JP2010129566A - Nitride semiconductor device, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nitride semiconductor device for inhibiting an increase in a leakage current via a buffer layer to prevent degradation of characteristics. <P>SOLUTION: The nitride semiconductor device has an insulator region 8A in an AlGaN layer 4. Thus, even if strain occurs in the buffer layer 2 due to heat, shock or the like to cause current to easily flow to the buffer layer 2, the insulator region 8A prevents the current from flowing as indicated by the dotted arrow (a) in Fig.1. Thus, the increase in the leakage current via the buffer layer 2 can be inhibited to prevent degradation in the characteristics. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a nitride semiconductor device such as a gallium nitride semiconductor device and a manufacturing method thereof.

  A nitride semiconductor device that has been developed in recent years is mainly a field effect transistor (FET).

  As shown in FIG. 13, an FET as an example of a conventional nitride semiconductor device includes a substrate 101 and a buffer layer 102, a GaN layer 103, and an AlGaN layer 104 that are sequentially stacked on the substrate 101. (Refer nonpatent literature 1).

With the buffer layer 102, the GaN layer 103 having a lattice different from that of the substrate 101 can be formed on the substrate 101. A source electrode 105, a drain electrode 106, and a gate electrode 107 are provided on the AlGaN layer 104.
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  However, in the conventional nitride semiconductor device, when distortion occurs in the buffer layer 102 due to heat, impact, or the like, the distortion of the buffer layer 102 makes it easier for current to flow through the buffer layer 102, as indicated by an arrow g. In addition, there is a problem that causes a leakage current. As a result, there is a problem in that the characteristics of the nitride semiconductor device are deteriorated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a nitride semiconductor device that suppresses an increase in leakage current through a buffer layer and prevents deterioration of characteristics.

In order to solve the above problems, a nitride semiconductor device of the present invention is
A substrate,
A buffer layer, a GaN layer, and an AlGaN layer stacked in order on this substrate,
It is characterized by having an insulator region in at least one of the GaN layer or the AlGaN layer.

  According to the nitride semiconductor device of the present invention, since at least one of the GaN layer or the AlGaN layer has an insulator region, the buffer layer is distorted by heat, impact, etc., and current easily flows through the buffer layer. However, by blocking the flow of current through the insulator region, an increase in leakage current through the buffer layer can be suppressed, and deterioration of characteristics can be prevented.

  In one embodiment, the nitride semiconductor device has a source electrode on the AlGaN layer, and the insulator region is located immediately below the source electrode.

  In one embodiment, the nitride semiconductor device has a source electrode and a gate electrode on the AlGaN layer, and the insulator region is formed on the gate electrode from directly below the source electrode in a direction parallel to the substrate. It is located in a region that extends directly below the part.

  According to the nitride semiconductor device of this embodiment, the insulator region is located in a region extending from directly below the source electrode to immediately below a part of the gate electrode in a direction parallel to the substrate. By forming the region up to the end of the gate electrode and raising the surface level, the channel directly under the gate electrode can be suppressed, and the movement of carriers from the source electrode can be suppressed.

  In one embodiment, the nitride semiconductor device has a drain electrode on the AlGaN layer, and the insulator region is located immediately below the drain electrode.

  In one embodiment, the nitride semiconductor device has a source electrode and a drain electrode on the AlGaN layer, and the insulator region is located immediately below the source electrode and immediately below the drain electrode.

  In the nitride semiconductor device according to one embodiment, the insulator region is located in the AlGaN layer.

  According to the nitride semiconductor device of this embodiment, since the insulator region is located in the AlGaN layer, ion implantation can be performed with low energy, and damage to the AlGaN layer can be suppressed.

  In the nitride semiconductor device according to one embodiment, the insulator region is located in the GaN layer.

  According to the nitride semiconductor device of this embodiment, since the insulator region is located in the GaN layer, the ion implantation amount can be made larger than in the case of implanting ions into the AlGaN layer, and the insulator region in the AlGaN layer. The effect of suppressing leakage current can be increased compared to the case of forming.

