Semiconductor device

Abstract

The semiconductor device includes: a channel layer; a barrier layer over the channel layer and including a material having an energy band gap different from an energy band gap of the channel layer; a gate electrode over the barrier layer; a gate semiconductor layer between the barrier layer and the gate electrode; a first source electrode on a first side of the gate electrode; and a first drain electrode on a second side, which is an opposite side of the gate electrode, the first source electrode and the first drain electrode being each connected to the channel layer; a lower protective layer covering the barrier layer and the gate electrode; a first field dispersion plate connected to the first source electrode and over the lower protective layer; and a first interlayer insulating layer over the first field dispersion plate and the lower protective layer and including a first element with respect to a first content (at%) of the entire first interlayer insulating layer. The lower protective layer includes a first element, and a second content (at%) of the first element is less than the first content (at%) with respect to the entire lower protective layer.

Description

[0001] Cross - reference to related applications

[0002] This application claims priority and the benefit of Korean Patent Application No. 10 - 2023 - 0187539, filed with the Korean Intellectual Property Office on December 20, 2023, the entire content of which is incorporated herein by reference. Technical field

[0003] The present disclosure relates to a semiconductor device. Background art

[0004] In modern society, semiconductor devices are closely related to daily life. Specifically, the importance of power semiconductor devices used in various fields such as the transportation field (such as electric vehicles, railways, trams), renewable energy systems (such as solar power generation and wind power generation), and mobile devices is gradually increasing. A power semiconductor device is a semiconductor device for handling high voltage or high current and performs functions such as power conversion and control in large - scale power systems or high - power electronic devices. A power semiconductor device has the ability to handle high power and durability, thereby handling a large amount of current and withstanding high voltage. For example, a power semiconductor device can handle voltages from several hundred volts to several thousand volts and currents from several tens of amperes to several thousand amperes. A power semiconductor device can improve the efficiency of electric energy use by minimizing power loss. In addition, even in an environment such as high temperature, a power semiconductor device can operate stably.

[0005] These power semiconductor devices can be classified according to materials, and examples include SiC power semiconductor devices and GaN power semiconductor devices. By manufacturing a power semiconductor device using SiC or GaN instead of a conventional silicon wafer (Si wafer), the disadvantage that silicon has unstable characteristics at high temperatures can be compensated for. An SiC power semiconductor device is heat - resistant and has low power loss, and can be applied to electric vehicles, renewable energy systems, etc. A GaN power semiconductor device requires high cost but is efficient in terms of speed and can be applied to high - speed charging of mobile devices. Summary of the invention

[0006] Aspects of the disclosed embodiments provide a semiconductor device having stable electrical characteristics and improved reliability.

[0007] According to an exemplary embodiment, a semiconductor device includes: a channel layer; a barrier layer that is located above the channel layer and includes a material having a bandgap different from that of the channel layer; a gate electrode that is located above the barrier layer; a gate semiconductor layer that is located between the barrier layer and the gate electrode; a first source electrode and a first drain electrode, the first source electrode being located on a first side of the gate electrode and the first drain electrode being located on a second side (opposite side) of the gate electrode, the first source electrode and the first drain electrode each being connected to the channel layer; a lower protective layer that covers the barrier layer and the gate electrode; a first field dispersion plate that is connected to the first source electrode and is located above the lower protective layer; and a first interlayer insulating layer that is located above the first field dispersion plate and the lower protective layer and includes a first element in a first content (at%) with respect to the entire first interlayer insulating layer. The lower protective layer includes the first element, and a second content (at%) of the first element with respect to the entire lower protective layer is less than the first content (at%).

[0008] According to an exemplary embodiment, a semiconductor device includes: a channel layer; a barrier layer that is located above the channel layer and includes a material having a bandgap different from that of the channel layer; a gate electrode that is located above the barrier layer; a gate semiconductor layer that is located between the barrier layer and the gate electrode; a first source electrode and a first drain electrode, the first source electrode being located on a first side of the gate electrode and the first drain electrode being located on a second side (opposite side) of the gate electrode, the first source electrode and the first drain electrode each being connected to the channel layer; a lower protective layer that covers the barrier layer and the gate electrode; a field dispersion plate that is connected to the source electrode and is located above the lower protective layer; and an interlayer insulating layer that is located above the field dispersion plate and the lower protective layer and includes nitrogen. The lower protective layer includes nitrogen in a content (at%) with respect to the entire lower protective layer that is less than the content (at%) of nitrogen in the interlayer insulating layer with respect to the entire interlayer insulating layer.

[0009] According to an exemplary embodiment, a semiconductor device includes: a substrate; a channel layer including GaN and located on the substrate; a barrier layer located above the channel layer and including AlGaN; a gate electrode located above the barrier layer and including a metal material; a gate semiconductor layer located between the barrier layer and the gate electrode and including GaN doped with a P-type impurity; a first source electrode and a first drain electrode, the first source electrode being located on a first side of the gate electrode, the first drain electrode being located on a second side (opposite side) of the gate electrode, and the first source electrode and the first drain electrode each being connected to the channel layer; a lower protective layer covering the barrier layer and the gate electrode; a first field spread plate connected to the first source electrode, integral with the first source electrode, and located above the lower protective layer; and a first interlayer insulating layer located above the first field spread plate and the lower protective layer and including a first element and a second element different from the first element. The lower protective layer includes the second element, or the second element and the first element, and a content (at%) of the first element of the lower protective layer with respect to the entire lower protective layer is less than a content (at%) of the first element of the first interlayer insulating layer with respect to the entire first interlayer insulating layer.

[0010] According to an embodiment, electrical characteristics and reliability of the semiconductor device can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 and Figure 2 is a cross-sectional view showing a semiconductor device according to an embodiment.

[0012] Figure 3 is a graph showing a concentration of a first element at positions of a lower protective layer and an interlayer insulating layer of a semiconductor device according to an embodiment.

[0013] Figures 4 to 9 is a graph showing a concentration of a first element at positions of a lower protective layer and an interlayer insulating layer of a semiconductor device according to some embodiments.

[0014] Figure 10 and Figure 11 is a cross-sectional view showing a semiconductor device according to some embodiments.

[0015] Figure 12 and Figure 13 is a graph showing a concentration of a first element at positions of a lower protective layer and an interlayer insulating layer of a semiconductor device according to some embodiments.

[0016] Figure 14 and Figure 15 is a cross-sectional view showing a semiconductor device according to some embodiments.

[0017] Figures 16 to 18is a graph showing the concentration of a first element indicating the positions of a lower protective layer and an interlayer insulating layer of a semiconductor device according to some embodiments.

[0018] Figure 19 and Figure 20 is a cross-sectional view of a semiconductor device according to some embodiments.

[0019] Figures 21 to 30 is a process cross-sectional view shown according to the process sequence of manufacturing a semiconductor device according to an embodiment. Detailed Description

[0020] The present disclosure will be described more fully hereinafter with reference to the accompanying drawings, which show exemplary embodiments of the present disclosure. As will be recognized by those skilled in the art, the described embodiments can be modified in various different ways, all of which do not depart from the spirit or scope of the present disclosure.

[0021] To clearly describe the present disclosure, parts not relevant to the description are omitted, and like reference numerals denote like elements throughout the specification.

[0022] In the drawings, for better understanding and ease of description, the dimensions and thicknesses of each element are approximately shown. Accordingly, the present disclosure is not limited to the drawings. In the drawings, the thicknesses of layers, films, panels, regions, etc. are exaggerated for clarity. In the drawings, the thicknesses of some layers and regions are exaggerated for ease of explanation.

[0023] It will be understood that when an element is referred to as being "connected" or "coupled" to another element or "on" another element, the element can be directly connected or directly coupled to the other element or directly on the other element, or there can be intervening elements. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, or as being "in contact" with another element or "contacting" another element (or any form of the word "contact"), there are no intervening elements at the point of contact. Further, in this specification, the words "on" or "above" mean located on or below an object portion and do not necessarily mean located on the upper side of the object portion based on the direction of gravity.

[0024] In addition, unless explicitly described to the contrary, the words "comprise" and variations such as "comprising" or "containing" will be understood to imply the inclusion of the stated elements but not the exclusion of any other elements.

[0025] Ordinal numbers such as “first,” “second,” “third,” etc. may simply be used as labels for certain elements, steps, etc. to distinguish such elements, steps, etc. from each other. Terms not described using “first,” “second,” etc. in the specification may still be referred to as “first” or “second” in the claims. Additionally, a term referred to by a specific ordinal number (e.g., “first” in a specific claim) may be described elsewhere using a different ordinal number (e.g., “second” in the specification or another claim).

[0026] Hereinafter, reference will be made to Figures 1 to 3 describe a semiconductor device according to an embodiment.

[0027] Figure 1 and Figure 2 is a cross-sectional view showing a semiconductor device according to an embodiment. Figure 3 is a graph showing the concentration of a first element indicating the positions of a lower protective layer and an interlayer insulating layer of a semiconductor device according to an embodiment. Figure 1 represents a case where the semiconductor device according to an embodiment is in an off state. Figure 2 represents a case where the semiconductor device according to an embodiment is in an on state. The semiconductor device may be a power semiconductor device such as a switch or other high-power device.

[0028] First, as Figure 1 shown in, a semiconductor device according to an embodiment may include a channel layer 132, a barrier layer 136 located on the channel layer 132, a gate electrode 155 located on the barrier layer 136, a gate semiconductor layer 152 located between the barrier layer 136 and the gate electrode 155, a lower protective layer 180 located on the barrier layer 136, an interlayer insulating layer 500 located on the lower protective layer 180, source electrodes 173 and drain electrodes 175 separated from each other on the channel layer 132, and a field dispersion layer 177 located on the lower protective layer 180.

[0029] The channel layer 132 is a layer that forms a channel between the source electrode 173 and the drain electrode 175, and a two-dimensional electron gas (2DEG) 134 may be located inside the channel layer 132. The two-dimensional electron gas 134 is a charge transport model used in solid-state physics and refers to a group of electrons that can move freely in two dimensions (e.g., in the xy-plane direction) but not in another dimension (e.g., the z-direction) and are tightly bound within the two-dimensional space. For example, the two-dimensional electron gas 134 may exist in a three-dimensional space in a two-dimensional paper-like form. The two-dimensional electron gas 134 mainly appears in semiconductor heterojunction structures and may appear at the interface between the channel layer 132 and the barrier layer 136 in a semiconductor device according to an embodiment. For example, the two-dimensional electron gas 134 may be generated in the portion of the channel layer 132 closest to the barrier layer 136.

[0030] The channel layer 132 may include one or more materials selected from III-V materials (such as nitrides including Al, Ga, In, B, or combinations thereof). Throughout the specification, when a component is described as "including" a particular element or group of elements, it is to be understood that, unless the context clearly and / or explicitly dictates otherwise, the component is formed solely of that element or group of elements, or that element or group of elements may be combined with additional elements to form the component. On the other hand, the term "consisting of" indicates that the component is formed solely of the listed (one or more) elements. The channel layer 132 may be composed of a single layer or multiple layers. The channel layer 132 may be Al x In y Ga (1-x-y) N (0 ≤ x ≤ 1, 0 ≤ y ≤ 1, x + y ≤ 1). For example, the channel layer 132 may be AlN, GaN, InN, InGaN, AlGaN, AlInN, AlInGaN, or a combination thereof. The channel layer 132 may be a layer with doped impurities or a layer with undoped impurities. The thickness of the channel layer 132 may be about several hundred nm or less.

[0031] The channel layer 132 may be located on the substrate 110, and the seed layer 115 and the buffer layer 120 may be located between the substrate 110 and the channel layer 132. The substrate 110, the seed layer 115, and the buffer layer 120 are layers necessary for forming the channel layer 132 and may be omitted in some cases. For example, when a substrate made of GaN is used as the channel layer 132, at least one of the substrate 110, the seed layer 115, and the buffer layer 120 may be omitted. Considering the relatively high price of the substrate made of GaN, a substrate 110 made of Si may be used to grow the channel layer 132 including GaN. Since the lattice structure of Si and the lattice structure of GaN are different, it may not be easy to directly grow the channel layer 132 on the substrate 110. Therefore, after first growing the seed layer 115 and the buffer layer 120 on the substrate 110, the channel layer 132 may be grown on the buffer layer 120. In addition, after using at least one of the substrate 110, the seed layer 115, and the buffer layer 120 in the manufacturing process, at least one of the substrate 110, the seed layer 115, and the buffer layer 120 may be removed from the final structure of the semiconductor device.

[0032] The substrate 110 may include semiconductor materials. For example, the substrate 110 may include sapphire, Si, SiC, AlN, GaN, or a combination thereof. The substrate 110 may be a silicon-on-insulator (SOI) substrate. However, the material of the substrate 110 is not limited thereto, and any commonly used substrate may be applied. In some cases, the substrate 110 may include insulating materials. For example, after forming a plurality of layers including the channel layer 132 on the semiconductor substrate first, the semiconductor substrate may be subsequently removed and replaced with an insulating substrate.

[0033] The buffer layer 120 may be located on the substrate 110. The seed layer 115 may also be located between the substrate 110 and the buffer layer 120. The seed layer 115 may be directly located on the substrate 110, for example, to contact the top surface of the substrate. However, it is not limited thereto, and another predetermined layer may also be located between the substrate 110 and the seed layer 115. The seed layer 115 is a layer that serves as a seed for growing the buffer layer 120 and may be made of a crystal lattice structure that becomes the seed of the buffer layer 120. The buffer layer 120 may be directly located on the seed layer 115. However, it is not limited thereto, and another predetermined layer may be located between the seed layer 115 and the buffer layer 120. As an example, the seed layer 115 may include AlN.

[0034] The buffer layer 120 may be located between the substrate 110 and the channel layer 132. The buffer layer 120 is a layer for reducing the difference in lattice constant and thermal expansion coefficient between the substrate 110 and the channel layer 132. The buffer layer 120 may include one or more materials selected from III-V group materials (such as nitrides including Al, Ga, In, B, or a combination thereof). The buffer layer 120 may be Al x In y Ga (1-x-y) N (0 ≤ x ≤ 1, 0 ≤ y ≤ 1, x + y ≤ 1). For example, the buffer layer 120 may include AlN, GaN, InN, InGaN, AlGaN, AlInN, AlInGaN, or a combination thereof. The buffer layer 120 may be composed of a single layer or multiple layers.

[0035] The buffer layer 120 of the semiconductor device according to an embodiment may further include a superlattice layer and / or a high-resistance layer. The superlattice layer and the high-resistance layer may be sequentially located on the seed layer 115.

[0036] The superlattice layer may be located above the seed layer 115. The superlattice layer may be directly on the seed layer 115. However, it is not limited thereto, and another predetermined layer may be located between the seed layer 115 and the superlattice layer. The superlattice layer is a layer for reducing the difference in lattice constant and coefficient of thermal expansion between the substrate 110 and the channel layer 132. The superlattice layer may include one or more materials selected from group III-V materials (such as nitrides including Al, Ga, In, B, or combinations thereof). The superlattice layer may be Al x In y Ga (1-x-y) N (0≤x≤1, 0≤y≤1, x + y≤1). For example, the superlattice layer may include AlN, GaN, InN, InGaN, AlGaN, AlInN, AlInGaN, or combinations thereof. The superlattice layer may be composed of a single layer or multiple layers. For example, the superlattice layer may have a structure in which layers made of AlGaN and layers made of GaN are repeatedly stacked. For example, AlGaN / GaN / AlGaN / GaN / AlGaN / GaN may be sequentially stacked to form the superlattice layer. The number of AlGaN layers and GaN layers constituting the superlattice layer may be changed in various ways, and the materials constituting the superlattice layer may be changed in various ways.

[0037] The high-resistance layer may be located above the superlattice layer. The high-resistance layer may be directly on the superlattice layer. However, it is not limited thereto, and another predetermined layer may be located between the superlattice layer and the high-resistance layer. The high-resistance layer may be located between the superlattice layer and the channel layer 132. The high-resistance layer is a layer for preventing the semiconductor device according to the embodiment including the channel layer 132 from being externally affected. The high-resistance layer may be made of a material with low conductivity so that the substrate 110 and the channel layer 132 are electrically insulated. The high-resistance layer may include one or more materials selected from group III-V materials (such as nitrides including Al, Ga, In, B, or combinations thereof). The high-resistance layer may be Al x In y Ga 1-x-y N (0≤x≤1, 0≤y≤1, x + y≤1). For example, the high-resistance layer may include AlN, GaN, InN, InGaN, AlGaN, AlInN, AlInGaN, or combinations thereof. The high-resistance layer may be made of a single layer or multiple layers. The high-resistance layer may be a layer in which no impurities are doped.

[0038] The barrier layer 136 may be located above the channel layer 132. The barrier layer 136 may be directly located on the channel layer 132. However, it is not limited thereto, and another predetermined layer may be located between the channel layer 132 and the barrier layer 136. The region of the channel layer 132 overlapping with the barrier layer 136 may become the drift region DTR. The drift region DTR may be located between the source electrode 173 and the drain electrode 175. The drift region DTR may represent the region to which carriers move when a potential difference occurs between the source electrode 173 and the drain electrode 175.

