Nitride semiconductor, semiconductor device, and method for manufacturing nitride semiconductor

Abstract

A nitride semiconductor, a semiconductor device, and a method for manufacturing a nitride semiconductor are provided, which can suppress warping. According to an embodiment, the nitride semiconductor includes a substrate, a nitride component, and an intermediate region provided between the substrate and the nitride component. The nitride component includes: a substrate containing Al x1 Ga 1‑x1 N's first nitride region, where 0 <x1≤1;以及含有Al x2 Ga 1‑x2 The second nitride region of N, where 0≤x2<1, x2 <x1。所述第1氮化物区域处于所述中间区域与所述第2氮化物区域之间。所述中间区域含有氮以及碳。所述中间区域中的碳的浓度是1.5×10 19 / cm 3 Above and 6×10 20 / cm 3 the following.

Description

[0001] This application is based on Japanese Patent Application No. 2021-132234 (filed on August 16, 2021) and claims priority from it. This application incorporates the entire contents of the application by reference. TECHNICAL FIELD

[0002] Embodiments of the present application relate to a nitride semiconductor, a semiconductor device, and a manufacturing method of a nitride semiconductor. BACKGROUND

[0003] For example, a semiconductor device is manufactured using a wafer including a nitride semiconductor. It is desirable to suppress warpage. SUMMARY

[0004] Embodiments of the present application provide a nitride semiconductor, a semiconductor device, and a manufacturing method of a nitride semiconductor, which can suppress warpage.

[0005] According to an embodiment of the present application, a nitride semiconductor includes a base, a nitride part, and an intermediate region provided between the base and the nitride part. The nitride part includes: a first nitride region containing Al x1 Ga 1-x1 N (0 < x1 < 1); and a second nitride region containing Al x2 Ga 1-x2 N (0 ≤ x2 < 1, x2 < x1). The first nitride region is between the intermediate region and the second nitride region. The intermediate region contains nitrogen and carbon. The concentration of carbon in the intermediate region is 1.5 x 10 19 / cm 3 or more and 6 x 10 20 / cm 3 or less.

[0006] According to the nitride semiconductor having the above structure, it is possible to provide a nitride semiconductor, a semiconductor device, and a manufacturing method of a nitride semiconductor, which can suppress warpage. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 is a schematic cross-sectional view illustrating a nitride semiconductor according to a first embodiment.

[0008] Figure 2 is a graph illustrating a nitride semiconductor according to the first embodiment.

[0009] Figure 3 is a graph illustrating a nitride semiconductor according to the first embodiment.

[0010] Figure 4is a schematic cross-sectional view illustrating a nitride semiconductor according to the first embodiment.

[0011] Figure 5 is a schematic cross-sectional view illustrating a semiconductor device according to the second embodiment.

[0012] Figure 6 is a schematic cross-sectional view illustrating a semiconductor device according to the second embodiment.

[0013] Figure 7 is a flowchart illustrating a manufacturing method of a nitride semiconductor according to the third embodiment.

[0014] (Symbol Explanation)

[0015] 10M: Nitride member; 10a to 10e: First to fifth partial regions; 11 to 15: First to fifth nitride regions; 11M: Intermediate region; 13a, 13b: First and second regions; 14a, 14b: First and second film regions; 15f: Sixth partial region; 15g: Seventh partial region; 18s: Substrate; 51 to 53: First to third electrodes; 61: Insulating member; 61p: First insulating region; 110, 111: Nitride semiconductor; 120, 121: Semiconductor device; 210, 211: Wafer; C(C), C(Si): Concentration; CC1: Concentration; Int_Al, Int_N: Second ion intensity; W1: Amount of warping; pZ: Position; t1, t2: First and second region thicknesses; tm1: Intermediate region thickness; tr1 to tr5: First to fifth nitride region thicknesses; tr4a, tr4b: First and second film region thicknesses. DETAILED DESCRIPTION

[0016] Hereinafter, each embodiment of the present application will be described with reference to the drawings. Figure 1

[0017] The drawings are schematic or conceptual views for more clearly and easily understanding the present application, and the relationship between the thickness and the width of each portion, the ratio of the sizes of portions, and the like are not necessarily the same as that of the actual one. Even in the case of representing the same portion, the dimensions and the ratios of each other are sometimes presented as different depending on the drawings.

[0018] In the present application specification and each drawing, the same elements as those which have been explained with respect to the already-explained drawing are given the same symbol and a detailed explanation is appropriately omitted.

[0019] (First Embodiment)

[0020] Figure 1 is a schematic cross-sectional view illustrating a nitride semiconductor according to the first embodiment.

[0021] As​Figure 2 The nitride semiconductor 110 according to the embodiment includes a base 18s, a nitride member 10M, and an intermediate region 11M. The intermediate region 11M is between the base 18s and the nitride member 10M. The wafer 210 includes the nitride semiconductor 110.

[0022] The base 18s contains, for example, silicon. The base 18s is, for example, a silicon substrate.

[0023] The nitride member 10M includes a first nitride region 11 and a second nitride region 12. The first nitride region 11 is between the intermediate region 11M and the second nitride region 12.

[0024] The nitride member 10M can also include a third nitride region 13, a fourth nitride region 14, and a fifth nitride region 15, and the like. The fourth nitride region 14 and the fifth nitride region 15 correspond to functional layers. The third nitride region 13, the fourth nitride region 14, and the fifth nitride region 15 are provided as needed, and can be omitted. It can also be considered that at least any one of the third nitride region 13, the fourth nitride region 14, and the fifth nitride region 15 is included in the second nitride region 12.

[0025] The first nitride region 11 contains Al x1 Ga 1-x1 N (0 < x1≤ 1). The composition ratio x1 of Al in the first nitride region 11 is, for example, 0.35 or more and 1 or less. In one example, the first nitride region 11 contains AlN.

[0026] The second nitride region 12 contains Al x2 Ga 1-x2 N (0≤ x2< 1, x2< x1). For example, the second nitride region 12 contains AlGaN or GaN.