In addition, the method for manufacturing the nitride semiconductor device of the present invention includes:
A step of sequentially laminating a buffer layer, a GaN layer, and an AlGaN layer on the substrate;
And a step of forming an insulator region by implanting ions into at least one of the GaN layer or the AlGaN layer.

  According to the method for manufacturing a nitride semiconductor device of the present invention, since the method includes the step of implanting ions into at least one of the GaN layer or the AlGaN layer to form an insulator region, the buffer layer can be formed by heat or impact. Even if distortion occurs and current easily flows through the buffer layer, the current flow is blocked by the insulator region, whereby an increase in leakage current through the buffer layer can be suppressed and deterioration of characteristics can be prevented.

  According to the nitride semiconductor device of the present invention, since at least one of the GaN layer or the AlGaN layer has an insulator region, an increase in leakage current through the buffer layer can be suppressed and deterioration of characteristics can be prevented. .

  According to the method for manufacturing a nitride semiconductor device of the present invention, since it includes a step of implanting ions into at least one of the GaN layer or the AlGaN layer to form an insulator region, the leakage current through the buffer layer It is possible to prevent the deterioration of the characteristics by suppressing the increase of.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

(First embodiment)
FIG. 1 is a sectional view showing a first embodiment of the nitride semiconductor device of the present invention. This nitride semiconductor device 10A is a FET (Heterojunction Field Effect Transistor).

  The nitride semiconductor device 10 </ b> A includes a substrate 1 and a buffer layer 2, a GaN layer 3, and an AlGaN layer 4 that are sequentially stacked on the substrate 1.

  A source electrode 5, a drain electrode 6 and a gate electrode 7 are provided on the AlGaN layer 4. The gate electrode 7 is located between the source electrode 5 and the drain electrode 6 in a direction parallel to the substrate 1.

  The AlGaN layer 4 has an insulator region 8A. The insulator region 8A is located directly under the source electrode 5.

The type of the substrate 1 is, for example, any one of Si, Al ₂ O ₃ , SiC, and GaN. The kind of the buffer layer 2 is, for example, one in which GaN and AlN are alternately stacked. The buffer layer 2 alleviates the mismatch in lattice coupling between the base substrate 1 and the GaN layer 3.

  The ohmic metal for forming the source electrode 5 and the drain electrode 6 is a constituent metal mainly composed of a Ti / Al film, a Ti / Ni film, an Hf / Al film, and a Mo / Al film. Alternatively, the metal of the source electrode 5 and the drain electrode 6 in which different constituent metals are re-formed is W / Au, WN / Au, Ti / Au, Ni / Au.

The insulator region 8A is formed by implanting ions into the AlGaN layer 4. The type of this ion is, for example, O ₂ .

  Next, a method for manufacturing the nitride semiconductor device 10A having the above configuration will be described.

  As shown in FIG. 2A, the buffer layer 2, the GaN layer 3, and the AlGaN layer 4 are sequentially stacked on the substrate 1, and then the barrier layer 11 is formed on the AlGaN layer 4. This barrier layer 11 is opened only in a region where ion implantation is performed.

  Then, as shown in FIG. 2B, ions are implanted into the AlGaN layer 4 in the direction of arrow I to form an ion implantation region 9A in the AlGaN layer 4 as shown in FIG. 2C.

  Thereafter, the barrier layer 11 is removed, and the surface of the AlGaN layer 4 is covered with a protective film, and then heat treatment at 1100 ° C. or higher is performed. This protective film prevents damage on the surface of the AlGaN layer 4 due to heat treatment.

  By this heat treatment, ion activation of the ion implantation region 9A is performed, and an insulator region 8A is formed in the AlGaN layer 4 as shown in FIG. 2D. Thereafter, the source electrode 5, the drain electrode 6, and the gate electrode 7 are formed on the AlGaN layer 4 to manufacture the nitride semiconductor device 10A. The source electrode 5 is formed so as to be located immediately above the insulator region 8A.

