JP7776382B2 - Semiconductor device and method for manufacturing the same - Google Patents

Description

Embodiments of the present invention relate to semiconductor devices and methods for manufacturing semiconductor devices.

There are semiconductor devices such as transistors that use silicon carbide (SiC). Good characteristics are required for semiconductor devices.

Japanese Patent Application Laid-Open No. 2005-109396

Embodiments of the present invention provide a semiconductor device and a method for manufacturing the semiconductor device that can improve characteristics.

According to an embodiment of the present invention, a method for manufacturing a semiconductor device includes preparing a structure including a silicon carbide member and a first film containing silicon and oxygen that is stacked on the silicon carbide member. The manufacturing method includes performing a first process of heat-treating the structure in a first atmosphere containing hydrogen. The manufacturing method also includes performing a second process, after the first process, of heat-treating the structure in a second atmosphere containing nitrogen and oxygen. The concentration of oxygen in the second atmosphere is 5 ppm or more and 1000 ppm or less.

FIG. 1 is a flowchart illustrating a method for manufacturing a semiconductor device according to an embodiment. FIG. 2 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. 3A to 3C are schematic views illustrating the method for manufacturing a semiconductor device according to the embodiment. 4A to 4C are schematic views illustrating the method for manufacturing a semiconductor device according to the embodiment. FIG. 5 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment. 6A and 6B are graphs illustrating the characteristics of the semiconductor device. 7A and 7B are graphs illustrating the characteristics of the semiconductor device. 8A and 8B are graphs illustrating the characteristics of the semiconductor device. FIG. 9 is a graph illustrating the characteristics of a semiconductor device. FIG. 10 is a graph illustrating the characteristics of a semiconductor device. FIG. 11 is a graph illustrating the characteristics of a semiconductor device. FIG. 12 is a graph illustrating the characteristics of the semiconductor device. FIG. 13 is a graph illustrating the characteristics of a semiconductor device. FIG. 14 is a graph illustrating the characteristics of the semiconductor device. FIG. 15 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Furthermore, even when the same part is shown, the dimensions and ratios may be different depending on the drawing.
In the present specification and the drawings, elements similar to those described above with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

FIG. 1 is a flowchart illustrating a method for manufacturing a semiconductor device according to an embodiment.
FIG. 2 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment.
1, the method for manufacturing a semiconductor device according to the embodiment includes preparing a structure (step S110), a first process (step S120), and a second process (step S130). The method may also include forming a conductive film (step S140), which will be described later.

As shown in FIG. 2, in the semiconductor device 110, a first film 10 is provided on a silicon carbide member 50. The structure 10B includes the silicon carbide member 50 and the first film 10. The first film 10 is stacked on the silicon carbide member 50. The silicon carbide member 50 includes silicon carbide (SiC). The silicon carbide member 50 includes, for example, 4H-SiC.

The first film 10 contains silicon and oxygen. The first film 10 is, for example, a silicon oxide film. For example, the first film 10 is deposited on the silicon carbide member 50. The first film 10 is formed, for example, by chemical vapor deposition (CVD). Chemical vapor deposition may include atomic layer deposition (ALD). The first film 10 may be formed, for example, by physical vapor deposition (PVD). The PVD method includes at least one of evaporation and sputtering. The method for manufacturing a semiconductor device according to the embodiment may further include depositing the first film 10 on the silicon carbide member 50 (one example of step S110).

The direction from the silicon carbide member 50 toward the first film 10 is defined as the Z-axis direction. For example, the first film 10 contacts the silicon carbide member 50. An interface 15 exists between the silicon carbide member 50 and the first film 10.

The thickness t1 of the first film 10 (thickness before the first process) is, for example, 20 nm or more and 100 nm or less. Thickness t1 is the length along the Z-axis direction. A first film 10 having such a thickness t1 can be used as a gate insulating film for a transistor. Such a thickness t1 provides appropriate insulation, appropriate electrical characteristics (e.g., threshold voltage), and good reliability. Thickness t1 may also be 30 nm or more and 60 nm or less.

The semiconductor device 110 may further include a first conductive film E1. The first conductive film E1 is, for example, a gate electrode. The first and second processes described above are performed before the formation of the first conductive film E1. The semiconductor device 110 includes a structure 10B and the first conductive film E1. The semiconductor device 110 is, for example, a transistor.

In the first process (step S120), the structure 10B is heat-treated in a first atmosphere containing hydrogen.

The second process (step S130) is performed after the first process. In the second process, the structure 10B is heat-treated in a second atmosphere containing nitrogen (N ₂ ) and oxygen (O ₂ ). The second atmosphere contains a trace amount of oxygen. For example, the concentration of oxygen (O ₂ ) in the second atmosphere is 5 ppm or more and 1000 ppm or less. This concentration is a volume ratio.

This process results in high carrier mobility in the semiconductor device 110.

3A to 3C are schematic views illustrating the method for manufacturing a semiconductor device according to the embodiment.
3 illustrates the change in temperature during the second process, where the horizontal axis represents time tm and the vertical axis represents temperature Tmp.

As shown in FIG. 3 , in the second treatment, the temperature of the structure 10B is increased from 700°C to 1300°C, then maintained at 1200°C, and then decreased to 700°C or lower. As shown in FIG. 3 , the time for maintaining the temperature at 1300°C (maximum temperature) is designated as time tx1. The time for maintaining the temperature at 1200°C is designated as time tx2. In one example (first sample), time tx1 is 3 hours. Time tx2 is 5.5 hours. The second atmosphere contains nitrogen (N ₂ ) and oxygen (O ₂ ). The oxygen concentration (volume ratio) in the second atmosphere is 500 ppm. Furthermore, a sample of a first reference example is fabricated in which the second atmosphere is nitrogen and substantially does not contain oxygen (the concentration is less than 0.1 ppm).