[0027] A direction from the first nitride region 11 toward the second nitride region 12 is set as a first direction. The first direction is set as a Z-axis direction. One direction perpendicular to the Z-axis direction is set as an X-axis direction. A direction perpendicular to the Z-axis direction and the X-axis direction is set as a Y-axis direction.

[0028] The base 18s, the intermediate region 11M, the first nitride region 11, and the second nitride region 12 are layered along an X-Y plane.

[0029] For example, the intermediate region 11M is in contact with the base 18s. For example, the intermediate region 11M is in contact with the first nitride region 11. For example, the first nitride region 11 is in contact with the second nitride region 12.

[0030] For example, at least a part of the intermediate region 11M can contain aluminum. For example, at least a part of the intermediate region 11M can contain silicon.

[0031] The intermediate region 11M contains nitrogen as well as carbon. The concentration of carbon in the intermediate region 11M is 1.5 x 10 19 / cm 3 or more and 6 x 10 20 / cm 3 or less. The concentration of carbon in the intermediate region 11M can also be 3 x 10 19 / cm 3 or more and 4 x 10 20 / cm 3 or less.

[0032] By providing such an intermediate region 11M, it is known that warping in the nitride semiconductor 110 (e.g., the wafer 210) can be suppressed.

[0033] Figure 2 is a graph illustrating a nitride semiconductor according to the first embodiment.

[0034] Figure 2 SIMS (Secondary Ion Mass Spectrometry) analysis results of the nitride semiconductor 110 are illustrated. In Figure 2 , the horizontal axis is the position pZ in the Z-axis direction. Figure 2 The vertical axis on the left side of the graph of Figure 2 is the concentration C(C) of carbon or the concentration C(Si) of silicon. The vertical axis on the right side of the graph of

[0035] is the secondary ion intensity Int_Al of Al or the secondary ion intensity Int_N of N. Figure 3 As shown in , an intermediate region 11M is provided between the substrate 18s and the first nitride region 11. The intermediate region 11M contains carbon. The intermediate region 11M contains nitrogen. In this example, the intermediate region 11M contains aluminum as well as silicon. The substrate 18s does not substantially contain nitrogen. The intermediate region 11M, the first nitride region 11, and the second nitride region 12 contain nitrogen.

[0036] As described later, such an intermediate region 11M is obtained by supplying a first gas containing carbon to the substrate 18s, then stopping the supply of the first gas containing carbon, and supplying a second gas containing nitrogen, and then forming the first nitride region 11 and the second nitride region 12.

[0037] The concentration C(C) of carbon in the intermediate region 11M can be controlled, for example, using the supply amount of the first gas containing carbon. The concentration C(C) of carbon in the intermediate region 11M can also be controlled, for example, using the temperature of heat treatment of the substrate 18s, and the like. If the supply amount of the first gas is large, the concentration C(C) of carbon in the intermediate region 11M becomes high. If the temperature of heat treatment is low, the concentration C(C) of carbon in the intermediate region 11M becomes high.

[0038] Hereinafter, an example of experimental results regarding changes in warpage when the concentration C(C) of carbon is changed will be described.

[0039] Figure 3 is a graph illustrating a nitride semiconductor according to the first embodiment.

[0040] Figure 3 The horizontal axis of is the concentration CCl of carbon in the intermediate region 11M. Figure 3 The vertical axis of is the amount of warpage Wl of the wafer 210. The amount of warpage Wl is normalized with respect to the amount of warpage in a case where the intermediate region 11M is not provided (first reference example). In the first reference example, the first nitride region 11 is in contact with the substrate 18s. In this experimental example, the amount of warpage in the first reference example is about 170 μm.

[0041] As shown in Figure 3 , when the concentration CCl of carbon in the intermediate region 11M is 1.5 x 10 19 / cm 3 or more and 6 x 10 20 / cm 3 or less, the amount of warpage Wl is small. When the concentration CCl of carbon is less than 1.5 x 10 19 / cm 3 , the amount of warpage Wl is large. When the concentration CCl of carbon exceeds 6 x 10 20 / cm 3 , the amount of warpage Wl is large.

[0042] In the first reference example, warpage occurs, for example, due to stress generated between the substrate 18s and the nitride member 10M. The stress occurs, for example, due to a difference in the coefficient of thermal expansion between the substrate 18s and the nitride member 10M, and the like.

[0043] When the concentration CCl of carbon in the intermediate region 11M is 1.5 x 10 19 / cm 3 or more and 6 x 10 20 / cm 3 or less, warpage can be suppressed. It is considered that by providing the intermediate region 11M having such a concentration CCl of carbon between the substrate 18s and the nitride member 10M, stress can be alleviated. Thus, warpage can be suppressed.

[0044] like Figure 3 As shown, the characteristics of the carbon concentration CC1 and the warpage W1 in the middle region 11M are critical. 19 / cm 3 The warpage amount W1 changes sharply near the concentration CC1 of about 6×10 20 / cm 3 Near the edge of the curve, the warping amount W1 changes sharply. Figure 2 As shown, the carbon concentration CC1 in the middle region 11M is 3×10 19 / cm 3 Above and 4×10 20 / cm 3 When φ is less than φ, the warpage amount W1 is even smaller.

[0045] like Figure 2 As shown, for example, the first nitride region 11 contains substantially no carbon. Alternatively, the carbon concentration C(C) in the first nitride region 11 is lower than the carbon concentration C(C) in the middle region 11M. By lowering the carbon concentration C(C) in the first nitride region 11, for example, the density of defects in the nitride member 10M is easily reduced. For example, the strain applied to the second nitride region 12 is increased, thereby reducing defects.

[0046] like Figure 2 As shown, for example, the second nitride region 12 contains carbon. The carbon concentration C (C) in the second nitride region 12 is higher than the carbon concentration C (C) in the first nitride region 11. The inclusion of carbon in the second nitride region 12 facilitates a low dislocation density in the nitride member 10M, for example. For example, dislocations in the second nitride region 12 containing carbon are more likely to bend. Consequently, the number of dislocations extending above the second nitride region 12 in the first direction (Z-axis direction) is reduced.