  According to the nitride semiconductor device 10A having the above configuration and the method for manufacturing the same, since the AlGaN layer 4 has the insulator region 8A, the buffer layer 2 is distorted by heat, impact, etc., and current easily flows through the buffer layer 2. Even so, as indicated by the dotted arrow a in FIG. 1, the current flow is blocked by the insulator region 8A, thereby suppressing an increase in leakage current through the buffer layer 2 and preventing deterioration of characteristics. it can.

  Further, since the insulator region 8A is located in the AlGaN layer 4, ion implantation can be performed with low energy, and damage to the AlGaN layer 4 can be suppressed.

(Second Embodiment)
FIG. 3 shows a second embodiment of the nitride semiconductor device of the present invention. The difference from the first embodiment will be described. In the second embodiment, the position of the insulator region is different. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 3, the nitride semiconductor device 10 </ b> B of the second embodiment has an insulator region 8 </ b> B in the GaN layer 3. The insulator region 8B is located immediately below the source electrode 5.

The insulator region 8B is formed by implanting ions into the GaN layer 3. The type of ion is, for example, any of O ₂ , Mg, and B.

  Next, a method for manufacturing the nitride semiconductor device 10B having the above configuration will be described.

  As illustrated in FIG. 4A, the buffer layer 2, the GaN layer 3, and the AlGaN layer 4 are sequentially stacked on the substrate 1, and then the barrier layer 11 is formed on the AlGaN layer 4. This barrier layer 11 is opened only in a region where ion implantation is performed.

  Then, as shown in FIG. 4B, ions are implanted into the GaN layer 3 in the direction of arrow I to form an ion implantation region 9B in the GaN layer 3 as shown in FIG. 4C.

  Thereafter, the barrier layer 11 is removed, and the surface of the AlGaN layer 4 is covered with a protective film, and then heat treatment at 1100 ° C. or higher is performed. This protective film prevents damage on the surface of the AlGaN layer 4 due to heat treatment.

  By this heat treatment, ion activation of the ion implantation region 9B is performed, and an insulator region 8B is formed in the GaN layer 3 as shown in FIG. 4D. Thereafter, the source electrode 5, the drain electrode 6, and the gate electrode 7 are formed on the AlGaN layer 4 to manufacture the nitride semiconductor device 10B. The source electrode 5 is formed so as to be located immediately above the insulator region 8B.

  According to the nitride semiconductor device 10B having the above-described configuration and the manufacturing method thereof, since the GaN layer 3 has the insulator region 8B, the buffer layer 2 is distorted by heat, impact, etc., and current easily flows through the buffer layer 2. Even so, as indicated by the dotted arrow b in FIG. 3, the current flow is blocked by the insulator region 8B, thereby suppressing an increase in leakage current through the buffer layer 2 and preventing deterioration of characteristics. it can.

  Also, since the insulator region 8B is located in the GaN layer 3, the amount of ion implantation can be made larger than when ions are implanted into the AlGaN layer 4, and leakage occurs compared with the case where the insulator region is formed in the AlGaN layer 4. The current suppression effect can be increased.

(Third embodiment)
FIG. 5 shows a third embodiment of the nitride semiconductor device of the present invention. The difference from the first embodiment will be described. In the third embodiment, the position of the insulator region is different. In the third embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, the nitride semiconductor device 10 </ b> C of the third embodiment has an insulator region 8 </ b> C in the AlGaN layer 4. The insulator region 8 </ b> C is located in a region extending from directly below the source electrode 5 to just below a part of the gate electrode 7 in a direction parallel to the substrate 1.

The insulator region 8C is formed by implanting ions into the AlGaN layer 4. The type of this ion is, for example, O ₂ .

  Next, a method for manufacturing the nitride semiconductor device 10C having the above configuration will be described.

  As illustrated in FIG. 6A, the buffer layer 2, the GaN layer 3, and the AlGaN layer 4 are sequentially stacked on the substrate 1, and then the barrier layer 11 is formed on the AlGaN layer 4. This barrier layer 11 is opened only in a region where ion implantation is performed.