[0039] The semiconductor device according to an embodiment may be turned on / off according to whether a voltage is applied to the gate electrode 155 and / or the magnitude of the voltage applied to the gate electrode 155, and thus, the movement of carriers in the drift region DTR may be achieved or blocked.

[0040] The barrier layer 136 may include one or more materials selected from III-V group materials (such as nitrides including Al, Ga, In, B, or combinations thereof). The barrier layer 136 may be Al x In y Ga 1-x-y N (0≤x≤1, 0≤y≤1, x + y≤1). The barrier layer 136 may include GaN, InN, AlGaN, AlInN, InGaN, AlN, AlInGaN, or combinations thereof. The energy band gap of the barrier layer 136 may be adjusted by adjusting the composition ratio of Al and / or In.

[0041] The barrier layer 136 may include a semiconductor material having characteristics different from those of the channel layer 132. The barrier layer 136 may be different from the channel layer 132 in at least one of polarization characteristics, energy band gap, and lattice constant. For example, the barrier layer 136 may include a material having a different energy band gap from the channel layer 132. At this time, the barrier layer 136 may have a higher energy band gap than the channel layer 132 and may have a higher polarization rate than the channel layer 132. The barrier layer 136 may induce a two-dimensional electron gas 134 in the channel layer 132 having a relatively low polarization rate. In this regard, the barrier layer 136 may also be referred to as a channel supply layer or a two-dimensional electron gas supply layer. The two-dimensional electron gas 134 may be formed in a portion of the channel layer 132 below the interface between the channel layer 132 and the barrier layer 136. The two-dimensional electron gas 134 may have a very high electron mobility.

[0042] The barrier layer 136 may be composed of a single layer or multiple layers. If the barrier layer 136 is composed of multiple layers, the energy band gaps of the materials of each layer constituting the multiple layers may be different. In one embodiment, the multiple layers constituting the barrier layer 136 may be arranged such that the energy band gap increases as it approaches the channel layer 132.

[0043] The gate electrode 155 may be located on the barrier layer 136. The gate electrode 155 may overlap with some regions of the barrier layer 136. The gate electrode 155 may overlap with a part of the drift region DTR of the channel layer 132. The gate electrode 155 may be located between the source electrode 173 and the drain electrode 175. The gate electrode 155 may be separated from the source electrode 173 and the drain electrode 175. For example, the gate electrode 155 may be positioned closer to the source electrode 173 than to the drain electrode 175. Therefore, the separation distance between the gate electrode 155 and the source electrode 173 may be less than the separation distance between the gate electrode 155 and the drain electrode 175, but it is not limited thereto.

[0044] The gate electrode 155 may include a conductive material. For example, the gate electrode 155 may include a metal, a metal alloy, a conductive metal nitride, a metal silicide, a doped semiconductor material, a conductive metal oxide, or a conductive metal oxynitride. For example, the gate electrode 155 may include titanium nitride (TiN), tantalum carbide (TaC), tantalum nitride (TaN), titanium silicon nitride (TiSiN), tantalum silicon nitride (TaSiN), tantalum titanium nitride (TaTiN), titanium aluminum nitride (TiAlN), tantalum aluminum nitride (TaAlN), tungsten nitride (WN), ruthenium (Ru), titanium aluminum (TiAl), titanium aluminum carbonitride (TiAlC-N), titanium aluminum carbide (TiAlC), titanium carbide (TiC), tantalum carbonitride (TaCN), tungsten (W), aluminum (Al), copper (Cu), cobalt (Co), titanium (Ti), tantalum (Ta), nickel (Ni), platinum (Pt), nickel platinum (NiPt), niobium (Nb), niobium nitride (NbN), niobium carbide (NbC), molybdenum (Mo), molybdenum nitride (MoN), molybdenum carbide (MoC), tungsten carbide (WC), rhodium (Rh), palladium (Pd), iridium (Ir), osmium (Os), silver (Ag), gold (Au), zinc (Zn), vanadium (V), or a combination thereof, but it is not limited thereto. The gate electrode 155 may be made of a single layer or multiple layers.

[0045] The gate semiconductor layer 152 may be located between the barrier layer 136 and the gate electrode 155. The gate semiconductor layer 152 may be located on the barrier layer 136, and the gate electrode 155 may be located on the gate semiconductor layer 152. The gate electrode 155 may have a Schottky contact or an ohmic contact with the gate semiconductor layer 152. The gate semiconductor layer 152 may overlap with the gate electrode 155. At this time, the gate semiconductor layer 152 may completely overlap with the gate electrode 155 in the vertical direction, and the upper surface of the gate semiconductor layer 152 may be completely covered by the gate electrode 155. For example, the gate semiconductor layer 152 may have substantially the same planar shape as the gate electrode 155 and may completely vertically overlap with the gate electrode 155. However, it is not limited thereto, and the gate electrode 155 may be positioned to cover at least a part of the gate semiconductor layer 152 instead of the entire gate semiconductor layer 152. This will be described later with reference toFigure 20 A description will be given.

[0046] The gate semiconductor layer 152 may be located between the source electrode 173 and the drain electrode 175. The gate semiconductor layer 152 may be separated from the source electrode 173 and the drain electrode 175. For example, the gate semiconductor layer 152 may be located between the first source electrode 173a and the first drain electrode 175a and spaced apart from the first source electrode 173a and the first drain electrode 175a. The gate semiconductor layer 152 may be positioned closer to the source electrode 173 than to the drain electrode 175. Accordingly, the separation distance between the gate semiconductor layer 152 and the source electrode 173 may be less than the separation distance between the gate semiconductor layer 152 and the drain electrode 175, but the exemplary embodiments are not limited thereto.

[0047] In an embodiment, the gate semiconductor layer 152 may overlap with the gate electrode 155 in a vertical direction (e.g., the thickness direction of the channel layer 132). For example, the gate semiconductor layer 152 may completely overlap with the gate electrode 155 in a vertical direction (e.g., the thickness direction of the channel layer 132). For example, the side surface of the gate semiconductor layer 152 may be aligned with the side surface of the gate electrode 155. However, the embodiments are not limited thereto, and the gate semiconductor layer 152 may partially overlap with the gate electrode 155. This will be described later with reference to Figure 20 A description will be given.

[0048] The gate semiconductor layer 152 may include one or more materials selected from III-V group materials (such as nitrides including Al, Ga, In, B, or combinations thereof). The gate semiconductor layer 152 may be Al x In y Ga 1-x-yN(0 ≤ x ≤ 1, 0 ≤ y ≤ 1, x + y ≤ 1). For example, the gate semiconductor layer 152 may include AlN, GaN, InN, InGaN, AlGaN, AlInN, AlInGaN, or a combination thereof. The gate semiconductor layer 152 may include a material having a bandgap different from that of the barrier layer 136. For example, the gate semiconductor layer 152 may include GaN, and the barrier layer 136 may include AlGaN. The gate semiconductor layer 152 may be doped with a predetermined impurity. The impurity doped in the gate semiconductor layer 152 may be a P-type dopant that can provide holes. For example, the gate semiconductor layer 152 may include GaN doped with a P-type impurity. For example, the gate semiconductor layer 152 may be made of a p-GaN layer. However, the embodiments are not limited thereto, and the gate semiconductor layer 152 may be a p-AlGaN layer. The impurity doped in the gate semiconductor layer 152 may be magnesium (Mg). When the doped impurity (e.g., magnesium) in the gate semiconductor layer 152 binds to an adjacent predetermined element, the hole concentration in the gate semiconductor layer 152 may be reduced, and the characteristics of the semiconductor device may be correspondingly deteriorated. The gate semiconductor layer 152 may be made of a single layer or multiple layers.

[0049] A depletion region DPR may be formed in the channel layer 132 through the gate semiconductor layer 152. The depletion region DPR may be located within the drift region DTR and may have a width narrower than that of the drift region DTR. When the gate semiconductor layer 152 having a bandgap different from that of the barrier layer 136 is located on the barrier layer 136, the energy level of the band of the portion of the barrier layer 136 overlapping with the gate semiconductor layer 152 may increase. Accordingly, the depletion region DPR may be formed in the region of the channel layer 132 overlapping with the gate semiconductor layer 152. The depletion region DPR may be a region in the channel path of the channel layer 132 where a two-dimensional electron gas 134 is not formed or has a lower electron concentration than the remaining regions. The depletion region DPR may refer to a region where the flow of the two-dimensional electron gas 134 is interrupted within the drift region DTR. When the depletion region DPR appears, current does not flow between the source electrode 173 and the drain electrode 175, and the channel path may be blocked. Accordingly, the semiconductor device according to the embodiment may have normally-off characteristics.

[0050] For example, the semiconductor device according to the embodiment may be a normally-off high electron mobility transistor (HEMT). As Figure 1 shown, in a normal state where no voltage is applied to the gate electrode 155, there is a depletion region DPR, and the semiconductor device according to the embodiment may be in an off state. As Figure 2As shown, when a voltage higher than the threshold voltage is applied to the gate electrode 155, the depletion region DPR disappears, and the two-dimensional electron gas 134 in the drift region DTR is not disconnected but can be connected. The two-dimensional electron gas 134 can be formed in the entire channel path between the source electrode 173 and the drain electrode 175, and the semiconductor device according to the embodiment can be in an on state. In summary, the semiconductor device according to the embodiment can include semiconductor layers having different polarization characteristics, and the semiconductor layer having a relatively high polarizability can induce the two-dimensional electron gas 134 in another semiconductor layer heterogeneously bonded thereto. The two-dimensional electron gas 134 can be used as a channel between the source electrode 173 and the drain electrode 175, and the connection or disconnection of the flow of the two-dimensional electron gas 134 can be controlled by a bias voltage applied to the gate electrode 155. In the gate cutoff state, the flow of the two-dimensional electron gas 134 is blocked, so that current can not flow between the source electrode 173 and the drain electrode 175. When the flow of the two-dimensional electron gas 134 continues in the gate on state, current can flow between the source electrode 173 and the drain electrode 175.

[0051] The previously described seed layer 115, buffer layer 120, channel layer 132, barrier layer 136, and gate semiconductor layer 152 can be sequentially stacked on the substrate 110. In the semiconductor device according to the embodiment, at least one of the seed layer 115, buffer layer 120, channel layer 132, barrier layer 136, and gate semiconductor layer 152 can be omitted. These seed layer 115, buffer layer 120, channel layer 132, barrier layer 136, and gate semiconductor layer 152 can be made of the same type of semiconductor material (e.g., can be formed of the same matrix semiconductor material), and the material composition ratio of each layer can be different in consideration of the function of each layer and the performance required for the semiconductor device.

[0052] The lower protective layer 180 can be located above the barrier layer 136 and the gate electrode 155. The lower protective layer 180 can cover the upper surface and the side surface of the gate electrode 155 and the side surface of the gate semiconductor layer 152. The lower surface of the lower protective layer 180 is in contact with the barrier layer 136 and the gate electrode 155. Therefore, the barrier layer 136, the gate semiconductor layer 152, and the gate electrode 155 can be protected by the lower protective layer 180. However, the embodiment is not limited thereto, and the gate electrode 155 can penetrate the lower protective layer 180 to connect to the gate semiconductor layer 152, and the lower protective layer 180 can not cover the upper surface of the gate electrode 155. In addition, the lower surface of the lower protective layer 180 can be in contact with the gate semiconductor layer 152. These examples are subsequently described with reference to Figure 20 are described.

[0053] In an embodiment, the lower protective layer 180 may be located between the source electrode 173 and the drain electrode 175, which will be described later. For example, the lower protective layer 180 may be located between the first source electrode 173a and the first drain electrode 175a, which will be described later. The side surface of the lower protective layer 180 may be in contact with the source electrode 173 and the drain electrode 175. For example, the lower protective layer 180 may be in contact with the side surfaces of the first source electrode 173a and the first drain electrode 175a.

[0054] The lower protective layer 180 may be located between the barrier layer 136 and the field dispersion layer 177, which will be explained later. For example, the lower protective layer may fill a portion between the barrier layer 136 and the first field dispersion layer 177a, which will be explained later. At least a portion of the lower protective layer 180 may overlap with the field dispersion layer 177 in the vertical direction (e.g., the thickness direction of the channel layer 132). Therefore, the portion of the lower protective layer 180 that overlaps with the field dispersion layer 177 in the vertical direction (e.g., the thickness direction of the channel layer 132) may cover the gate semiconductor layer 152 and the gate electrode 155.

[0055] In an embodiment, the lower protective layer 180 may include an insulating material. For example, the lower protective layer 180 may include silicon oxide (SiO2), silicon oxycarbide (SiOC), or a combination thereof. In addition, the lower protective layer 180 may include silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon oxycarbonitride (SiOCN), silicon nitride (SiN), or a combination thereof. For another example, the lower protective layer 180 may include a material such as aluminum oxide (Al2O3).

[0056] In an embodiment, the lower protective layer 180 may include a first element and a second element different from the first element. Here, the first element may be nitrogen (N), and the second element may be silicon (Si). For example, if the lower protective layer 180 includes silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon oxycarbonitride (SiOCN), silicon nitride (SiN), or a combination thereof, the first element may be nitrogen (N), and the second element may be silicon (Si).

[0057] The lower protective layer 180 may include a first element in a second content (at%). Here, the first element in the second content (at%) of the lower protective layer 180 may represent the content (at%) of the first element among the entire content of the lower protective layer 180. For example, if the lower protective layer 180 includes silicon oxynitride (SiON), the content (at%) of nitrogen (N) may refer to the content of nitrogen compared to the entire content of silicon (Si), nitrogen (N), and oxygen (O) of the entire lower protective layer 180, and may be described as the content (at%) relative to the entire content of the lower protective layer 180. As another example, if the lower protective layer 180 includes silicon nitride (SiN), the content (at%) of nitrogen (N) may refer to the content of nitrogen compared to the entire content of silicon (Si) and nitrogen (N) in the entire lower protective layer 180. For example, the second content (at%) of the first element of the lower protective layer 180 may be about 0 at% or greater and less than about 1 at% (e.g., greater than 0% and less than or equal to 1%). For example, when the lower protective layer 180 includes silicon oxynitride (SiON), the second content (at%) of nitrogen (N) in the lower protective layer 180 may be about 0 at% or greater and less than about 1 at% (e.g., greater than 0% and less than or equal to 1%). On the other hand, when the lower protective layer 180 includes silicon dioxide (SiO2), the second content (at%) of nitrogen (N) in the lower protective layer 180 may be 0 at%. As described herein, the content refers to the amount of a specific element or material in a structure. For example, the content may refer to the amount of an element in a layer. The amount may refer to an absolute amount or a relative amount (e.g., a ratio or a percentage). An example of a relative amount (e.g., relative content) as described herein is at% (atomic percentage), but the relative content may refer to an atomic ratio, a weight percentage, or other relative values. In addition, as discussed in connection with the various figures, based on the distance from the bottom surface of the lower protective layer 180, the content in a vertical section of the layer may change. In these cases, the content at a specific vertical section or height may be described as the content at a specific height, the content at a specific vertical level, or the content of a vertical level slice. Therefore, the overall content of the entire layer may be described as the content over the entire thickness of the entire layer, while the content of a vertical level slice within a specific layer may be referred to as a sub-content or a vertical level slice content.

[0058] In an embodiment, the lower protective layer 180 is described as being formed of a single layer, but the embodiment is not limited thereto. For example, the lower protective layer 180 may be composed of multiple layers sequentially stacked on the barrier layer 136. This is described subsequently with reference to Figures 11 to 13 as follows.

[0059] Since the lower protective layer 180 of the semiconductor device according to the embodiment includes a first element having a second content (at%), moisture or oxygen can be prevented from penetrating into the channel layer 132, and the dangling bond state of the insulating material at the interface of the barrier layer 136 can be removed.

[0060] The interlayer insulating layer 500 may be located on the lower protective layer 180. The interlayer insulating layer 500 may cover the lower protective layer 180. For example, the interlayer insulating layer 500 may be located on the lower protective layer 180 between the source electrode 173 and the drain electrode 175. The interlayer insulating layer 500 may overlap with the drift region DTR of the channel layer 132 in a vertical direction (e.g., the thickness direction of the channel layer 132). The interlayer insulating layer 500 may not contact the gate electrode 155 or the gate semiconductor layer 152, but the embodiment is not limited thereto. The bottom surface of the interlayer insulating layer 500 may contact the lower protective layer 180 and the first field dispersion layer 177a. The side surfaces of the interlayer insulating layer 500 may contact the source electrode 173 and the drain electrode 175. However, the embodiment is not limited thereto. In some embodiments, the interlayer insulating layer 500 may cover at least a portion of the upper surfaces of the source electrode 173 and the drain electrode 175.

[0061] The interlayer insulating layer 500 of the semiconductor device according to the embodiment may include a first interlayer insulating layer 510 and a second interlayer insulating layer 520.