[0047] For example, the carbon concentration C (C) in the second nitride region 12 is lower than the carbon concentration C (C) in the middle region 11M. By preventing the carbon concentration C (C) in the second nitride region 12 from becoming excessively high, for example, the strain applied to the second nitride region 12 is increased. For example, during the formation of the second nitride region 12, the strain applied to the second nitride region 12 is less likely to be alleviated. This facilitates control of warpage.

[0048] like Figure 1As shown, for example, the silicon concentration C(Si) in the first nitride region 11 is lower than the carbon concentration C(C) in the first nitride region 11. For example, the ratio of the silicon concentration C(Si) in the first nitride region 11 to the carbon concentration C(C) in the first nitride region 11 is 0.0001 or higher and 0.01 or lower. By lowering the silicon concentration C(Si) in the first nitride region 11, for example, when forming the second nitride region 12, the strain applied to the second nitride region 12 is less likely to be alleviated. This makes it easier to control warpage.

[0049] For example, the silicon concentration C(Si) in the second nitride region 12 is lower than the carbon concentration C(C) in the second nitride region 12. For example, the ratio of the silicon concentration C(Si) in the second nitride region 12 to the carbon concentration C(C) in the second nitride region 12 is 0.0001 or higher and 0.1 or lower. By lowering the silicon concentration C(Si) in the second nitride region 12, for example, strain applied to the second nitride region 12 is less likely to be alleviated. This makes it easier to control warpage.

[0050] In the embodiment, the thickness of the middle region 11M (middle region thickness tm1 (see Figure 1 ))For example, it is greater than 0.5nm and less than 100nm.

[0051] The thickness of the first nitride region 11 (first nitride region thickness tr1 (see Figure 1 ))For example, it is greater than 5nm and less than 500nm.

[0052] The thickness of the second nitride region 12 (the second nitride region thickness tr2 (refer to Figure 1 ))For example, it is greater than 50nm and less than 200nm.

[0053] like Figure 1 As shown, the nitride member 10M may also include a third nitride region 13. The third nitride region 13 may contain, for example, Al x3 Ga 1-x3 N (0≤x3≤1). The third nitride region 13 contains, for example, AlGaN or GaN. As described later, the third nitride region 13 may have, for example, a stacked structure. The thickness of the third nitride region 13 (third nitride region thickness tr3 (refer to Figure 1 ))For example, it is greater than 100nm and less than 8000nm.

[0054] like Figure 1 As shown, the nitride member 10M may include the fourth nitride region 14 and the fifth nitride region 15 as described above. The fourth nitride region 14 contains Al x4 Ga1-x4 N (0≤x4<1). The Al composition ratio x4 in the fourth nitride region 14 is, for example, greater than 0 and less than 0.5. The fourth nitride region 14 contains, for example, GaN. The Al composition ratio x4 in the fourth nitride region 14 is lower than the Al composition ratio in the third nitride region 13. The thickness of the fourth nitride region 14 (the fourth nitride region thickness tr4 (refer to Figure 1 ))For example, it is greater than 50nm and less than 5000nm.

[0055] like Figure 1 As shown, the fourth nitride region 14 may also include a first film region 14a and a second film region 14b. The first film region 14a is located between the third nitride region 13 and the second film region 14b. The first film region 14a contains carbon. The second film region 14b does not contain carbon. Alternatively, the concentration of carbon in the second film region 14b is lower than the concentration of carbon in the first film region 14a. By providing the first film region 14a containing carbon, it is easy to obtain a low dislocation density, for example. By providing the second film region 14b with a low carbon concentration, it is easy to obtain a high electron mobility, for example. The thickness of the first film region 14a (first film region thickness tr4a (refer to Figure 1 )) is, for example, 100 nm or more and 3000 nm or less. The thickness of the second film region 14b (the second film region thickness tr4b (refer to Figure 1 ))For example, it is greater than 50nm and less than 2000nm.

[0056] The fifth nitride region 15 contains Al x5 Ga 1-x5 N(0 <x5≤1,x4<x5)。第5氮化物区域15中的Al的组成比x5例如是0.05以上且0.35以下。第5氮化物区域15例如是AlGaN。第5氮化物区域15的厚度(第5氮化物区域厚度tr5(参照 Figure 4 )) is, for example, not less than 15 nm and not more than 50 nm. The second nitride region 12 is located between the first nitride region 11 and the fifth nitride region 15. The third nitride region 13 is located between the second nitride region 12 and the fifth nitride region 15. The fourth nitride region 14 is located between the third nitride region 13 and the fifth nitride region 15. The fourth nitride region 14 is located between the second nitride region 12 and the fifth nitride region 15.

[0057] For example, a carrier region is formed in the portion of the fourth nitride region 14 that faces the fifth nitride region 15. The carrier region is, for example, a two-dimensional electron gas. In a semiconductor device based on the nitride semiconductor 110, the carrier region is used for the operation of the semiconductor device.

[0058] For example, the nitride semiconductor 10M is formed by a method such as MOCVD (metal organic chemical vapor deposition) using a raw material gas containing a Group III element (Al or Ga) and a raw material gas containing a Group V element (N).

[0059] Figure 4 is a schematic cross-sectional view illustrating a nitride semiconductor according to the first embodiment.

[0060] As shown in Figure 5 , in the nitride semiconductor 111 and the wafer 211 according to the embodiment, the third nitride region 13 has a stacked structure.

[0061] For example, the third nitride region 13 includes a plurality of first regions 13a and a plurality of second regions 13b. In a first direction (Z-axis direction) from the first nitride region 11 toward the second nitride region 12, one of the plurality of first regions 13a is positioned between one of the plurality of second regions 13b and another of the plurality of second regions 13b. The one of the plurality of second regions 13b is positioned between the one of the plurality of first regions 13a and the another of the plurality of first regions 13a. For example, the first regions 13a and the second regions 13b are alternately arranged along the Z-axis direction.