  Then, ions are implanted into the AlGaN layer 4 in the direction of arrow I as shown in FIG. 6B to form an ion implantation region 9C in the AlGaN layer 4 as shown in FIG. 6C.

  Thereafter, the barrier layer 11 is removed, and the surface of the AlGaN layer 4 is covered with a protective film, and then heat treatment at 1100 ° C. or higher is performed. This protective film prevents damage on the surface of the AlGaN layer 4 due to heat treatment.

  By this heat treatment, ion activation of the ion implantation region 9C is performed, and an insulator region 8C is formed in the AlGaN layer 4 as shown in FIG. 6D. Thereafter, the source electrode 5, the drain electrode 6, and the gate electrode 7 are formed on the AlGaN layer 4 to manufacture the nitride semiconductor device 10C. The source electrode 5 and a part of the gate electrode 7 are formed so as to be located immediately above the insulator region 8C.

  According to the nitride semiconductor device 10C having the above configuration and the method for manufacturing the same, since the AlGaN layer 4 has the insulator region 8C, the buffer layer 2 is distorted by heat, impact, etc., and current easily flows through the buffer layer 2. Even so, as shown by the dotted arrow c in FIG. 5, the current flow is blocked by the insulator region 8C, thereby suppressing an increase in leakage current through the buffer layer 2 and preventing deterioration of characteristics. it can.

  Further, since the insulator region 8C is located in a region extending from directly under the source electrode 5 to a portion directly under the gate electrode 7, the insulator region 8C is formed up to the end of the gate electrode 7 and the surface level is set. By raising, the channel directly under the gate electrode 7 can be suppressed, and the movement of carriers from the source electrode 5 can be suppressed.

  Further, since the insulator region 8C is located in the AlGaN layer 4, ion implantation can be performed with low energy, and damage to the AlGaN layer 4 can be suppressed.

(Fourth embodiment)
FIG. 7 shows a fourth embodiment of the nitride semiconductor device of the present invention. The difference from the first embodiment will be described. In the fourth embodiment, the position of the insulator region is different. Note that in the fourth embodiment, the same portions as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 7, the nitride semiconductor device 10 </ b> D of the fourth embodiment has an insulator region 8 </ b> D in the GaN layer 3. The insulator region 8 </ b> D is located in a region extending from directly below the source electrode 5 to a portion directly below the gate electrode 7 in a direction parallel to the substrate 1.

The insulator region 8D is formed by implanting ions into the GaN layer 3. The type of ion is, for example, any of O ₂ , Mg, and B.

  Next, a method for manufacturing the nitride semiconductor device 10D having the above configuration will be described.

  As illustrated in FIG. 8A, the buffer layer 2, the GaN layer 3, and the AlGaN layer 4 are sequentially stacked on the substrate 1, and then the barrier layer 11 is formed on the AlGaN layer 4. This barrier layer 11 is opened only in a region where ion implantation is performed.

  Then, as shown in FIG. 8B, ions are implanted into the GaN layer 3 in the direction of arrow I to form an ion implantation region 9D in the GaN layer 3 as shown in FIG. 8C.

  Thereafter, the barrier layer 11 is removed, and the surface of the AlGaN layer 4 is covered with a protective film, and then heat treatment at 1100 ° C. or higher is performed. This protective film prevents damage on the surface of the AlGaN layer 4 due to heat treatment.

  By this heat treatment, ion activation of the ion implantation region 9D is performed, and an insulator region 8D is formed in the GaN layer 3 as shown in FIG. 8D. Thereafter, the source electrode 5, the drain electrode 6, and the gate electrode 7 are formed on the AlGaN layer 4 to manufacture the nitride semiconductor device 10D. The source electrode 5 and a part of the gate electrode 7 are formed so as to be located immediately above the insulator region 8D.

  According to the nitride semiconductor device 10D having the above configuration and the method for manufacturing the same, since the GaN layer 3 has the insulator region 8D, the buffer layer 2 is distorted by heat, impact, etc., and current easily flows through the buffer layer 2. Even so, as indicated by the dotted arrow d in FIG. 7, the current flow is blocked by the insulator region 8D, thereby suppressing an increase in leakage current through the buffer layer 2 and preventing the deterioration of characteristics. it can.