The carrier mobility in the first sample is lower than that in the sample of the first reference example. A sample containing a trace amount of oxygen exhibits higher carrier mobility than a sample containing no oxygen. According to the embodiment, a method for manufacturing a semiconductor device capable of improving characteristics can be provided.

The high carrier mobility achieved in samples grown in an atmosphere containing a trace amount of oxygen is thought to be related to the fact that the heat treatment in the second atmosphere containing trace amounts of oxygen and nitrogen improves the condition of the interface 15 between the silicon carbide member 50 and the first film 10.

For example, a low interface state density and high carrier mobility can be obtained by performing the second process in a second atmosphere (an atmosphere containing trace amounts of oxygen and nitrogen). This is thought to be due to the silicon atoms being effectively terminated with nitrogen at the interface 15 between the silicon carbide member 50 and the first film 10. Meanwhile, the trace amount of oxygen repairs oxygen vacancies in the first film 10 (silicon oxide film). In this way, the second process improves the nitrogen termination at the interface 15 and the film quality of the first film 10. This results in a low interface state density and high carrier mobility.

In this embodiment, the temperature in the second treatment is preferably 1200°C or higher and 1300°C or lower. At such a temperature, the interface state density can be suppressed, resulting in high carrier mobility. According to this embodiment, a method for manufacturing a semiconductor device capable of improving its characteristics can be provided.

The time during which the temperature exceeds 1200°C in the second treatment (time tm2 shown in Figure 3) is preferably 1 hour or more and 10 hours or less. This ensures that the interface state density is suppressed. High carrier mobility can be more reliably obtained.

In an embodiment, for example, the oxygen in the second atmosphere is _O2 , and the nitrogen in the second atmosphere is _N2 . In an embodiment, the second atmosphere preferably does not substantially contain NO. For example, the concentration of NO in the second atmosphere is preferably less than 0.3 ppm. This concentration is a volume ratio.

When the second atmosphere is substantially free of NO, for example, silicon atoms are effectively terminated with nitrogen, improving the film quality of the first film 10. That is, nitrogen in the second atmosphere acts on the interface 15, and oxygen in the second atmosphere acts on the first film 10. When the second atmosphere contains NO, nitrogen atoms and oxygen atoms are present simultaneously. This makes it difficult to achieve the above-mentioned effect.

The concentration of nitrogen (e.g., _N2 ) contained in the second atmosphere is preferably 0.1% or more and less than 100%. The concentration of nitrogen (e.g., _N2 ) contained in the second atmosphere may be 99.9% or less. The interface state density can be reliably suppressed. High carrier mobility can be more reliably obtained. The above concentrations are volume ratios.

An example of a temperature profile for the second process is shown in Figure 3. In one example, the rate of temperature increase from 700°C to 900°C is, for example, about 10°C/min. The rate of temperature increase from 900°C to 1270°C is, for example, about 5°C/min. The rate of temperature increase from 1270°C to 1300°C is, for example, about 3°C/min. The rate of temperature decrease from 1300°C to 1200°C is, for example, about 5°C/min.

In this embodiment, it is preferable that the first treatment be performed before the second treatment. The first treatment is a heat treatment in a first atmosphere containing hydrogen.

For example, in a sample that has undergone a first treatment followed by a second treatment in an atmosphere containing substantially no oxygen but containing nitrogen, the interface state density is approximately 2.5×10 ¹² /cm ⁻² . In contrast, in a sample that has undergone a first treatment followed by a second treatment in a second atmosphere containing nitrogen and a trace amount of oxygen, the interface state density can be reduced to approximately 2.1×10 ¹² /cm ⁻² or less.

For example, by heat treatment in a first atmosphere containing hydrogen, carbon atoms are removed and a silicon-rich silicon carbide region is formed in a region including the interface 15 between the silicon carbide member 50 and the first film 10.

The formation of a silicon-rich silicon carbide region in the region including the interface 15 facilitates bonding of nitrogen with silicon. The subsequent second process more reliably terminates the silicon with nitrogen. This facilitates the formation of a connection region that effectively connects the silicon carbide member 50 and the first film 10 at the interface 15 between the silicon carbide member 50 and the first film 10. In the connection region, silicon is terminated with nitrogen, resulting in a stable low interface state density. For example, the second process includes bonding nitrogen to silicon present in the region between the silicon carbide member 50 and the first film 10.

For example, unnecessary oxygen in the first film 10 is removed by the first process in a first atmosphere containing hydrogen. This unnecessary oxygen may oxidize the silicon carbide at high temperatures in the second process. If silicon carbide is oxidized, carbon atoms may remain in the oxide film, making it difficult to achieve high properties (e.g., high carrier mobility). Therefore, it is preferable to suppress the oxidation of silicon carbide. By removing unnecessary oxygen in the first process, undesirable oxidation of silicon carbide in the second process is suppressed.

The first process, performed in a first atmosphere containing hydrogen, may cause oxygen vacancies in the first film 10. The second process, performed in a second atmosphere containing a trace amount of oxygen, repairs the oxygen vacancies. This results in high film quality.

The second process, performed in an atmosphere containing nitrogen and trace amounts of oxygen, repairs oxygen vacancies, improving film quality. In the second process, the oxygen concentration is set low, suppressing oxidation of silicon carbide.

The hydrogen concentration in the first atmosphere is 0.01% or more and 100% or less. The first atmosphere preferably does not contain NO. The NO concentration in the first atmosphere is, for example, 0.001 ppm or less. These concentrations are volume ratios.

If the first atmosphere in the first process contains oxygen, it becomes difficult to remove carbon from the silicon carbide, making it difficult to effectively terminate with nitrogen. For example, the reduction of interface states is likely to be insufficient. If the first atmosphere in the first process contains oxygen, it becomes difficult to remove unnecessary oxygen contained in the first film 10. In this case, the silicon carbide is likely to be oxidized in the second process. It becomes difficult to achieve high characteristics (for example, high carrier mobility).