[0062] The first interlayer insulating layer 510 may be located above the lower protective layer 180 and the first field dispersion layer 177a, which will be explained later. The first interlayer insulating layer 510 may cover the lower protective layer 180 and the first field dispersion layer 177a, which will be explained later. The first interlayer insulating layer 510 may be located between the first field dispersion layer 177a and the second field dispersion layer 177b. For example, the first interlayer insulating layer 510 may be located on the lower protective layer 180 between the second source electrode 173b and the second drain electrode 175b. The first interlayer insulating layer 510 may overlap with the drift region DTR of the channel layer 132 in a vertical direction (e.g., the thickness direction of the channel layer 132). The first interlayer insulating layer 510 may not contact the gate electrode 155 and the gate semiconductor layer 152, but the embodiment is not limited thereto. The bottom surface of the first interlayer insulating layer 510 may contact the lower protective layer 180 and the first field dispersion layer 177a. The side surfaces of the first interlayer insulating layer 510 may contact the second source electrode 173b and the second drain electrode 175b. However, the embodiment is not limited thereto. In some embodiments, the first interlayer insulating layer 510 may cover at least a portion of the upper surfaces of the first source electrode 173a and the first drain electrode 175a.

[0063] In an embodiment, the first interlayer insulating layer 510 may include an insulating material. For example, the first interlayer insulating layer 510 may include silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon oxycarbonitride (SiOCN), silicon nitride (SiN), or a combination thereof. In addition, the first interlayer insulating layer 510 may include a material such as aluminum oxide (Al2O3).

[0064] In an embodiment, the first interlayer insulating layer 510 may include a first element and a second element different from the first element. For example, the first element may be nitrogen (N), and the second element may be silicon (Si). For example, if the first interlayer insulating layer 510 includes silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon oxycarbonitride (SiOCN), silicon nitride (SiN), or a combination thereof, the first element may be nitrogen (N), and the second element may be silicon (Si).

[0065] The first interlayer insulating layer 510 may include a first content (at%) of the first element. Here, the first content (at%) of the first element in the first interlayer insulating layer 510 may represent the content (at%) of the first element in the entire content of the first interlayer insulating layer 510. For example, if the first interlayer insulating layer 510 includes silicon oxynitride (SiON), the content (at%) of nitrogen (N) may refer to the content of nitrogen compared to the entire content of silicon (Si), nitrogen (N), and oxygen (O) in the first interlayer insulating layer 510, and may be described as the content (at%) relative to the entire first interlayer insulating layer 510. For example, the first content (at%) of the first element in the first interlayer insulating layer 510 may be greater than about 0 at% and less than about 60 at%, preferably, in some embodiments, about 3 at% to about 30 at%.

[0066] Further referring to Figure 3 In an embodiment, the first content (at%) of the first element in the first interlayer insulating layer 510 may be greater than the second content (at%) of the first element in the lower protective layer 180. For example, the first content (at%) of the first element in the first interlayer insulating layer 510 and the second content (at%) of the first element in the lower protective layer 180 may have constant values regardless of the distance from the bottom surface 180_B of the lower protective layer 180. For example, the first content N1 (at%) of the first element in the first interlayer insulating layer 510 may be greater than the second content N2 (at%) of the first element in the lower protective layer 180. However, the embodiment is not limited thereto. In some embodiments, the first content (at%) of the first element in the first interlayer insulating layer 510 and / or the second content (at%) of the first element in the lower protective layer 180 may have different values according to the distance from the bottom surface 180_B of the lower protective layer 180. This is described subsequently with reference to Figures 4 to 9 for description.

[0067] As an example, when the first interlayer insulating layer 510 and the lower protective layer 180 include the same material such as silicon oxynitride (SiON), the first content (at%) of nitrogen (N) in the first interlayer insulating layer 510 may be greater than the second content (at%) of nitrogen (N) in the lower protective layer 180. Accordingly, the sum of the content (at%) of silicon (Si) and the content of oxygen (O) among the total content (at%) of the first interlayer insulating layer 510 may be less than the sum of the content (at%) of silicon (Si) and the content of oxygen (O) among the total content (at%) of the lower protective layer 180. As another example, if the first interlayer insulating layer 510 includes silicon oxynitride (SiON) and the lower protective layer 180 includes silicon dioxide (SiO2), the first content (at%) of nitrogen (N) in the first interlayer insulating layer 510 may be greater than the second content (at%) of nitrogen (N) in the lower protective layer 180. In this case, the lower protective layer 180 may not include a first element (e.g., nitrogen (N)). That is, the second content (at%) of the first element of the lower protective layer 180 may be 0 at%.

[0068] As another example, when the first interlayer insulating layer 510 and the lower protective layer 180 include silicon nitride (SiN), the first content (at%) of nitrogen (N) in the first interlayer insulating layer 510 may be greater than the second content (at%) of nitrogen (N) in the lower protective layer 180. Accordingly, the content (at%) of silicon (Si) among the total content (at%) of the first interlayer insulating layer 510 may be less than the content (at%) of silicon (Si) among the total content (at%) of the lower protective layer 180.

[0069] In the embodiment, the first interlayer insulating layer 510 is described as being composed of a single layer, but is not limited thereto. For example, the first interlayer insulating layer 510 may be composed of multiple layers sequentially stacked on the lower protective layer 180. This is described with reference to Figures 14 to 18 is described.

[0070] When the first interlayer insulating layer 510 of the semiconductor device according to the embodiment includes a first element at a first content (at%), the semiconductor device may have stable electrical characteristics and may improve reliability.

[0071] The second interlayer insulating layer 520 may be located above the first interlayer insulating layer 510 and the second field dispersion layer 177b, which will be explained later. The second interlayer insulating layer 520 may cover the first interlayer insulating layer 510 and the second field dispersion layer 177b, which will be explained later. For example, the second interlayer insulating layer 520 may be located on the first interlayer insulating layer 510 between the third source electrode 173c and the third drain electrode 175c. The second interlayer insulating layer 520 may overlap with the drift region DTR of the channel layer 132 in the vertical direction (e.g., the thickness direction of the channel layer 132). The second interlayer insulating layer 520 may not contact the gate electrode 155 or the gate semiconductor layer 152, but the embodiments are not limited thereto. The bottom surface of the second interlayer insulating layer 520 may contact the first interlayer insulating layer 510 and the second field dispersion layer 177b. The side surface of the second interlayer insulating layer 520 may contact the third source electrode 173c and the third drain electrode 175c. However, the embodiments are not limited thereto. In some embodiments, the second interlayer insulating layer 520 may cover at least a part of the upper surfaces of the third source electrode 173c and the third drain electrode 175c.

[0072] In an embodiment, the second interlayer insulating layer 520 may include an insulating material. The second interlayer insulating layer 520 may include the same material as or be composed of the same material as the first interlayer insulating layer 510, but the embodiments are not limited thereto. For example, the second interlayer insulating layer 520 may include silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon oxycarbonitride (SiOCN), silicon nitride (SiN), or a combination thereof. In addition, the second interlayer insulating layer 520 may include a material such as aluminum oxide (Al2O3).

[0073] In an embodiment, the second interlayer insulating layer 520 may include a first element and a second element different from the first element. Here, the first element may be nitrogen (N), and the second element may be silicon (Si). As an example, if the second interlayer insulating layer 520 includes silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon oxycarbonitride (SiOCN), silicon nitride (SiN), or a combination thereof, the first element may be nitrogen (N), and the second element may be silicon (Si).

[0074] The second interlayer insulating layer 520 may include a first element in a third content (at%). Here, the third content (at%) of the first element in the second interlayer insulating layer 520 may represent the content (at%) of the first element among the entire content of the second interlayer insulating layer 520. For example, when the second interlayer insulating layer 520 includes silicon oxynitride (SiON), the content (at%) of nitrogen (N) may refer to the content of nitrogen compared to the entire content of silicon (Si), nitrogen (N), and oxygen (O) in the entire second interlayer insulating layer 520, and may be described as being relative to the content (at%) of the entire second interlayer insulating layer 520.

[0075] Further referring to Figure 3 , in an embodiment, the third content (at%) of the first element in the second interlayer insulating layer 520 may be greater than the second content (at%) of the first element in the lower protective layer 180. For example, the third content (at%) of the first element in the second interlayer insulating layer 520 and the second content (at%) of the first element in the lower protective layer 180 may be constant values throughout the entire vertical thickness of each layer, without changing based on the distance from the bottom surface 180_B of the lower protective layer 180, and the third content N3 (at%) of the first element in the second interlayer insulating layer 520 may be greater than the second content N2 (at%) of the first element in the lower protective layer 180. However, the embodiment is not limited thereto. In some embodiments, the third content N3 (at%) of the first element in the second interlayer insulating layer 520 may include a portion that is equal to or less than the second content N2 (at%) of the first element in the lower protective layer 180. In this example, one or both of the third content N3 (at%) and the second content N2 (at%) may not be constant throughout the entire vertical thickness of the corresponding layer.

[0076] In addition, the third content (at%) of the first element in the second interlayer insulating layer 520 may be less than the first content (at%) of the first element in the first interlayer insulating layer 510. For example, the third content (at%) of the first element in the second interlayer insulating layer 520 and the first content (at%) of the first element in the first interlayer insulating layer 510 may have constant values, without (e.g., throughout the entire vertical thickness of each layer) being related to the distance from the bottom surface 180_B of the lower protective layer 180, and the third content N3 (at%) of the first element in the second interlayer insulating layer 520 may be less than the first content N1 (at%) of the first element in the first interlayer insulating layer 510. However, the embodiment is not limited thereto. In some embodiments, the third content (at%) of the first element in the second interlayer insulating layer 520, the first content (at%) of the first element in the first interlayer insulating layer 510, and / or the second content (at%) of the first element in the lower protective layer 180 may have different values based on the distance from the bottom surface of the lower protective layer 180.

[0077] In an exemplary embodiment, when the second interlayer insulating layer 520, the first interlayer insulating layer 510, and the lower protective layer 180 include silicon oxynitride (SiON), the third content (at%) of nitrogen (N) in the second interlayer insulating layer 520 may be greater than the second content (at%) of nitrogen (N) in the lower protective layer 180. In addition, the third content (at%) of nitrogen (N) in the second interlayer insulating layer 520 may be less than the first content (at%) of nitrogen (N) in the first interlayer insulating layer 510. Therefore, the sum of the content (at%) of silicon (Si) and the content (at%) of oxygen (O) in the total content (at%) of the second interlayer insulating layer 520 may be less than the sum of the content (at%) of silicon (Si) and the content (at%) of oxygen (O) in the total content (at%) of the lower protective layer 180. In addition, the sum of the content (at%) of silicon (Si) and the content (at%) of oxygen (O) in the total content (at%) of the second interlayer insulating layer 520 may be greater than the sum of the content (at%) of silicon (Si) and the content (at%) of oxygen (O) in the total content (at%) of the first interlayer insulating layer 510. As another example, when the second interlayer insulating layer 520 includes silicon oxynitride (SiON) and the lower protective layer 180 includes silicon dioxide (SiO2), the third content (at%) of nitrogen (N) in the second interlayer insulating layer 520 may be greater than the second content (at%) of nitrogen (N) in the lower protective layer 180. In this case, the lower protective layer 180 may not include a first element (e.g., nitrogen (N)). That is, the second content (at%) of the first element in the lower protective layer 180 may be 0 at%.

[0078] As another example, when the second interlayer insulating layer 520, the first interlayer insulating layer 510, and the lower protective layer 180 include silicon nitride (SiN), the third content (at%) of nitrogen (N) in the second interlayer insulating layer 520 may be greater than the second content (at%) of nitrogen (N) in the lower protective layer 180. In addition, the third content (at%) of nitrogen (N) in the second interlayer insulating layer 520 may be less than the first content (at%) of nitrogen (N) in the first interlayer insulating layer 510. Therefore, the content (at%) of silicon (Si) in the total content (at%) of the second interlayer insulating layer 520 may be less than the content (at%) of silicon (Si) in the total content (at%) of the lower protective layer 180. In addition, the content (at%) of silicon (Si) in the total content (at%) of the second interlayer insulating layer 520 may be greater than the content (at%) of silicon (Si) in the total content (at%) of the first interlayer insulating layer 510.

[0079] In one embodiment, the second interlayer insulating layer 520 is described as being composed of a single layer, but is not limited thereto. For example, the second interlayer insulating layer 520 may be composed of multiple layers sequentially stacked on top of the first interlayer insulating layer 510.

[0080] When the second interlayer insulating layer 520 of the semiconductor device according to the embodiment includes a first element having a third content (at%), the semiconductor device may have stable electrical characteristics and may improve reliability.

[0081] In addition, the interlayer insulating layer 500 of the semiconductor device according to the embodiment is described as being composed of two layers, but is not limited thereto. As an example, the interlayer insulating layer 500 may be composed of a single layer. However, even in this case, the content (at%) of the first element of the interlayer insulating layer 500 may be greater than the content of the first element of the lower protective layer 180. As another example, the interlayer insulating layer 500 may be composed of three or more layers. In this case, the content of the first element of the interlayer insulating layer 500 directly above the lower protective layer 180 may be greater than the content of the first element of the interlayer insulating layer 500 positioned to be separated from the lower protective layer 180. As can be seen in Figure 1 and other embodiments, the lower protective layer 180 may be formed of a continuous material layer that is horizontally continuously formed between a position on a side surface thereof in contact with the source electrode 173 and a position on a facing side surface thereof in contact with the drain electrode 175. Therefore, between these side surfaces, the lower protective layer 180 may have a continuous structure to form a single piece or material without grain boundaries therebetween. The same applies to the first interlayer insulating layer 510 and the second interlayer insulating layer 520.

[0082] The source electrode 173 and the drain electrode 175 may be located above the channel layer 132. The source electrode 173 and the drain electrode 175 may be in contact with the channel layer 132 and may be electrically connected to the channel layer 132. The source electrode 173 and the drain electrode 175 may be spaced apart from each other, and the gate electrode 155 and the gate semiconductor layer 152 may be located between the source electrode 173 and the drain electrode 175. The gate electrode 155 and the gate semiconductor layer 152 may be separated from the source electrode 173 and the drain electrode 175. For example, the source electrode 173 may be electrically connected to the channel layer 132 on one side of the gate electrode 155, and the drain electrode 175 may be electrically connected to the channel layer 132 on the other side of the gate electrode 155. The source electrode 173 and the drain electrode 175 may be located outside the drift region DTR of the channel layer 132. The interface between the source electrode 173 and the channel layer 132 may be one edge of the drift region DTR. Similarly, the interface between the drain electrode 175 and the channel layer 132 may be the other edge (e.g., the opposite edge) of the drift region DTR.

[0083] However, the present disclosure is not limited thereto, and the source electrode 173 and the drain electrode 175 may not be located outside the drift region DTR of the channel layer 132. For example, in one embodiment, the channel layer 132 may not be recessed at the positions where it overlaps with the source electrode 173 and the drain electrode 175, and the source electrode 173 and the drain electrode 175 may be located on the upper surface of the channel layer 132. The bottom surfaces of the source electrode 173 and the drain electrode 175 may be in contact with the top surface of the channel layer 132. The portions of the barrier layer 136 that are in contact with the source electrode 173 and the drain electrode 175 may be doped at a high concentration. Carriers passing through the two-dimensional electron gas 134 may pass through the portions of the barrier layer 136 that are doped at a high concentration (e.g., the upper portion of the barrier layer 136), and be transmitted to the source electrode 173 and the drain electrode 175. In some embodiments where the side surfaces of the source electrode 173 and the drain electrode 175 contact the side surfaces of the channel layer, the source electrode 173 and the drain electrode 175 may contact the two-dimensional electron gas 134 in the horizontal direction. However, in other embodiments, for example, if no recess is formed in the channel layer 132, the source electrode 173 and the drain electrode 175 may not contact the two-dimensional electron gas 134 in the horizontal direction. The horizontal direction refers to the direction parallel to the upper surface of the channel layer 132 or the barrier layer 136.

[0084] The source electrode 173 and the drain electrode 175 may include a conductive material. For example, the source electrode 173 and the drain electrode 175 may include a metal, a metal alloy, a conductive metal nitride, a metal silicide, a doped semiconductor material, a conductive metal oxide, or a conductive metal oxynitride. For example, the source electrode 173 and the drain electrode 175 may include titanium nitride (TiN), tantalum carbide (TaC), tantalum nitride (TaN), titanium silicon nitride (TiSiN), tantalum silicon nitride (TaSiN), tantalum titanium nitride (TaTiN), titanium aluminum nitride (TiAlN), tantalum aluminum nitride (TaAlN), tungsten nitride (WN), ruthenium (Ru), titanium aluminum (TiAl), titanium aluminum carbonitride (TiAlC-N), titanium aluminum carbide (TiAlC), titanium carbide (TiC), tantalum carbonitride (TaCN), tungsten (W), aluminum (Al), copper (Cu), cobalt (Co), titanium (Ti), tantalum (Ta), nickel (Ni), platinum (Pt), nickel platinum (Ni-Pt), niobium (Nb), niobium nitride (NbN), niobium carbide (NbC), molybdenum (Mo), molybdenum nitride (MoN), molybdenum carbide (MoC), tungsten carbide (WC), rhodium (Rh), palladium (Pd), iridium (Ir), osmium (Os), silver (Ag), gold (Au), zinc (Zn), vanadium (V), or a combination thereof, but is not limited thereto. The source electrode 173 and the drain electrode 175 may be made of a single layer or multiple layers. The source electrode 173 and the drain electrode 175 may be in ohmic contact with the channel layer 132. The region in contact with the source electrode 173 and the drain electrode 175 within the channel layer 132 may be doped at a relatively high concentration compared to other regions (other regions at a different vertical level and / or at a different horizontal position from the contact region).

