semiconductor device 10 may include a nitride of various different components, such as Al x In y Ga (1-x-y) N, one of (0 < x ≤ 1, 0 ≤ y ≤ 1).
[0090] Again, for example, the material of the barrier layer 5 in the semiconductor device 10 may include nitrides of various different components, such as Al x In y Ga (1-x-y) N, multiple (greater than or equal to two) of (0 < x ≤ 1, 0 ≤ y ≤ 1).
[0091] Exemplarily, the barrier layer 5 in the semiconductor device 10 can be formed by processes such as Metal-organic Chemical Vapor Deposition (MOCVD), Molecular Beam Epitaxy (MBE), or Physical Vapor Deposition (PVD).
[0092] Exemplarily, the barrier layer 5 in the semiconductor device 10 can be a single-layer structure. That is, along the third direction (i.e., the thickness direction of the substrate 1) Z, the barrier layer 5 includes a single-layer film structure.
[0093] Alternatively, the barrier layer 5 in the semiconductor device 10 may be a multi-layer (greater than or equal to two layers) structure. That is, along the third direction (ie, the thickness direction of the substrate 1 ) Z, the barrier layer 5 includes a multi-layer (greater than or equal to two layers) film structure.
[0094] For example, please refer to Figure 2 and Figure 3 , the barrier layer 5 in the semiconductor device 10 can be arranged on a side of the channel layer 4 away from the substrate 1 . That is, the channel layer 4 is arranged between the barrier layer 5 and the substrate 1 .
[0095] When the barrier layer 5 in the semiconductor device 10 is arranged on the side of the channel layer 4 away from the substrate 1, and the band gap width (Band gap) of the material of the barrier layer 5 (for example, aluminum gallium nitride (AlGaN)) is greater than the band gap width (Band gap) of the material of the channel layer 4 (for example, gallium nitride (GaN)), due to the different electron affinities (Electron Affinity) and work functions (Work Function) of the material of the barrier layer 5 (for example, aluminum gallium nitride (AlGaN)) and the material of the channel layer 4 (for example, gallium nitride (GaN)), a heterojunction structure will be formed at the connection interface between the barrier layer 5 and the channel layer 4. This heterojunction structure will cause the band structure of the channel layer 4 to bend, thereby forming a potential well in the channel layer 4. In order to balance the charge distribution at the connection interface between the barrier layer 5 and the channel layer 4, the electrons in the barrier layer 5 will transfer to the potential well in the channel layer 4. The potential well in the channel layer 4 can restrict the electrons so that the electrons can only move freely in the direction parallel to the connection interface between the barrier layer 5 and the channel layer 4, thereby inducing the formation of a two-dimensional electron gas (2DEG) near the connection interface between the barrier layer 5 and the channel layer 4, which is beneficial to improving the electron mobility and enhancing the performance of the semiconductor device 10.
[0096] It should be noted that the above-mentioned band gap refers to the fact that the energy of electrons in solids cannot take continuous values, but forms some discontinuous energy bands, among which the energy difference between the conduction band and the valence band is the band gap. Specifically, for bound electrons to become free electrons or holes, they must obtain enough energy to jump from the valence band to the conduction band, and the minimum value of this energy is the band gap.
[0097] For example, please refer to Figure 2 and Figure 3In the case where a two-dimensional electron gas (2DEG) is formed in the semiconductor device 10 , the semiconductor device 10 may be used to form a high electron mobility transistor (HEMT).
[0098] For example, please refer to Figure 3 In the case where the barrier layer 5 in the semiconductor device 10 is disposed on a side of the channel layer 4 away from the substrate 1, the semiconductor device 10 may further include a second insertion layer 32. The second insertion layer 32 in the semiconductor device 10 may be disposed between the channel layer 4 and the barrier layer 5 in the semiconductor device 10.
[0099] The material of the second insertion layer 32 in the semiconductor device 10 may include aluminum nitride (AIN) or the like.
[0100] By setting a second insertion layer 32 between the channel layer 4 and the barrier layer 5 in the semiconductor device 10, on the one hand, the second insertion layer 32 in the semiconductor device 10 can enhance the polarization effect between the channel layer 4 and the barrier layer 5, which is beneficial to increase the concentration of two-dimensional electron gas (2DEG) near the connection interface between the barrier layer 5 and the channel layer 4.
[0101] On the other hand, the second insertion layer 32 in the semiconductor device 10 can enhance the confinement of the two-dimensional electron gas (2DEG) near the connection interface between the barrier layer 5 and the channel layer 4, so that the two-dimensional electron gas (2DEG) near the connection interface between the barrier layer 5 and the channel layer 4 is further confined within a certain dimension (for example, a two-dimensional plane), which is beneficial to improving the electron mobility in the semiconductor device 10, and further beneficial to improving the performance of the semiconductor device 10.
[0102] In some embodiments, please refer to Figure 2 and Figure 3 The semiconductor device 10 may further include a gate layer G. The gate layer G may be disposed on a side of the barrier layer 5 in the semiconductor device 10 away from the substrate 1 .
[0103] The gate layer G in the semiconductor device 10 is a key electrode for controlling the conductivity of the semiconductor device 10 . The gate layer G does not directly participate in the conduction of current, but controls the carrier concentration in the channel layer 4 in the semiconductor device 10 through the electric field effect, thereby controlling the current in the semiconductor device 10 .
[0104] By way of example, the material of the gate layer G in the semiconductor device 10 may include at least one of conductive materials such as nickel (Ni), gold (Au), titanium (Ti), and titanium nitride (TiN).
[0105] For example, the material of the gate layer G in the semiconductor device 10 may include one of conductive materials such as nickel (Ni), gold (Au), titanium (Ti), and titanium nitride (TiN).
[0106] For another example, the material of the gate layer G in the semiconductor device 10 may include multiple (greater than or equal to two) conductive materials such as nickel (Ni), gold (Au), titanium (Ti), and titanium nitride (TiN).
[0107] In some embodiments, please refer to Figure 2 and Figure 3 The semiconductor device 10 may further include a source S and a drain D. The source S and the drain D are located on opposite sides of the gate layer G in the semiconductor device 10 along the first direction X, and are both arranged on a side of the barrier layer 5 in the semiconductor device 10 away from the substrate 1. The first direction X is parallel to the substrate 1 in the semiconductor device 10.
[0108] For example, please refer to Figure 2 and Figure 3 In the case where a two-dimensional electron gas (2DEG) is formed in the semiconductor device 10, the source S and the drain D in the semiconductor device 10 can form an ohmic contact with the two-dimensional electron gas (2DEG), which can reduce the contact resistance between the source S in the semiconductor device 10 and the two-dimensional electron gas (2DEG), and the contact resistance between the drain D in the semiconductor device 10 and the two-dimensional electron gas (2DEG), and can form a low-impedance current channel between the source S, the drain D and the two-dimensional electron gas (2DEG) in the semiconductor device 10, so that the current can flow smoothly, which is beneficial to improving the performance of the semiconductor device 10.
[0109] In some embodiments, please refer to Figure 2 and Figure 3 The semiconductor device 10 may further include a passivation layer 7 . The passivation layer 7 may cover the gate layer G, the source electrode S, and the drain electrode D in the semiconductor device 10 .
[0110] By setting a passivation layer 7 in the semiconductor device 10, and the passivation layer 7 covers the gate layer G, the source S and the drain D in the semiconductor device 10, on the one hand, the passivation layer 7 can block harmful substances in the external environment (for example, oxygen, water, etc.), and avoid direct contact between harmful substances in the external environment (for example, oxygen, water, etc.) and the source S, drain D, and gate layer G in the semiconductor device 10, thereby preventing the source S, drain D, and gate layer G in the semiconductor device 10 from being damaged, which is beneficial to improving the stability of the semiconductor device 10 and extending the service life of the semiconductor device 10.
[0111] On the other hand, the passivation layer 7 has a certain mechanical strength, which can protect the source S, drain D and gate layer G in the semiconductor device 10 to a certain extent, and prevent the source S, drain D and gate layer G in the semiconductor device 10 from being mechanically damaged, which is beneficial to further improve the stability of the semiconductor device 10 and further extend the service life of the semiconductor device 10.
[0112] Exemplarily, the material of the passivation layer 7 in the semiconductor device 10 may include at least one of silicon nitride (Si 3 N 4 ), silicon oxide (SiO 2 ), aluminum nitride (AlN), aluminum oxide (Al 2 O 3 ), and the like.
[0113] For example, the material of the passivation layer 7 in the semiconductor device 10 may include one of silicon nitride (Si 3 N 4 ), silicon oxide (SiO 2 ), aluminum nitride (AlN), aluminum oxide (Al 2 O 3 ), and the like.
[0114] For another example, the material of the passivation layer 7 in the semiconductor device 10 may include multiple (greater than or equal to two) of silicon nitride (Si3N4), silicon oxide (SiO2), aluminum nitride (AlN), and aluminum oxide (Al2O3).
[0115] Exemplarily, the passivation layer 7 in the semiconductor device 10 may be a single-layer structure, that is, along the third direction (ie, the thickness direction of the substrate 1 ) Z, the passivation layer 7 includes a film layer structure.