If the oxygen concentration in the second atmosphere of the second treatment exceeds 1000 pm, the surface of the silicon carbide becomes more susceptible to oxidation. It becomes difficult to achieve high performance (e.g., high carrier mobility).

For example, there is a reference example in which the first treatment is not performed, and the interface states are terminated with nitrogen by oxynitridation in a nitric oxide (NO) atmosphere or a nitrous oxide (N ₂ O) atmosphere. In this reference example, an oxidation reaction occurs along with the nitrogen termination. Therefore, the characteristics deteriorate due to oxidation of silicon carbide.

In contrast, in this embodiment, nitrogen and an appropriate concentration of oxygen can appropriately suppress oxidation of silicon carbide, thereby suppressing deterioration of characteristics.

In an embodiment, in a second process performed after a first process in a first atmosphere containing hydrogen, the second atmosphere may contain at least one of nitric oxide and nitrous oxide. The first process promotes nitrogen termination and suppresses oxidation. High carrier mobility is more easily achieved compared to the above reference example in which the first process is not performed. When the second process is performed in a second atmosphere containing at least one of nitric oxide and nitrous oxide after the first process in the first atmosphere, the concentration of nitric oxide or nitrous oxide may be set lower than in the reference example.

4A to 4C are schematic views illustrating the method for manufacturing a semiconductor device according to the embodiment.
4 illustrates the temperature change in the first and second processes, where the horizontal axis represents time tm and the vertical axis represents temperature Tmp.

For example, in the first treatment, heat treatment is performed at a first temperature T1 in a first atmosphere containing hydrogen. The first temperature T1 is, for example, 1200°C or higher and 1350°C or lower. The time tm1 of the first treatment (the time during which the temperature Tmp exceeds 1200°C) is preferably, for example, 15 minutes or higher and 10 hours or lower.

The second treatment is performed at a second temperature T2 in a second atmosphere containing trace amounts of oxygen and nitrogen. The time tm2 of the second treatment is preferably 1 hour or more and 20 hours or less.

As shown in FIG. 4, between the first and second processes, the structure 10B may be heated to a temperature (third temperature T3) lower than the first temperature T1. The first and second processes may be performed continuously in the same apparatus. The first and second processes may also be performed discontinuously in separate apparatus. In the structure 10B, a stable first film 10 is provided on the surface of the silicon carbide member 50. Therefore, adverse effects are suppressed even if the structure 10B is removed from the apparatus. This facilitates the process.

In this embodiment, the first process and the second process are performed after the first film 10 is formed. For example, if the first film 10 is formed after the first process, the surface of the silicon carbide member 50 is likely to be contaminated.

As shown in FIG. 2, the silicon carbide member 50 may include a first region 50r. In a first direction (Z-axis direction) from the silicon carbide member 50 to the first film 10, the first region 50r is spaced apart from the interface 15 between the silicon carbide member 50 and the first film 10. For example, the first region 50r does not contain nitrogen. Alternatively, the nitrogen concentration at the interface 15 is higher than the nitrogen concentration in the first region 50r. The nitrogen localized near the interface 15 terminates the silicon near the interface with nitrogen. The first region 50r is a bulk region spaced apart from the interface. The distance between the interface 15 and the first region 50r may be, for example, 20 nm or more.

FIG. 5 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment.
5, the semiconductor device 111 includes a first semiconductor region 51 of a first conductivity type, a second semiconductor region 52 of a second conductivity type, a third semiconductor region 53 of the first conductivity type, a fourth semiconductor region 54 of the second conductivity type, a first film 10, a first conductive film E1, a second conductive film E2, a third conductive film E3, and an insulating film I1. The semiconductor device 111 is a transistor. The semiconductor regions include, for example, silicon carbide. For example, the second semiconductor region 52 corresponds to the silicon carbide member 50. The first film 10 corresponds, for example, to a gate insulating film. The first conductive film E1 corresponds to a gate electrode. The second conductive film E2 corresponds, for example, to a source electrode. The third conductive film E3 corresponds, for example, to a drain electrode. In this example, a substrate 55 (SiC substrate) is provided.

The direction perpendicular to the Z-axis direction is the X-axis direction. The direction perpendicular to the Z-axis direction and the X-axis direction is the Y-axis direction.

In this example, in the Z-axis direction, the first conductive film E1 is provided between the second conductive film E2 and the third conductive film E3. The substrate 55 is located between the first conductive film E1 and the third conductive film E3. A portion of the first semiconductor region 51 is located between the first conductive film E1 and the substrate 55. The first film 10 is located between the first conductive film E1 and this portion of the first semiconductor region 51. An insulating film I1 is provided between the second conductive film E2 and the first conductive film E1. The insulating film I1 provides insulation between the second conductive film E2 and the first conductive film E1.

A second semiconductor region 52 is provided between another portion of the first semiconductor region 51 and a portion of the second conductive film E2. A third semiconductor region 53 and a fourth semiconductor region 54 are located between the portion of the second semiconductor region 52 and the above-mentioned portion of the second conductive film E2. In the X-axis direction, the third semiconductor region 53 is located between a portion of the first semiconductor region 51 and the fourth semiconductor region 54. A portion of the second semiconductor region 52 is located between this portion of the first semiconductor region 51 and the third semiconductor region 53. The third semiconductor region 53 and the fourth semiconductor region 54 are in ohmic contact with the second conductive film E2.

High mobility is achieved in semiconductor device 111.

An example of an experimental result will be described below. In the experiment, a structure 10B is prepared. The structure 10B includes a silicon carbide member 50 and a first film 10. In the experiment, the first film 10 is a _SiO2 film. In a first process, the structure 10B is heat-treated in a first atmosphere containing hydrogen. Then, in a second process, the structure 10B is heat-treated in a second atmosphere containing nitrogen and oxygen.