[0085] The source electrode 173 may include a first source electrode 173a, a second source electrode 173b, and a third source electrode 173c. The second source electrode 173b may be located above the first source electrode 173a. The third source electrode 173c may be located above the second source electrode 173b. The first source electrode 173a may be described as a first source electrode layer or sub-layer, the second source electrode 173b may be described as a second source electrode layer or sub-layer, and the third source electrode 173c may be described as a third source electrode layer or sub-layer. The first source electrode 173a may contact the channel layer 132 and be electrically connected to the channel layer 132. The second source electrode 173b and the third source electrode 173c may not contact the channel layer 132 and may be electrically connected to the channel layer 132 through the first source electrode 173a.

[0086] In addition, the drain electrode 175 may include a first drain electrode 175a, a second drain electrode 175b, and a third drain electrode 175c. The second drain electrode 175b may be located above the first drain electrode 175a. The third drain electrode 175c may be located above the second drain electrode 175b. The first drain electrode 175a may be described as a first drain electrode layer or sub-layer, the second drain electrode 175b may be described as a second drain electrode layer or sub-layer, and the third drain electrode 175c may be described as a third drain electrode layer or sub-layer. The first drain electrode 175a may contact the channel layer 132 and may be electrically connected to the channel layer 132. The second drain electrode 175b and the third drain electrode 175c may not contact the channel layer 132 and may be electrically connected to the channel layer 132 through the first drain electrode 175a.

[0087] The first source electrode 173a and the first drain electrode 175a may be located above the channel layer 132. The first source electrode 173a and the first drain electrode 175a may be formed of the same material as each other and may be formed at the same vertical level (e.g., having a bottom surface at the same vertical level above the top surface of the substrate 110 and a top surface at the same vertical level above the top surface of the substrate 110). The first source electrode 173a and the first drain electrode 175a may contact the channel layer 132. Specifically, trenches that penetrate the lower protective layer 180 and the barrier layer 136 and recess the upper surface of the channel layer 132 may be located on opposite sides of the gate electrode 155 and spaced apart from each other. The first source electrode 173a and the first drain electrode 175a may be respectively located in the trenches positioned on opposite sides of the gate electrode 155. The first source electrode 173a and the first drain electrode 175a may be formed to fill the trenches. Inside the trenches, the first source electrode 173a and the first drain electrode 175a may contact the channel layer 132 and the barrier layer 136. The channel layer 132 may form the bottom surface and sidewalls of the trenches, and the barrier layer 136 may form the sidewalls of the trenches. Accordingly, the first source electrode 173a and the first drain electrode 175a may contact the upper surface and side surfaces of the channel layer 132. In addition, the first source electrode 173a and the first drain electrode 175a may contact the side surfaces of the barrier layer 136. Accordingly, the first source electrode 173a and the first drain electrode 175a may cover the side surfaces of the channel layer 132 and the barrier layer 136.

[0088] In an embodiment, the first source electrode 173a and the first drain electrode 175a may cover (and contact) the side surfaces of the lower protective layer 180. The upper surfaces of the first source electrode 173a and the first drain electrode 175a may protrude (in the vertical direction) from the upper surface of the lower protective layer 180. However, the embodiment is not limited thereto. In one embodiment, the first source electrode 173a and the first drain electrode 175a may cover at least a part of the side surfaces of the lower protective layer 180 and may not cover the remaining part of the side surfaces of the lower protective layer 180.

[0089] The second source electrode 173b may be located above the first source electrode 173a. The first source electrode 173a may contact the channel layer 132 and be electrically connected to the channel layer 132. The second source electrode 173b may not contact the channel layer 132 and may be electrically connected to the channel layer 132 through the first source electrode 173a.

[0090] The second drain electrode 175b may be located above the first drain electrode 175a. The first drain electrode 175a may contact the channel layer 132 and be electrically connected to the channel layer 132. The second drain electrode 175b may not contact the channel layer 132 and may be electrically connected to the channel layer 132 through the first drain electrode 175a.

[0091] The second source electrode 173b and the second drain electrode 175b may penetrate the first interlayer insulating layer 510, which will be explained later. Specifically, the opening penetrating the first interlayer insulating layer 510 may be positioned to overlap with the first source electrode 173a, and the second source electrode 173b may be located within the opening. The second source electrode 173b may be formed to fill the opening. Within the opening, the second source electrode 173b may contact the first source electrode 173a. The second source electrode 173b may be connected to the first source electrode 173a through the opening. Another opening penetrating the first interlayer insulating layer 510 may be positioned to overlap with the first drain electrode 175a, and the second drain electrode 175b may be located within the opening. The second drain electrode 175b may be formed to fill the opening. Within the opening, the second drain electrode 175b may contact the first drain electrode 175a. The second drain electrode 175b may be connected to the first drain electrode 175a through the opening. The upper surfaces of the second source electrode 173b and the second drain electrode 175b may protrude from the upper surface of the first interlayer insulating layer 510, but the embodiments are not limited thereto.

[0092] The opening filled with the second source electrode 173b may overlap with the trench filled with the first source electrode 173a. The opening filled with the second source electrode 173b may completely overlap with the first source electrode 173a. However, the embodiments are not limited thereto, and in some cases, at least a part of the opening filled with the second source electrode 173b may not overlap with the first source electrode 173a. In addition, the opening filled with the second drain electrode 175b may overlap with the trench filled with the first drain electrode 175a. The opening filled with the second drain electrode 175b may completely overlap with the first drain electrode 175a. However, the embodiments are not limited thereto, and in some cases, at least a part of the opening filled with the second drain electrode 175b may not overlap with the first drain electrode 175a.

[0093] The third source electrode 173c may be located above the second source electrode 173b. The third source electrode 173c may not contact the channel layer 132 and may be electrically connected to the channel layer 132 through the second source electrode 173b and the first source electrode 173a. In addition, the third drain electrode 175c may be located above the second drain electrode 175b. The third drain electrode 175c may not contact the channel layer 132 and may be electrically connected to the channel layer 132 through the second drain electrode 175b and the first drain electrode 175a.

[0094] The third source electrode 173c and the third drain electrode 175c may penetrate the second interlayer insulating layer 520, which will be explained later. Specifically, the opening penetrating the second interlayer insulating layer 520 may be positioned to overlap with the second source electrode 173b, and the third source electrode 173c may be located within the opening. The third source electrode 173c may be formed to fill the opening. Within the opening, the third source electrode 173c may contact the second source electrode 173b. The third source electrode 173c may be connected to the second source electrode 173b through the opening. Since the remaining descriptions of the third source electrode 173c and the third drain electrode 175c are substantially the same as those of the second source electrode 173b and the second drain electrode 175b, they will be omitted.

[0095] In Figure 1 and Figure 2 , the semiconductor device according to the embodiment is shown to include three pairs of sub-layers of the source electrode 173 and the drain electrode 175, but the number of sub-layers of the source electrode 173 and the drain electrode 175 is not limited thereto. For example, the semiconductor device according to the embodiment may include two pairs or fewer pairs of sub-layers of the source electrode 173 and the drain electrode 175. Alternatively, each of the source electrode 173 and the drain electrode 175 may include four pairs or more pairs of sub-layers.

[0096] The field dispersion layer 177 may be located between the source electrode 173 and the drain electrode 175. The field dispersion layer 177 may cover the gate electrode 155. The field dispersion layer 177 may overlap with the gate electrode 155 in the vertical direction (e.g., the thickness direction of the channel layer 132). The field dispersion layer 177 may be electrically connected to the source electrode 173. For example, the field dispersion layer 177 may be connected to the source electrode 173, for example, to extend from the source electrode 173.

[0097] The field dispersion layer 177 of the semiconductor device according to the embodiment may include a first field dispersion layer 177a, a second field dispersion layer 177b, and a third field dispersion layer 177c (each may be described as a sub-layer).

[0098] The first field dispersion layer 177a may be located above the lower protective layer 180. The first field dispersion layer 177a may be located between the source electrode 173 and the drain electrode 175. The first field dispersion layer 177a may overlap with the gate electrode 155 in the vertical direction (e.g., the thickness direction of the channel layer 132). The gate electrode 155 may be covered by the first field dispersion layer 177a. The first field dispersion layer 177a may be located between the lower protective layer 180 and the first interlayer insulating layer 510. The first field dispersion layer 177a may be in contact with the lower protective layer 180 and the first interlayer insulating layer 510.

[0099] The first field dispersion layer 177a may be electrically connected to the source electrode 173. For example, the first field dispersion layer 177a may be connected to the first source electrode 173a. The first field dispersion layer 177a may include the same material as the first source electrode 173a and may be a part of the same layer as the first source electrode 173a. The first field dispersion layer 177a may be formed simultaneously in the same process as the first source electrode 173a. The grain boundary between the first field dispersion layer 177a and the first source electrode 173a may not exist, and the first field dispersion layer 177a may be integrally formed with the first source electrode 173a to form a monolithic material. However, the embodiment is not limited thereto, and the first field dispersion layer 177a may be a component separated from the first source electrode 173a. In addition, the first field dispersion layer 177a may be located in a different layer from the first source electrode 173a and may be formed in a different process. In some cases, the first field dispersion layer 177a may be electrically connected to the gate electrode 155. For example, an opening overlapping with the gate electrode 155 may be formed in the lower protective layer 180, and the first field dispersion layer 177a may be connected to the gate electrode 155 through the opening. In this case, the first field dispersion layer 177a may not be directly connected to the source electrode 173 (or not integrally formed with the source electrode 173).

[0100] The first field dispersion layer 177a may be used to disperse the electric field concentrated around the gate electrode 155 and may be a conductive layer described as a field dispersion plate or a field dispersion cover plate. If a high voltage is applied to the drain electrode 175 in the gate cutoff state, the electric field may be concentrated on the gate electrode 155. When the electric field is concentrated on the gate electrode 155 and the gate semiconductor layer 152, the leakage current may increase and the breakdown voltage may decrease. The semiconductor device according to the embodiment includes the first field dispersion layer 177a, and thus can disperse the electric field concentrated around the gate electrode 155. Therefore, the leakage current can be reduced and the breakdown voltage can be increased. The first field dispersion layer 177a may have a convex shape protruding vertically at the position where it covers the gate electrode 155.

[0101] The second field dispersion layer 177b may be located above the first interlayer insulating layer 510. The second field dispersion layer 177b may be located between the source electrode 173 and the drain electrode 175. The second field dispersion layer 177b may overlap with the gate electrode 155. The second field dispersion layer 177b may overlap with the first field dispersion layer 177a. The gate electrode 155 and the first field dispersion layer 177a may be covered by the second field dispersion layer 177b. The second field dispersion layer 177b may be located between the first interlayer insulating layer 510 and the second interlayer insulating layer 520. The second field dispersion layer 177b may be in contact with the first interlayer insulating layer 510 and the second interlayer insulating layer 520. The second field dispersion layer 177b may have a convex shape that protrudes vertically at the position where it covers the gate electrode 155.

[0102] The width of the second field dispersion layer 177b may be wider than the width of the first field dispersion layer 177a. The second field dispersion layer 177b may completely cover the first field dispersion layer 177a. That is, one end of the second field dispersion layer 177b may be positioned closer to the drain electrode 175 than the corresponding end of the first field dispersion layer 177a. However, the embodiments are not limited thereto, and the width and position relationship between the first field dispersion layer 177a and the second field dispersion layer 177b may be changed in various ways. The second field dispersion layer 177b may be electrically connected to the source electrode 173. For example, the second field dispersion layer 177b may be connected to the second source electrode 173b.

[0103] The second field dispersion layer 177b may include the same material as the second source electrode 173b and may be a part of the same layer as the second source electrode 173b. The second field dispersion layer 177b may be formed simultaneously in the same process as the second source electrode 173b. The grain boundary between the second field dispersion layer 177b and the second source electrode 173b may not exist, and the second field dispersion layer 177b may be integrally formed with the second source electrode 173b to form a monolithic material. However, the embodiments are not limited thereto, and the second field dispersion layer 177b may be a component separated from the second source electrode 173b. In addition, the second field dispersion layer 177b may be located in a layer different from the second source electrode 173b and may be formed in a different process. In some cases, the second field dispersion layer 177b may be electrically connected to the gate electrode 155. For example, the first field dispersion layer 177a may be connected to the gate electrode 155 through an opening formed in the lower protection layer 180, and the second field dispersion layer 177b may be connected to the first field dispersion layer 177a through an opening formed in the first interlayer insulating layer 510.

[0104] The third field dispersion layer 177c may be located above the second interlayer insulating layer 520. The third field dispersion layer 177c may be located between the source electrode 173 and the drain electrode 175. The third field dispersion layer 177c may overlap with the gate electrode 155. The third field dispersion layer 177c may overlap with the first field dispersion layer 177a and the second field dispersion layer 177b. The gate electrode 155, the first field dispersion layer 177a, and the second field dispersion layer 177b may be covered by the third field dispersion layer 177c.

[0105] The third field dispersion layer 177c may be wider than the widths of the first field dispersion layer 177a and the second field dispersion layer 177b. The third field dispersion layer 177c may completely cover the first field dispersion layer 177a and the second field dispersion layer 177b. In one embodiment, one end of the third field dispersion layer 177c may be positioned closer to the drain electrode 175 than the corresponding end of the second field dispersion layer 177b. However, the embodiment is not limited thereto, and the width and positional relationships of the first field dispersion layer 177a, the second field dispersion layer 177b, and the third field dispersion layer 177c may be changed in various ways. The third field dispersion layer 177c may be electrically connected to the source electrode 173. For example, the third field dispersion layer 177c may be connected to the third source electrode 173c.

[0106] The third field dispersion layer 177c may include the same material as the third source electrode 173c and may be a part of the same layer as the third source electrode 173c. The third field dispersion layer 177c may be formed simultaneously in the same process as the third source electrode 173c. The grain boundary between the third field dispersion layer 177c and the third source electrode 173c is not clear, and the third field dispersion layer 177c may be integrally formed with the third source electrode 173c to form a monolithic material. However, the embodiment is not limited thereto, and the third field dispersion layer 177c may be a component separated from the third source electrode 173c. In addition, the third field dispersion layer 177c may be located in a layer different from the third source electrode 173c and may be formed in a different process.

[0107] In some cases, at least one of the field dispersion layers 177 may be omitted. For example, the semiconductor device according to an embodiment may include the first field dispersion layer 177a and the second field dispersion layer 177b and may not include the third field dispersion layer 177c. Alternatively, the semiconductor device according to an embodiment may include the second field dispersion layer 177b and may not include the first field dispersion layer 177a. Alternatively, the semiconductor device according to an embodiment may not include the first field dispersion layer 177a and the second field dispersion layer 177b.

[0108] Hereinafter, with reference to Figures 4 to 9 the content (at%) of the first element of the lower protective layer 180 and the interlayer insulating layer 500 of the semiconductor device according to an embodiment will be described in detail.

[0109] Figures 4 to 9 is a graph showing the concentration of a first element indicating the positions of a lower protective layer and an interlayer insulating layer of a semiconductor device according to some embodiments. Figures 4 to 9 is showing according to Figure 1 the content (at%) of the first element in the vertical direction (e.g., the thickness direction of the channel layer 132) of the lower protective layer 180, the content (at%) of the first element in the vertical direction (e.g., the thickness direction of the channel layer 132) of the first interlayer insulating layer 510, and the content (at%) of the first element in the vertical direction (e.g., the thickness direction of the channel layer 132) of the second interlayer insulating layer 520. In Figures 4 to 9 it, for each layer, separately, the thickness is indicated by the vertical axis, and the distance from the bottom surface of the lower protective layer 180 is indicated by the horizontal axis. The leftmost side along the horizontal axis of each layer indicates the level closer to the bottom surface of the lower protective layer 180, and the rightmost side along the horizontal axis of each layer indicates the level farther from the bottom surface of the lower protective layer 180.

[0110] Further referring to Figures 4 to 9 , as the distance from the bottom surface of the lower protective layer 180 increases, at least one of the lower protective layer 180, the first interlayer insulating layer 510, and the second interlayer insulating layer 520 of the semiconductor device according to some embodiments may contain different contents (at%) of the first element.