[0116] Alternatively, the passivation layer 7 in the semiconductor device 10 may be a multi-layer (greater than or equal to two layers) structure. That is, along the third direction Z (ie, the thickness direction of the substrate 1 ), the passivation layer 7 includes a multi-layer (greater than or equal to two layers) film structure.
[0117] For example, the passivation layer 7 in the semiconductor device 10 may be a two-layer structure. Along the third direction (ie, the thickness direction of the substrate 1 ) Z, the passivation layer 7 may include a silicon nitride (Si 3 N 4 ) layer and an aluminum nitride (AlN) layer.
[0118] For example, the passivation layer 7 in the semiconductor device 10 may be formed by at least one of a chemical vapor deposition process (CVD) and a physical vapor deposition process (PVD).
[0119] For example, the passivation layer 7 in the semiconductor device 10 may be formed by a process selected from the group consisting of a chemical vapor deposition process (CVD) and a physical vapor deposition process (PVD).
[0120] For another example, the passivation layer 7 in the semiconductor device 10 may be formed by multiple (greater than or equal to two) processes including a chemical vapor deposition process (Chemical Vapor Deposition, CVD) and a physical vapor deposition process (Physical Vapor Deposition, PVD).
[0121] In some embodiments, please refer to Figure 2 and Figure 3 The semiconductor device 10 may further include a fourth capping layer 64. The fourth capping layer 64 may be disposed on a side of the barrier layer 5 in the semiconductor device 10 away from the substrate 1. The fourth capping layer 64 includes a P-type doped semiconductor material, and the doping concentration of the fourth capping layer 64 (i.e., the concentration of the P-type impurities in the fourth capping layer 64) is greater than or equal to 5×10 18 cm -3 , and less than or equal to 1×10 20 cm -3 .
[0122] The semiconductor device 10 includes a fourth cap layer 64, which is disposed on a side of the barrier layer 5 in the semiconductor device 10 away from the substrate 1, and the fourth cap layer 64 includes a P-type doped semiconductor material, and the doping concentration of the fourth cap layer 64 (i.e., the concentration of the P-type impurities in the fourth cap layer 64) is greater than or equal to 5×10 18 cm -3 , and less than or equal to 1×10 20 cm -3On the one hand, an energy band difference (for example, a conduction band difference) can be created between the fourth cap layer 64 and the barrier layer 5, and the energy band difference (for example, a conduction band difference) between the fourth cap layer 64 and the barrier layer 5 can be used to regulate the two-dimensional electron gas (2DEG) near the connection interface between the barrier layer 5 and the channel layer 4, which is beneficial to depleting the two-dimensional electron gas (2DEG) under the fourth cap layer 64, thereby enabling the semiconductor device 10 to achieve an enhanced operating mode.
[0123] On the other hand, due to the depletion effect of the fourth cap layer 64 in the semiconductor device 10 on the two-dimensional electron gas (2DEG) located below the fourth cap layer 64, the semiconductor device 10 needs to overcome a higher potential barrier when turned on, which is beneficial to improving the threshold voltage of the semiconductor device 10.
[0124] For example, the material of the fourth capping layer 64 in the semiconductor device 10 may include p-type gallium nitride (p-GaN), which may be formed by doping gallium nitride (GaN) material with elements such as iron (Fe) and magnesium (Mg).
[0125] Please continue reading Figure 2 and Figure 3 During the process of forming the fourth capping layer 64 in the semiconductor device 10 , P-type impurities (eg, magnesium (Mg)) are generally doped into the semiconductor material (eg, gallium nitride (GaN)) as impurities to provide hole carriers, thereby adjusting the conductivity of the fourth capping layer 64 .
[0126] Ideally, the P-type impurities (e.g., magnesium (Mg)) in the fourth capping layer 64 should be evenly distributed in the semiconductor material (e.g., gallium nitride (GaN)) in the fourth capping layer 64. However, in the actual preparation process, due to the influence of various factors (e.g., temperature, electric field, etc.), the P-type impurities (e.g., magnesium (Mg)) in the fourth capping layer 64 may diffuse and may diffuse into the barrier layer 5 in the semiconductor device 10.
[0127] When P-type impurities (for example, magnesium (Mg)) in the fourth cap layer 64 diffuse into the barrier layer 5 in the semiconductor device 10, on the one hand, it is easy to cause changes in the characteristics of the connection interface between the fourth cap layer 64 and the barrier layer 5 (for example, the density of trap states at the connection interface between the fourth cap layer 64 and the barrier layer 5 increases, etc.), and affect the control ability of the gate layer G in the semiconductor device 10, thereby causing problems such as dynamic on-resistance degradation in the semiconductor device 10, thereby reducing the reliability of the semiconductor device 10.
[0128] On the other hand, when the P-type impurities (for example, magnesium (Mg)) in the fourth capping layer 64 diffuse into the barrier layer 5, additional charges and electric fields will be introduced into the barrier layer 5, which may easily interfere with the polarization effect of the barrier layer 5, and further easily affect the two-dimensional electron gas (2DEG) in the semiconductor device 10, and easily cause the performance of the semiconductor device 10 to be reduced.
[0129] Based on this, in some embodiments, such as Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, Figure 4 , Figure 5 , Figure 6 and Figure 7 All are cross-sectional schematic diagrams of semiconductor devices 10 according to some embodiments. The semiconductor device 10 may further include a first cap layer 61 and a second cap layer 62. The first cap layer 61 is disposed on a side of the barrier layer 5 in the semiconductor device 10 away from the substrate 1. The second cap layer 62 is at least partially embedded in the first cap layer 61, and the first cap layer 61 covers at least part of the side surfaces of the second cap layer 62 on the opposite sides along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), and a side surface of the second cap layer 62 close to the substrate 1. In other words, the first cap layer 61 in the semiconductor device 10 is closer to the barrier layer 5 than the second cap layer 62.
[0130] The first capping layer 61 and the second capping layer 62 in the semiconductor device 10 both include P-type doped semiconductor materials, and the doping concentration of the first capping layer 61 is lower than the doping concentration of the second capping layer 62 .
[0131] The semiconductor device 10 includes a first cap layer 61 and a second cap layer 62, the first cap layer 61 is arranged on a side of the barrier layer 5 in the semiconductor device 10 away from the substrate 1, the second cap layer 62 is at least partially embedded in the first cap layer 61, the first cap layer 61 covers at least part of the side surfaces of the second cap layer 62 on the opposite sides along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), and a side surface of the second cap layer 62 close to the substrate 1, and the first cap layer 61 and the second cap layer 62 both include P-type doped semiconductor materials, the doping concentration of the first cap layer 61 is less than the doping concentration of the second cap layer 62, on the one hand, because the second cap layer 62 is at least partially embedded in the first cap layer 61, and the first cap layer 61 covers the second cap layer 62 At least part of the side surfaces on the two opposite sides along the first direction X, and the surface of one side of the second cap layer 62 close to the substrate 1, that is, part of the first cap layer 61 is located between the second cap layer 62 and the barrier layer 5. In the process of forming the second cap layer 62 in the semiconductor device 10, when the P-type impurities in the second cap layer 62 diffuse, the P-type impurities in the second cap layer 62 will diffuse into the first cap layer 61 first, which can avoid or alleviate the diffusion of the P-type impurities in the second cap layer 62 into the barrier layer 5, and can reduce the probability of the P-type impurities introducing additional charges and electric fields into the barrier layer 5 and interfering with the polarization effect of the barrier layer 5, which is beneficial to improving the polarization effect of the barrier layer 5, and further beneficial to enhancing the two-dimensional electron gas (Two-dimensional electron gas) in the semiconductor device 10. The invention can improve the performance of the semiconductor device 10 and reduce the probability of changes in the characteristics of the connection interface between the first cap layer 61 and the barrier layer 5 (for example, an increase in the density of trap states at the connection interface between the first cap layer 61 and the barrier layer 5, etc.), and affect the control ability of the gate layer G in the semiconductor device 10, which is beneficial to reduce the probability of problems such as dynamic on-resistance degradation in the semiconductor device 10, thereby improving the reliability of the semiconductor device 10.
[0132] On the other hand, since the doping concentration of the first cap layer 61 (i.e., the concentration of the P-type impurities in the first cap layer 61) is less than the doping concentration of the second cap layer 62 (i.e., the concentration of the P-type impurities in the second cap layer 62), that is, the doping concentration of the first cap layer 61 is relatively small, in the process of forming the first cap layer 61 in the semiconductor device 10, the P-type impurities in the first cap layer 61 may not diffuse or may diffuse only a small amount into the barrier layer 5, which can further reduce the probability of the P-type impurities introducing additional charges and electric fields into the barrier layer 5 and interfering with the polarization effect of the barrier layer 5, which is beneficial to further improve the polarization effect of the barrier layer 5, and further enhance the two-dimensional electron gas (Two-dimensional electron gas) in the semiconductor device 10. Electron gas, 2DEG), and is beneficial to further improve the performance of the semiconductor device 10, and can also further reduce the probability of changes in the characteristics of the connection interface between the first cap layer 61 and the barrier layer 5 (for example, the density of trap states at the connection interface between the first cap layer 61 and the barrier layer 5 increases, etc.), and affecting the control ability of the gate layer G in the semiconductor device 10, which is beneficial to further reduce the probability of problems such as dynamic on-resistance degradation in the semiconductor device 10, and further help to further improve the reliability of the semiconductor device 10.