  Further, since the insulator region 8D is located in a region extending from directly below the source electrode 5 to a portion directly below the gate electrode 7, the insulator region 8D is formed up to the end of the gate electrode 7, and the surface level is set. By raising, the channel directly under the gate electrode 7 can be suppressed, and the movement of carriers from the source electrode 5 can be suppressed.

  Further, since the insulator region 8D is located in the GaN layer 3, the amount of ion implantation can be increased as compared with the case where ions are implanted into the AlGaN layer 4, and the leakage region is larger than when the insulator region is formed in the AlGaN layer 4. The current suppression effect can be increased.

(Fifth embodiment)
FIG. 9 shows a fifth embodiment of the nitride semiconductor device of the present invention. The difference from the first embodiment will be described. In the fifth embodiment, the position of the insulator region is different. In the fifth embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 9, the nitride semiconductor device 10 </ b> E of the fifth embodiment has an insulator region 8 </ b> E in the GaN layer 3. The insulator region 8E is located immediately below the drain electrode 6.

The insulator region 8E is formed by implanting ions into the GaN layer 3. The type of ion is, for example, any of O ₂ , Mg, and B.

  Next, a method for manufacturing the nitride semiconductor device 10E having the above configuration will be described.

  As illustrated in FIG. 10A, the buffer layer 2, the GaN layer 3, and the AlGaN layer 4 are sequentially stacked on the substrate 1, and then the barrier layer 11 is formed on the AlGaN layer 4. This barrier layer 11 is opened only in a region where ion implantation is performed.

  Then, ions are implanted into the GaN layer 3 in the direction of arrow I as shown in FIG. 10B to form an ion implantation region 9E in the GaN layer 3 as shown in FIG. 10C.

  Thereafter, the barrier layer 11 is removed, and the surface of the AlGaN layer 4 is covered with a protective film, and then heat treatment at 1100 ° C. or higher is performed. This protective film prevents damage on the surface of the AlGaN layer 4 due to heat treatment.

  By this heat treatment, ion activation of the ion implantation region 9E is performed, and an insulator region 8E is formed in the GaN layer 3 as shown in FIG. 10D. Thereafter, the source electrode 5, the drain electrode 6, and the gate electrode 7 are formed on the AlGaN layer 4 to manufacture the nitride semiconductor device 10E. The drain electrode 6 is formed so as to be located immediately above the insulator region 8E.

  According to the nitride semiconductor device 10E having the above configuration and the manufacturing method thereof, since the GaN layer 3 has the insulator region 8E, the buffer layer 2 is distorted by heat, impact, or the like, and current easily flows through the buffer layer 2. Even so, as indicated by the dotted arrow e in FIG. 9, the current flow is blocked by the insulator region 8E, thereby suppressing an increase in leakage current through the buffer layer 2 and preventing deterioration of characteristics. it can.

  Further, since the insulator region 8E is located in the GaN layer 3, the amount of ion implantation can be made larger than when ions are implanted into the AlGaN layer 4, and leakage occurs compared with the case where the insulator region is formed in the AlGaN layer 4. The current suppression effect can be increased.

(Sixth embodiment)
FIG. 11 shows a sixth embodiment of the nitride semiconductor device of the present invention. The difference from the first embodiment will be described. In the sixth embodiment, the position of the insulator region is different. Note that in the sixth embodiment, the same portions as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in FIG. 11, in the nitride semiconductor device 10F of the sixth embodiment, the GaN layer 3 has insulator regions 8F ₁ and 8F ₂ . The first insulator region 8F ₁ is directly below the drain electrode 6 is located. The second insulator region 8F ₂ is directly below the source electrode 5, are located.

The insulator regions 8F ₁ and 8F ₂ are formed by implanting ions into the GaN layer 3. The type of ion is, for example, any of O ₂ , Mg, and B.

  Next, a method for manufacturing the nitride semiconductor device 10F having the above configuration will be described.