[0111] Referring to Figure 4 , as the distance from the bottom surface of the lower protective layer 180 increases, the second content (at%) of the first element in the lower protective layer 180, the first content (at%) of the first element in the first interlayer insulating layer 510, and the third content (at%) of the first element in the second interlayer insulating layer 520 may increase. In this case, as the distance from the bottom surface of the lower protective layer 180 increases, the second content (at%) of the first element in the lower protective layer 180, the first content (at%) of the first element in the first interlayer insulating layer 510, and the third content (at%) of the first element in the second interlayer insulating layer 520 may increase at a constant rate.

[0112] Therefore, the second content (at%) of the first element above the lower protective layer 180 may be greater than the second content (at%) of the first element below the lower protective layer 180. For example, on the bottom surface 180_B of the lower protective layer 180, the second content (at%) of the first element may have a minimum value, and on the upper surface of the lower protective layer 180, the second content (at%) of the first element may have a maximum value.

[0113] The first content (at%) of the first element at the upper part of the first interlayer insulating layer 510 may be greater than the first content (at%) of the first element at the lower part of the first interlayer insulating layer 510. For example, on the bottom surface of the first interlayer insulating layer 510, the first content (at%) of the first element may have a minimum value, and on the top surface of the first interlayer insulating layer 510, the first content (at%) of the first element may have a maximum value.

[0114] In an embodiment, the first content (at%) of the first element in the first interlayer insulating layer 510 may be greater than the second content (at%) of the first element in the lower protective layer 180. For example, the first minimum value N1min of the first content (at%) of the first element in the first interlayer insulating layer 510 may be greater than the second maximum value N2max of the second content (at%) of the first element in the lower protective layer 180. The first maximum value N1max of the first content (at%) of the first element in the first interlayer insulating layer 510 may be greater than the second maximum value N2max of the second content (at%) of the first element in the lower protective layer 180. In addition, the first minimum value N1min of the first content (at%) of the first element in the first interlayer insulating layer 510 may be greater than the second minimum value N2min of the second content (at%) of the first element in the lower protective layer 180. The total content (at%) of the first element in the entire first interlayer insulating layer 510 may be greater than the total content (at%) of the first element in the entire lower protective layer 180. In addition, there may be a sudden jump in the content (at%) of the first element at the interface between the top of the lower protective layer 180 and the bottom of the first interlayer insulating layer 510.

[0115] The third content (at%) of the first element at the upper part of the second interlayer insulating layer 520 may be greater than the third content (at%) of the first element at the lower part of the second interlayer insulating layer 520. For example, the third content (at%) of the first element on the bottom surface of the second interlayer insulating layer 520 may have a minimum value, and the third content (at%) of the first element on the upper surface of the second interlayer insulating layer 520 may have a maximum value.

[0116] In an embodiment, a third content (at%) of a first element of the second interlayer insulating layer 520 may be greater than or equal to a second content (at%) of the first element of the lower protective layer 180. For example, a third minimum value N3min of the third content (at%) of the first element of the second interlayer insulating layer 520 may be the same as or greater than a second maximum value N2max of the second content (at%) of the first element of the lower protective layer 180. In addition, a third maximum value N3max of the third content (at%) of the first element of the second interlayer insulating layer 520 may be greater than a second minimum value N2min of the second content (at%) of the first element of the lower protective layer 180. In Figure 4 the embodiment, the third maximum value N3max of the third content (at%) of the first element of the second interlayer insulating layer 520 is greater than the second maximum value N2max of the second content (at%) of the first element of the lower protective layer 180, and the third minimum value N3min of the third content (at%) of the first element of the second interlayer insulating layer 520 is greater than the second minimum value N2min of the second content (at%) of the first element of the lower protective layer 180. In addition, a sudden jump (e.g., decrease) in the content (at%) of the first element may exist at an interface between the top of the first interlayer insulating layer 510 and the bottom of the second interlayer insulating layer 520.

[0117] Referring to Figure 5 and Figure 6 , as the distance from the bottom surface of the lower protective layer 180 increases, the second content (at%) of the first element of the lower protective layer 180, the first content (at%) of the first element of the first interlayer insulating layer 510, and the third content (at%) of the first element of the second interlayer insulating layer 520 may increase.

[0118] In some embodiments, as shown in Figure 5 , an increase ratio d(N) / d(D) (also described herein as an increase rate) of the second content (at%) of the first element of the lower protective layer 180, the first content (at%) of the first element of the first interlayer insulating layer 510, and the third content (at%) of the first element of the second interlayer insulating layer 520 may decrease as the distance from the bottom surface of the lower protective layer 180 increases. Here, the increase ratio d(N) / d(D) of the second content (at%) of the first element of the lower protective layer 180 may represent a change amount of the content d(N), and the change amount of the content d(N) depends on a change amount of the distance d(D) in the vertical direction (e.g., the thickness direction of the channel layer 132) (e.g., divided by the change amount of the distance d(D)). As shown in Figure 5 , the increase rate d(N) / d(D) may be a slope of a tangent line of a graph showing the content (at%) according to the position.

[0119] In addition, as Figure 6 shown in Figure 6 it, the increase rate d(N) / d(D) of the second content (at%) of the first element of the lower protective layer 180, the first content (at%) of the first element of the first interlayer insulating layer 510, and the third content (at%) of the first element of the second interlayer insulating layer 520 can increase as the distance from the bottom surface of the lower protective layer 180 increases. Here, the increase rate d(N) / d(D) of the second content (at%) of the first element of the lower protective layer 180 can represent the change amount of the content d(N), and the change amount of the content d(N) depends on the change amount of the distance d(D) in the vertical direction (e.g., the thickness direction of the channel layer 132) (e.g., divided by the change amount of the distance d(D)). As

[0120] shown in Figure 5 and Figure 6 it, the first content (at%) of the first element of the first interlayer insulating layer 510 can be greater than the second content (at%) of the first element of the lower protective layer 180. For example, the first minimum value N1min of the first content (at%) of the first element of the first interlayer insulating layer 510 can be greater than the second maximum value N2max of the second content (at%) of the first element of the lower protective layer 180. The first maximum value N1max of the first content (at%) of the first element of the first interlayer insulating layer 510 can be greater than the second maximum value N2max of the second content (at%) of the first element of the lower protective layer 180. In addition, the third content (at%) of the first element of the second interlayer insulating layer 520 can be greater than or equal to the second content (at%) of the first element of the lower protective layer 180. As can be seen from the graph, Figure 5 and Figure 6 the other relationships between the contents (at%) of different layers in Figure 4 it can be similar or the same as those described above in combination with

[0121] Refer to Figure 7, at least one of the increase ratio d(N) / d(D) of the second content (at%) of the first element of the lower protective layer 180, the first content (at%) of the first element of the first interlayer insulating layer 510, and the third content (at%) of the first element of the second interlayer insulating layer 520 may increase as the distance from the bottom surface of the lower protective layer 180 increases. In addition, another increase ratio d(N) / d(D) of the second content (at%) of the first element of the lower protective layer 180, the first content (at%) of the first element of the first interlayer insulating layer 510, and the third content (at%) of the first element of the second interlayer insulating layer 520 may decrease as the distance from the bottom surface of the lower protective layer 180 increases. In addition, another increase ratio d(N) / d(D) of the second content (at%) of the first element of the lower protective layer 180, the first content (at%) of the first element of the first interlayer insulating layer 510, and the third content (at%) of the first element of the second interlayer insulating layer 520 may be constant as the distance from the bottom surface of the lower protective layer 180 increases.

[0122] For example, as Figure 7 shown, the second content (at%) of the first element of the lower protective layer 180, the first content (at%) of the first element of the first interlayer insulating layer 510, and the third content (at%) of the first element of the second interlayer insulating layer 520 may increase as the distance from the bottom surface 180_B of the lower protective layer 180 increases. The increase ratio d(N) / d(D) of the second content (at%) of the first element of the lower protective layer 180 may increase as it moves away from the bottom surface 180_B of the lower protective layer 180. In addition, the increase ratio d(N) / d(D) of the first content (at%) of the first element of the first interlayer insulating layer 510 may decrease as it moves away from the bottom surface 180_B of the lower protective layer 180. In addition, the increase ratio (d(N) / d(D)) of the third content (at%) of the first element of the second interlayer insulating layer 520 may be constant as it moves away from the bottom surface 180_B of the lower protective layer 180. However, the increase ratio d(N) / d(D) of the second content (at%) of the first element of the lower protective layer 180, the first content (at%) of the first element of the first interlayer insulating layer 510, and the third content (at%) of the first element of the second interlayer insulating layer 520 is not limited thereto and may vary in various ways. As can be seen from the graph, Figure 7 the other relationships between the contents (at%) of different layers in Figure 4 may be similar or the same as those described above in combination, and therefore, for the sake of brevity, their detailed descriptions are omitted.

[0123] Referring to Figure 8, the second content (at%) of the first element of the lower protective layer 180 may further include a portion that decreases as the distance from the bottom surface 180_B of the lower protective layer 180 increases.

[0124] For example, the lower protective layer 180 may include a portion where the second content (at%) of the first element increases as the distance from the bottom surface 180_B of the lower protective layer 180 increases, and a portion where the second content (at%) of the first element decreases as the distance from the bottom surface 180_B of the lower protective layer 180 increases. The second maximum value N2max of the second content (at%) of the first element of the lower protective layer 180 may be less than the first maximum value N1max of the first content (at%) of the first element of the first interlayer insulating layer 510. In addition, the second maximum value N2max of the second content (at%) of the first element of the lower protective layer 180 may be less than the first minimum value N1min of the first content (at%) of the first element of the first interlayer insulating layer 510.

[0125] In some embodiments, the second content (at%) of the first element of the lower protective layer 180 is described as further including a portion that decreases as the distance from the bottom surface 180_B of the lower protective layer 180 increases, but the embodiments are not limited thereto. For example, at least one of the second content (at%) of the first element of the lower protective layer 180, the first content (at%) of the first element of the first interlayer insulating layer 510, and the third content (at%) of the first element of the second interlayer insulating layer 520 may further include a portion where the content (at%) of the first element decreases as the distance from the bottom surface 180_B of the lower protective layer 180 increases.

[0126] In some embodiments, the second content (at%) of the first element of the lower protective layer 180 increases and then decreases as the distance from the bottom surface 180_B of the lower protective layer 180 increases, and the second content (at%) of the first element on the bottom surface 180_B of the lower protective layer 180 may be substantially the same as the second content (at%) of the first element on the upper surface of the lower protective layer 180. However, the embodiments are not limited thereto, and the second content (at%) of the first element on the bottom surface 180_B of the lower protective layer 180 may be different from the second content (at%) of the first element on the upper surface of the lower protective layer 180. As can be seen from the graph, Figure 8 the other relationships between the contents (at%) of different layers in Figure 4 may be similar or the same as those described above in combination, and therefore, for the sake of brevity, their detailed descriptions are omitted.

[0127] Referring to Figure 9, for example, throughout the entire thickness of each layer, the third content (at%) of the first element in the second interlayer insulating layer 520 may be less than the first content (at%) of the first element in the first interlayer insulating layer 510. For example, the third maximum value N3max of the third content (at%) of the first element in the second interlayer insulating layer 520 may be less than the first minimum value N1min of the first content (at%) of the first element in the first interlayer insulating layer 510. In addition, the third maximum value N3max of the third content (at%) of the first element in the second interlayer insulating layer 520 may be less than the first maximum value N1max of the first content (at%) of the first element in the first interlayer insulating layer 510. In addition, the third minimum value N3min of the third content (at%) of the first element in the second interlayer insulating layer 520 may be less than the first minimum value N1min of the first content (at%) of the first element in the first interlayer insulating layer 510.

[0128] In addition, for example, throughout the entire thickness of each layer, the third content (at%) of the first element in the second interlayer insulating layer 520 may be greater than the second content (at%) of the first element in the lower protective layer 180. For example, the third minimum value N3min of the third content (at%) of the first element in the second interlayer insulating layer 520 may be greater than the second maximum value N2max of the second content (at%) of the first element in the lower protective layer 180. The third minimum value N3min of the third content (at%) of the first element in the second interlayer insulating layer 520 may be greater than the second minimum value N2min of the second content (at%) of the first element in the lower protective layer 180. In addition, the third maximum value N3max of the third content (at%) of the first element in the second interlayer insulating layer 520 may be greater than the second maximum value N2max of the second content (at%) of the first element in the lower protective layer 180. Hereinafter, reference is made to Figures 10 to 13 Describe a semiconductor device according to some embodiments.

[0129] Figure 10 and Figure 11 is a cross-sectional view showing a semiconductor device according to some embodiments. Figure 12 and Figure 13 is a graph showing the concentration of the first element at the positions of the lower protective layer and the interlayer insulating layer of a semiconductor device according to some embodiments. Figure 12 and Figure 13 is a graph showing the content (at%) of the first element in the vertical direction (e.g., the thickness direction of the channel layer 132) of the first lower protective layer 180a to the third lower protective layer 180c.

[0130] Figures 10 to 13 is according to to Figures 1 to 3 Many variations of the semiconductor device according to the embodiments shown in. Figures 10 to 13The embodiments shown in Figures 1 to 3 are the same in many parts as the embodiments shown in

[0131] and thus their description will be omitted and the differences will be mainly explained. In addition, the same reference numerals are used for the same components as in the previous embodiments. Figure 10 and Figure 11 , a semiconductor device according to an embodiment may include a channel layer 132, a barrier layer 136 on the channel layer 132, a gate electrode 155 on the barrier layer 136, a gate semiconductor layer 152 between the barrier layer 136 and the gate electrode 155, a lower protection layer 180 on the barrier layer 136, an interlayer insulating layer 500 on the lower protection layer 180, source electrodes 173 and drain electrodes 175 separated from each other on the channel layer 132, and a field dispersion layer 177 on the lower protection layer 180.

[0132] The lower protection layer 180 according to some embodiments may include multiple layers sequentially stacked from the upper surface of the barrier layer 136.

[0133] For example, as Figure 10 shown, the lower protection layer 180 may include a first lower protection layer 180a and a second lower protection layer 180b sequentially positioned from the upper surface of the barrier layer 136. The first lower protection layer 180a may be located above the barrier layer 136. The first lower protection layer 180a may cover the gate electrode 155. The second lower protection layer 180b may be located above the first lower protection layer 180a. The first lower protection layer 180a and the second lower protection layer 180b may be located between the barrier layer 136 and the first field dispersion layer 177a. The first lower protection layer 180a may be in contact with the barrier layer 136, and the second lower protection layer 180b may be in contact with the first field dispersion layer 177a.

[0134] As another example, as Figure 11 shown, the lower protection layer 180 may include a first lower protection layer 180a to a third lower protection layer 180c sequentially positioned from the upper surface of the barrier layer 136. The first lower protection layer 180a may be located above the barrier layer 136. The first lower protection layer 180a may cover the gate electrode 155. The second lower protection layer 180b may be located above the first lower protection layer 180a. The third lower protection layer 180c may be located above the second lower protection layer 180b. The first lower protection layer 180a to the third lower protection layer 180c may be located between the barrier layer 136 and the first field dispersion layer 177a. The first lower protection layer 180a may be in contact with the barrier layer 136, and the third lower protection layer 180c may be in contact with the first field dispersion layer 177a.

[0135] Further referring to Figure 12 and Figure 13, the first lower protection layer 180a to the third lower protection layer 180c may include a first element and a second element different from the first element. Here, the first element may be nitrogen (N), and the second element may be silicon (Si). As an example, when the first lower protection layer 180a to the third lower protection layer 180c include silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon oxycarbonitride (SiOCN), silicon nitride (SiN), or a combination thereof, the first element may be nitrogen (N), and the second element may be silicon (Si).

[0136] In some embodiments, the first lower protection layer 180a may include a first element with a fourth content N2a (at%), the second lower protection layer 180b may include a first element with a fifth content N2b (at%), and the third lower protection layer 180c may include a first element with a sixth content N2c (at%). The content (at%) of the first element included in the first lower protection layer 180a to the third lower protection layer 180c may be different. For example, as Figure 12 shown, the fourth content N2a (at%) of the first element in the first lower protection layer 180a may be less than the fifth content N2b (at%) of the first element in the second lower protection layer 180b. In addition, the fifth content N2b (at%) of the first element in the second lower protection layer 180b may be less than the sixth content N2c (at%) of the first element in the third lower protection layer 180c. The sixth content N2c (at%) of the first element in the third lower protection layer 180c may be less than the first content N1 (at%) of the first element in the first interlayer insulating layer 510. In addition, the sixth content N2c (at%) of the first element in the third lower protection layer 180c may be less than the third content N3 (at%) of the first element in the second interlayer insulating layer 520.