In the experiments described below, the second process includes a first step process and a second step process that follows the first step process. The first step process corresponds to the process at time tx1 illustrated in FIG. 3. The second step process corresponds to the process at time tx2 illustrated in FIG. 3. The temperature of the first step process is 1300°C. The atmosphere in the first step process (second atmosphere) contains nitrogen ( _N2 ) containing oxygen ( _O2 ) at a concentration of 100 ppm. The temperature of the second step process is 1200°C. The atmosphere in the second step process contains nitrogen ( _N2 ) that does not contain oxygen.

After the second process, a first conductive film E1 is formed on the first film 10. Meanwhile, another conductive film is formed below the silicon carbide member 50. A voltage is applied between this other conductive film and the first conductive film E1. The capacitance between the other conductive film and the first conductive film E1 is measured as the applied voltage is changed. The interface state density is obtained from the measurement results.

6A and 6B are graphs illustrating the characteristics of the semiconductor device.
6(a) and 6(b), the first atmosphere in the first process is nitrogen ( _N2 ) containing 0.3% hydrogen. In the first process, a heat treatment is performed at 1350°C for 60 minutes. Then, the second process is performed. The horizontal axis of these graphs represents the thickness t1 of the first film 10.

The vertical axis in Figure 6(a) is the interface state density D1. The interface state density D1 corresponds to the density of interface states at 0.2 eV. The vertical axis in Figure 6(b) is the interface state density D2. The interface state density D2 corresponds to the density of interface states at 0.5 eV. In Figures 6(a) and 6(b), the results for the first reference sample RS1, which was not subjected to the first treatment, are shown at the position where the thickness t1 is 0 nm for convenience. In the first reference sample RS1, the thickness t1 is 55 nm.

As shown in Figure 6(a), when the thickness t1 is between 25 nm and 100 nm, the interface state density D1 is lower than the interface state density D1 in the first reference sample RS1. As shown in Figure 6(b), when the thickness t1 is between 25 nm and 50 nm, the interface state density D2 is lower than the interface state density D1 in the first reference sample RS1. In this way, a low interface state density is obtained by performing the first process in the first atmosphere containing hydrogen.

7A and 7B are graphs illustrating the characteristics of the semiconductor device.
7A and 7B, the first atmosphere in the first process is nitrogen (N ₂ ) containing 1% hydrogen. In the first process, a heat treatment is performed at 1350° C. for 60 minutes. Then, the second process is performed. The horizontal axis of these graphs represents the thickness t1 of the first film 10.

The vertical axis in Figure 7(a) is the interface state density D1. The vertical axis in Figure 7(b) is the interface state density D2. In Figures 7(a) and 7(b), the results for the first reference sample RS1, which was not subjected to the first treatment, are shown at the position where the thickness t1 is 0 nm for convenience.

As shown in Figure 7(a), when the thickness t1 is between 25 nm and 100 nm, the interface state density D1 is lower than the interface state density D1 in the first reference sample RS1. As shown in Figure 7(b), when the thickness t1 is between 25 nm and 50 nm, the interface state density D2 is lower than the interface state density D1 in the first reference sample RS1. In this way, a low interface state density is obtained by performing the first process in the first atmosphere containing hydrogen.

8A and 8B are graphs illustrating the characteristics of the semiconductor device.
8(a) and 8(b), the first atmosphere in the first process is nitrogen ( _N2 ) containing 5% hydrogen. In the first process, a heat treatment is performed at 1350°C for 10 minutes. Then, the second process is performed. The horizontal axis of these graphs represents the thickness t1 of the first film 10.

The vertical axis in Figure 8(a) is the interface state density D1. The vertical axis in Figure 8(b) is the interface state density D2. In Figures 8(a) and 8(b), the results for the first reference sample RS1, which was not subjected to the first treatment, are shown at the position where the thickness t1 is 0 nm for convenience.

As shown in Figure 8(a), when the thickness t1 is between 25 nm and 60 nm, the interface state density D1 is lower than the interface state density D1 in the first reference sample RS1. As shown in Figure 8(b), when the thickness t1 is between 25 nm and 60 nm, the interface state density D2 is lower than the interface state density D1 in the first reference sample RS1. In this way, a low interface state density is obtained by performing the first process in the first atmosphere containing hydrogen.

From the above results, it is preferable that the thickness t1 of the first film 10 be 25 nm or more and less than 90 nm. The thickness t1 may also be 25 nm or more and 80 nm or less. The thickness t1 may also be 25 nm or more and 60 nm or less.

In another experiment, the temperature in the first treatment was set to 1370°C, followed by the second treatment. The interface state density in this case was not sufficiently low compared to the interface state density in the first reference sample RS1, which was not subjected to the first treatment. In this embodiment, the temperature (maximum temperature) in the first treatment is preferably less than 1370°C (e.g., 1350°C or less).

As described above, a low interface state density is obtained by performing a first process in a first atmosphere containing hydrogen and a second process in a second atmosphere containing oxygen and nitrogen after the first process. It has been found that such special processes result in a characteristic profile in the structure 10B including the silicon carbide member 50 and the first film 10.

9 to 14 are graphs illustrating the characteristics of the semiconductor device.
9, 11, and 13 correspond to the first sample SP1. The thickness t1 of the first film 10 in the first sample SP1 is 50 nm. The first sample SP1 is subjected to a first process at 1350° C. for 60 minutes in a first atmosphere containing 1% (volume ratio) hydrogen, followed by a second process. In the second process, the first step process and the second step process described above are performed.

Figures 10, 12, and 14 correspond to the second sample SP2. In the second sample SP2, the thickness t1 of the first film 10 is 50 nm. In the second sample SP2, the first process is not performed, but the second process is performed. In the second process, the first step process and second step process described above are performed. The second sample SP2 corresponds to the first reference sample RS1 described above. The interface state density in the first sample SP1 is lower than the interface state density in the second sample SP2.

The horizontal axis in these figures represents the position pZ along the Z-axis. The vertical axis on the left side of Figures 9 and 10 represents the concentration C0 of Si-N bonds or C-N bonds. The vertical axis on the right side of Figures 9 and 10 represents the secondary ion intensity Int of Si. The secondary ion intensity Int of Si corresponds to the concentration of Si.