  As illustrated in FIG. 12A, the buffer layer 2, the GaN layer 3, and the AlGaN layer 4 are sequentially stacked on the substrate 1, and then the barrier layer 11 is formed on the AlGaN layer 4. This barrier layer 11 is opened only in a region where ion implantation is performed.

Then, as shown in FIG. 12B, ions are implanted into the GaN layer 3 in the direction of arrow I. As shown in FIG. 12C, the first ion implantation region 9F ₁ and the second ion implantation region GaN are injected into the GaN layer 3. forming an ion implantation region 9F _2. First ion implantation region 9F ₁ and the second ion implantation region 9F ₂ is in a position spaced apart.

  Thereafter, the barrier layer 11 is removed, and the surface of the AlGaN layer 4 is covered with a protective film, and then heat treatment at 1100 ° C. or higher is performed. This protective film prevents damage on the surface of the AlGaN layer 4 due to heat treatment.

By this heat treatment, ion implantation regions 9F ₁ and 9F ₂ are ion-activated, and insulator regions 8F ₁ and 8F ₂ are formed in the GaN layer 3 as shown in FIG. 12D. The first insulator region 8F ₁ and the second insulator region 8F ₂ is in a position spaced apart. Thereafter, the source electrode 5, the drain electrode 6, and the gate electrode 7 are formed on the AlGaN layer 4 to manufacture the nitride semiconductor device 10F. The drain electrode 6, so as to be positioned directly above the first insulator region 8F _1, is formed. The source electrode 5, so as to be positioned directly above the second insulator regions 8F _2, is formed.

According to the nitride semiconductor device 10F having the above configuration and the manufacturing method thereof, since the GaN layer 3 has the insulator regions 8F ₁ and 8F ₂ , the buffer layer 2 is distorted by heat, impact, etc. even when the current becomes easy to flow, as indicated by the arrow f ₁ in dotted lines in FIG. 11, with the first insulator region 8F ₁ prevents the flow of current, as indicated by the arrow f ₂ of dotted lines in FIG. 11 to, by blocking the flow of the second through the insulator region 8F ₂ current, by suppressing the increase in leakage current through the buffer layer 2 can prevent deterioration of the characteristics.

Further, since the insulator regions 8F ₁ and 8F ₂ are located in the GaN layer 3, the ion implantation amount can be made larger than when ions are implanted into the AlGaN layer 4, and the insulator region is formed in the AlGaN layer 4. As a result, the effect of suppressing the leakage current can be increased.

  In addition, this invention is not limited to the above-mentioned embodiment. For example, you may make it have an insulator area | region in both a GaN layer and an AlGaN layer. In this case, the amount of ion implantation into the GaN layer is preferably larger than the amount of ion implantation into the AlGaN layer.