[0133] On the other hand, since the doping concentration of the first capping layer 61 (i.e., the concentration of P-type impurities in the first capping layer 61) is less than the doping concentration of the second capping layer 62 (i.e., the concentration of P-type impurities in the second capping layer 62), that is, the doping concentration of the second capping layer 62 is relatively large, there is an energy band difference (e.g., conduction band difference) between the second capping layer 62 and the barrier layer 5. The energy band difference (e.g., conduction band difference) between the second capping layer 62 and the barrier layer 5 can be used to regulate the two-dimensional electron gas (2DEG) near the connection interface between the barrier layer 5 and the channel layer 4, which is beneficial to depleting the two-dimensional electron gas (2DEG) below the second capping layer 62, thereby enabling the semiconductor device 10 to achieve an enhanced operating mode.
[0134] Furthermore, due to the depletion effect of the second cap layer 62 in the semiconductor device 10 on the two-dimensional electron gas (2DEG) below the second cap layer 62 , the semiconductor device 10 needs to overcome a higher potential barrier when turned on, which is beneficial to increasing the threshold voltage of the semiconductor device 10 .
[0135] For example, the material of the first cap layer 61 and the material of the second cap layer 62 in the semiconductor device 10 may both include p-type gallium nitride (p-GaN). P-type gallium nitride (p-GaN) may be formed by doping gallium nitride (GaN) material with elements such as iron (Fe) and magnesium (Mg).
[0136] For example, when doping elements such as iron (Fe) and magnesium (Mg) into gallium nitride (GaN) materials to form p-type gallium nitride (p-GaN), a gas-phase doping process or an ion implantation process may be used.
[0137] For example, the doping concentration of the first capping layer 61 in the semiconductor device 10 may be less than or equal to 5×10 17 cm -3 That is, the concentration of the P-type impurities (eg, magnesium (Mg)) in the first capping layer 61 may be less than or equal to 5×10 17 cm -3 .
[0138] For example, the doping concentration of the first capping layer 61 in the semiconductor device 10 may be 3×10 17 cm -3 , 4×10 17 cm -3 or 5×10 17 cm -3 wait.
[0139] For example, the doping concentration of the second capping layer 62 in the semiconductor device 10 may be greater than or equal to 5×10 18 cm -3 , and less than or equal to 10×10 19 cm -3 That is, the concentration of the P-type impurities (eg, magnesium (Mg)) in the second capping layer 62 may be greater than or equal to 5×10 18 cm -3 , and less than or equal to 10×10 19 cm -3 .
[0140] For example, the doping concentration of the second capping layer 62 in the semiconductor device 10 may be 5×10 18 cm -3 , 6×10 18 cm -3 ,7×10 18 cm -3 , 8×10 18 cm -3 ,9×10 18 cm-3 , 10×10 18 cm -3 , 3×10 19 cm -3 , 5×10 19 cm -3 , 8×10 19 cm -3 or 10×10 19 cm -3 wait.
[0141] For example, please refer to Figure 4 , Figure 5 , Figure 6 and Figure 7 , the semiconductor device 10 includes at least one second capping layer 62 .
[0142] For example, see Figure 4 and Figure 5 , the semiconductor device 10 may include a second capping layer 62 .
[0143] For another example, please continue to see Figure 6 and Figure 7 The semiconductor device 10 may include a plurality of second capping layers 62. When the semiconductor device 10 includes a plurality of second capping layers 62, the plurality of second capping layers 62 may be spaced apart along the first direction X (ie, the arrangement direction of the source S and the drain D in the semiconductor device 10).
[0144] It should be noted that Figure 6 and Figure 7 In the illustrated embodiment, only the semiconductor device 10 including two second capping layers 62 is used as an example for illustration. However, when the semiconductor device 10 includes multiple second capping layers 62, the number of second capping layers 62 in the semiconductor device 10 is not limited to this. The number of second capping layers 62 in the semiconductor device 10 can be set based on actual needs. For example, the number of second capping layers 62 in the semiconductor device 10 can be 3, 4, 5, 6, 7 or 8, etc.
[0145] In the following, some embodiments of the present disclosure are schematically described by taking the semiconductor device 10 including a second cap layer 62 as an example.
[0146] For example, please refer to Figure 4 , Figure 5 , Figure 6 and Figure 7, a dimension h2 of the second capping layer 62 in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10 ) is smaller than a dimension h1 of the first capping layer 61 in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10 ).
[0147] Understandably, please continue to refer to Figure 4 , Figure 5 , Figure 6 and Figure 7 In the case where a dimension h2 of the second capping layer 62 in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) is smaller than a dimension h1 of the first capping layer 61 in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), two side surfaces of the second capping layer 62 that are oppositely arranged along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) are at least partially covered by the first capping layer 61.
[0148] It should be noted that Figure 4 , Figure 5 , Figure 6 and Figure 7 Only the example that two side surfaces of the second capping layer 62 in the semiconductor device 10 that are oppositely arranged along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) are completely covered by the first capping layer 61 is used for illustration, but the positional relationship between the two side surfaces of the second capping layer 62 in the semiconductor device 10 that are oppositely arranged along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) and the first capping layer 61 in the present disclosure is not limited thereto. For example, two side surfaces of the second capping layer 62 in the semiconductor device 10 that are oppositely arranged along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) may be partially covered by the first capping layer 61.
[0149] For example, Figure 8 and Fig. 9 As shown, Figure 8 and Fig. 9 1 and 1 are schematic top views of the first capping layer 61 and the second capping layer 62 in the semiconductor device 10 according to some embodiments. It should be noted that: Figure 8 and Fig. 9 The difference is that Figure 8 In the illustrated embodiment, the semiconductor device 10 includes a second capping layer 62. Fig. 9 In the illustrated embodiment, the semiconductor device 10 includes a plurality of (eg, two) second capping layers 62 .
[0150] A dimension d2 of the second capping layer 62 in the semiconductor device 10 along the second direction Y is the same as a dimension d1 of the first capping layer 61 in the semiconductor device 10 along the second direction Y. The second direction Y is perpendicular to the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), and the second direction Y is parallel to the substrate 1 in the semiconductor device 10.
[0151] Understandably, please continue to refer to Figure 8 and Fig. 9 When the dimension d2 of the second capping layer 62 along the second direction Y in the semiconductor device 10 is the same as the dimension d1 of the first capping layer 61 along the second direction Y in the semiconductor device 10 , the first capping layer 61 does not cover the two side surfaces of the second capping layer 62 that are oppositely arranged along the second direction Y.
[0152] It should be noted that the above “the dimension d2 of the second capping layer 62 in the semiconductor device 10 along the second direction Y is the same as the dimension d1 of the first capping layer 61 in the semiconductor device 10 along the second direction Y” means that the difference between the dimension d2 of the second capping layer 62 in the semiconductor device 10 along the second direction Y and the dimension d1 of the first capping layer 61 in the semiconductor device 10 along the second direction Y is within a preset threshold range. The threshold range is a relatively small numerical range. For example, the threshold range can be a process accuracy range when forming the first capping layer 61 and the second capping layer 62 with the same dimension along the second direction Y.
[0153] When the dimension d2 of the second capping layer 62 in the semiconductor device 10 along the second direction Y is the same as the dimension d1 of the first capping layer 61 in the semiconductor device 10 along the second direction Y, the threshold range of the difference between the dimension d2 of the second capping layer 62 in the semiconductor device 10 along the second direction Y and the dimension d1 of the first capping layer 61 in the semiconductor device 10 along the second direction Y can be 0~0.1μm.
[0154] For example, when the dimension d2 of the second capping layer 62 in the semiconductor device 10 along the second direction Y is the same as the dimension d1 of the first capping layer 61 in the semiconductor device 10 along the second direction Y, the difference between the dimension d2 of the second capping layer 62 in the semiconductor device 10 along the second direction Y and the dimension d1 of the first capping layer 61 in the semiconductor device 10 along the second direction Y can be 0, 0.01μm, 0.03μm, 0.05μm, 0.06μm, 0.08μm or 0.1μm, etc.
[0155] For example, please refer to Figure 4 , Figure 5 , Figure 6 and Figure 7When the semiconductor device 10 includes a first capping layer 61 and a second capping layer 62 , the source S and the drain D in the semiconductor device 10 can be located on opposite sides of the first capping layer 61 along the first direction X, and both are arranged on the side of the barrier layer 5 away from the substrate 1 .
[0156] For example, please refer to Figure 4 and Figure 6 In the case where the source S and the drain D in the semiconductor device 10 are located on opposite sides of the first cap layer 61 along the first direction X, at least one of the source S and the drain D in the semiconductor device 10 and the first cap layer 61 may have a spacing in the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10).
[0157] For example, when the source S and the drain D in the semiconductor device 10 are located on opposite sides of the first cap layer 61 along the first direction X, one of the source S and the drain D in the semiconductor device 10 and the first cap layer 61 may have a spacing in the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10).
[0158] For another example, please continue to see Figure 4 and Figure 6 , the source S in the semiconductor device 10 and the first cap layer 61 may have a spacing ds in the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10). The drain D in the semiconductor device 10 and the first cap layer 61 may have a spacing dd in the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10).
