JP5759398B2 - Diamond field effect transistor and method for producing the same - Google Patents

Description

  The present invention relates to a diamond field effect transistor and a manufacturing method thereof.

  Diamond has the highest thermal conductivity in the material. Diamond also has a high breakdown field and a high carrier velocity. For this reason, field effect transistors using diamond are expected to operate at high currents even in high temperature environments, which cannot be realized in principle by field effect transistors using existing materials such as Si and GaAs.

  However, in a diamond field effect transistor using a hole conduction layer generated by the formation of an adsorption layer of atmospheric molecules on the hydrogen-terminated diamond surface, the operating current is small because the hole density that can be induced is low. Furthermore, there is a problem in that the hole density decreases because the adsorption layer is desorbed from the surface in a high temperature and vacuum environment. For this reason, it is extremely difficult to produce a diamond field effect transistor that operates with a large current even in a high temperature environment.

  A conventional diamond field effect transistor will be described below. FIG. 1 is a diagram illustrating a process for producing a diamond field effect transistor using a hole conduction layer according to the prior art.

  First, as shown in FIG. 1A, the surface of the diamond substrate 100 is terminated with hydrogen by hydrogen radicals to form a surface layer 102 containing hydrogen. Next, by exposing the surface layer 102 to the atmosphere, an adsorption layer 104 made of molecules in the atmosphere is formed on the surface layer 102 (FIG. 1B). Next, as shown in FIG. 1C, a metal film to be the source electrode 106 and a gold thin film to be the drain electrode 108 are formed on the surface of the adsorption layer 104 in spatially separated regions. Next, as illustrated in FIG. 1D, a gate electrode 110 is formed in a spatially separated region between the source electrode 106 and the drain electrode 108.

FIG. 2 shows drain current-voltage characteristics of the diamond field effect transistor prepared by the process shown in FIG. Since the maximum hole density induced on the diamond surface is as low as about 1 × 10 ¹³ cm ⁻² , the diamond field effect transistor produced by the conventional technique cannot be operated with a large drain current of 100 mA / mm or more.

  FIG. 3 is a graph showing the relationship between the sample temperature in vacuum and the maximum drain current in the diamond field effect transistor sample prepared by the process shown in FIG. When the sample temperature rises, the drain current decreases monotonously, and when the sample temperature exceeds 300 ° C., the drain current decreases dramatically. Therefore, when the sample temperature exceeds 300 ° C., the transistor operation itself cannot be obtained. This is because the adsorption layer is desorbed from the surface of the sample and the hole density of the hole conduction layer is very low.

  In the following description of the present specification, the sample temperature at which the transistor operation cannot be obtained is referred to as Tc. Once the sample temperature exceeds Tc, the drain current does not return even if the sample temperature is lowered again (see Non-Patent Document 1 and Non-Patent Document 2).

J.U. Ristein, F. Maier, M. Riedel, M. Stammer, and L. Ley, Diamond and Related Materials 416-422 (2001). M. Kubovic, Y. Yamauchi, M. Kasu, “Improvements in Thermal Stability of Hydrogen-terminated Diamond FETs”, Extended Abstract of the 2008 International Conference on Solid State Devices and Materials, Tsukuba, 2008, pp. 1036-1037.

  The first object of the present invention is to solve the problem that the drain current of a diamond field effect transistor is low and to provide a structure of a diamond field effect transistor capable of operating at a large current.

  A second object of the present invention is to solve the problem that a diamond field effect transistor cannot operate in a high temperature environment and to provide a structure of the diamond field effect transistor that can operate in a high temperature environment.

A first aspect of the present invention is a diamond field effect transistor comprising a diamond substrate, a surface layer formed by terminating the surface of the diamond substrate with hydrogen atoms, and a surface layer exposed to the atmosphere. formed on the layer, a first adsorption layer comprising a molecule in the air, formed apart from each other in the first adsorption layer, a source electrode and a drain electrode, the source electrode and the drain electrode A second adsorption layer composed of NO ₂ molecules formed so as to cover the entire upper part of the first adsorption layer, and a protection composed of an oxygen-containing compound formed on the second adsorption layer. and a layer, on the protective layer, which is formed spaced apart between the source electrode and the drain electrode, characterized in that a gate electrode.