[0062] The first region 13a contains Al y1 Ga 1-y1 N (0 < y1 < 1). The second region 13b contains Al y2 Ga 1-y2 N (0 < y2 < y1).

[0063] The Al composition ratio (composition ratio y1) in the first region 13a is, for example, 0.75 or more and 1 or less. In one example, the first region 13a is AlN.

[0064] The Al composition ratio (composition ratio y2) in the second region 13b is, for example, 0.06 or more and 0.3 or less. In one example, the second region 13b is Al 0.13 Ga 0.87 N.

[0065] In one example, the composition ratio y1 is lower than the composition ratio x1. In one example, the composition ratio y2 is higher than the composition ratio x2.

[0066] For example, one of the plurality of first regions 13a can also be in contact with the second nitride region 12. For example, one of the plurality of second regions 13b can also be in contact with the second nitride region 12. For example, one of the plurality of first regions 13a can also be in contact with the fourth nitride region 14. For example, one of the plurality of second regions 13b can also be in contact with the fourth nitride region 14. The plurality of first regions 13a and the plurality of second regions 13b can also form a superlattice structure, for example. The absolute value of the difference between the number of the plurality of first regions 13a and the number of the plurality of second regions 13b can be either 0 or 1. The number of the plurality of first regions 13a is, for example, 10 or more and 200 or less. One of the plurality of first regions 13a can also be regarded as the second nitride region 12.

[0067] Each of the plurality of first regions 13a has a first region thickness tl along the first direction (Z-axis direction). The first region thickness tl is thinner than a second nitride region thickness tr2 of the second nitride region 12 along the first direction, for example. Each of the plurality of second regions 13b has a second region thickness t2 along the first direction. The second region thickness t2 is thinner than the second nitride region thickness tr2, for example. The first region thickness tl is thinner than the second region thickness t2, for example.

[0068] The first region thickness tl of each of the plurality of first regions 13a is thinner than a first nitride region thickness trl of the first nitride region 11 along the first direction, for example. The second region thickness t2 of each of the plurality of second regions 13b is thinner than the first nitride region thickness trl.

[0069] The first region thickness tl is, for example, 3 nm or more and 10 nm or less. In one example, the first region thickness tl is 5 nm. The second region thickness t2 is, for example, 15 nm or more and 40 nm or less. In one example, the second region thickness t2 is 25 nm.

[0070] In the third nitride region 13 having such a structure, dislocations are easily bent, for example, at the interface between the first region 13a and the second region 13b. A lower dislocation density is easily obtained. By providing a plurality of regions having different composition ratios of Al, a high withstand voltage is easily obtained, for example.

[0071] Hereinafter, an example of a method of manufacturing the nitride semiconductor 111 (wafer 211) will be described.

[0072] The substrate 18s is subjected to organic cleaning and acid cleaning. The substrate 18s is introduced into a MOCVD apparatus. The surface of the substrate 18s is heat-treated at 1000°C in a hydrogen atmosphere. By the heat treatment, for example, an oxide film on the surface of the substrate 18s is removed.

[0073] After that, the intermediate region 11M is formed. For example, a first gas containing carbon is supplied at 580°C. By this, carbon is attached to the surface of the substrate 18s. The first gas containing carbon includes, for example, trimethylaluminum (TMAl). The first gas containing carbon can also include, for example, acetylene, ethylene, or the like. After that, the supply of the first gas containing carbon is stopped.

[0074] After that, a second gas containing nitrogen is supplied. The second gas contains, for example, ammonia (NH3). While the second gas is being supplied, the temperature is changed from, for example, 580°C to 1040°C. By the supply of the second gas, the intermediate region 11M is formed.

[0075] The concentration C(C) of carbon in the intermediate region 11M can be controlled, for example, by the amount (for example, partial pressure) of the first gas containing carbon supplied or the supply time of the first gas. The concentration C(C) of carbon in the intermediate region 11M can also be controlled by the temperature of the substrate 18s. For example, by increasing the amount of the first gas supplied, the concentration C(C) of carbon in the intermediate region 11M increases. By lengthening the supply time of the first gas, the concentration C(C) of carbon in the intermediate region 11M increases. If the temperature of the substrate 18s is low, the concentration C(C) of carbon in the intermediate region 11M increases. The temperature of the substrate 18s while the second gas is being supplied in the formation of the intermediate region 11M is, for example, 550°C or higher and 800°C or lower.

[0076] After the second gas is supplied, the first nitride region 11 is formed. For example, an AlN layer serving as the first nitride region 11 is formed at 1040° C. using TMAl and NH 3 . The thickness of the first nitride region 11 (first nitride region thickness tr1 ) is, for example, 150 nm (for example, greater than 5 nm and less than 500 nm). For example, the first nitride region 11 does not contain carbon. For example, the carbon concentration in the first nitride region 11 is lower than the carbon concentration in the middle region 11M. For example, the ratio of the carbon concentration in the first nitride region 11 to the carbon concentration in the middle region 11M is less than 0.05. For example, the ratio of the carbon concentration in the first nitride region 11 to the carbon concentration in the middle region 11M may also be greater than 0.0001. For example, the oxygen concentration in the first nitride region 11 is lower than the oxygen concentration in the middle region 11M. For example, the ratio of the oxygen concentration in the first nitride region 11 to the oxygen concentration in the intermediate region 11M is 0.05 or less. Alternatively, the ratio of the oxygen concentration in the first nitride region 11 to the oxygen concentration in the intermediate region 11M may be 0.0001 or more.