[0159] Alternatively, continue to Figure 5 and Figure 7 When the source S and the drain D in the semiconductor device 10 are located on opposite sides of the first cap layer 61 along the first direction X, at least one of the source S and the drain D in the semiconductor device 10 may contact the side surface of the first cap layer 61 .
[0160] For example, when the source S and the drain D in the semiconductor device 10 are located at opposite sides of the first capping layer 61 along the first direction X, one of the source S and the drain D in the semiconductor device 10 may contact the side surface of the first capping layer 61 .
[0161] For another example, please continue to see Figure 5 and Figure 7 When the source S and the drain D in the semiconductor device 10 are located on opposite sides of the first cap layer 61 along the first direction X, the source S and the drain D in the semiconductor device 10 can contact the side surfaces of the first cap layer 61 .
[0162] When at least one of the source S and the drain D in the semiconductor device 10 is in contact with the side of the first cap layer 61, when forming the first cap layer 61 in the semiconductor device 10, a partial area of the first cap layer 61 close to at least one of the source S and the drain D in the semiconductor device 10 does not need to be removed, which is beneficial to reduce the difficulty of preparing the first cap layer 61, and further helps to reduce the difficulty of preparing the semiconductor device 10.
[0163] In the following, some embodiments of the present disclosure are schematically described by taking the example that the source S in the semiconductor device 10 and the first cap layer 61 have a spacing ds in the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), and the drain D in the semiconductor device 10 and the first cap layer 61 have a spacing dd in the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) as an example.
[0164] In some embodiments, Fig.10 As shown, Fig.10 1 is a cross-sectional view of a semiconductor device 10 according to some embodiments. In the first capping layer 61 in the semiconductor device 10 , the doping concentration (ie, the concentration of the P-type impurities in the first capping layer 61 ) gradually decreases along a direction M away from the second capping layer 62 .
[0165] That is to say, in the first capping layer 61 within the semiconductor device 10, the closer the area is to the second capping layer 62, the higher the doping concentration (i.e., the concentration of P-type impurities in the first capping layer 61), and the farther the area is from the second capping layer 62, the lower the doping concentration (i.e., the concentration of P-type impurities in the first capping layer 61).
[0166] It should be noted that Fig.10In the illustrated embodiment, only the setting manner of the doping concentration of the first capping layer 61 in the semiconductor device 10 (i.e., the concentration of the P-type impurities in the first capping layer 61) is taken as an example when the semiconductor device 10 includes a second capping layer 62, and the source S and the drain D in the semiconductor device 10 are spaced from the first capping layer 61 in the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), and the setting manner of the doping concentration of the first capping layer 61 (i.e., the concentration of the P-type impurities in the first capping layer 61) is schematically described, but the embodiments of the present disclosure are not limited thereto. For example, in the case where the semiconductor device 10 includes a plurality of second capping layers 62, the doping concentration of the first capping layer 61 in the semiconductor device 10 (i.e., the concentration of the P-type impurities in the first capping layer 61) can also be set as described above. For another example, when at least one of the source S and the drain D in the semiconductor device 10 is in contact with the side of the first cap layer 61, the doping concentration of the first cap layer 61 in the semiconductor device 10 (i.e., the concentration of P-type impurities in the first cap layer 61) can also be set as above.
[0167] In some embodiments, Fig.11 As shown, Fig.11 is a cross-sectional schematic diagram of a semiconductor device 10 according to some embodiments. The first cap layer 61 in the semiconductor device 10 may include a first sublayer 611 and a second sublayer 612 stacked in a third direction Z (i.e., along the thickness direction of the substrate 1), and the first sublayer 611 is closer to the barrier layer 5 than the second sublayer 612. At least part of the second cap layer 62 is disposed in the second sublayer 612 and penetrates the second sublayer 612 along the third direction Z (i.e., along the thickness direction of the substrate 1). Among them, the doping concentration of the first sublayer 611 in the first cap layer 61 (i.e., the concentration of P-type impurities in the first sublayer 611) and the doping concentration of the second sublayer 612 (i.e., the concentration of P-type impurities in the second sublayer 612) are both less than the doping concentration of the second cap layer 62 (i.e., the concentration of P-type impurities in the second cap layer 62).
[0168] For example, please refer to Fig.11 , the first sublayer 611 in the first capping layer 61 may include a P-type doped semiconductor material, and the second sublayer 612 in the first capping layer 61 may include a complex and a P-type doped semiconductor material.
[0169] For example, see Fig.11 In the case where the second capping layer 62 in the semiconductor device 10 is doped with magnesium, the complex in the second sub-layer 612 of the first capping layer 61 may include a magnesium hydride (Mg—H) complex.
[0170] For example, please refer to Fig.11, the doping concentration of the first sublayer 611 in the first capping layer 61 (ie, the concentration of the P-type impurities in the first sublayer 611 ) and the doping concentration of the second sublayer 612 (ie, the concentration of the P-type impurities in the second sublayer 612 ) may be different.
[0171] For example, the doping concentration of the first sublayer 611 in the first capping layer 61 (ie, the concentration of P-type impurities in the first sublayer 611 ) may be greater than the doping concentration of the second sublayer 612 (ie, the concentration of P-type impurities in the second sublayer 612 ).
[0172] For another example, the doping concentration of the first sublayer 611 in the first capping layer 61 (ie, the concentration of P-type impurities in the first sublayer 611 ) may be less than the doping concentration of the second sublayer 612 (ie, the concentration of P-type impurities in the second sublayer 612 ).
[0173] Alternatively, continue to Fig.11 , the doping concentration of the first sublayer 611 in the first capping layer 61 (ie, the concentration of the P-type impurities in the first sublayer 611 ) and the doping concentration of the second sublayer 612 (ie, the concentration of the P-type impurities in the second sublayer 612 ) may be the same.
[0174] It should be noted that Fig.11 In the illustrated embodiment, only the arrangement of the structure of the first cap layer 61 in the semiconductor device 10 is taken as an example, when the semiconductor device 10 includes a second cap layer 62, and the source S and the drain D in the semiconductor device 10 are spaced from the first cap layer 61 in the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), to schematically illustrate the structure of the first cap layer 61, but the embodiments of the present disclosure are not limited thereto. For example, when the semiconductor device 10 includes a plurality of second cap layers 62, the structure of the first cap layer 61 in the semiconductor device 10 may also be arranged as described above. For another example, when at least one of the source S and the drain D in the semiconductor device 10 is in contact with the side of the first cap layer 61, the structure of the first cap layer 61 in the semiconductor device 10 may also be arranged as described above.
[0175] In some embodiments, please refer to Figure 4 , Figure 5 , Figure 6 , Figure 7 , Fig.10 and Fig.11 , and combined with Fig.12 and Fig.13 , Fig.12 and Fig.13All of them are cross-sectional schematic diagrams of semiconductor devices 10 according to some embodiments. In the case where the semiconductor device 10 includes a first cap layer 61 and a second cap layer 62, the gate layer G in the semiconductor device 10 can be disposed on a side of the first cap layer 61 away from the substrate 1, and the gate layer G covers at least a portion of the surface of the first cap layer 61 away from the substrate 1, and a surface of the second cap layer 62 away from the substrate 1.
[0176] In the case where the semiconductor device 10 includes a first cap layer 61 and a second cap layer 62, by making the gate layer G in the semiconductor device 10 be arranged on the side of the first cap layer 61 away from the substrate 1, and the gate layer G covers at least a portion of the surface of the side of the first cap layer 61 away from the substrate 1, and the surface of the side of the second cap layer 62 away from the substrate 1, that is, the second cap layer 62 is not arranged between a partial area in the gate layer G and the first cap layer 61, when the semiconductor device 10 is turned on (that is, the gate layer G in the semiconductor device 10 is under a forward voltage bias), part of the two-dimensional electron gas (2DEG) in the semiconductor device 10 can pass through the first cap layer 61 and be collected by a partial area in the gate layer G and between the first cap layer 61 where the second cap layer 62 is not arranged, without passing through the second cap layer 62.
[0177] On the one hand, since the doping concentration of the first capping layer 61 (i.e., the concentration of P-type impurities in the first capping layer 61) is less than the doping concentration of the second capping layer 62 (i.e., the concentration of P-type impurities in the second capping layer 62), that is, the doping concentration of the first capping layer 61 is relatively small, there are fewer electron traps in the first capping layer 61, which is beneficial to reducing the probability of electrons in the two-dimensional electron gas (2DEG) being captured by electron traps during transmission, and further beneficial to maintaining the concentration of the two-dimensional electron gas (2DEG) near the connection interface between the barrier layer 5 and the channel layer 4, so that the concentration of the two-dimensional electron gas (2DEG) is more stable, thereby avoiding or reducing the probability of a positive drift of the threshold voltage due to the capture of electrons by electron traps during transmission, which is beneficial to improving the stability of the threshold voltage of the semiconductor device 10.
[0178] On the other hand, since the doping concentration of the first capping layer 61 (i.e., the concentration of P-type impurities in the first capping layer 61) is relatively small, there is an approximately uniformly distributed electric field in the first capping layer 61, which is beneficial for electrons to accelerate in the first capping layer 61 and smoothly transition to the interface between the first capping layer 61 and the gate layer G, which can reduce the scattering and energy loss of electrons during the transmission process, and is beneficial to improving the performance stability of the semiconductor device 10.