The vertical axis on the left in Figures 11 and 12 is the concentration C0 of Si-N bonds or C (carbon). The vertical axis on the right in Figures 11 and 12 is the secondary ion intensity Int of O (oxygen). The secondary ion intensity Int of oxygen corresponds to the oxygen concentration. The vertical axis in Figures 13 and 14 is the concentration C0 of Si-N bonds.

As shown in Figure 9, the profile of the Si-N bond concentration for the first sample SP1 has a peak. The concentration of Si-N bonds decreases significantly to the left of the peak position in the figure.

As shown in Figure 10, the profile of the Si-N bond concentration in the second sample SP2 has a peak. To the left of the peak in the figure, the concentration of Si-N bonds is higher than the concentration in the first sample SP1. Thus, there is a difference in the profile of the Si-N bond concentration between the first sample SP1 and the second sample SP2.

9 , at a first position p1 in a first direction (Z-axis direction) from the silicon carbide member 50 to the first film 10, the Si—N concentration of bonds between silicon and nitrogen is a first peak value vp1. In the first sample SP1, the first peak value vp1 is approximately 2.0×10 ²¹ /cm ^3. At a second position p2 in the first direction, the C—N concentration of bonds between carbon and nitrogen is a second peak value vp2. In the first sample SP1, the second peak value vp2 is approximately 3.2×10 ²⁰ /cm ^3. At a third position p3 in the first direction, the C—N concentration is low and stable. In this example, at the third position p3 in the first direction, the C-N concentration v_C-N is ^{approximately} 1.1 x ¹⁰ /cm, and at the third position p3 in the first direction, the C-N concentration v_C-N is 1/2800 of the second peak value vp2. The third position p3 is the position where the C-N concentration v_C-N is 1/2800 of the second peak value vp2 in the direction from the silicon carbide member 50 to the first film 10.

In this example, in the first sample SP1, the Si-N concentration v_Si-N at this third position p3 is 1/24 of the first peak value vp1. In an embodiment, the Si-N concentration (v_Si-N) at this third position p3 is, for example, less than 1/20 of the first peak value vp1.

10 , the Si—N concentration of silicon and nitrogen bonds at the first position p1 is a first peak value vp1. In the second sample SP2, the first peak value vp1 is approximately 2.2×10 ²¹ /cm ^3. At the second position p2 in the first direction, the C—N concentration of carbon and nitrogen bonds is a second peak value vp2. In the second sample SP2, the second peak value vp2 is approximately 3.5×10 ²⁰ /cm ^3. At the third position p3 in the first direction, the C—N concentration v_C-N is approximately 1.3×10 ¹⁷ /cm ^3. Thus, in the second sample SP2, at the third position p3 in the first direction, the C—N concentration v_C-N is 1/2800 of the second peak value vp2.

In the second sample SP2, the Si—N concentration (v_Si-N) at the third position p3 is 1.4×10 ²⁰ /cm ^3. Thus, in the second sample SP2, the Si—N concentration (v_Si-N) at the third position p3 is 1/16 of the first peak value vp1. In the second sample SP2, the Si—N concentration (v_Si-N) at the third position p3 is 1/20 or more of the first peak value vp1. In the second sample SP2, the Si—N concentration is not sufficiently low.

In this embodiment, it is believed that a low interface state density can be obtained by having a sufficiently low Si-N concentration (v_Si-N) at the third position p3.

For example, in the embodiment, the first peak value vp1 may be 1.7×10 ²¹ /cm ³ or more. At the second position p2 in the first direction, the C—N concentration of carbon and nitrogen bonds is the second peak value vp2. At the third position p3 in the first direction, the C—N concentration (v_C-N) is 1/2800 of the second peak value vp2. The Si—N concentration (v_Si-N) at such a third position p3 is 1.0×10 ²⁰ /cm ³ or less. In the embodiment, it is considered that a low interface state density is obtained because the Si—N concentration (v_Si-N) at the third position p3 is sufficiently low. The first peak value vp1 may be 1.9×10 ²¹ /cm ³ or more. The Si—N concentration (v_Si-N) at the third position p3 may be 0.9×10 ²⁰ /cm ³ or less.

As shown in Figures 9 and 10, the first position p1 substantially coincides with the position of the interface 15 between the silicon carbide member 50 and the first film 10. At the interface 15, the Si-N concentration of silicon-nitrogen bonds reaches a first peak value vp1. Information regarding the position of the interface 15 may be obtained, for example, from electron microscope observation of the structure 10B. The second position p2 may substantially coincide with the first position p1.

As shown in Figures 9 and 10, the Si concentration reaches a minimum in the first film 10. The position where this minimum occurs is, for example, the fourth position p4. There is a difference in the Si-N concentration (v_Si-N) at the fourth position p4 between the first sample SP1 and the second sample SP2. In the TOF-SIMS profile, there is a surface effect in the surface region of the sample (in the example of Figures 9 and 10, the region on the left side of the figure where pZ is 5 nm or less). For this reason, the surface region of the sample is ignored when determining the position of the minimum Si concentration.

As shown in FIG. 9, at a first position p1 in a first direction (Z-axis direction) from the silicon carbide member 50 to the first film 10, the Si-N concentration of silicon and nitrogen bonds is a first peak value vp1. At a fourth position p4 in the first direction, the silicon concentration is a minimum value in the first film 10. In the example of FIG. 9, the Si-N concentration (v_Si-N) at the fourth position p4 is 1/24 of the first peak value vp1. Thus, in this embodiment, the Si-N concentration (v_Si-N) at the fourth position p4 is less than 1/20 of the first peak value vp1.

In the second sample SP2 shown in Figure 10, the Si-N concentration (v_Si-N) at the fourth position p4 is 1/16 of the first peak value vp1.