[0077] Then, the second nitride region 12 is formed. For example, an AlGaN layer that becomes at least a portion of the second nitride region 12 is formed at 960°C using TMAl, trimethylgallium (TMGa), and ammonia. This AlGaN layer is, for example, Al doped with carbon. 0.12 Ga 0.88 N layer. The thickness of the second nitride region 12 (second nitride region thickness tr2) is, for example, 250 nm (for example, 50 nm or more and 2000 nm or less). The carbon concentration C (C) in the second nitride region 12 is, for example, 4.0×10 18 / cm 3 The oxygen concentration in the second nitride region 12 is, for example, 7.9×10 15 / cm 3 For example, the carbon concentration in the second nitride region 12 is lower than the carbon concentration in the middle region 11M. For example, the carbon concentration in the second nitride region 12 is higher than the carbon concentration in the first nitride region 11. For example, the oxygen concentration in the second nitride region 12 is lower than the oxygen concentration in the middle region 11M. For example, the oxygen concentration in the second nitride region 12 is lower than the oxygen concentration in the first nitride region 11.

[0078] Next, the third nitride region 13 is formed. For example, the third nitride region 13 includes a plurality of first regions 13a and a plurality of second regions 13b. For example, the AlN layer forming the first region 13a is formed using TMAl and ammonia in an atmosphere containing nitrogen and hydrogen. The temperature for forming the first region 13a is, for example, 940°C. The thickness of the first region 13a (first region thickness t1) is, for example, 5 nm (e.g., greater than 2 nm and less than 15 nm).

[0079] On the first region 13a, Al is formed to become the second region 13b using TMAl, TMGa, and ammonia. 0.13 Ga 0.87 The N layer. The temperature for forming the second region 13b is, for example, 940°C. The thickness of the second region 13b (second region thickness t2) is, for example, 25 nm (e.g., 15 nm to 40 nm). This formation of the first region 13a and the second region 13b is repeated a total of 125 times. The first region 13a is further formed on the last second region 13b. Thus, the third nitride region 13 is formed.

[0080] The carbon concentration in the third nitride region 13 is, for example, 1.5×10 19 / cm 3 (For example, 5×10 18 / cm 3 Above and 9×10 19 / cm 3 The oxygen concentration in the third nitride region 13 is, for example, 3.9×10 16 / cm 3 (For example, 5×10 15 / cm 3 Above and 1×10 17 / cm 3 (hereinafter). For example, the carbon concentration in the third nitride region 13 is higher than the carbon concentration in the middle region 11M. For example, the oxygen concentration in the third nitride region 13 is higher than the oxygen concentration in the middle region 11M. For example, the carbon concentration in the third nitride region 13 is higher than the carbon concentration in the second nitride region 12. For example, the oxygen concentration in the third nitride region 13 is higher than the oxygen concentration in the second nitride region 12. For example, the carbon concentration in the third nitride region 13 is higher than the carbon concentration in the first nitride region 11. For example, the oxygen concentration in the third nitride region 13 is lower than the oxygen concentration in the first nitride region 11.

[0081] After that, the temperature of the substrate 18s is set to, for example, 940°C, and the first film region 14a is formed using TMGa and ammonia in a hydrogen atmosphere. The first film region 14a is, for example, a GaN layer. The first film region 14a contains carbon. The thickness of the first film region 14a is, for example, 1000 nm (for example, 600 nm or more and 3000 nm or less). The concentration of carbon in the first film region 14a is, for example, 3 x 10 19 / cm 3 (for example, 5 x 10 18 / cm 3 or more and 9 x 10 19 / cm 3 or less).

[0082] After that, the temperature of the substrate 18s is set to, for example, 1040°C, and the second film region 14b is formed using TMGa and ammonia. The second film region 14b is, for example, an undoped GaN layer. The thickness of the second film region 14b is, for example, 500 nm (for example, 50 nm or more and 2000 nm or less).

[0083] After that, the temperature of the substrate 18s is set to, for example, 1020°C, and the fifth nitride region 15 is formed using TMGa, TMAl, and ammonia. The fifth nitride region 15 is, for example, an undoped Al 0.2 Ga 0.8 N layer. The thickness of the fifth nitride region 15 is, for example, 30 nm (for example, 15 nm or more and 50 nm or less).

[0084] The first film region 14a, the second film region 14b, and the fifth nitride region 15 become a part of a functional layer.

[0085] (Second Embodiment)

[0086] The second embodiment relates to a semiconductor device.

[0087] Figure 5 is a schematic cross-sectional view illustrating a semiconductor device according to the second embodiment.

[0088] As shown in Figure 6 , the semiconductor device 120 according to the embodiment includes the nitride semiconductor (in this example, the nitride semiconductor 110) according to the first embodiment, the first electrode 51, the second electrode 52, the third electrode 53, and the insulating member 61.

[0089] The direction from the first electrode 51 toward the second electrode 52 is a second direction intersecting the first direction (Z-axis direction). The second direction is, for example, the X-axis direction. The position of the third electrode 53 in the second direction is between the position of the first electrode 51 in the second direction and the position of the second electrode 52 in the second direction.

[0090] The nitride member 10M includes first to fifth nitride regions 11 to 15. The fourth nitride region 14 includes a first partial region 10a, a second partial region 10b, a third partial region 10c, a fourth partial region 10d, and a fifth partial region 10e. A direction from the first partial region 10a toward the first electrode 51 is along the first direction (Z-axis direction). A direction from the second partial region 10b toward the second electrode 52 is along the first direction. The third partial region 10c is between the first partial region 10a and the second partial region 10b in the second direction (X-axis direction). A direction from the third partial region 10c toward the third electrode 53 is along the first direction. The fourth partial region 10d is between the first partial region 10a and the third partial region 10c in the second direction. The fifth partial region 10e is between the third partial region 10c and the second partial region 10b in the second direction.

[0091] The fifth nitride region 15 includes a sixth partial region 15f and a seventh partial region 15g. A direction from the fourth partial region 10d toward the sixth partial region 15f is along the first direction (Z-axis direction). A direction from the fifth partial region 10e toward the seventh partial region 15g is along the first direction.

[0092] The insulating member 61 is between the nitride member 10M and the third electrode 53. For example, the insulating member 61 includes a first insulating region 61p. The first insulating region 61p is provided between the third partial region 10c and the third electrode 53 in the first direction (Z-axis direction).