[0179] On the other hand, since the doping concentration of the first capping layer 61 (i.e., the concentration of P-type impurities in the first capping layer 61) is less than the doping concentration of the second capping layer 62 (i.e., the concentration of P-type impurities in the second capping layer 62), that is, the doping concentration of the second capping layer 62 is relatively large, there is an energy band difference (e.g., conduction band difference) between the second capping layer 62 and the barrier layer 5. The energy band difference (e.g., conduction band difference) between the second capping layer 62 and the barrier layer 5 can be used to regulate the two-dimensional electron gas (2DEG) near the connection interface between the barrier layer 5 and the channel layer 4, which is beneficial to depleting the two-dimensional electron gas (2DEG) below the second capping layer 62, thereby enabling the semiconductor device 10 to achieve an enhanced operating mode.
[0180] Furthermore, due to the depletion effect of the second cap layer 62 in the semiconductor device 10 on the two-dimensional electron gas (2DEG) below the second cap layer 62 , the semiconductor device 10 needs to overcome a higher potential barrier when turned on, which is beneficial to increasing the threshold voltage of the semiconductor device 10 .
[0181] In summary, when the semiconductor device 10 includes a first cap layer 61 and a second cap layer 62, by setting the gate layer G in the semiconductor device 10 on the side of the first cap layer 61 away from the substrate 1, and the gate layer G covers at least a portion of the surface of the first cap layer 61 away from the substrate 1, and the surface of the second cap layer 62 away from the substrate 1, the threshold voltage of the semiconductor device 10 can be increased while improving the stability of the threshold voltage of the semiconductor device 10 and the performance stability of the semiconductor device 10.
[0182] For example, please refer to Figure 4 , Figure 5 , Figure 6 , Figure 7 , Fig.12 and Fig.13, a dimension hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10 ) is less than or equal to a dimension h1 of the first cap layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10 ).
[0183] For example, see Figure 4 and Figure 6 In the case where at least one of the source S and the drain D in the semiconductor device 10 and the first cap layer 61 has a spacing in the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), the size hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) may be smaller than the size h1 of the first cap layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10).
[0184] For another example, please continue to see Figure 5 and Figure 7 When at least one of the source S and the drain D in the semiconductor device 10 contacts the side of the first cap layer 61, the dimension hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) may also be smaller than the dimension h1 of the first cap layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10).
[0185] For another example, please refer to Fig.12 and Fig.13 In the case where the source S and the drain D in the semiconductor device 10 are spaced apart from the first cap layer 61 in the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), the size hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) may be equal to the size h1 of the first cap layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10).
[0186] When the dimension hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) is equal to the dimension h1 of the first cap layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), since the source S and the drain D in the semiconductor device 10 are spaced apart from the first cap layer 61 in the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), the probability of at least one of the source S and the drain D in the semiconductor device 10 being directly connected to the gate layer G can be avoided or reduced, which is beneficial to improving the yield of the semiconductor device 10.
[0187] It should be noted that the above “the dimension hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) is equal to the dimension h1 of the first cap layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10)” means that the difference between the dimension hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) and the dimension h1 of the first cap layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) is within a preset threshold range. The threshold range is a relatively small numerical range. For example, the threshold range can be a process accuracy range when forming the first cap layer 61 and the gate layer G with equal dimensions along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10).
[0188] When a dimension hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) is equal to a dimension h1 of the first cap layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), a threshold range of the difference between the dimension hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) and the dimension h1 of the first cap layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) may be 0-2 μm.
[0189] For example, when a dimension hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) is equal to a dimension h1 of the first cap layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), the difference between the dimension hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) and the dimension h1 of the first cap layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) can be 0, 0.1μm, 0.3μm, 0.6μm, 0.8μm, 1μm, 1.2μm, 1.5μm, 1.6μm, 1.8μm or 2μm, etc.
[0190] For example, Fig.14 As shown, combined with Figure 4 , Figure 5 , Figure 6 and Figure 7 , Fig.14Schematic diagram of a top view of a first capping layer 61 and a gate layer G in a semiconductor device 10 according to some embodiments. When a dimension hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) is smaller than a dimension h1 of the first capping layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), in an orthographic projection onto the substrate 1 in the semiconductor device 10, along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), the gate layer G may be located within the boundary range of the first capping layer 61, and has a spacing dG between the gate layer G and the boundary of the first capping layer 61.
[0191] For example, please refer to Figure 4 , Figure 5 , Figure 6 , Figure 7 , Fig.12 and Fig.13 , the gate layer G in the semiconductor device 10 may be in contact with at least a portion of the surface of the first cap layer 61 on a side away from the substrate 1 .
[0192] For example, please refer to Figure 4 , Figure 5 , Figure 6 , Figure 7 , Fig.12 and Fig.13 , the gate layer G in the semiconductor device 10 may be in contact with a surface of the second cap layer 62 that is away from the substrate 1 .
[0193] In some embodiments, Fig.15 As shown, Fig.15 1 is a schematic cross-sectional view of a semiconductor device 10 according to some embodiments. The first capping layer 61 in the semiconductor device 10 may also cover a surface of the second capping layer 62 that is away from the substrate 1 .
[0194] Or, if Fig.16 As shown, Fig.16 1 is a schematic cross-sectional view of a semiconductor device 10 according to some embodiments. A portion of the second capping layer 62 in the semiconductor device 10 may be embedded in the first capping layer 61 , and the remaining portion of the second capping layer 62 may be covered by the gate layer G.
[0195] The method for manufacturing the semiconductor device 10 is described in detail below.
[0196] In some embodiments, Fig.17 and Fig.18 As shown, Fig.17 and Fig.18 1 and 2 are flowcharts of methods for manufacturing a semiconductor device 10 according to some embodiments. It should be noted that: Fig.17 and Fig.18 The method for preparing the semiconductor device 10 shown in FIG. 1 is not exclusive and may also be Fig.17 and Fig.18 Other steps are performed before, after or between any steps in the method for manufacturing the semiconductor device 10. The method for manufacturing the semiconductor device 10 includes steps S1 to S3.
[0197] S1: Fig.19 As shown, Fig.19 for Fig.17 and Fig.18 A schematic structural diagram of the semiconductor device 10 corresponding to step S1 in the flowchart of the method for preparing the semiconductor device 10 in FIG.
[0198] For example, the barrier layer 5 may be formed on one side of the substrate 1 in the semiconductor device 10 by a process such as Metal-organic Chemical Vapor Deposition (MOCVD), Molecular Beam Epitaxy (MBE), or Physical Vapor Deposition (PVD).
[0199] S2: Fig. 20 As shown, Fig. 20 for Fig.17 and Fig.18 A schematic diagram of the structure of the semiconductor device 10 corresponding to step S2 in the flowchart of the method for preparing the semiconductor device 10 in FIG. A first cap layer 61 and a second cap layer 62 are formed on the side of the barrier layer 5 away from the substrate 1. The second cap layer 62 is at least partially embedded in the first cap layer 61, and the first cap layer 61 covers at least part of the side surfaces of the second cap layer 62 on opposite sides along the first direction X, and a side surface of the second cap layer 62 close to the substrate 1, and the first direction X is parallel to the substrate 1.
[0200] The first capping layer 61 and the second capping layer 62 in the semiconductor device 10 both include P-type doped semiconductor materials, and the doping concentration of the first capping layer 61 is less than the doping concentration of the second capping layer 62 .
[0201] For example, the material of the first cap layer 61 and the material of the second cap layer 62 in the semiconductor device 10 may both include p-type gallium nitride (p-GaN). P-type gallium nitride (p-GaN) may be formed by doping gallium nitride (GaN) material with elements such as iron (Fe) and magnesium (Mg).
[0202] For example, when doping elements such as iron (Fe) and magnesium (Mg) into gallium nitride (GaN) materials to form p-type gallium nitride (p-GaN), a gas-phase doping process or an ion implantation process may be used.
[0203] S3: Fig.21 As shown, Fig.21 for Fig.17 and Fig.18 A schematic diagram of the structure of the semiconductor device 10 corresponding to step S3 in the flowchart of the method for preparing the semiconductor device 10 in FIG. A source electrode S and a drain electrode D are formed. The source electrode S and the drain electrode D are located on opposite sides of the first cap layer 61 along the first direction X, and are both arranged on the side of the barrier layer 5 away from the substrate 1.
[0204] Exemplarily, part of the barrier layer 5 in the source region and the drain region may be removed by a photolithography process to reduce the thickness of the barrier layer 5 to facilitate the formation of the source S and the drain D.
[0205] When removing part of the barrier layer 5 in the source region and the drain region by a photolithography process, a mixed gas such as Cl2 / ClB3 may be used as an etching gas.
[0206] Exemplarily, source and drain metals (e.g., titanium (Ti), aluminum (Al), titanium nitride (TiN), etc.) can be grown by a sputtering process, and the source and drain metals (e.g., titanium (Ti), aluminum (Al), titanium nitride (TiN), etc.) outside the source region and the drain region can be removed by a dry etching process to form a source S and a drain D.