The second aspect of the present invention includes a diamond substrate, a surface layer formed by terminating the surface of the diamond substrate with hydrogen atoms, and an atmosphere formed on the surface layer by exposing the surface layer to the atmosphere. A first adsorbing layer comprising molecules therein, a source electrode and a drain electrode formed on the first adsorbing layer and spaced apart from each other, and a first adsorbing layer exposed between the source electrode and the drain electrode A second adsorbing layer made of NO ₂ molecules formed so as to cover the entire upper part of the electrode, and a gate electrode and a source electrode formed on the second adsorbing layer apart from the source electrode and the drain electrode the exposed between the drain electrode, is formed to cover the second adsorption layer and the gate electrodes, characterized in that it comprises a protective layer made of a compound containing oxygen and.

A third aspect of the present invention is a diamond field effect transistor comprising a diamond substrate, a surface layer formed by terminating the surface of the diamond substrate with hydrogen atoms, and a surface layer exposed to the atmosphere. formed on the layer, a first adsorption layer comprising a molecule in the atmosphere, is formed on the first adsorption layer, and the second adsorption layer consisting of NO ₂ molecules, the second adsorption layer formed apart from each other, and a source conductive Goku及 beauty drain electrode, exposed between the source electrode and the drain electrode, which is formed so as to cover the entire upper portion of the second adsorption layer, a compound containing oxygen And a gate electrode formed on the protective layer at a distance from the source electrode and the drain electrode .

According to a fourth aspect of the present invention, there is provided a diamond substrate, a surface layer formed by terminating the surface of the diamond substrate with hydrogen atoms, and an atmosphere formed on the surface layer by exposing the surface layer to the atmosphere. A first adsorption layer composed of the following molecules; a second adsorption layer composed of NO ₂ molecules formed on the first adsorption layer; a source electrode formed on the second adsorption layer and spaced apart from each other; Exposed between the drain electrode, the gate electrode formed on the second adsorption layer so as to be separated between the source electrode and the drain electrode, between the source electrode and the gate electrode, and between the gate electrode and the drain electrode It is characterized by comprising a second adsorbing layer and a protective layer made of a compound containing oxygen and formed so as to cover the entire upper part of the gate electrode.

A fifth aspect of the present invention is a method for producing a diamond field effect transistor, comprising the steps of forming a surface layer by terminating the surface of the diamond substrate with hydrogen atoms, and exposing the surface layer to the atmosphere to expose the surface layer to the atmosphere. in forming a first adsorption layer comprising a molecule in the air, forming a source electrode and a drain electrode spaced apart from each other in the first adsorption layer, between the source electrode and the drain electrode so as to cover the first adsorption layer exposed, and forming and forming a second adsorption layer consisting of NO ₂ molecules, the second adsorbent layer, a protective layer made of a compound containing oxygen, Forming a gate electrode on the second adsorption layer so as to be spaced between the source electrode and the drain electrode.

A sixth aspect of the present invention is a method for producing a diamond field effect transistor, comprising the steps of forming a surface layer by terminating the surface of the diamond substrate with hydrogen atoms, and exposing the surface layer to the atmosphere. forming a forming a first adsorption layer comprising a molecule in the atmosphere, so as to cover the first adsorption layer on the second adsorption layer consisting of NO ₂ molecules, the second adsorption layer Forming a source electrode and a drain electrode spaced apart from each other; and forming a protective layer made of a compound containing oxygen so as to cover the second adsorption layer exposed between the source electrode and the drain electrode. And a step of forming a gate electrode on the second adsorption layer so as to be spaced between the source electrode and the drain electrode.

  According to the present invention, a practical diamond field effect transistor having a high maximum operating temperature can be produced. Further, according to the present invention, a practical diamond field effect transistor having a high maximum drain current can be produced.