[0093] The semiconductor device 120 can also include the nitride semiconductor 111. In the semiconductor device 120, a current flowing between the first electrode 51 and the second electrode 52 can be controlled by a potential of the third electrode 53. The potential of the third electrode 53 is, for example, a potential with reference to a potential of the first electrode 51. The first electrode 51 functions as, for example, a source electrode. The second electrode 52 functions as, for example, a drain electrode. The third electrode 53 functions as, for example, a gate electrode. In one example, the semiconductor device 120 is a HEMT (High Electron Mobility Transistor). According to the embodiment, a semiconductor device capable of improving characteristics can be provided.

[0094] In the semiconductor device 120, at least a part of the third electrode 53 is between the sixth partial region 15f and the seventh partial region 15g in the second direction (for example, the X-axis direction). At least a part of the third electrode 53 can also be between the fourth partial region 10d and the fifth partial region 10e in the second direction (for example, the X-axis direction). The semiconductor device 120 is, for example, a normally-off type.

[0095] Figure 6 is a schematic cross-sectional view illustrating a semiconductor device according to a second embodiment.

[0096] As Figure 7 shown, the semiconductor device 121 according to the embodiment includes the nitride semiconductor (in this example, the nitride semiconductor 110) according to the first embodiment, the first electrode 51, the second electrode 52, the third electrode 53, and the insulating member 61. In the semiconductor device 121, the third electrode 53 does not overlap the sixth partial region 15f and the seventh partial region 15g in the second direction (for example, the X-axis direction). The third electrode 53 does not overlap the fourth partial region 10d and the fifth partial region 10e in the second direction (for example, the X-axis direction). The semiconductor device 121 is, for example, a normally-on type.

[0097] (Third Embodiment)

[0098] The third embodiment relates to a method of manufacturing a nitride semiconductor. The method of manufacturing a nitride semiconductor according to the third embodiment can also be applied to a method of manufacturing a wafer or a method of manufacturing a semiconductor device.

[0099] Figure 7 is a flowchart illustrating the method of manufacturing a nitride semiconductor according to the third embodiment.

[0100] As ​ shown, in the method of manufacturing a nitride semiconductor according to the embodiment, a first gas containing carbon is supplied over the substrate 18s (step S120). After the first gas is supplied, a second gas containing nitrogen is supplied (step S130). Over the substrate 18s after the second gas is supplied, a first nitride region 11 containing Al x1 Ga 1-x1 N (0 < x1 < 1) is formed (step S140). After the first nitride region 11 is formed, a second nitride region 12 containing Al x2 Ga 1-x2 N (0 ≤ x2 < 1, x2 < x1) is formed (step S150). The intermediate region 11M is formed by steps S110 and S120.

[0101] The intermediate region 11M between the base 18s and the first nitride region 11 contains nitrogen and carbon. The concentration of carbon in the intermediate region 11M is 1.5 x 10 19 / cm 3 or more and 6 x 10 20 / cm 3 or less. The warping can be suppressed.

[0102] For example, at least a part of the supply of the second gas is not supplied with the first gas. For example, the supply of the first gas is stopped, and the second gas containing nitrogen is supplied (step S130). Thus, the intermediate region 11M targeted can be stably formed. The base 18s can be heat-treated before the first gas is supplied (step S110). Thus, an unnecessary layer (for example, a silicon oxide layer) on the surface of the base 18s is removed. Oxygen contained in the intermediate region 11M can be reduced. Thus, the intermediate region 11M targeted can be stably formed.

[0103] For example, the first gas contains aluminum and carbon. For example, the second gas contains ammonia. For example, the first gas can contain carbon and hydrogen. For example, the second gas can contain nitrogen.

[0104] In the embodiment, information about the shape of the nitride region and the like is obtained, for example, by electron microscope observation and the like. Information about the composition and the element concentration in the nitride region is obtained, for example, by EDX (Energy Dispersive X-ray Spectroscopy) or SIMS (Secondary Ion Mass Spectrometry) and the like. Information about the composition in the nitride region can also be obtained, for example, by X-ray reciprocal lattice space mapping and the like.

[0105] The embodiment can include the following technical solutions.

[0106] (Technical Solution 1)

[0107] A nitride semiconductor includes:

[0108] a base;

[0109] a nitride member; and

[0110] an intermediate region provided between the base and the nitride member,

[0111] the nitride member includes:

[0112] a first nitride region containing Al x1Ga 1-x1 N (0 < x1 < 1); and

[0113] a second nitride region containing Al x2 Ga 1-x2 N (0 < x2 < 1, x2 < x1),

[0114] the first nitride region is between the intermediate region and the second nitride region,

[0115] the intermediate region contains nitrogen and carbon,

[0116] the concentration of carbon in the intermediate region is 1.5 x 10 19 / cm 3 and 6 x 10 20 / cm 3 or less.

[0117] (Embodiment 2)

[0118] The nitride semiconductor according to Embodiment 1, wherein

[0119] the intermediate region is in contact with the base.

[0120] (Embodiment 3)

[0121] The nitride semiconductor according to Embodiment 2, wherein

[0122] the intermediate region is in contact with the first nitride region.

[0123] (Embodiment 4)

[0124] The nitride semiconductor according to Embodiment 3, wherein

[0125] the first nitride region is in contact with the second nitride region.

[0126] (Embodiment 5)

[0127] The nitride semiconductor according to any one of Embodiments 1 to 4, wherein

[0128] at least a portion of the intermediate region contains aluminum.

[0129] (Embodiment 6)

[0130] The nitride semiconductor according to any one of Embodiments 1 to 5, wherein

[0131] at least a portion of the intermediate region contains silicon.

[0132] (Embodiment 7)

[0133] The nitride semiconductor according to any one of the technical solutions 1-6, wherein

[0134] The first nitride region contains AlN.

[0135] (technical solution 8)

[0136] The nitride semiconductor according to any one of the technical solutions 1-7, wherein

[0137] The base contains silicon.