[0137] As another example, as Figure 13 shown, the fifth content N2b (at%) of the first element in the second lower protection layer 180b may be greater than the sixth content N2c (at%) of the first element in the third lower protection layer 180c. The fifth content N2b (at%) of the first element in the second lower protection layer 180b may be less than the first content N1 (at%) of the first element in the first interlayer insulating layer 510. In addition, the sixth content N2c (at%) of the first element in the third lower protection layer 180c may be less than the third content N3 (at%) of the first element in the second interlayer insulating layer 520. However, the embodiments are not limited thereto, and the content of the first element in the first lower protection layer 180a to the third lower protection layer 180c may vary in various ways within a range smaller than the content (at%) of the first element in the second interlayer insulating layer 520 and the content (at%) of the first element in the first interlayer insulating layer 510.

[0138] InFigure 10 and Figure 11 In the embodiments of Figure 11 , the lower protective layer 180 is described as being composed of two or three layers, but is not limited thereto, and the lower protective layer 180 may be composed of four or more layers.

[0139] In Figure 12 and Figure 13 it is described Figure 11 the content (at%) of the first element in the first lower protective layer 180a to the third lower protective layer 180c of the embodiment of Figure 11 according to the vertical direction (for example, the thickness direction of the channel layer 132), but of course it can be equivalently applied to Figure 10 the first lower protective layer 180a and the second lower protective layer 180b of the embodiment of Figure 10 .

[0140] Hereinafter, a semiconductor device according to some embodiments will be described with reference to Figures 14 to 18 Figures 14 to 18 .

[0141] Figure 14 and Figure 15 are cross-sectional views showing a semiconductor device according to some embodiments. Figures 16 to 18 is a graph showing the concentration of the first element at the positions of the lower protective layer and the interlayer insulating layer of a semiconductor device according to some embodiments. Figures 16 to 18 shows Figure 15 a graph of the content (at%) of the first element in the first sub-interlayer insulating layer 510a to the third sub-interlayer insulating layer 510c of Figure 15 according to the vertical direction (for example, the thickness direction of the channel layer 132).

[0142] Figures 14 to 18 is a semiconductor device according to Figures 1 to 3 many variations of the embodiment shown in Figures 1 to 3 . Figures 14 to 18 The embodiment shown in Figures 14 to 18 includes many features the same as those of the embodiment shown in Figures 1 to 3 Figures 1 to 3 , so its description will be omitted and the differences will be mainly explained. In addition, the same or similar reference numerals are used for the same or similar components as in the previous embodiments.

[0143] First, with reference to Figure 14 and Figure 15 , a semiconductor device according to an embodiment may include a channel layer 132, a barrier layer 136 located on the channel layer 132, a gate electrode 155 located on the barrier layer 136, a gate semiconductor layer 152 located between the barrier layer 136 and the gate electrode 155, a lower protective layer 180 located on the barrier layer 136, an interlayer insulating layer 500 located on the lower protective layer 180, a source electrode 173 and a drain electrode 175 separated from each other on the channel layer 132, and a field dispersion layer 177 located on the lower protective layer 180.

[0144] The first interlayer insulating layer 510 according to some embodiments may include multiple layers sequentially stacked from the upper surface of the lower protective layer 180.

[0145] For example, as Figure 14 shown, the first interlayer insulating layer 510 may include a first sub-interlayer insulating layer 510a and a second sub-interlayer insulating layer 510b sequentially positioned from the upper surfaces of the lower protective layer 180 and the first field dispersion layer 177a. The first sub-interlayer insulating layer 510a may be located above the lower protective layer 180 and the first field dispersion layer 177a. The first sub-interlayer insulating layer 510a may cover the gate electrode 155. In addition, the first sub-interlayer insulating layer 510a may cover the first field dispersion layer 177a. The second sub-interlayer insulating layer 510b may be located above the first sub-interlayer insulating layer 510a. The first sub-interlayer insulating layer 510a and the second sub-interlayer insulating layer 510b may be located between the first field dispersion layer 177a and the second field dispersion layer 177b. The first sub-interlayer insulating layer 510a may be in contact with the first field dispersion layer 177a and the lower protective layer 180, and the second sub-interlayer insulating layer 510b may be in contact with the second field dispersion layer 177b and the second interlayer insulating layer 520.

[0146] As another example, as Figure 15 shown, the first interlayer insulating layer 510 may include a first sub-interlayer insulating layer 510a to a third sub-interlayer insulating layer 510c sequentially positioned from the upper surface of the lower protective layer 180 and the upper surface of the first field dispersion layer 177a. The first sub-interlayer insulating layer 510a may be located above the lower protective layer 180 and the first field dispersion layer 177a. The first sub-interlayer insulating layer 510a may cover the gate electrode 155. The first sub-interlayer insulating layer 510a may cover the first field dispersion layer 177a. The second sub-interlayer insulating layer 510b may be located above the first sub-interlayer insulating layer 510a. The third sub-interlayer insulating layer 510c may be located above the second sub-interlayer insulating layer 510b. The first sub-interlayer insulating layer 510a to the third sub-interlayer insulating layer 510c may be located between the first field dispersion layer 177a and the second field dispersion layer 177b. The first sub-interlayer insulating layer 510a may be in contact with the first field dispersion layer 177a and the lower protective layer 180, and the third sub-interlayer insulating layer 510c may be in contact with the second field dispersion layer 177b and the second interlayer insulating layer 520.

[0147] In Figure 14 and Figure 15In the embodiments, the first interlayer insulating layer 510 is described as being composed of two or three layers, but is not limited thereto, and the first interlayer insulating layer 510 may be composed of four or more layers. In various embodiments, different layers (e.g., the lower protective layer 180 or the first interlayer insulating layer 510 as discussed above) may include a plurality of sub-layers. Each sub-layer may have a different content (e.g., a higher or lower content) of the first element. Nevertheless, in various embodiments, each sub-layer extends horizontally to be disposed in the regions of one or more layers covering the field dispersion layer 177, the region adjacent to the source electrode 173, and the region adjacent to the drain electrode 175. In some embodiments, each sub-layer may be continuously formed through these regions. Further, as can be seen in the various figures, the lower protective layer 180, the first interlayer insulating layer 510, and the second interlayer insulating layer may be stacked in a manner interleaved with the first field dispersion layer 177a to the third field dispersion layer 177c.

[0148] With further reference to Figures 16 to 18 , the first sub-interlayer insulating layer 510a to the third sub-interlayer insulating layer 510c may include a first element and a second element different from the first element. Here, the first element may be nitrogen (N), and the second element may be silicon (Si). As an example, if the first sub-interlayer insulating layer 510a to the third sub-interlayer insulating layer 510c include silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon oxycarbonitride (SiOCN), silicon nitride (SiN), or a combination thereof, the first element may be nitrogen (N), and the second element may be silicon (Si).

[0149] In some embodiments, the first sub-interlayer insulating layer 510a may include a seventh content N1a (at%) of the first element, the second sub-interlayer insulating layer 510b may include an eighth content N1b (at%) of the first element, and the third sub-interlayer insulating layer 510c may include a ninth content N1c (at%) of the first element.

[0150] At this time, the content (at%) of the first element included in the first sub-interlayer insulating layer 510a to the third sub-interlayer insulating layer 510c may be different. For example, as Figure 16As shown, the seventh content N1a (at%) of the first element of the first interlayer insulating layer 510a can be less than the eighth content N1b (at%) of the first element of the second interlayer insulating layer 510b. In addition, the eighth content N1b (at%) of the first element of the second interlayer insulating layer 510b can be less than the ninth content N1c (at%) of the first element of the third interlayer insulating layer 510c. The seventh content N1a (at%) of the first element of the first interlayer insulating layer 510a can be greater than the second content (at%) of the first element of the lower protective layer 180. In addition, the seventh content N1a (at%) of the first element of the first interlayer insulating layer 510a can be greater than the third content (at%) of the first element of the second interlayer insulating layer 520.

[0151] As another example, as Figure 17 shown, the eighth content N1b (at%) of the first element of the second interlayer insulating layer 510b can be greater than the ninth content N1c (at%) of the first element of the third interlayer insulating layer 510c. The eighth content N1b (at%) of the first element of the second interlayer insulating layer 510b can be greater than the second content (at%) of the first element of the lower protective layer 180. In addition, the ninth content N1c (at%) of the first element of the third interlayer insulating layer 510c can be greater than the second content (at%) of the first element of the lower protective layer 180. However, the embodiments are not limited thereto, and the content of the first element in the first interlayer insulating layer 510a to the third interlayer insulating layer 510c can be changed in various ways within a range greater than the content (at%) of the first element in the second interlayer insulating layer 520 and the content (at%) of the first element in the lower protective layer 180.

[0152] As another example, referring to Figure 18 , the seventh content N1a (at%) of the first element of the first interlayer insulating layer 510a and the ninth content N1c (at%) of the first element of the third interlayer insulating layer 510c can be less than the eighth content N1b (at%) of the first element of the second interlayer insulating layer 510b. Therefore, the seventh content N1a (at%) of the first element of the first interlayer insulating layer 510a and the ninth content N1c (at%) of the first element of the third interlayer insulating layer 510c can be less than the third content N3 (at%) of the first element of the second interlayer insulating layer 520. However, even in this case, the seventh content N1a (at%) of the first element of the first interlayer insulating layer 510a and the ninth content N1c (at%) of the first element of the third interlayer insulating layer 510c can also be greater than the second content (at%) of the first element of the lower protective layer 180.

[0153] In Figures 16 to 18 it is described that Figure 15The content (at%) of the first element according to the vertical direction (e.g., the thickness direction of the channel layer 132) of the first interlayer insulating layer 510a to the third interlayer insulating layer 510c of the embodiment, but these examples can be equivalently applied to Figure 14 the first interlayer insulating layer 510a and the second interlayer insulating layer 510b of the embodiment.

[0154] In Figures 14 to 18 the embodiment, the second interlayer insulating layer 520 is shown as being composed of a single layer, but is not limited thereto. For example, the second interlayer insulating layer 520 may be composed of multiple layers including different contents (at%) of the first element, such as Figures 14 to 18 the first interlayer insulating layer 510 in the embodiment. In addition, although the content (at%) of each layer is shown in Figures 14 to 18 without referring to different alternatives of the content distribution in the entire layer, similar content profiles as depicted in Figures 4 to 9 can be used for Figures 14 to 18 (and in the embodiments of Figure 19 and Figure 20 described in more detail below).

[0155] Hereinafter, a semiconductor device according to an embodiment will be described with reference to Figure 19 .

[0156] Figure 19 is a cross-sectional view showing a semiconductor device according to some embodiments.

[0157] With reference to Figure 19 , a semiconductor device according to some embodiments may include a source electrode 173 and a drain electrode 175 located on a channel layer 132.

[0158] In some embodiments, each of the source electrode 173 and the drain electrode 175 may be formed of a single layer. For example, the sides of the source electrode 173 and the drain electrode 175 may be in contact with the channel layer 132, the barrier layer 136, the lower protective layer 180, the first interlayer insulating layer 510, and the second interlayer insulating layer 520. The source electrode 173 and the drain electrode 175 may be spaced apart from each other, and the gate electrode 155 and the gate semiconductor layer 152 may be located between the source electrode 173 and the drain electrode 175.

[0159] At a horizontal position where the second interlayer insulating layer 520 contacts each of the source electrode 173 and the drain electrode 175, the uppermost surface of the source electrode 173 and the uppermost surface of the drain electrode 175 may be at a level higher than the upper surface of the second interlayer insulating layer 520, but the embodiment is not limited thereto. For example, at a horizontal position where the second interlayer insulating layer 520 contacts each of the source electrode 173 and the drain electrode 175, the upper surface of the source electrode 173 and the upper surface of the drain electrode 175 may be farther from the upper surface of the substrate 110 than the upper surface of the second interlayer insulating layer 520.

[0160] In some embodiments, the first field dispersion layer 177a to the third field dispersion layer 177c may be connected to the source electrode 173. The first field dispersion layer 177a to the third field dispersion layer 177c may include the same material as the source electrode 173 and may be formed integrally with the source electrode 173.

[0161] Hereinafter, reference is made to Figure 20 Describe a semiconductor device according to an embodiment.

[0162] Figure 20 is a cross-sectional view showing a semiconductor device according to an embodiment.

[0163] Reference is made to Figure 20 , a semiconductor device according to some embodiments includes a channel layer 132, a barrier layer 136 located on the channel layer 132, a gate electrode 155 located on the barrier layer 136, a gate semiconductor layer 152 located between the barrier layer 136 and the gate electrode 155, a source electrode 173 and a drain electrode 175 spaced apart from each other on the channel layer 132, a lower protective layer 180 located on the barrier layer 136, an intermediate protective layer 190 located on the lower protective layer 180, an interlayer insulating layer 500 located on the intermediate protective layer 190, and a field dispersion layer 177 located on the intermediate protective layer 190.

[0164] The intermediate protective layer 190 may be located above the lower protective layer 180. The intermediate protective layer 190 may cover the sides of the source electrode 173 and the drain electrode 175. For example, the intermediate protective layer 190 may cover the sides of the first source electrode 173a, the second source electrode 173b, the first drain electrode 175a, and the second drain electrode 175b. In addition, at least a part of the intermediate protective layer 190 may cover the upper surfaces of the source electrode 173 and the drain electrode 175 (for example, the upper surfaces of the first source electrode 173a and the first drain electrode 175a).

[0165] The gate electrode 155 of the semiconductor device according to some embodiments may be connected to the gate semiconductor layer 152 through the lower protective layer 180 and the intermediate protective layer 190.

[0166] In some embodiments, the gate electrode 155 may penetrate the lower protection layer 180 and the intermediate protection layer 190. For example, the gate electrode 155 may penetrate the lower protection layer 180 and the intermediate protection layer 190 above the gate semiconductor layer 152. Accordingly, at least a part of the side surface of the gate electrode 155 may be in contact with the lower protection layer 180 and the intermediate protection layer 190. The gate electrode 155 may overlap with the gate semiconductor layer 152 in the vertical direction (e.g., the thickness direction of the channel layer 132). The bottom surface of the gate electrode 155 may be in contact with the top surface of the gate semiconductor layer 152. The gate electrode 155 may be located on at least a part of the gate semiconductor layer 152. For example, the gate electrode 155 may be located on a part of the gate semiconductor layer 152 (e.g., to contact a part of the top surface of the gate semiconductor layer 152), and the lower protection layer 180 may be located on the remaining part of the gate semiconductor layer 152 (e.g., to contact the remaining part of the top surface of the gate semiconductor layer 152). Accordingly, the top surface of the gate semiconductor layer 152 may be in contact with the gate electrode 155 and the lower protection layer 180. However, the embodiments are not limited thereto, and the top surface of the gate semiconductor layer 152 may completely overlap with the bottom surface of the gate electrode 155.

[0167] In some embodiments, the first field dispersion layer 177a may be located above the intermediate protection layer 190. For example, the first field dispersion layer 177a may be located between the gate electrode 155 and the drain electrode 175. Although not shown in the drawings, the first field dispersion layer 177a may be connected to the gate electrode 155 or the source electrode 173. However, the embodiments are not limited thereto, and the first field dispersion layer 177a may not be connected to the gate electrode 155 and the source electrode 173. In addition, the first field dispersion layer 177a may extend in one direction. For example, the first field dispersion layer 177a may extend in a direction parallel to the gate electrode 155, the source electrode 173, and the drain electrode 175.

[0168] Hereinafter, refer to Figures 21 to 30 A method of manufacturing a semiconductor device according to an embodiment will be described.

[0169] Figures 21 to 30 is a process cross-sectional view according to the process sequence of manufacturing a semiconductor device according to an embodiment.

[0170] First, as Figure 21 shown, a seed layer 115, a buffer layer 120, a channel layer 132, a barrier layer 136, and a gate semiconductor material layer 152a may be sequentially formed on a substrate 110.

[0171] The substrate 110 may include a semiconductor material. For example, the substrate 110 may include sapphire, Si, SiC, AlN, GaN, or a combination thereof. The substrate 110 may be a silicon-on-insulator (SOI) substrate. However, the material of the substrate 110 is not limited thereto, and any commonly used substrate may be used.

[0172] The seed layer, the buffer layer 120, the channel layer 132, the barrier layer 136, and the gate semiconductor material layer 152a may be sequentially formed, for example, using an epitaxial growth method. The seed layer 115 may be first formed on the substrate 110, and the buffer layer 120 may be formed on the seed layer 115. Next, the channel layer 132 may be formed on the buffer layer 122, the barrier layer 136 may be formed on the channel layer 132, and the gate semiconductor material layer 152a may be formed on the barrier layer 136. Although not shown, the buffer layer 120 may include a superlattice layer and a high-resistance layer. For example, the superlattice layer and the high-resistance layer may be formed on the seed layer 115 of the semiconductor device according to an embodiment. In this case, the superlattice layer and the high-resistance layer may be located between the buffer layer 120 and the channel layer 132.