9, in the embodiment, the first peak value vp1 is 1.7×10 ²¹ /cm ³ or more. In this example, the first peak value vp1 is 2.0×10 ²¹ /cm ^3. At a fourth position p4 in the first direction, the silicon concentration is a minimum value in the first film 10. The Si—N concentration (v_Si—N) at such a fourth position p4 is 1.0×10 ²⁰ /cm ³ or less. In the example shown in FIG. 9, the Si—N concentration (v_Si—N) at the fourth position p4 is 0.8×10 ²⁰ /cm ³ .

In the second sample SP2 shown in FIG. 10, the first peak value vp1 is 2.2×10 ²¹ /cm ³ or more, and the Si—N concentration (v_Si—N) at the fourth position p4 is 1.4×10 ²⁰ /cm ³ .

As shown in Figures 11 and 12, the oxygen concentration is minimal in the first film 10. The position where this minimum occurs is, for example, the fifth position p5. There is a difference in the Si-N concentration at the fifth position p5 between the first sample SP1 and the second sample SP2. In the TOF-SIMS profile, the surface region of the sample is ignored when determining the position of the minimal oxygen concentration.

As shown in FIG. 11, at the first position p1, the Si-N concentration of silicon and nitrogen bonds is the first peak value vp1. At the fifth position p5 in the first direction, the oxygen concentration is at a minimum value in the first film 10. In the example of FIG. 9, the Si-N concentration (v_Si-N) at the fifth position p5 is 1/24 of the first peak value vp1. In an embodiment, for example, the Si-N concentration (v_Si-N) at the fifth position p5 is less than 1/20 of the first peak value vp1.

In the second sample SP2 shown in Figure 12, the Si-N concentration (v_Si-N) at the fifth position p5 is 1/16 of the first peak value vp1.

11 , in the embodiment, the first peak value vp1 is 1.7×10 ²¹ /cm ³ or more. In this example, the first peak value vp1 is 2.0×10 ²¹ /cm ^3. At a fifth position p5 in the first direction, the silicon concentration is a minimum value in the first film 10. The Si—N concentration (v_Si—N) at such a fifth position p5 is 1.0×10 ²⁰ /cm ³ or less. In the example shown in FIG. 11 , the Si—N concentration (v_Si—N) at the fifth position p5 is 0.8×10 ²⁰ /cm ³ .

In the second sample SP2 shown in FIG. 12, the first peak value vp1 is 2.2×10 ²¹ /cm ³ or more, and the Si—N concentration (v_Si—N) at the fifth position p5 is 1.4×10 ²⁰ /cm ³ .

As shown in Figures 13 and 14, in the direction from the silicon carbide member 50 toward the first film 10, there is a position (sixth position p6) that is 10 nm from the first position p1 (e.g., interface 15). There is a difference in the Si-N concentration (v_Si-N) at the sixth position p6 between the first sample SP1 and the second sample SP2.

For example, as shown in FIG. 13, the Si-N concentration of silicon and nitrogen bonds at a first position p1 in the first direction is a first peak value vp1. In the embodiment, the Si-N concentration (v_Si-N) at a sixth position p6 in the first direction is less than 1/20 of the first peak value. In the example of FIG. 9, the Si-N concentration (v_Si-N) at the sixth position p6 is 1/24 of the first peak value. The sixth position p6 is located in the first film 10. The distance dZ in the first direction between the first position p1 and the sixth position p6 is 10 nm. The low Si-N concentration (v_Si-N) at the sixth position p6 results in a low interface state density.

In the second sample SP2 shown in Figure 14, the Si-N concentration (v_Si-N) at the sixth position p6 is 1/16 of the first peak value vp1.

13 , at a first position p1 in the first direction, the Si—N concentration of bonds between silicon and nitrogen has a first peak value vp1. In the embodiment, the first peak value is 1.7×10 ²¹ /cm ³ or more. In the embodiment, at a sixth position p6 in the first direction, the Si—N concentration (v_Si—N) is 1.0×10 ²⁰ /cm ³ or less. The sixth position p6 is located in the first film 10. A distance dZ in the first direction between the first position p1 and the sixth position p6 is 10 nm.

By having a low Si-N concentration (v_Si-N) at at least one of the third position p3, fourth position p4, fifth position p5, and sixth position p6, a low interface state density is obtained. For example, high carrier mobility is obtained.

In this embodiment, the Si-N concentration (v_Si-N) is low at at least one of the third position p3, fourth position p4, fifth position p5, and sixth position p6, which is thought to be due to, for example, the densification of the first film 10 as a result of the first process.

In an example embodiment, a special structure may be obtained in which the Si concentration is at a minimum at the fourth position p4. In an example embodiment, a special structure may be obtained in which the oxygen concentration is at a minimum at the fifth position p5.

FIG. 15 is a schematic cross-sectional view illustrating the semiconductor device according to the embodiment.
15, in a semiconductor device 111 according to the embodiment, the silicon carbide member 50 may be a first semiconductor region 51 of a first conductivity type. The silicon carbide member 50 may be, for example, an n-type semiconductor region.

In the first sample SP1 and the second sample SP2 described above, the silicon carbide member 50 is n-type. In the silicon carbide member 50 in the first sample SP1 and the second sample SP2, the concentration of the n-type impurity (N in this example) is approximately 5×10 ¹⁵ /cm ^3. In the embodiment, the concentration of the n-type impurity (P or N) in the silicon carbide member 50 (first semiconductor region 51) may be 1×10 ¹⁵ /cm ³ or more and 5×10 ²⁰ /cm ³ or less. The concentration of the n-type impurity (P or N) in the first semiconductor region 51 may be 1×10 ¹⁶ /cm ³ or more and 5×10 ¹⁸ /cm ³ or less. As already described, in the embodiment, the silicon carbide member 50 may correspond to the second semiconductor region 52 of the second conductivity type.