[0138] (technical solution 9)

[0139] The nitride semiconductor according to any one of the technical solutions 1-8, wherein

[0140] The concentration of carbon in the intermediate region is 3x10 19 / cm 3 and 4x10 20 / cm 3 .

[0141] (technical solution 10)

[0142] The nitride semiconductor according to any one of the technical solutions 1-9, wherein

[0143] The first nitride region contains no carbon, or the concentration of carbon in the first nitride region is lower than the concentration of carbon in the intermediate region.

[0144] (technical solution 11)

[0145] The nitride semiconductor according to the technical solution 10, wherein

[0146] The second nitride region contains carbon,

[0147] The concentration of carbon in the second nitride region is higher than the concentration of carbon in the first nitride region.

[0148] (technical solution 12)

[0149] The nitride semiconductor according to the technical solution 11, wherein

[0150] The concentration of carbon in the second nitride region is lower than the concentration of carbon in the intermediate region.

[0151] (technical solution 13)

[0152] The nitride semiconductor according to any one of the technical solutions 1-12, wherein

[0153] The nitride component further comprises a region containing Alx3 Ga 1-x3 N (0 < x3 < 1),

[0154] The second nitride region is between the first nitride region and the third nitride region.

[0155] (Technical Solution 14)

[0156] The nitride semiconductor according to Technical Solution 13, wherein

[0157] The third nitride region includes a plurality of first regions and a plurality of second regions,

[0158] In a first direction from the first nitride region toward the second nitride region, one of the plurality of first regions is between one of the plurality of second regions and another of the plurality of second regions, the one of the plurality of second regions being between the one of the plurality of first regions and another of the plurality of first regions,

[0159] The first region contains Al y1 Ga 1-y1 N (0 < y1 < 1),

[0160] The second region contains Al y2 Ga 1-y2 N (0 < y2 < y1).

[0161] (Technical Solution 15)

[0162] The nitride semiconductor according to Technical Solution 13, wherein

[0163] The nitride component further includes:

[0164] A fourth nitride region containing Al x4 Ga 1-x4 N (0 < x4 < 1) ; and

[0165] A fifth nitride region containing Al x5 Ga 1-x5 N (0 < x5 < 1, x4 < x5),

[0166] The third nitride region is between the first nitride region and the fifth nitride region,

[0167] The fourth nitride region is between the third nitride region and the fifth nitride region.

[0168] (Technical Solution 16)

[0169] A semiconductor device including:

[0170] The nitride semiconductor according to claim 15;

[0171] A first electrode;

[0172] A second electrode;

[0173] A third electrode; and

[0174] An insulating member,

[0175] a second direction intersecting a direction from the first nitride region toward the second nitride region,

[0176] a position of the third electrode in the second direction is between a position of the first electrode in the second direction and a position of the second electrode in the second direction,

[0177] the fourth nitride region includes a first partial region, a second partial region, a third partial region, a fourth partial region, and a fifth partial region,

[0178] the first partial region is in the first direction from the first nitride region toward the first electrode,

[0179] the second partial region is in the first direction from the second nitride region toward the second electrode,

[0180] the third partial region is between the first partial region and the second partial region in the second direction, and is in the first direction from the third partial region toward the third electrode,

[0181] the fourth partial region is between the first partial region and the third partial region in the second direction,

[0182] the fifth partial region is between the third partial region and the second partial region in the second direction,

[0183] the fifth nitride region includes a sixth partial region and a seventh partial region,

[0184] the sixth partial region is in the first direction from the fourth partial region toward the sixth partial region,

[0185] the seventh partial region is in the first direction from the fifth partial region toward the seventh partial region,

[0186] the insulating member is between the nitride member and the third electrode.

[0187] (Technical Solution 17)

[0188] A method of manufacturing a nitride semiconductor, wherein

[0189] a first gas containing carbon is supplied over a substrate,

[0190] the supply of the first gas is stopped,

[0191] a second gas containing nitrogen is supplied,

[0192] a first nitride region containing Al x1 Ga 1-x1 N (0 < x1≤ 1) is formed over the substrate after the supply of the second gas,

[0193] a second nitride region containing Al x2 Ga 1-x2 N (0≤ x2< 1, x2< x1) is formed after the formation of the first nitride region.

[0194] (Technical Solution 18)

[0195] The method of manufacturing a nitride semiconductor according to Technical Solution 17, wherein

[0196] an intermediate region between the substrate and the first nitride region contains nitrogen and carbon,

[0197] a concentration of carbon in the intermediate region is 1.5 x 10 19 / cm 3 or more and 6 x 10 20 / cm 3 or less.

[0198] (Technical Solution 19)

[0199] The method of manufacturing a nitride semiconductor according to Technical Solution 17 or 18, wherein

[0200] the substrate is heat-treated before the supply of the first gas.

[0201] (Technical Solution 20)

[0202] The method of manufacturing a nitride semiconductor according to any one of Technical Solutions 17 to 19, wherein

[0203] the first gas contains aluminum and carbon,

[0204] the second gas contains ammonia.

[0205] (Technical Solution 21)

[0206] The method for manufacturing a nitride semiconductor according to any one of the aspects 17 to 19, wherein

[0207] The first gas contains a hydrocarbon,

[0208] The second gas contains ammonia.

[0209] According to the embodiments, it is possible to provide a nitride semiconductor capable of suppressing warpage, a semiconductor device, and a method for manufacturing a nitride semiconductor.

[0210] The above has explained the embodiments of the present application with reference to specific examples. However, the present application is not limited to these specific examples. For example, as to the specific structure of each element such as the nitride member, the nitride region, and the substrate included in the nitride semiconductor, as long as a person skilled in the art can implement the present application and obtain the same effects by appropriately selecting from the known range, it is included in the scope of the present application.

[0211] Further, a scheme obtained by combining any two or more elements in each specific example in a technically achievable range as long as it includes the gist of the present application is included in the scope of the present application.