It is sectional drawing which shows 1st Embodiment of the nitride semiconductor device of this invention. FIG. 7 is a cross-sectional view showing a first step of the method for manufacturing the nitride semiconductor device of FIG. 1. FIG. 7 is a cross-sectional view showing a second step of the method for manufacturing the nitride semiconductor device of FIG. 1. FIG. 7 is a cross-sectional view showing a third step of the method for manufacturing the nitride semiconductor device of FIG. 1. FIG. 8 is a cross-sectional view showing a fourth step of the method for manufacturing the nitride semiconductor device in FIG. 1. It is sectional drawing which shows 2nd Embodiment of the nitride semiconductor device of this invention. FIG. 4 is a cross-sectional view showing a first step of the method for manufacturing the nitride semiconductor device of FIG. 3. FIG. 4 is a cross-sectional view showing a second step of the method for manufacturing the nitride semiconductor device of FIG. 3. FIG. 6 is a cross-sectional view showing a third step of the method for manufacturing the nitride semiconductor device of FIG. 3. FIG. 6 is a cross-sectional view showing a fourth step of the method for manufacturing the nitride semiconductor device of FIG. 3. It is sectional drawing which shows 3rd Embodiment of the nitride semiconductor device of this invention. FIG. 6 is a cross-sectional view showing a first step of the method for manufacturing the nitride semiconductor device of FIG. 5. FIG. 6 is a cross-sectional view showing a second step of the method for manufacturing the nitride semiconductor device of FIG. 5. FIG. 6 is a cross-sectional view showing a third step of the method for manufacturing the nitride semiconductor device of FIG. 5. FIG. 6 is a cross-sectional view showing a fourth step of the method for manufacturing the nitride semiconductor device of FIG. 5. It is sectional drawing which shows 4th Embodiment of the nitride semiconductor device of this invention. FIG. 8 is a cross-sectional view showing a first step of the method for manufacturing the nitride semiconductor device of FIG. 7. FIG. 8 is a cross-sectional view showing a second step of the method for manufacturing the nitride semiconductor device of FIG. 7. FIG. 8 is a cross-sectional view showing a third step of the method for manufacturing the nitride semiconductor device of FIG. 7. FIG. 8 is a cross-sectional view showing a fourth step of the method for manufacturing the nitride semiconductor device of FIG. 7. It is sectional drawing which shows 5th Embodiment of the nitride semiconductor device of this invention. FIG. 10 is a cross-sectional view showing a first step of the method for manufacturing the nitride semiconductor device of FIG. 9. FIG. 10 is a cross-sectional view showing a second step of the method for manufacturing the nitride semiconductor device of FIG. 9. FIG. 10 is a cross-sectional view showing a third step of the method for manufacturing the nitride semiconductor device of FIG. 9. FIG. 10 is a cross-sectional view showing a fourth step of the method for manufacturing the nitride semiconductor device of FIG. 9. It is sectional drawing which shows 6th Embodiment of the nitride semiconductor device of this invention. FIG. 12 is a cross-sectional view showing a first step of the method for manufacturing the nitride semiconductor device of FIG. 11. FIG. 12 is a cross-sectional view showing a second step of the method for manufacturing the nitride semiconductor device of FIG. 11. FIG. 12 is a cross-sectional view showing a third step of the method for manufacturing the nitride semiconductor device of FIG. 11. FIG. 12 is a cross-sectional view showing a fourth step of the method for manufacturing the nitride semiconductor device of FIG. 11. It is sectional drawing which shows the conventional nitride semiconductor device.

Explanation of symbols

1 substrate 2 buffer layer 3 GaN layer 4 AlGaN layer 5 source electrode 6 drain electrode 7 gate electrodes 8A-8F _1, 8F ₂ insulator regions 9A-9F _1, 8F ₂ ion implantation region 10A~10F nitride semiconductor device 11 barrier layer

Claims (8)

A substrate,
A buffer layer, a GaN layer, and an AlGaN layer stacked in order on this substrate,
A nitride semiconductor device having an insulator region in at least one of the GaN layer or the AlGaN layer. The nitride semiconductor device according to claim 1,
A source electrode on the AlGaN layer;
The nitride semiconductor device, wherein the insulator region is located immediately below the source electrode. The nitride semiconductor device according to claim 1,
A source electrode and a gate electrode on the AlGaN layer;
The nitride semiconductor device, wherein the insulator region is located in a region extending from directly below the source electrode to immediately below a part of the gate electrode in a direction parallel to the substrate. The nitride semiconductor device according to claim 1,
Having a drain electrode on the AlGaN layer;
The nitride semiconductor device, wherein the insulator region is located immediately below the drain electrode. The nitride semiconductor device according to claim 1,
A source electrode and a drain electrode on the AlGaN layer;
The nitride semiconductor device according to claim 1, wherein the insulator region is located immediately below the source electrode and immediately below the drain electrode. In the nitride semiconductor device according to any one of claims 1 to 3,
The nitride semiconductor device, wherein the insulator region is located in the AlGaN layer. The nitride semiconductor device according to any one of claims 1 to 5,
The nitride semiconductor device, wherein the insulator region is located in the GaN layer. A step of sequentially laminating a buffer layer, a GaN layer, and an AlGaN layer on the substrate;
And a step of forming an insulator region by implanting ions into at least one of the GaN layer or the AlGaN layer.

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