[0207] The semiconductor device 10 includes a first cap layer 61 and a second cap layer 62, the first cap layer 61 is arranged on a side of the barrier layer 5 in the semiconductor device 10 away from the substrate 1, the second cap layer 62 is at least partially embedded in the first cap layer 61, the first cap layer 61 covers at least part of the side surfaces of the second cap layer 62 on the opposite sides along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), and a side surface of the second cap layer 62 close to the substrate 1, and the first cap layer 61 and the second cap layer 62 both include P-type doped semiconductor materials, the doping concentration of the first cap layer 61 is less than the doping concentration of the second cap layer 62, on the one hand, because the second cap layer 62 is at least partially embedded in the first cap layer 61, and the first cap layer 61 covers the second cap layer 62 At least part of the side surfaces on the two opposite sides along the first direction X, and the surface of one side of the second cap layer 62 close to the substrate 1, that is, part of the first cap layer 61 is located between the second cap layer 62 and the barrier layer 5. In the process of forming the second cap layer 62 in the semiconductor device 10, when the P-type impurities in the second cap layer 62 diffuse, the P-type impurities in the second cap layer 62 will diffuse into the first cap layer 61 first, which can avoid or alleviate the diffusion of the P-type impurities in the second cap layer 62 into the barrier layer 5, and can reduce the probability of the P-type impurities introducing additional charges and electric fields into the barrier layer 5 and interfering with the polarization effect of the barrier layer 5, which is beneficial to improving the polarization effect of the barrier layer 5, and further beneficial to enhancing the two-dimensional electron gas (Two-dimensional electron gas) in the semiconductor device 10. The invention can improve the performance of the semiconductor device 10 and reduce the probability of changes in the characteristics of the connection interface between the first cap layer 61 and the barrier layer 5 (for example, an increase in the density of trap states at the connection interface between the first cap layer 61 and the barrier layer 5, etc.), and affect the control ability of the gate layer G in the semiconductor device 10, which is beneficial to reduce the probability of problems such as dynamic on-resistance degradation in the semiconductor device 10, thereby improving the reliability of the semiconductor device 10.
[0208] On the other hand, since the doping concentration of the first cap layer 61 (i.e., the concentration of the P-type impurities in the first cap layer 61) is less than the doping concentration of the second cap layer 62 (i.e., the concentration of the P-type impurities in the second cap layer 62), that is, the doping concentration of the first cap layer 61 is relatively small, in the process of forming the first cap layer 61 in the semiconductor device 10, the P-type impurities in the first cap layer 61 may not diffuse or may diffuse only a small amount into the barrier layer 5, which can further reduce the probability of the P-type impurities introducing additional charges and electric fields into the barrier layer 5 and interfering with the polarization effect of the barrier layer 5, which is beneficial to further improve the polarization effect of the barrier layer 5, and further enhance the two-dimensional electron gas (Two-dimensional electron gas) in the semiconductor device 10. Electron gas, 2DEG), and is beneficial to further improve the performance of the semiconductor device 10, and can also further reduce the probability of changes in the characteristics of the connection interface between the first cap layer 61 and the barrier layer 5 (for example, the density of trap states at the connection interface between the first cap layer 61 and the barrier layer 5 increases, etc.), and affecting the control ability of the gate layer G in the semiconductor device 10, which is beneficial to further reduce the probability of problems such as dynamic on-resistance degradation in the semiconductor device 10, and further help to further improve the reliability of the semiconductor device 10.
[0209] On the other hand, since the doping concentration of the first cap layer 61 (i.e., the concentration of the P-type impurities in the first cap layer 61) is less than the doping concentration of the second cap layer 62 (i.e., the concentration of the P-type impurities in the second cap layer 62), that is, the doping concentration of the second cap layer 62 is relatively large, there is an energy band difference (e.g., conduction band difference) between the second cap layer 62 and the barrier layer 5, and the energy band difference (e.g., conduction band difference) between the second cap layer 62 and the barrier layer 5 can be used to regulate the two-dimensional electron gas (2DEG) near the connection interface between the barrier layer 5 and the channel layer 4, which is conducive to depleting the two-dimensional electron gas (2DEG) below the second cap layer 62, so that the semiconductor device 10 realizes an enhanced working mode. And due to the depletion effect of the second cap layer 62 in the semiconductor device 10 on the two-dimensional electron gas (2DEG) located below the second cap layer 62, the semiconductor device 10 needs to overcome a higher barrier when it is turned on, which is conducive to increasing the threshold voltage of the semiconductor device 10.
[0210] In some embodiments, please refer to Fig.17 , step S2 (ie, forming a first cap layer 61 and a second cap layer 62 on a side of the barrier layer 5 away from the substrate 1 ) in the method for preparing the semiconductor device 10 includes steps S21 to S23 .
[0211] S21: Fig. 22 As shown, Fig. 22 for Fig.17 A schematic structural diagram of the semiconductor device 10 corresponding to step S21 in the flowchart of the method for preparing the semiconductor device 10 in FIG.
[0212] For example, a first initial capping layer 61 a may be formed on a side of the barrier layer 5 in the semiconductor device 10 away from the substrate 1 by a process such as a metal-organic chemical vapor deposition process (MOCVD), a molecular beam epitaxy process (MBE), or a physical vapor deposition process (PVD).
[0213] Exemplarily, the first initial capping layer 61 a includes a P-type doped semiconductor material.
[0214] For example, the material of the first preliminary capping layer 61 a may include p-type gallium nitride (p-GaN), which may be formed by doping gallium nitride (GaN) material with elements such as iron (Fe) and magnesium (Mg).
[0215] For example, when the first initial capping layer 61a includes a P-type doped semiconductor material, a gas-phase doping process or an ion implantation process may be used to dope P-type impurities (e.g., magnesium (Mg)) into the semiconductor material (e.g., gallium nitride (GaN)) to form the first initial capping layer 61a.
[0216] S22: Fig.23 As shown, Fig.23 for Fig.17 A schematic structural diagram of the semiconductor device 10 corresponding to step S22 in the flowchart of the method for preparing the semiconductor device 10 in FIG.
[0217] For example, a gas-phase doping process or an ion implantation process may be used to dope a portion of the first initial capping layer 61a with elements such as iron (Fe) and magnesium (Mg) to form the second capping layer 62. The doping concentration of the second capping layer 62 (i.e., the concentration of the P-type impurities in the second capping layer 62) is greater than the doping concentration of the first initial capping layer 61a (i.e., the concentration of the P-type impurities in the first initial capping layer 61a).
[0218] Please continue reading Fig.23 In the process of forming the second capping layer 62, some P-type impurities (for example, magnesium (Mg)) in the second capping layer 62 may diffuse into the first initial capping layer 61a, so that the doping concentration in the first initial capping layer 61a in the semiconductor device 10 (i.e., the concentration of P-type impurities in the first initial capping layer 61a) gradually decreases along the direction M away from the second capping layer 62.
[0219] That is to say, within the first initial capping layer 61a within the semiconductor device 10, the closer the region is to the second capping layer 62, the higher the doping concentration (i.e., the concentration of P-type impurities within the first initial capping layer 61a), and the farther the region is from the second capping layer 62, the lower the doping concentration (i.e., the concentration of P-type impurities within the first initial capping layer 61a).
[0220] S23: Fig.24 As shown, combined with Fig.23 , Fig.24 for Fig.17 The first initial capping layer 61a of the to-be-formed source region Sa and the to-be-formed drain region Da is removed to form a first capping layer 61.
[0221] Exemplarily, a photolithography process may be used to remove the first initial capping layer 61 a where the source region Sa to be formed and the drain region Da to be formed, so as to form the first capping layer 61 .
[0222] When the first initial capping layer 61 a of the to-be-formed source region Sa and the to-be-formed drain region Da is removed by using a photolithography process, a mixed gas such as Cl 2 / N 2 / O 2 may be used as an etching gas.
[0223] In other embodiments, please refer to Fig.18 , step S2 (ie, forming a first cap layer 61 and a second cap layer 62 on a side of the barrier layer 5 away from the substrate 1 ) in the method for preparing the semiconductor device 10 includes steps S21 to S23 .
[0224] S21: Fig.25 As shown, Fig.25 for Fig.18 A schematic diagram of the structure of the semiconductor device 10 corresponding to step S21 in the flowchart of the method for preparing the semiconductor device 10 in FIG. A first initial cap layer 61a and a second initial cap layer 62a are sequentially formed on the side of the barrier layer 5 away from the substrate 1, and the doping concentration of the second initial cap layer 62a is greater than the doping concentration of the first initial cap layer 61a.
[0225] For example, a first initial capping layer 61 a and a second initial capping layer 62 a may be formed in sequence on a side of the barrier layer 5 in the semiconductor device 10 away from the substrate 1 by a process such as a metal-organic chemical vapor deposition (MOCVD), a molecular beam epitaxy (MBE), or a physical vapor deposition (PVD).
[0226] Exemplarily, both the first initial capping layer 61 a and the second initial capping layer 62 a include P-type doped semiconductor materials, and the doping concentration of the second initial capping layer 62 a is greater than the doping concentration of the first initial capping layer 61 a .