It is a figure which shows the creation process of the diamond field effect transistor which concerns on a prior art. It is a graph which shows the drain current voltage characteristic of the diamond field effect transistor which concerns on a prior art. It is a graph which shows the relationship between the sample temperature of the diamond field effect transistor which concerns on a prior art, and maximum drain current. It is a figure which shows the creation process of the diamond field effect transistor which concerns on the 1st Embodiment of this invention. It is a graph which shows the drain current voltage characteristic of the diamond field effect transistor which concerns on the 1st Embodiment of this invention. It is a graph which shows the relationship between the sample temperature of the diamond field effect transistor which concerns on the 1st Embodiment of this invention, and the maximum drain current. It is a figure which shows the structure of the diamond field effect transistor which concerns on the 2nd Embodiment of this invention. It is a figure which shows the creation process of the diamond field effect transistor which concerns on the 3rd Embodiment of this invention. It is a graph which shows the drain current voltage characteristic of the diamond field effect transistor which concerns on the 3rd Embodiment of this invention. It is a graph which shows the relationship between the sample temperature of the diamond field effect transistor which concerns on the 3rd Embodiment of this invention, and a maximum drain current. It is a figure which shows the structure of the diamond field effect transistor which concerns on the 4th Embodiment of this invention.

The diamond field effect transistor according to the present invention includes (1) an adsorption layer (referred to as a second adsorption layer) composed of NO ₂ molecules so that the drain-source adsorption layer (referred to as a first adsorption layer) is not exposed. And (2) further comprising a protective layer made of a compound containing oxygen so that the first adsorption layer and the second adsorption layer between the drain and the source are not exposed.

By forming a second adsorption layer consisting of NO ₂ molecules so that the first adsorption layer between the drain and source is not exposed, the hole density of the hole conduction layer compared to the case of the first adsorption layer alone Increases about 5 to 10 times. Therefore, the resistance between the drain and the source of the diamond field effect transistor is reduced to about 1/5 to 1/10 times, and a drain current greatly exceeding that of the conventional device can be obtained.

  By forming a protective layer made of a compound containing oxygen so that the first adsorption layer and the second adsorption layer between the drain and the source are not exposed, the surface layer of the first adsorption layer and the second adsorption layer is formed. Can be prevented from being detached. Therefore, a high drain current can be obtained even at a high temperature.

  By having both the configuration (1) and the configuration (2), a large current operation of 100 mA / mm or more can be maintained even at a high temperature of 300 ° C. or higher, which could not be achieved by the transistor operation of the conventional device.

The structure of the diamond field effect transistor according to the present invention is that the second adsorption layer made of NO ₂ molecules is formed, the second adsorption layer completely covers the drain and source, and the second This is different from the prior art in that a protective layer containing oxygen is formed on the adsorption layer and that the protective layer completely covers the second adsorption layer between the drain and the source.

(First embodiment)
FIG. 4 shows a process for producing a diamond field effect transistor according to the first embodiment of the present invention. First, the surface of the diamond substrate 400 is terminated with hydrogen by irradiating the surface of the diamond substrate 400 with hydrogen radicals to form a surface layer 402 containing hydrogen (FIG. 4A). Next, by exposing the surface layer 402 to the atmosphere, a first adsorption layer 404 made of molecules including any of hydrogen, nitrogen, and oxygen is formed on the surface layer 402 (FIG. 4B). . Next, a metal film to be the source electrode 406 and a gold thin film to be the drain electrode 408 are formed on the first adsorption layer 404 in a spatially separated region (FIG. 4C). The gold thin film is formed by resistance heating vapor deposition. Next, the sample is set in a stainless steel chamber, and 2% NO ₂ gas diluted with N ₂ gas is introduced for 30 minutes, so that the first adsorption layer is formed between the source electrode 406 and the drain electrode 408. A second adsorption layer 410 made of NO ₂ molecules is formed on 404 (FIG. 4D). After the formation of the second adsorption layer 410, Al ₂ O ₃ is formed as a protective layer 412 as a compound containing oxygen. The thickness of the protective layer 412 is 8 nm. Al ₂ O ₃ was grown using atomic layer deposition (ALD) (FIG. 4E). Trimethylaluminum (TMA), which is an Al raw material, and H ₂ O, which is an O raw material, were introduced into the ALD apparatus using an N ₂ carrier gas. The sample temperature during the growth of the protective layer is 80 ° C. Finally, a gate electrode 414 is formed on a spatially separated region between the source electrode 406 and the drain electrode 408 and on the Al ₂ O ₃ protective layer 412 (FIG. 4F).