When the silicon carbide member 50 according to the embodiment is provided in the semiconductor device 111, the silicon carbide member 50 may be applied to a region to which an electric field is applied during operation of the semiconductor device 111. The silicon carbide member 50 may be applied to a region that is at least part of the current path during operation of the semiconductor device 111. A low interface state density results in stable operation.

The embodiment may include the following configurations (e.g., technical solutions).
(Configuration 1)
a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
At a second position in the first direction, the C—N concentration of carbon and nitrogen bonds is a second peak value;
At a third position in the first direction, the C—N concentration is 1/2800 of the second peak value;
The Si—N concentration at the third position is less than 1/20 of the first peak value.

(Configuration 2)
a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
the first peak value is 1.7×10 ²¹ /cm ³ or more,
At a second position in the first direction, the C—N concentration of carbon and nitrogen bonds is a second peak value;
the C—N concentration at a third position in the first direction is 1/2800 of the second peak value,
The semiconductor device, wherein the Si—N concentration at the third position is 1.0×10 ²⁰ /cm ³ or less.

(Configuration 3)
a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
At a fourth position in the first direction, the concentration of silicon is at a minimum in the first film;
the Si—N concentration at the fourth position is less than 1/20 of the first peak value.

(Configuration 4)
a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
the first peak value is 1.7×10 ²¹ /cm ³ or more,
At a fourth position in the first direction, the concentration of silicon is at a minimum in the first film;
The semiconductor device, wherein the Si—N concentration at the fourth position is 1.0×10 ²⁰ /cm ³ or less.

(Configuration 5)
a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
At a fifth position in the first direction, the concentration of oxygen is a minimum value in the first film;
the Si—N concentration at the fifth position is less than 1/20 of the first peak value.

(Configuration 6)
a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
the first peak value is 1.7×10 ²¹ /cm ³ or more,
At a fifth position in the first direction, the concentration of oxygen is a minimum value in the first film;
The semiconductor device, wherein the Si—N concentration at the fifth position is 1.0×10 ²⁰ /cm ³ or less.

(Configuration 7)
a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
the Si—N concentration at a sixth position in the first direction is less than 1/20 of the first peak value;
the sixth location is in the first membrane;
The semiconductor device, wherein the distance in the first direction between the first position and the sixth position is 10 nm.

(Configuration 8)
a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
the first peak value is 1.7×10 ²¹ /cm ³ or more,
the Si—N concentration at a sixth position in the first direction is 1.0×10 ²⁰ /cm ³ or less;
the sixth location is in the first membrane;
The semiconductor device, wherein the distance in the first direction between the first position and the sixth position is 10 nm.

(Configuration 9)
Further comprising a first conductive film;
9. The semiconductor device according to any one of configurations 1 to 8, wherein the first film is provided between the silicon carbide member and the first conductive film.

(Configuration 10)
preparing a structure including a silicon carbide member and a first film containing silicon and oxygen and laminated on the silicon carbide member;
performing a first process of heat treating the structure in a first atmosphere containing hydrogen;
After the first treatment, a second treatment is performed in which the structure is heat-treated in a second atmosphere containing nitrogen and oxygen;
The method for manufacturing a semiconductor device, wherein the concentration of oxygen in the second atmosphere is 5 ppm or more and 1000 ppm or less.

(Configuration 11)
11. The method for manufacturing a semiconductor device according to configuration 10, wherein the temperature in the second treatment is 1200° C. or more and 1300° C. or less.

(Configuration 12)
12. The method for manufacturing a semiconductor device according to claim 11, wherein the time during which the temperature exceeds 1200° C. in the second treatment is from 1 hour to 20 hours.

(Configuration 13)
The oxygen in the second atmosphere is _O2 ;
13. The method for manufacturing a semiconductor device according to any one of configurations 10 to 12, wherein the nitrogen in the second atmosphere is _N2 .

(Configuration 14)
14. The method for manufacturing a semiconductor device according to any one of configurations 10 to 13, wherein the concentration of the nitrogen contained in the second atmosphere is equal to or greater than 0.1% and less than 100%.

(Configuration 15)
15. The method for manufacturing a semiconductor device according to any one of configurations 10 to 14, wherein the thickness of the first film is 25 nm or more and 60 nm or less.

(Configuration 16)
16. The method for manufacturing a semiconductor device according to any one of configurations 10 to 15, wherein the first film is in contact with the silicon carbide member.

(Configuration 17)
17. The method for manufacturing a semiconductor device according to any one of configurations 10 to 16, wherein the concentration of hydrogen in the first atmosphere is 0.01% or more and 100% or less.

(Configuration 18)
18. The method for manufacturing a semiconductor device according to any one of configurations 10 to 17, wherein the temperature in the first treatment is 1200° C. or higher and 1350° C. or lower.

(Configuration 19)
19. The method of manufacturing a semiconductor device according to configuration 18, wherein the first treatment is performed for a period of 15 minutes to 10 hours.

(Configuration 20)
20. The method of claim 10, wherein the second treatment includes bonding nitrogen to silicon present in a region between the silicon carbide member and the first film.

(Configuration 21)
the silicon carbide member includes a first region, the first region being spaced apart from an interface between the silicon carbide member and the first film in a first direction from the silicon carbide member to the first film;
21. The method for manufacturing a semiconductor device according to any one of configurations 10 to 20, wherein the first region does not contain nitrogen, or the concentration of nitrogen at the interface is higher than the concentration of nitrogen in the first region.

(Configuration 22)
22. The method for manufacturing a semiconductor device according to any one of configurations 10 to 21, further comprising: between the first treatment and the second treatment, bringing the structure to a temperature lower than the first temperature.

(Configuration 23)
23. The method of manufacturing a semiconductor device according to any one of configurations 10 to 22, further comprising forming a conductive film on the first film after the second treatment.

According to the embodiment, a method for manufacturing a semiconductor device that can improve characteristics can be provided.