[0173] Two or more of the seed layer 115, the buffer layer 120, the channel layer 132, the barrier layer 136, and the gate semiconductor material layer 152a may be made of the same matrix semiconductor material. However, considering the function of each layer and the performance required for the semiconductor device, the material composition ratios of each layer may be different. The seed layer, the buffer layer 120, the channel layer 132, the barrier layer 136, and the gate semiconductor material layer 152a may include one or more materials selected from III-V materials (such as nitrides including Al, Ga, In, B, or a combination thereof). The seed layer, the buffer layer 120, the channel layer 132, the barrier layer 136, and the gate semiconductor material layer 152a may be Al x In y Ga (1-x-y) N (0 ≤ x ≤ 1, 0 ≤ y ≤ 1, x + y ≤ 1). For example, the seed layer 115, the buffer layer 120, the channel layer 132, the barrier layer 136, and the gate semiconductor material layer 152a may include AlN, GaN, InN, InGaN, AlGaN, AlInN, AlInGaN, or a combination thereof. The barrier layer 136 may include a material having a different bandgap from that of the channel layer 132. The barrier layer 136 may have a higher bandgap than the channel layer 132. The gate semiconductor material layer 152a may include a material having a different bandgap from that of the barrier layer 136.

[0174] As an example, the substrate 110 may include Si, the seed layer 115 may include AlN, and the buffer layer 120 may include GaN. The channel layer 132 may include GaN, and the barrier layer 136 may include AlGaN. The channel layer 132 and the barrier layer 136 may or may not be doped with impurities. The gate semiconductor material layer 152a may include GaN and may be doped with impurities. The gate semiconductor material layer 152a may be doped with a p-type impurity such as magnesium (Mg).

[0175] Since the lattice structure of Si is different from that of GaN, it may not be easy to directly grow the channel layer 132 made of GaN on the substrate 110 made of Si. In the method of manufacturing a semiconductor device according to an embodiment, by first forming the seed layer 115 and the buffer layer 120 on the substrate 110 and then forming the channel layer 132, the lattice structure of the channel layer 132 can be stably formed.

[0176] As Figure 22 shown, a gate electrode material layer 155a may be formed on the gate semiconductor material layer 152a. The gate semiconductor material layer 152a is located between the barrier layer 136 and the gate electrode material layer 155a.

[0177] The gate electrode material layer 155a may be formed using a deposition process. For example, at least one of physical vapor deposition (PVD), thermal chemical vapor deposition (thermal CVD), low pressure chemical vapor deposition (LP-CVD), plasma enhanced chemical vapor deposition (PE-CVD), and atomic layer deposition (ALD) techniques may be used to form the gate electrode material layer 155a, but is not limited thereto.

[0178] The gate electrode material layer 155a may include a conductive material. For example, the gate electrode material layer 155a may include a metal, a metal alloy, a conductive metal nitride, a metal silicide, a doped semiconductor material, a conductive metal oxide, or a conductive metal oxynitride, etc. For example, the gate electrode material layer 155a may include titanium nitride (TiN), tantalum carbide (TaC), tantalum nitride (TaN), titanium silicon nitride (TiSiN), tantalum silicon nitride (TaSiN), tantalum titanium nitride (TaTiN), titanium aluminum nitride (TiAlN), tantalum aluminum nitride (TaAlN), tungsten nitride (WN), ruthenium (Ru), titanium aluminum (TiAl), titanium aluminum carbonitride (TiAlC-N), titanium aluminum carbide (TiAlC), titanium carbide (TiC), tantalum carbonitride (TaCN), tungsten (W), aluminum (Al), copper (Cu), cobalt (Co), titanium (Ti), tantalum (Ta), nickel (Ni), platinum (Pt), nickel platinum (Ni-Pt), niobium (Nb), niobium nitride (NbN), niobium carbide (NbC), molybdenum (Mo), molybdenum nitride (MoN), molybdenum carbide (MoC), tungsten carbide (WC), rhodium (Rh), palladium (Pd), iridium (Ir), osmium (Os), silver (Ag), gold (Au), zinc (Zn), vanadium (V), or a combination thereof, but not limited thereto. The gate electrode material layer 155a may be made of a single layer or multiple layers.

[0179] Next, as Figure 23 shown in, the gate electrode 155 and the gate semiconductor layer 152 can be formed by patterning the gate electrode material layer 155a and the gate semiconductor material layer 152a via a lithography process.

[0180] For example, a hard mask layer and a photoresist layer can be sequentially formed on the gate electrode material layer 155a. The photoresist pattern can be formed by patterning the photoresist layer via a lithography process. The hard mask pattern can be formed by etching the hard mask layer using the photoresist pattern as a mask. At this time, at least a part of the gate electrode material layer 155a can be removed during the process of etching the hard mask layer. Then, by etching the gate semiconductor material layer 152a using the hard mask pattern as a mask, at least a part of the gate semiconductor material layer 152a can be removed. Therefore, the remaining part of the gate electrode material layer 155a can become the gate electrode 155. In addition, the remaining part of the gate semiconductor material layer 152a can become the gate semiconductor layer 152. The gate semiconductor layer 152 is located between the barrier layer 136 and the gate electrode 155. The gate electrode 155 can be in Schottky contact or ohmic contact with the gate semiconductor layer 152.

[0181] By patterning the gate semiconductor material layer 152a and the gate electrode material layer 155a via the use of the same mask, the gate semiconductor layer 152 and the gate electrode 155 can have the same pattern. That is, the gate semiconductor layer 152 and the gate electrode 155 can have the same planar shape. In a cross-sectional view, the gate semiconductor layer 152 and the gate electrode 155 can have the same width. The gate semiconductor layer 152 can completely overlap the gate electrode 155 in the vertical direction, and the upper surface of the gate semiconductor layer 152 can be completely covered by the gate electrode 155, but the embodiments are not limited thereto. For example, the gate semiconductor layer 152 and the gate electrode 155 can only partially overlap in the vertical direction.

[0182] As Figure 24 shown, a lower protective layer 180 can be formed on the barrier layer 136 and the gate electrode 155. A deposition process can be used to form the lower protective layer 180. The lower protective layer 180 can be located above the barrier layer 136 and the gate electrode 155. The lower protective layer 180 can cover the upper surface and the side surface of the gate electrode 155 and the side surface of the gate semiconductor layer 152. The bottom surface of the lower protective layer 180 can be in contact with the barrier layer 136 and the gate electrode 155. Accordingly, the barrier layer 136, the gate semiconductor layer 152, and the gate electrode 155 can be protected by the lower protective layer 180.

[0183] In an embodiment, the lower protective layer 180 can include an insulating material. For example, the lower protective layer 180 can include silicon oxide (SiO2), silicon oxycarbide (SiOC), or a combination thereof. In addition, the lower protective layer 180 can include silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon oxycarbonitride (SiOCN), silicon nitride (SiN), or a combination thereof. As another example, the lower protective layer 180 can include a material such as aluminum oxide (Al2O3).

[0184] In an embodiment, the lower protective layer 180 can include a first element and a second element different from the first element. Here, the first element can be nitrogen (N), and the second element can be silicon (Si). For example, if the lower protective layer 180 includes silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon oxycarbonitride (SiOCN), silicon nitride (SiN), or a combination thereof, the first element can be nitrogen (N), and the second element can be silicon (Si).

[0185] At this time, the lower protection layer 180 may include a first element in a second content (at%). Here, the first element in the second content (at%) of the lower protection layer 180 may represent the content (at%) of the first element among the entire content of the lower protection layer 180. For example, if the lower protection layer 180 includes silicon oxynitride (SiON), the second content (at%) may be the content (at%) of nitrogen (N) among the entire content of silicon (Si), nitrogen (N), and oxygen (O) of the lower protection layer 180. As another example, if the lower protection layer 180 includes silicon nitride (SiN), the second content (at%) may be the content (at%) of nitrogen (N) among the entire content of silicon (Si) and nitrogen (N) in the lower protection layer 180. For example, the second content (at%) of the first element of the lower protection layer 180 may be 0 at% or greater and less than about 1 at%. For example, when the lower protection layer 180 includes silicon oxynitride (SiON), the second content (at%) of nitrogen (N) in the lower protection layer 180 may be greater than 0 at% and less than about 1 at%. On the other hand, when the lower protection layer 180 includes silicon dioxide (SiO2), the second content (at%) of nitrogen (N) in the lower protection layer 180 may be 0 at%.

[0186] In an embodiment, the lower protection layer 180 is described as being formed of a single layer, but is not limited thereto. For example, the lower protection layer 180 may be composed of multiple layers sequentially stacked on the barrier layer 136.

[0187] The sides of the gate electrode 155 and the gate semiconductor layer 152 may be covered by the lower protection layer 180. The sides of the gate electrode 155 and the gate semiconductor layer 152 may be in contact with the lower protection layer 180. A step may occur between the portion of the lower protection layer 180 overlapping the gate electrode 155 and the gate semiconductor layer 152 and the remaining portion. However, the embodiment is not limited thereto, and in some cases, the upper surface of the lower protection layer 180 may be completely flat. For example, if the thickness of the lower protection layer 180 is relatively thick, a step may not occur between the portion of the lower protection layer 180 overlapping the gate electrode 155 and the gate semiconductor layer 152 and the remaining portion.

[0188] As Figure 25 shown, the first trench 141 and the second trench 143 may be formed by patterning the lower protection layer 180 via a lithography process. At this time, not only the lower protection layer 180 but also the barrier layer 136 and the channel layer 132 may be patterned together.

[0189] For example, a photoresist pattern may be formed on the lower protection layer 180, and the lower protection layer 180, the barrier layer 136, and the channel layer 132 may be sequentially etched using the photoresist pattern as a mask. At this time, the lower protection layer 180 and the barrier layer 136 may be completely penetrated by the first trench 141 and the second trench 143, and the upper surface of the channel layer 132 may be recessed. The channel layer 132 may not be completely penetrated by the first trench 141 or the second trench 143. That is, the depth of the recess of the upper surface of the channel layer 132 may be less than the entire thickness of the channel layer 132. At this time, the depth of the recess of the upper surface of the channel layer 132 may be much smaller than the entire thickness of the channel layer 132. In addition, the depth of the recess of the upper surface of the channel layer 132 may be less than the thickness of the barrier layer 136. However, the embodiments are not limited thereto, and the depth of the recess of the upper surface of the channel layer 132 may be changed in various ways.

[0190] Through the first trench 141 and the second trench 143, the side surfaces of the lower protection layer 180 and the barrier layer 136 may be exposed to the outside, and the upper surface and the side surfaces of the channel layer 132 may be exposed. The channel layer 132 may form the bottom surface and the sidewalls of the first trench 141 and the second trench 143, and the barrier layer 136 and the lower protection layer 180 may form the sidewalls of the first trench 141 and the second trench 143.

[0191] The first trench 141 and the second trench 143 may be spaced apart from each other. The first trench 141 and the second trench 143 may be located on both sides of the gate electrode 155. The first trench 141 may be located on one side of the gate electrode 155 to be spaced apart from the gate electrode 155. The second trench 143 may be located on the other side of the gate electrode 155 to be spaced apart from the gate electrode 155. The distance by which the first trench 141 is separated from the gate electrode 155 may be less than the distance by which the second trench 143 is separated from the gate electrode 155. The shapes such as the widths and depths of the first trench 141 and the second trench 143 are shown to be similar, but are not limited thereto. The shapes of the first trench 141 and the second trench 143 may be changed in various ways. The channel layer 132, the barrier layer 136, and the lower protection layer 180 may be located outside the first trench 141 and the second trench 143.

[0192] As Figure 26 shown, a conductive material may be deposited in the first trench 141 and the second trench 143 and the conductive material may be patterned to form the first source electrode 173a and the first drain electrode 175a.

[0193] The first source electrode 173a and the first drain electrode 175a may include a conductive material. For example, the first source electrode 173a and the first drain electrode 175a may include a metal, a metal alloy, a conductive metal nitride, a metal silicide, a doped semiconductor material, a conductive metal oxide, or a conductive metal oxynitride. The first source electrode 173a and the first drain electrode 175a may be made of a single layer or multiple layers. For example, a plurality of conductive layers including different materials may be stacked and then patterned to form the first source electrode 173a and the first drain electrode 175a. At this time, a plurality of conductive layers may be etched simultaneously or sequentially using one mask pattern. For example, Ti, Al, Ti, and TiN may be sequentially stacked and then patterned to form the first source electrode 173a and the first drain electrode 175a. At this time, the thicknesses of the four conductive layers constituting the first source electrode 173a and the first drain electrode 175a may be similar to or different from each other. For example, the layer made of Al may be relatively thick compared to other layers.

[0194] The first source electrode 173a may be formed to fill the inside of the first trench 141. Inside the first trench 141, the first source electrode 173a may be in contact with the channel layer 132 and the barrier layer 136. The first source electrode 173a may be in contact with the side surfaces of the channel layer 132 and the barrier layer 136. The first source electrode 173a may cover the side surfaces of the channel layer 132 and the barrier layer 136. The first source electrode 173a may be electrically connected to the channel layer 132 through the first trench 141. The upper surface of the first source electrode 173a may protrude from the upper surface of the lower protective layer 180.

[0195] The first drain electrode 175a may be formed to fill the inside of the second trench 143. Inside the second trench 143, the first drain electrode 175a may be in contact with the channel layer 132 and the barrier layer 136. The first drain electrode 175a may be in contact with the side surfaces of the channel layer 132 and the barrier layer 136. The first drain electrode 175a may cover the side surfaces of the channel layer 132 and the barrier layer 136. The first drain electrode 175a may be electrically connected to the channel layer 132 through the second trench 143. The upper surface of the first drain electrode 175a may protrude from the upper surface of the lower protective layer 180.

[0196] The first source electrode 173a and the first drain electrode 175a may be in ohmic contact with the channel layer 132. The regions in the channel layer 132 that are in contact with the first source electrode 173a and the first drain electrode 175a may be doped at a relatively high concentration compared to other regions. For example, the channel layer 132 may be doped by an ion implantation process, an annealing process, or the like. However, the embodiments are not limited thereto, and the doping process of the channel layer 132 may be composed of various other processes. The doping process of the channel layer 132 may be performed before the first source electrode 173a and the first drain electrode 175a are formed. In some cases, the channel layer 132 may not be doped.

[0197] Inside the channel layer 132, a two-dimensional electron gas 134 can be formed in a portion adjacent to the barrier layer 136. The two-dimensional electron gas 134 can be located at the interface between the channel layer 132 and the barrier layer 136. The two-dimensional electron gas 134 can be located in the drift region DTR between the first source electrode 173a and the first drain electrode 175a. A depletion region DPR can be formed in the channel layer 132 by a gate semiconductor layer 152 having a different bandgap from that of the barrier layer 136. Therefore, the semiconductor device according to the embodiment can have normally-off characteristics. For example, the semiconductor device according to the embodiment can be a normally-off high electron mobility transistor (HEMT). In the gate-off state, the two-dimensional electron gas 134 can be located in the drift region DTR except for the depletion region DPR of the channel layer 132. In the gate-on state, the flow of the two-dimensional electron gas 134 is continuous in the depletion region DPR, allowing the two-dimensional electron gas 134 to be entirely located in the drift region DTR.

[0198] In the step of forming the first source electrode 173a and the first drain electrode 175a, a first field dispersion layer 177a can be formed together. The first field dispersion layer 177a can be located between the first source electrode 173a and the first drain electrode 175a. The first field dispersion layer 177a can overlap with the gate electrode 155. The first field dispersion layer 177a can be electrically connected to the first source electrode 173a. The first field dispersion layer 177a can be formed integrally with the first source electrode 173a. The first field dispersion layer 177a can include the same material as the first source electrode 173a and can be located in the same layer as the first source electrode 173a.

[0199] Therefore, the lower protective layer 180 can be located on the barrier layer 136 between the first source electrode 173a and the first drain electrode 175a. The lower protective layer 180 can overlap with the drift region DTR of the channel layer 132 in the vertical direction (e.g., the thickness direction of the channel layer 132).

[0200] In addition, the lower protective layer 180 can be located between the barrier layer 136 and the first field dispersion layer 177a. At least a part of the lower protective layer 180 can overlap with the first field dispersion layer 177a in the vertical direction (e.g., the thickness direction of the channel layer 132). Therefore, the part of the lower protective layer 180 that overlaps with the field dispersion layer 177 in the vertical direction (e.g., the thickness direction of the channel layer 132) can cover the gate semiconductor layer 152 and the gate electrode 155. Therefore, the barrier layer 136, the gate semiconductor layer 152, and the gate electrode 155 can be protected by the lower protective layer 180.

[0201] As Figure 27As shown, the first interlayer insulating layer 510 may be formed on the first source electrode 173a, the first field dispersion layer 177a, the lower protective layer 180, and the first drain electrode 175a. The first interlayer insulating layer 510 may be located above the lower protective layer 180 and the first field dispersion layer 177a. The first interlayer insulating layer 510 may cover the lower protective layer 180 and the first field dispersion layer 177a.

[0202] In an embodiment, the first interlayer insulating layer 510 may include an insulating material. For example, the first interlayer insulating layer 510 may include silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon oxycarbonitride (SiOCN), silicon nitride (SiN), or a combination thereof. In addition, the first interlayer insulating layer 510 may include a material such as aluminum oxide (Al2O3).