In the above example, Al ₂ O ₃ is used as the compound protective layer containing oxygen, but the same applies when using HfO, SiO ₂ , SrTiO ₃ , Ga ₂ O ₃ , LiNbO ₃ , LaAlO ₃ , or PZT. Through the steps, the diamond field effect transistor according to the present embodiment can be produced. In the above example, ALD is used as a method for growing a compound protective layer containing oxygen, but when using molecular beam epitaxy (MBE), the diamond field effect transistor according to this embodiment is obtained through the same process. Can be created.

FIG. 5 shows drain current-voltage characteristics of a diamond field effect transistor having a _second adsorption layer containing NO ₂ molecules and an Al ₂ O ₃ protective layer according to this embodiment. A large current operation with a drain current of 1000 mA / mm was obtained at room temperature, and according to the present invention, the drain current was increased 10 times that of the conventional device.

  FIG. 6 shows the relationship between the sample temperature of the diamond field effect transistor according to the present embodiment and the drain current. The diamond field effect transistor according to the present embodiment has a Tc of 600 ° C., and can be operated at a high temperature of 300 ° C. or higher, which cannot be realized with a conventional device. In addition, the drain current is 800 mA / mm or more at a temperature lower than Tc, and it is possible to maintain a large current operation of 8 times or more compared with the conventional device even at a high temperature of 300 ° C. or higher, which could not be achieved by the transistor operation of the conventional device.

  Table 1 summarizes the maximum drain current and the maximum operating temperature Tc in the diamond field effect transistor according to the present embodiment. The maximum drain current was evaluated at a sample temperature of 30 ° C.

In the diamond field effect transistor according to the present embodiment, HfO, SiO ₂ , SrTiO ₃ , Ga ₂ O ₃ , LiNbO ₃ , LaAlO ₃ , or PZT is used for the protective layer, and ALD or MBE is used as a growth method. The relationship between the maximum drain current and Tc is the same as the result shown in Table 1, and is greatly improved over the conventional method (100 mA / mm, 300 ° C.).

  In the present embodiment, the growth temperature of the protective layer has been described as 80 ° C. However, when the growth temperature of the protective layer is 350 ° C. or less, the same results as those shown in Table 1 were obtained.

(Second Embodiment)
FIG. 7 shows the structure of a diamond field effect transistor according to the second embodiment of the present invention.

A process for producing a diamond field effect transistor according to the present embodiment will be described below. First, the surface of the diamond substrate 700 is terminated with hydrogen by irradiating the surface of the diamond substrate 700 with hydrogen radicals, and a surface layer 702 containing hydrogen is formed. Next, the surface layer 702 is exposed to the atmosphere, whereby the first adsorption layer 704 made of molecules including any of hydrogen, nitrogen, and oxygen is formed on the surface layer 702. Next, a metal film to be the source electrode 706 and a gold thin film to be the drain electrode 708 are formed on the first adsorption layer 704 in spatially separated regions. The gold thin film is formed by resistance heating vapor deposition. Next, the sample is set in a stainless steel chamber, and 2% concentration of NO ₂ gas diluted with N ₂ gas is introduced for 30 minutes, so that the first adsorption layer is formed between the source electrode 706 and the drain electrode 708. A second adsorption layer 710 made of NO ₂ molecules is formed on 704. After the formation of the second adsorption layer 710, a gate electrode 714 is formed on the second adsorption layer 710 in a spatially separated region between the source electrode 706 and the drain electrode 708. Finally, Al ₂ O ₃ is formed as a protective layer 714 as a compound containing oxygen.

  In the production process of the present embodiment, the steps from (a) to (d) of the embodiment shown in FIG. 4 are the same, but the first embodiment is that a protective layer is formed after the gate electrode is formed. And different.

In the diamond field effect transistor according to this embodiment, when the protective layer is Al ₂ O ₃ and the growth method is ALD, the maximum drain current is 1000 mA / mm and Tc is 540 ° C. The maximum drain current is the same as in the first embodiment. Compared to the first embodiment, Tc is 10% lower than the first embodiment because there is no protective layer between the gate electrode and the second adsorption layer, but much more than the conventional method (100 mA / mm, 300 ° C). To rise.