In this specification, "vertical" and "parallel" do not only mean strictly vertical and strictly parallel, but also include variations in the manufacturing process, for example, and are sufficient as long as they are substantially vertical and substantially parallel.

Embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the specific configurations of the elements included in the semiconductor device, such as the silicon carbide member, semiconductor region, first film, and conductive film, are within the scope of the present invention as long as a person skilled in the art can implement the present invention in a similar manner and obtain similar effects by appropriately selecting them from within the known range.

Furthermore, any combination of two or more elements of each specific example, to the extent technically possible, is also included within the scope of the present invention, as long as it encompasses the gist of the present invention.

In addition, all semiconductor devices and semiconductor device manufacturing methods that can be implemented by a person skilled in the art by making appropriate design modifications based on the semiconductor device and semiconductor device manufacturing method described above as embodiments of the present invention also fall within the scope of the present invention, as long as they include the gist of the present invention.

In addition, within the scope of the concept of this invention, a person skilled in the art may conceive of various modifications and alterations, and it is understood that these modifications and alterations also fall within the scope of this invention.

While several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments may be embodied in a variety of other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their variations are within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as set forth in the claims.

10...first film, 10B...structure, 15...interface, 50...silicon carbide member, 50r...first region, 51-54...first to fourth semiconductor regions, 55...substrate, 110, 111...semiconductor device,
C0...concentration,
D1, D2...interface state density,
E1 to E3...first to third conductive films,
I1...insulating film,
Int...secondary ion intensity,
RS1: First reference sample;
SP1, SP2...first and second samples,
T1 to T3...first to third temperature, Tmp...temperature,
dZ...distance,
p1 to p6...first to sixth positions,
t1...thickness, tm, tm1, tm2, tx1, tx2...time,
v_C-N...CN concentration,
v_Si-N...Si-N concentration,
vp1, vp2...first and second peak values,

Claims (18)

a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
At a second position in the first direction, the C—N concentration of carbon and nitrogen bonds is a second peak value;
At a third position in the first direction, the C—N concentration is 1/2800 of the second peak value;
the Si—N concentration at the third position is less than 1/20 of the first peak value. a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
the first peak value is 1.7×10 ²¹ /cm ³ or more,
At a second position in the first direction, the C—N concentration of carbon and nitrogen bonds is a second peak value;
the C—N concentration at a third position in the first direction is 1/2800 of the second peak value,
The semiconductor device, wherein the Si—N concentration at the third position is 1.0×10 ²⁰ /cm ³ or less. a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
At a fourth position in the first direction, the concentration of silicon is at a minimum in the first film;
the Si—N concentration at the fourth position is less than 1/20 of the first peak value. a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
the first peak value is 1.7×10 ²¹ /cm ³ or more,
At a fourth position in the first direction, the concentration of silicon is at a minimum in the first film;
The semiconductor device, wherein the Si—N concentration at the fourth position is 1.0×10 ²⁰ /cm ³ or less. a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
At a fifth position in the first direction, the concentration of oxygen is a minimum value in the first film;
the Si—N concentration at the fifth position is less than 1/20 of the first peak value. a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
the first peak value is 1.7×10 ²¹ /cm ³ or more,
At a fifth position in the first direction, the concentration of oxygen is a minimum value in the first film;
The semiconductor device, wherein the Si—N concentration at the fifth position is 1.0×10 ²⁰ /cm ³ or less. a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
the Si—N concentration at a sixth position in the first direction is less than 1/20 of the first peak value;
the sixth location is in the first membrane;
The semiconductor device, wherein the distance in the first direction between the first position and the sixth position is 10 nm. a silicon carbide member;
a first film laminated with the silicon carbide member and containing silicon and oxygen;
Equipped with
a Si—N concentration of silicon and nitrogen bonds at a first position in a first direction from the silicon carbide member to the first film is a first peak value;
the first peak value is 1.7×10 ²¹ /cm ³ or more,
the Si—N concentration at a sixth position in the first direction is 1.0×10 ²⁰ /cm ³ or less;
the sixth location is in the first membrane;
The semiconductor device, wherein the distance in the first direction between the first position and the sixth position is 10 nm. Further comprising a first conductive film;
9. The semiconductor device according to claim 1, wherein said first film is provided between said silicon carbide member and said first conductive film. preparing a structure including a silicon carbide member and a first film containing silicon and oxygen and laminated on the silicon carbide member;
performing a first process of heat treating the structure in a first atmosphere containing hydrogen;
After the first treatment, a second treatment is performed in which the structure is heat-treated in a second atmosphere containing nitrogen and oxygen;
the concentration of oxygen in the second atmosphere is 5 ppm or more and 1000 ppm or less,
the temperature in the first treatment is 1200°C or higher and 1350°C or lower,
The method for manufacturing a semiconductor device , wherein the temperature in the second treatment is 1200° C. or higher and 1300° C. or lower . The method for manufacturing a semiconductor device according to claim 10 , wherein the time during which the temperature exceeds 1200° C. in the second treatment is from 1 hour to 20 hours. The oxygen in the second atmosphere is _O2 ;
The method for manufacturing a semiconductor device according to claim 10, wherein the nitrogen in the second atmosphere is _N2 . The method for manufacturing a semiconductor device according to claim 10, wherein the concentration of nitrogen contained in the second atmosphere is greater than or equal to 0.1% and less than 100%. The method for manufacturing a semiconductor device described in claim 10, wherein the thickness of the first film is 25 nm or more and 60 nm or less. The method for manufacturing a semiconductor device described in claim 10, wherein the first film contacts the silicon carbide member. The method for manufacturing a semiconductor device according to claim 10, wherein the hydrogen concentration in the first atmosphere is 0.01% or more and 100% or less. The method for manufacturing a semiconductor device according to claim 10 , wherein the first treatment is performed for a period of 15 minutes to 10 hours. The method for manufacturing a semiconductor device according to claim 10 , wherein the second treatment includes bonding nitrogen to silicon present in a region between the silicon carbide member and the first film.