[0212] Furthermore, based on the nitride semiconductor, the semiconductor device, and the method for manufacturing a nitride semiconductor described above as the embodiments of the present application, all of the nitride semiconductor, the semiconductor device, and the method for manufacturing a nitride semiconductor that a person skilled in the art can implement by appropriately making design changes as long as it includes the gist of the present application belongs to the scope of the present application.

[0213] Further, within the scope of the idea of the present application, various modifications and corrections can be conceived by a person skilled in the art, and it should be understood that these modifications and corrections also belong to the scope of the present application.

[0214] Although several embodiments of the present application have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the application. These new embodiments can be implemented in other various ways, and various omissions, substitutions, and changes can be made within the scope of the gist of the application. These embodiments and modifications thereof are included in the scope of the application, the gist, and the scope of the application recited in the claims.

Claims

1. A nitride semiconductor comprising: matrix; Nitride components; as well as an intermediate region disposed between the substrate and the nitride component, The nitride component comprises: The first nitride region contains Al x1 Ga 1-x1 N, where 0 < x1 ≤ 1; and The second nitride region contains Al x2 Ga 1-x2 N, where 0≤x2<1, x2 <x1, The first nitride region is located between the middle region and the second nitride region. The middle region contains nitrogen and carbon, The concentration of carbon in the middle region is 1.5×10 19 / cm 3 Above and 6×10 20 / cm 3 the following, At least a portion of the intermediate region contains silicon.

2. The nitride semiconductor according to claim 1, wherein The middle region is connected to the base body.

3. The nitride semiconductor according to claim 2, wherein The intermediate region is in contact with the first nitride region.

4. The nitride semiconductor according to claim 3, wherein The first nitride region is in contact with the second nitride region.

5. The nitride semiconductor according to claim 1, wherein At least a portion of the intermediate region contains aluminum. The nitride semiconductor according to claim 1 , wherein The first nitride region contains AlN.

7. The nitride semiconductor according to claim 1, wherein The matrix contains silicon.

8. The nitride semiconductor according to claim 1, wherein The concentration of carbon in the middle region is 3×10 19 / cm 3 Above and 4×10 20 / cm 3 the following.

9. The nitride semiconductor according to claim 1, wherein The first nitride region does not contain carbon, or the concentration of carbon in the first nitride region is lower than the concentration of carbon in the middle region.

10. The nitride semiconductor according to claim 9, wherein The second nitride region contains carbon, The concentration of carbon in the second nitride region is higher than the concentration of carbon in the first nitride region.

11. The nitride semiconductor according to claim 10, wherein The concentration of carbon in the second nitride region is lower than the concentration of carbon in the middle region.

12. The nitride semiconductor according to claim 1, wherein The nitride component further includes a material containing Al x3 Ga 1-x3 The third nitride region of N, where 0≤x3≤1, The second nitride region is located between the first nitride region and the third nitride region.

13. The nitride semiconductor according to claim 12, wherein The third nitride region includes a plurality of first regions and a plurality of second regions. In a first direction from the first nitride region toward the second nitride region, one of the plurality of first regions is located between one of the plurality of second regions and another second region among the plurality of second regions, and the one of the plurality of second regions is located between the one of the plurality of first regions and another first region among the plurality of first regions. The first region contains Al y1 Ga 1-y1 N, where 0 <y1≤1, The second region contains Al y2 Ga 1-y2 N, where 0≤y2 <y1。 14. The nitride semiconductor according to claim 1, wherein The nitride component further comprises: The fourth nitride region contains Al x4 Ga 1-x4 N, where 0≤x4<1; and The fifth nitride region contains Al x5 Ga 1-x5 N, where 0 <x5≤1,x4<x5, The fourth nitride region is located between the second nitride region and the fifth nitride region.

15. A semiconductor device comprising: The nitride semiconductor according to claim 14; 1st electrode; 2nd electrode; a third electrode; and Insulation parts, The direction from the first electrode toward the second electrode is along a second direction intersecting with the direction from the first nitride region toward the second nitride region. The position of the third electrode in the second direction is between the position of the first electrode in the second direction and the position of the second electrode in the second direction. The fourth nitride region includes a first partial region, a second partial region, a third partial region, a fourth partial region, and a fifth partial region. The direction from the first partial region toward the first electrode is along a first direction from the first nitride region toward the second nitride region. The direction from the second partial region toward the second electrode is along the first direction, The third partial region is located between the first partial region and the second partial region in the second direction, and a direction from the third partial region toward the third electrode is along the first direction. The fourth partial region is located between the first partial region and the third partial region in the second direction. The fifth partial region is located between the third partial region and the second partial region in the second direction. The fifth nitride region includes a sixth partial region and a seventh partial region, The direction from the fourth partial area toward the sixth partial area is along the first direction, The direction from the fifth partial area toward the seventh partial area is along the first direction, The insulating member is located between the nitride member and the third electrode.

16. A method for manufacturing a nitride semiconductor, wherein: A first gas containing carbon is supplied onto a substrate containing silicon. stopping the supply of the first gas, A second gas containing nitrogen is supplied to form an intermediate region containing silicon. After the supply of the second gas, a layer containing Al is formed on the substrate. x1 Ga 1-x1 N's first nitride region, where 0 <x1≤1, After the formation of the first nitride region, a layer containing Al is formed. x2 Ga 1-x2 The second nitride region of N, where 0≤x2<1, x2 <x1。 17. The method for manufacturing a nitride semiconductor according to claim 16, wherein: The intermediate region between the substrate and the first nitride region contains nitrogen and carbon. The concentration of carbon in the middle region is 1.5×10 19 / cm 3 Above and 6×10 20 / cm 3 the following.

18. The method for manufacturing a nitride semiconductor according to claim 16, wherein: Before the supply of the first gas, the substrate is heat-treated.

19. The method for manufacturing a nitride semiconductor according to claim 16, wherein: The first gas contains aluminum and carbon, The second gas contains ammonia.

20. The method for manufacturing a nitride semiconductor according to claim 16, wherein The first gas contains hydrocarbons, The second gas contains ammonia.

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