[0203] In an embodiment, the first interlayer insulating layer 510 may include a first element and a second element different from the first element. Here, the first element may be nitrogen (N), and the second element may be silicon (Si). For example, if the first interlayer insulating layer 510 includes silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon oxycarbonitride (SiOCN), silicon nitride (SiN), or a combination thereof, the first element may be nitrogen (N), and the second element may be silicon (Si).

[0204] At this time, the first interlayer insulating layer 510 may include a first content (at%) of the first element. Here, the first content (at%) of the first element of the first interlayer insulating layer 510 may represent the content (at%) of the first element among the entire content of the first interlayer insulating layer 510. For example, if the first interlayer insulating layer 510 includes silicon oxynitride (SiON), the first content (at%) may represent the content (at%) of nitrogen (N) among the entire content of silicon (Si), nitrogen (N), and oxygen (O) of the first interlayer insulating layer 510. For example, the first content (at%) of the first element of the first interlayer insulating layer 510 may be greater than 0 at% and less than about 60 at%, preferably about 3 at% to about 30 at%.

[0205] In an embodiment, the first content (at%) of the first element of the first interlayer insulating layer 510 may be greater than the second content (at%) of the first element of the lower protective layer 180. For example, the first content (at%) of the first element of the first interlayer insulating layer 510 and the second content (at%) of the first element of the lower protective layer 180 may have a constant value regardless of the distance from the bottom surface 180_B of the lower protective layer 180. The first content ( Figure 3 N1 (at%)) of the first element of the first interlayer insulating layer 510 may be greater than the second content ( Figure 3(at%) of N2). However, the embodiments are not limited thereto, and the first content (at%) of the first element of the first interlayer insulating layer 510 and / or the second content (at%) of the first element of the lower protective layer 180 may have different values according to the distance from the bottom surface of the lower protective layer 180.

[0206] As an example, when the first interlayer insulating layer 510 and the lower protective layer 180 include silicon oxynitride (SiON), the first content (at%) of nitrogen (N) in the first interlayer insulating layer 510 may be greater than the second content (at%) of nitrogen (N) in the lower protective layer 180. Accordingly, the sum of the content (at%) of silicon (Si) and the content of oxygen (O) among the entire content (at%) of the first interlayer insulating layer 510 may be less than the sum of the content (at%) of silicon (Si) and the content of oxygen (O) among the entire content (at%) of the lower protective layer 180. As another example, if the first interlayer insulating layer 510 includes silicon oxynitride (SiON) and the lower protective layer 180 includes silicon dioxide (SiO2), the first content (at%) of nitrogen (N) in the first interlayer insulating layer 510 may be greater than the second content (at%) of nitrogen (N) in the lower protective layer 180. In this case, the lower protective layer 180 may not include the first element (e.g., nitrogen (N)). That is, the second content (at%) of the first element of the lower protective layer 180 may be 0 at%.

[0207] As another example, when the first interlayer insulating layer 510 and the lower protective layer 180 include silicon nitride (SiN), the first content (at%) of nitrogen (N) in the first interlayer insulating layer 510 may be greater than the second content (at%) of nitrogen (N) in the lower protective layer 180. Accordingly, the content (at%) of silicon (Si) among the entire content (at%) of the first interlayer insulating layer 510 may be less than the sum of the content (at%) of silicon (Si) among the entire content (at%) of the lower protective layer 180.

[0208] In the embodiment, the first interlayer insulating layer 510 is described as being composed of a single layer, but is not limited thereto. For example, the first interlayer insulating layer 510 may be composed of multiple layers sequentially stacked on the lower protective layer 180.

[0209] As Figure 28 shown, at least a part of the first interlayer insulating layer 510 may be removed, a conductive material may be deposited and then patterned to form the second source electrode 173b and the second drain electrode 175b.

[0210] First, at least a portion of the first interlayer insulating layer 510 located on the first source electrode 173a and the first drain electrode 175a can be etched to form a third trench and a fourth trench. Accordingly, the portions of the first interlayer insulating layer 510 located on the first source electrode 173a and the first drain electrode 175a can be penetrated by the third trench and the fourth trench. The inner walls of the third trench and the fourth trench can be defined by the first interlayer insulating layer 510. The bottom surface of the third trench can be defined by the first source electrode 173a. The bottom surface of the fourth trench can be defined by the first drain electrode 175a. Accordingly, the upper surfaces of the first source electrode 173a and the first drain electrode 175a can be exposed.

[0211] Next, a conductive material can be deposited in the third trench and the fourth trench and then patterned to form a second source electrode 173b and a second drain electrode 175b. Since the process of forming the second source electrode 173b and the second drain electrode 175b is substantially the same as the process of forming the first source electrode 173a and the first drain electrode 175a, a detailed description thereof will be omitted.

[0212] In the step of forming the second source electrode 173b and the second drain electrode 175b, a second field dispersion layer 177b can be formed together. The second field dispersion layer 177b can be located between the second source electrode 173b and the second drain electrode 175b. The second field dispersion layer 177b can overlap with the gate electrode 155. The second field dispersion layer 177b can be electrically connected to the second source electrode 173b. The second field dispersion layer 177b can be formed integrally with the second source electrode 173b. The second field dispersion layer 177b can include the same material as the second source electrode 173b and can be located in the same layer as the second source electrode 173b.

[0213] As Figure 29 shown, a second interlayer insulating layer 520 can be formed on the second source electrode 173b, the second field dispersion layer 177b, the first interlayer insulating layer 510, and the second drain electrode 175b. The second interlayer insulating layer 520 can be located above the first interlayer insulating layer 510 and the second field dispersion layer 177b. The second interlayer insulating layer 520 can cover the first interlayer insulating layer 510 and the second field dispersion layer 177b.

[0214] In an embodiment, the second interlayer insulating layer 520 can include an insulating material. The second interlayer insulating layer 520 can include the same material as the first interlayer insulating layer 510, but is not limited thereto. For example, the second interlayer insulating layer 520 can include silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon oxycarbonitride (SiOCN), silicon nitride (SiN), or a combination thereof. In addition, the second interlayer insulating layer 520 can include a material such as aluminum oxide (Al2O3).

[0215] In an embodiment, the second interlayer insulating layer 520 may include a first element and a second element different from the first element. Here, the first element may be nitrogen (N), and the second element may be silicon (Si). As an example, if the second interlayer insulating layer 520 includes silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon oxycarbonitride (SiOCN), silicon nitride (SiN), or a combination thereof, the first element may be nitrogen (N), and the second element may be silicon (Si).

[0216] At this time, the second interlayer insulating layer 520 may include a third content (at%) of the first element. Here, the third content (at%) of the first element in the second interlayer insulating layer 520 may represent the content (at%) of the first element among the entire content of the second interlayer insulating layer 520. For example, when the second interlayer insulating layer 520 includes silicon oxynitride (SiON), it may represent the content (at%) of nitrogen (N) among the entire content of silicon (Si), nitrogen (N), and oxygen (O) in the second interlayer insulating layer 520.

[0217] Further referring to Figure 3 In an embodiment, the third content (at%) of the first element in the second interlayer insulating layer 520 may be greater than the second content (at%) of the first element in the lower protective layer 180. In addition, the third content (at%) of the first element in the second interlayer insulating layer 520 may be less than the first content (at%) of the first element in the first interlayer insulating layer 510.

[0218] As shown in Figure 30 At least a part of the second interlayer insulating layer 520 may be removed, a conductive material may be deposited and then patterned to form the third source electrode 173c and the third drain electrode 175c.

[0219] For example, first, at least a part of the second interlayer insulating layer 520 located on the second source electrode 173b and the second drain electrode 175b may be etched to form a fifth trench and a sixth trench. Accordingly, the portion of the second interlayer insulating layer 520 located above the second source electrode 173b and the second drain electrode 175b may be penetrated by the fifth trench and the sixth trench. The inner walls of the fifth trench and the sixth trench may be defined by the second interlayer insulating layer 520. The bottom surface of the fifth trench may be defined by the second source electrode 173b. The bottom surface of the sixth trench may be defined by the second drain electrode 175b. Accordingly, the upper surfaces of the second source electrode 173b and the second drain electrode 175b may be exposed.

[0220] Subsequently, a conductive material may be deposited in the fifth groove and the sixth groove, and then patterned to form a third source electrode 173c and a third drain electrode 175c. Since the process of forming the third source electrode 173c and the third drain electrode 175c is substantially the same as the process of forming the first source electrode 173a and the first drain electrode 175a, a detailed description thereof will be omitted.

[0221] In the step of forming the third source electrode 173c and the third drain electrode 175c, a third field dispersion layer 177c may be formed together. The third field dispersion layer 177c may be located between the third source electrode 173c and the third drain electrode 175c. The third field dispersion layer 177c may overlap with the gate electrode 155. The third field dispersion layer 177c may be electrically connected to the third source electrode 173c. The third field dispersion layer 177c may be formed integrally with the third source electrode 173c. The third field dispersion layer 177c may include the same material as the third source electrode 173c and may be located in the same layer as the third source electrode 173c.

[0222] Accordingly, a semiconductor device according to various embodiments may be formed.

[0223] Although the present disclosure has been described in connection with presently considered practical examples, it is to be understood that the present disclosure is not limited to the disclosed embodiments, but on the contrary, the present disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0224] <Description of symbols>

[0225] 110: Substrate

[0226] 132: Channel layer

[0227] 134: Two-dimensional electron gas

[0228] 136: Barrier layer

[0229] 152: Gate semiconductor layer

[0230] 155: Gate electrode

[0231] 173: Source electrode

[0232] 175: Drain electrode

[0233] 180: Lower protective layer

[0234] 500: Interlayer insulating layer

[0235] 510: First interlayer insulating layer

[0236] 520: Second interlayer insulating layer

Claims

1. A semiconductor device comprising: Channel layer, a barrier layer located above the channel layer and including a material having an energy bandgap different from an energy bandgap of the channel layer, a gate electrode located above the barrier layer, a gate semiconductor layer, which is located between the barrier layer and the gate electrode, a first source electrode and a first drain electrode, the first source electrode being located on a first side of the gate electrode, the first drain electrode being located on a second side which is an opposite side of the gate electrode, the first source electrode and the first drain electrode being each connected to the channel layer, a lower protective layer covering the barrier layer and the gate electrode, a first field spreading plate connected to the first source electrode and located above the lower protection layer, and a first interlayer insulating layer located above the first field spreading plate and the lower protective layer and including a first element at a first content (at %) relative to the entire first interlayer insulating layer, The lower protective layer includes the first element, and a second content (at %) of the first element relative to the entire lower protective layer is less than the first content (at %).

2. The semiconductor device according to claim 1, wherein: The first content (at %) is not constant throughout the entire thickness of the first interlayer insulating layer, and increases with increasing distance from a bottom surface of the lower protective layer.

3. The semiconductor device according to claim 1, wherein: The second content (at %) is not constant throughout the entire thickness of the lower protective layer, and increases with increasing distance from a bottom surface of the lower protective layer, at least for a portion of the lower protective layer.

4. The semiconductor device according to claim 3, wherein: A maximum value of the second content (at %) in any vertical horizontal slice of the lower protective layer is smaller than a minimum value of the first content (at %) in any vertical horizontal slice of the first interlayer insulating layer.

5. The semiconductor device according to claim 1, wherein: The first element is nitrogen.

6. The semiconductor device according to claim 5, wherein: The first interlayer insulating layer and the lower protective layer each include silicon oxynitride, silicon carbon nitride, silicon carbon oxynitride, silicon nitride, or a combination thereof.

7. The semiconductor device according to claim 5, wherein: The first interlayer insulating layer includes silicon oxynitride, silicon carbonitride, silicon carbonitride oxynitride, silicon nitride or a combination thereof, and The lower protection layer includes silicon oxide, silicon oxycarbide or a combination thereof.

8. The semiconductor device according to claim 1, wherein: A second content (at %) of the first element of the lower protective layer is greater than 0 at % and less than 1 at %.

9. The semiconductor device according to claim 8, wherein: A first content (at %) of the first element of the first interlayer insulating layer is equal to or greater than 3 at % and less than 30 at %.

10. The semiconductor device according to claim 1, further comprising: a second source electrode, which is located above the first source electrode, a second drain electrode, which is located above the first drain electrode, a second field spreading plate connected to the second source electrode and located above the first interlayer insulating layer, and a second interlayer insulating layer located above the second field spreading plate and the first interlayer insulating layer and including a third content (at %) of the first element relative to the entire second interlayer insulating layer, the third content (at %) being different from the first content (at %) and the second content (at %).

11. The semiconductor device according to claim 10, wherein: The third content (at %) of the second interlayer insulating layer is greater than or equal to the second content (at %) of the lower protective layer.

12. The semiconductor device according to claim 10, wherein: A third content (at %) of the second interlayer insulating layer is less than a first content (at %) of the first interlayer insulating layer.

13. The semiconductor device according to claim 10, wherein: The second field spreading plate is formed at the same layer as the second source electrode, includes the same material as the second source electrode, and is integral with the second source electrode.

14. The semiconductor device according to claim 1, wherein: The lower protective layer comprises: a first lower protective layer located on the barrier layer and including a first element at a third content (at %) relative to the entire first lower protective layer, and a second lower protective layer located between the first lower protective layer and the first field dispersion plate and including a fourth content (at%) of the first element relative to the entire second lower protective layer, the fourth content (at%) being different from the third content (at%), and The third content (at %) and the fourth content (at %) are less than the first content (at %) of the first element of the first interlayer insulating layer.

15. The semiconductor device according to claim 14, wherein: The first interlayer insulating layer comprises: a first inter-sub-layer insulating layer which is located above the first field spreading plate and includes a first element at a fifth content (at %) relative to the entire first inter-sub-layer insulating layer, and a second inter-sublayer insulating layer, which is located above the first inter-sublayer insulating layer and includes a sixth content (at%) of the first element relative to the entire second inter-sublayer insulating layer, the sixth content (at%) being different from the fifth content (at%), and The fifth content (at %) and the sixth content (at %) are greater than the second content (at %) of the first element of the lower protective layer.

16. A semiconductor device comprising: Channel layer, a barrier layer located above the channel layer and including a material having an energy bandgap different from an energy bandgap of the channel layer, a gate electrode located above the barrier layer, a gate semiconductor layer, which is located between the barrier layer and the gate electrode, a first source electrode and a first drain electrode, the first source electrode being located on a first side of the gate electrode, the first drain electrode being located on a second side which is an opposite side of the gate electrode, the first source electrode and the first drain electrode being each connected to the channel layer, a lower protective layer covering the barrier layer and the gate electrode, a field spreading plate connected to the source electrode and located above the lower protective layer, and an interlayer insulating layer located over the field spreading plate and the lower protective layer and including nitrogen, The lower protective layer includes a nitrogen content (at %) smaller than a nitrogen content (at %) of the interlayer insulating layer relative to the entire lower protective layer than that of the entire interlayer insulating layer.

17. The semiconductor device according to claim 16, wherein: The field dispersion plate comprises: a first field spreading plate connected to the first source electrode and located above the lower protection layer, and a second field dispersion plate, which is located on the first field dispersion plate, The interlayer insulating layer comprises: a first interlayer insulating layer located between the first field spreading plate and the second field spreading plate and including nitrogen at a first content (at %) with respect to the entire first interlayer insulating layer, and a second interlayer insulating layer located on the second field spreading plate and the first interlayer insulating layer, and The lower protective layer includes a second content (at %) of nitrogen smaller than the first content (at %) with respect to the entire lower protective layer.

18. The semiconductor device according to claim 17, wherein: The second interlayer insulating layer includes nitrogen at a third content (at %) with respect to the entire second interlayer insulating layer, the third content (at %) being greater than or equal to the second content (at %).

19. A semiconductor device comprising: Substrate, a channel layer comprising GaN and located on the substrate, a barrier layer located above the channel layer and comprising AlGaN, a gate electrode located above the barrier layer and comprising a metal material, a gate semiconductor layer, which is located between the barrier layer and the gate electrode and includes GaN doped with P-type impurities, a first source electrode and a first drain electrode, the first source electrode being located on a first side of the gate electrode, the first drain electrode being located on a second side which is an opposite side of the gate electrode, the first source electrode and the first drain electrode being each connected to the channel layer, a lower protective layer covering the barrier layer and the gate electrode, a first field dispersion plate connected to the first source electrode, integral with the first source electrode, and located above the lower protection layer, and a first interlayer insulating layer, which is located above the first field spreading plate and the lower protective layer and includes a first element and a second element different from the first element, Wherein, the lower protective layer includes the second element, or the second element and the first element, and the content (at%) of the first element of the lower protective layer relative to the entire lower protective layer is less than the content (at%) of the first element of the first interlayer insulating layer relative to the entire first interlayer insulating layer.

20. The semiconductor device according to claim 19, wherein: The first element is nitrogen, and the second element is silicon.

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