[0227] For example, the material of the first initial capping layer 61a and the material of the second initial capping layer 62a may both include p-type gallium nitride (p-GaN), which may be formed by doping GaN material with elements such as iron (Fe) and magnesium (Mg).
[0228] Exemplarily, when the first initial capping layer 61a and the second initial capping layer 62a both include P-type doped semiconductor materials, and the doping concentration of the second initial capping layer 62a is greater than the doping concentration of the first initial capping layer 61a, a gas-phase doping process or an ion implantation process may be used to dope P-type impurities (e.g., magnesium (Mg)) into the semiconductor material (e.g., gallium nitride (GaN)) to form the first initial capping layer 61a and the second initial capping layer 62a, respectively.
[0229] Alternatively, a gas-phase doping process or an ion implantation process may be used to dope P-type impurities (eg, magnesium (Mg)) into a semiconductor material (eg, gallium nitride (GaN)) to form the second initial capping layer 62 a .
[0230] During the formation of the second initial capping layer 62a, part of the P-type impurities (eg, magnesium (Mg)) in the second initial capping layer 62a diffuses into the first initial capping layer 61a, so that the first initial capping layer 61a includes a P-type doped semiconductor material.
[0231] S22: Fig.26 As shown, Fig.26 for Fig.18 A schematic diagram of the structure of the semiconductor device 10 corresponding to step S22 in the flowchart of the method for preparing the semiconductor device 10 in FIG. Part of the second initial capping layer 62a is processed so that the part of the second initial capping layer 62a forms the third capping layer 63, and the remaining area of the second initial capping layer 62a forms the second capping layer 62, and the doping concentration of the third capping layer 63 is less than the doping concentration of the second capping layer 62.
[0232] For example, please refer to Fig.26 , a partial area of the second initial cap layer 62a can be hydrogenated so that hydrogen atoms react with P-type impurities in the second initial cap layer 62a to form a complex, thereby reducing the doping concentration of a partial area of the second initial cap layer 62a to form a third cap layer 63.
[0233] For example, when the P-type impurities in the second initial capping layer 62a include magnesium (Mg), hydrogen atoms can react with magnesium (Mg) to form a magnesium hydride (Mg-H) complex to reduce the concentration of magnesium (Mg) in some areas of the second initial capping layer 62a, thereby reducing the doping concentration in some areas of the second initial capping layer 62a to form a third capping layer 63.
[0234] It is understood that the third capping layer 63 includes a complex (eg, a magnesium hydride (Mg—H) complex) and a P-type doped semiconductor material.
[0235] S23: Fig. 27 As shown, combined with Fig.26 , Fig. 27 for Fig.18 The first initial capping layer 61a and the third capping layer 63 of the to-be-formed source region Sa and the to-be-formed drain region Da are removed, and the remaining first initial capping layer 61a and the third capping layer 63 form the first capping layer 61.
[0236] For example, please refer to Fig.26 and Fig. 27, the first initial capping layer 61a and the third capping layer 63 of the source region Sa to be formed and the drain region Da to be formed are removed, the remaining first initial capping layer 61a forms the first sub-layer 611, and the remaining third capping layer 63 forms the second sub-layer 612. The first capping layer 61 includes the first sub-layer 611 and the second sub-layer 612.
[0237] The first sub-layer 611 in the first capping layer 61 may include a P-type doped semiconductor material, and the second sub-layer 612 in the first capping layer 61 may include a complex and a P-type doped semiconductor material.
[0238] For example, see Fig. 27 In the case where the second capping layer 62 in the semiconductor device 10 is doped with magnesium (Mg) element, the complex in the second sub-layer 612 of the first capping layer 61 may include a magnesium hydride (Mg—H) complex.
[0239] Exemplarily, a photolithography process may be used to remove the first initial capping layer 61 a and the third capping layer 63 where the source region Sa to be formed and the drain region Da to be formed to form the first capping layer 61 .
[0240] When the first initial capping layer 61 a and the third capping layer 63 of the to-be-formed source region Sa and the to-be-formed drain region Da are removed by using a photolithography process, a mixed gas such as Cl 2 / N 2 / O 2 may be used as an etching gas.
[0241] In some embodiments, please refer to Fig.17 and Fig.18 The method for preparing the semiconductor device 10 may further include step S4.
[0242] S4: Fig.28 As shown, Fig.28 for Fig.17 and Fig.18 The schematic diagram of the structure of the semiconductor device 10 corresponding to step S4 in the flowchart of the method for preparing the semiconductor device 10 in FIG. A gate layer G is formed on the side of the first cap layer 61 away from the substrate 1. The gate layer G covers at least a portion of the surface of the first cap layer 61 away from the substrate 1, and a surface of the second cap layer 62 away from the substrate 1.
[0243] For example, a gate metal (eg, titanium nitride (TiN) etc.) may be grown by a sputtering process, and the gate metal (eg, titanium nitride (TiN) etc.) outside the gate region may be removed by a dry etching process to form a gate layer G.
[0244] In the case where the semiconductor device 10 includes a first cap layer 61 and a second cap layer 62, by making the gate layer G in the semiconductor device 10 be arranged on the side of the first cap layer 61 away from the substrate 1, and the gate layer G covers at least a portion of the surface of the side of the first cap layer 61 away from the substrate 1, and the surface of the side of the second cap layer 62 away from the substrate 1, that is, the second cap layer 62 is not arranged between a partial area in the gate layer G and the first cap layer 61, when the semiconductor device 10 is turned on (that is, the gate layer G in the semiconductor device 10 is under a forward voltage bias), part of the two-dimensional electron gas (2DEG) in the semiconductor device 10 can pass through the first cap layer 61 and be collected by a partial area in the gate layer G and between the first cap layer 61 where the second cap layer 62 is not arranged, without passing through the second cap layer 62.
[0245] On the one hand, since the doping concentration of the first capping layer 61 (i.e., the concentration of P-type impurities in the first capping layer 61) is less than the doping concentration of the second capping layer 62 (i.e., the concentration of P-type impurities in the second capping layer 62), that is, the doping concentration of the first capping layer 61 is relatively small, there are fewer electron traps in the first capping layer 61, which is beneficial to reducing the probability of electrons in the two-dimensional electron gas (2DEG) being captured by electron traps during transmission, and further beneficial to maintaining the concentration of the two-dimensional electron gas (2DEG) near the connection interface between the barrier layer 5 and the channel layer 4, so that the concentration of the two-dimensional electron gas (2DEG) is more stable, thereby avoiding or reducing the probability of a positive drift of the threshold voltage due to the capture of electrons by electron traps during transmission, which is beneficial to improving the stability of the threshold voltage of the semiconductor device 10.
[0246] On the other hand, since the doping concentration of the first capping layer 61 (i.e., the concentration of P-type impurities in the first capping layer 61) is relatively small, there is an approximately uniformly distributed electric field in the first capping layer 61, which is beneficial for electrons to accelerate in the first capping layer 61 and smoothly transition to the interface between the first capping layer 61 and the gate layer G, which can reduce the scattering and energy loss of electrons during the transmission process, and is beneficial to improving the performance stability of the semiconductor device 10.
[0247] On the other hand, since the doping concentration of the first capping layer 61 (i.e., the concentration of P-type impurities in the first capping layer 61) is less than the doping concentration of the second capping layer 62 (i.e., the concentration of P-type impurities in the second capping layer 62), that is, the doping concentration of the second capping layer 62 is relatively large, there is an energy band difference (e.g., conduction band difference) between the second capping layer 62 and the barrier layer 5. The energy band difference (e.g., conduction band difference) between the second capping layer 62 and the barrier layer 5 can be used to regulate the two-dimensional electron gas (2DEG) near the connection interface between the barrier layer 5 and the channel layer 4, which is beneficial to depleting the two-dimensional electron gas (2DEG) below the second capping layer 62, thereby enabling the semiconductor device 10 to achieve an enhanced operating mode. Furthermore, due to the depletion effect of the second cap layer 62 in the semiconductor device 10 on the two-dimensional electron gas (2DEG) below the second cap layer 62 , the semiconductor device 10 needs to overcome a higher potential barrier when turned on, which is beneficial to increasing the threshold voltage of the semiconductor device 10 .
[0248] In summary, when the semiconductor device 10 includes a first cap layer 61 and a second cap layer 62, by setting the gate layer G in the semiconductor device 10 on the side of the first cap layer 61 away from the substrate 1, and the gate layer G covers at least part of the surface of the first cap layer 61 away from the substrate 1, and the surface of the second cap layer 62 away from the substrate 1, the threshold voltage of the semiconductor device 10 can be increased while improving the stability of the threshold voltage of the semiconductor device 10 and the performance stability of the semiconductor device 10.
[0249] In some embodiments, please refer to Fig.17 and Fig.18 The method for preparing the semiconductor device 10 may further include step S5.
[0250] S5: Fig.29 As shown, Fig.29 for Fig.17 and Fig.18 The schematic diagram of the structure of the semiconductor device 10 is shown in step S5 of the flowchart of the method for preparing the semiconductor device 10. A passivation layer 7 is formed. The passivation layer 7 covers the gate layer G, the source electrode S and the drain electrode D in the semiconductor device 10.
[0251] For example, the passivation layer 7 in the semiconductor device 10 may be formed by at least one of a chemical vapor deposition process (CVD) and a physical vapor deposition process (PVD).
[0252] By forming a passivation layer 7 in the semiconductor device 10, and the passivation layer 7 covers the gate layer G, the source S and the drain D in the semiconductor device 10, on the one hand, the passivation layer 7 can block harmful substances in the external environment (for example, oxygen, water, etc.), and avoid direct contact between harmful substances in the external environment (for example, oxygen, water, etc.) and the source S, drain D, and gate layer G in the semiconductor device 10, thereby preventing the source S, drain D, and gate layer G in the semiconductor device 10 from being damaged, which is beneficial to improving the stability of the semiconductor device 10 and extending the service life of the semiconductor device 10.
[0253] On the other hand, the passivation layer 7 has a certain mechanical strength, which can protect the source S, drain D and gate layer G in the semiconductor device 10 to a certain extent, and prevent the source S, drain D and gate layer G in the semiconductor device 10 from being mechanically damaged, which is beneficial to further improve the stability of the semiconductor device 10 and further extend the service life of the semiconductor device 10.
[0254] It should be noted that Fig. 20 , Fig.21 , Fig.23 , Fig.24 , Fig.26 , Fig. 27 , Fig.28 and Fig.29 In the present invention, only the semiconductor device 10 including a second cap layer 62 is taken as an example to schematically illustrate step S2, step S3, step S22, step S23, step S4 and step S5 in the method for preparing the semiconductor device 10. Fig.21 , Fig.28 and Fig.29 In the process, only the source S in the semiconductor device 10 and the first cap layer 61 have a spacing ds in the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10), and the drain D in the semiconductor device 10 and the first cap layer 61 have a spacing dd in the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) are taken as an example to schematically illustrate steps S3, S4 and S5 in the method for preparing the semiconductor device 10. Fig.28 and Fig.29In the figure, only the dimension hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) being smaller than the dimension h1 of the first cap layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) is taken as an example to schematically illustrate steps S4 and S5 in the method for preparing the semiconductor device 10. However, in the present disclosure, the number of second capping layers 62 in the semiconductor device 10, the positional relationship between the source S and the drain D in the semiconductor device 10 and the first capping layer 61, and the size relationship between the size hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) and the size h1 of the first capping layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) are not limited to this, and the number of second capping layers 62 in the semiconductor device 10, the positional relationship between the source S and the drain D in the semiconductor device 10 and the first capping layer 61, and the size relationship between the size hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) and the size h1 of the first capping layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) can be set according to actual needs.
[0255] For example, there may be a plurality of second capping layers 62 in the semiconductor device 10 .
[0256] For another example, at least one of the source S and the drain D in the semiconductor device 10 may be in contact with the side surface of the first capping layer 61 .
[0257] For another example, a dimension hG of the gate layer G in the semiconductor device 10 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) and a dimension h1 of the first cap layer 61 along the first direction X (i.e., the arrangement direction of the source S and the drain D in the semiconductor device 10) may be equal.
[0258] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.
Claims
1. A semiconductor device, characterized in that: include: substrate; A barrier layer, disposed on one side of the substrate; A first capping layer is disposed on a side of the barrier layer away from the substrate; A source electrode and a drain electrode are located on opposite sides of the first cap layer along a first direction, and are both arranged on a side of the barrier layer away from the substrate; the first direction is parallel to the substrate; A second capping layer is at least partially embedded in the first capping layer, and the first capping layer covers at least part of the side surfaces of the second capping layer on two opposite sides along the first direction, and a surface of one side of the second capping layer close to the substrate; The first capping layer and the second capping layer both include P-type doped semiconductor materials, and the doping concentration of the first capping layer is less than the doping concentration of the second capping layer.
2. The semiconductor device according to claim 1, wherein: The semiconductor device includes a plurality of the second capping layers, and the plurality of the second capping layers are spaced apart along the first direction.
3. The semiconductor device according to claim 1, wherein: In the first capping layer, the doping concentration gradually decreases in a direction away from the second capping layer.
4. The semiconductor device according to claim 1, wherein: The first capping layer includes a first sublayer and a second sublayer stacked along the thickness direction of the substrate, wherein the first sublayer is closer to the barrier layer than the second sublayer; At least a portion of the second capping layer is disposed in the second sub-layer and penetrates the second sub-layer along the thickness direction of the substrate; The doping concentration of the first sub-layer and the doping concentration of the second sub-layer are both less than the doping concentration of the second capping layer.
5. The semiconductor device according to claim 4, characterized in that The material of the first sub-layer includes a P-type doped semiconductor material, and the material of the second sub-layer includes a complex and a P-type doped semiconductor material.
6. The semiconductor device according to claim 5, characterized in that The second capping layer is doped with magnesium element; The complex in the second sublayer includes a magnesium hydride complex.
7. The semiconductor device according to claim 4, characterized in that The doping concentration of the first sub-layer is different from the doping concentration of the second sub-layer.
8. The semiconductor device according to claim 1, wherein: The semiconductor device further comprises a gate layer, which is arranged on a side of the first cap layer away from the substrate; The gate layer covers at least a portion of a surface of the first cap layer on a side away from the substrate, and a surface of the second cap layer on a side away from the substrate.
9. The semiconductor device according to claim 8, characterized in that A dimension of the gate layer along the first direction is smaller than or equal to a dimension of the first capping layer along the first direction.
10. The semiconductor device according to claim 9, characterized in that In an orthographic projection onto the substrate, along the first direction, the gate layer is located within a boundary range of the first cap layer and has a distance from a boundary of the first cap layer.
11. The semiconductor device according to claim 1, wherein: A size of the second capping layer along a second direction is the same as a size of the first capping layer along the second direction, the second direction is perpendicular to the first direction, and the second direction is parallel to the substrate.
12. The semiconductor device according to claim 1, wherein: The doping concentration of the first capping layer is less than or equal to 5×10 17 cm -3 .
13. The semiconductor device according to claim 12, characterized in that The doping concentration of the second capping layer is greater than or equal to 5×10 18 cm -3 , and less than or equal to 10×10 19 cm -3 .
14. The semiconductor device according to any one of claims 1 to 13, characterized in that: At least one of the source electrode and the drain electrode contacts a side surface of the first capping layer.
15. The semiconductor device according to any one of claims 1 to 13, characterized in that: At least one of the source electrode and the drain electrode and the first capping layer have a distance in the first direction.
16. The semiconductor device according to any one of claims 1 to 13, characterized in that: The first capping layer also covers a surface of the second capping layer that is away from the substrate.
17. The semiconductor device according to any one of claims 8 to 10, characterized in that: A portion of the second capping layer is embedded in the first capping layer, and the remaining portion of the second capping layer is covered by the gate layer.
18. A method for preparing a semiconductor device, characterized in that: include: forming a barrier layer on one side of the substrate; A first cap layer and a second cap layer are formed on a side of the barrier layer away from the substrate; the second cap layer is at least partially embedded in the first cap layer, and the first cap layer covers at least part of the side surfaces of the second cap layer on two opposite sides along a first direction, and a surface of one side of the second cap layer close to the substrate; the first direction is parallel to the substrate; forming a source electrode and a drain electrode; the source electrode and the drain electrode are located at opposite sides of the first cap layer along the first direction, and are both arranged on a side of the barrier layer away from the substrate; The first capping layer and the second capping layer both include P-type doped semiconductor materials, and the doping concentration of the first capping layer is less than the doping concentration of the second capping layer.
19. The method for preparing a semiconductor device according to claim 18, characterized in that: The step of forming a first cap layer and a second cap layer on a side of the barrier layer away from the substrate comprises: forming a first initial capping layer on a side of the barrier layer away from the substrate; Doping a partial area of the first initial capping layer with a P-type material to form a second capping layer; The first initial capping layer in the region where the source electrode is to be formed and the region where the drain electrode is to be formed is removed to form a first capping layer.
20. The method for preparing a semiconductor device according to claim 18, characterized in that: The step of forming a first cap layer and a second cap layer on a side of the barrier layer away from the substrate comprises: Forming a first initial capping layer and a second initial capping layer in sequence on a side of the barrier layer away from the substrate; the doping concentration of the second initial capping layer is greater than the doping concentration of the first initial capping layer; Processing a partial area of the second initial capping layer so that the partial area of the second initial capping layer forms a third capping layer, and the remaining area of the second initial capping layer forms the second capping layer; the doping concentration of the third capping layer is less than the doping concentration of the second capping layer; The first initial capping layer and the third capping layer in the source region to be formed and the drain region to be formed are removed, and the remaining first initial capping layer and the third capping layer form the first capping layer.
21. The method for preparing a semiconductor device according to claim 20, characterized in that: The processing of a partial area of the second initial capping layer so that the partial area of the second initial capping layer forms a third capping layer includes: A partial area of the second initial capping layer is hydrogenated to allow hydrogen atoms to react with P-type impurities in the second initial capping layer to form a complex, thereby reducing the doping concentration of the partial area of the second initial capping layer to form a third capping layer.
22. A chip, characterized in that: Comprising the semiconductor device according to any one of claims 1 to 17.
23. An electronic device, characterized in that: include: Circuit boards; The chip as claimed in claim 22, wherein the chip is electrically connected to the circuit board.
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