(Third embodiment)
FIG. 8 shows a production process of a diamond field effect transistor according to the third embodiment of the present invention. First, the surface of the diamond substrate 800 is terminated with hydrogen by irradiating the surface of the diamond substrate 800 with hydrogen radicals, thereby forming a surface layer 802 containing hydrogen (FIG. 8A). Next, by exposing the surface layer 802 to the atmosphere, a first adsorption layer 804 made of molecules containing any one of hydrogen, nitrogen, and oxygen is formed on the surface layer 802 (FIG. 8B). . Next, the sample is set in a stainless steel chamber, and NO ₂ gas having a concentration of 2% diluted with N ₂ gas is introduced for 30 minutes, so that the second adsorption composed of NO ₂ molecules is formed on the first adsorption layer 804. A layer 806 is formed (FIG. 8C). Next, a metal film to be the source electrode 808 and a metal film to be the drain electrode 810 are formed on the second adsorption layer 806 in a spatially separated region (FIG. 8D). The gold thin film is formed by resistance heating vapor deposition. Next, Al ₂ O ₃ is formed as a protective layer 812 as a compound containing oxygen between the source electrode 808 and the drain electrode 810 and on the second adsorption layer 806. The thickness of the protective layer 812 is 8 nm. Al ₂ O ₃ was grown using atomic layer deposition (ALD) (FIG. 8 (e)). Trimethylaluminum (TMA), which is an Al raw material, and H ₂ O, which is an O raw material, were introduced into the ALD apparatus using an N ₂ carrier gas. The sample temperature during the growth of the protective layer is 80 ° C. Finally, a gate electrode 814 is formed on a spatially separated region between the source electrode 808 and the drain electrode 810 and on the Al ₂ O ₃ protective layer 812 (FIG. 8F).

In the above example, Al ₂ O ₃ is used as the compound protective layer containing oxygen, but the same applies when using HfO, SiO ₂ , SrTiO ₃ , Ga ₂ O ₃ , LiNbO ₃ , LaAlO ₃ , or PZT. Through the steps, the diamond field effect transistor according to the present embodiment can be produced. In the above example, ALD is used as a method for growing a compound protective layer containing oxygen, but when using molecular beam epitaxy (MBE), the diamond field effect transistor according to this embodiment is obtained through the same process. Can be created.

FIG. 9 shows drain current-voltage characteristics of a diamond field effect transistor having a _second adsorption layer containing NO ₂ molecules and an Al ₂ O ₃ protective layer according to this embodiment. A large current operation with a drain current of 1100 mA / mm was obtained at room temperature, and according to the present invention, the drain current increased to 11 times that of the conventional device. This is because the hole density of the hole conduction layer immediately below the source electrode and the drain electrode is increased and the contact resistance is reduced.

  FIG. 10 shows the relationship between the sample temperature and the drain current of the diamond field effect transistor according to this embodiment. The diamond field effect transistor according to the present embodiment has a Tc of 600 ° C., and can be operated at a high temperature of 300 ° C. or higher, which cannot be realized with a conventional device. In addition, the drain current is 850 mA / mm or more at a temperature lower than Tc, and a current operation that is 8 times or more that of the conventional device can be maintained even at a high temperature of 300 ° C. or higher, where the transistor operation cannot be obtained with the conventional device.

  Table 2 summarizes the maximum drain current and the maximum operating temperature Tc in the diamond field effect transistor according to the present embodiment. The maximum drain current was evaluated at a sample temperature of 30 ° C.

In the diamond field effect transistor according to the present embodiment, HfO, SiO ₂ , SrTiO ₃ , Ga ₂ O ₃ , LiNbO ₃ , LaAlO ₃ , or PZT is used for the protective layer, and ALD or MBE is used as a growth method. The relationship between the maximum drain current and Tc is the same as the result shown in Table 2, which is a significant improvement over the conventional method (100 mA / mm, 300 ° C.).

  In the present embodiment, the growth temperature of the protective layer is described as 80 ° C., but when the growth temperature of the protective layer is 350 ° C. or less, the same results as those shown in Table 2 were obtained. Compared with the first embodiment, the maximum drain current is increased by reducing the contact resistance, but the same value of Tc was obtained.

(Fourth embodiment)
FIG. 11 shows the structure of a diamond field effect transistor according to the fourth embodiment of the present invention.

A process for producing a diamond field effect transistor according to the present embodiment will be described below. First, the surface of the diamond substrate 1100 is terminated with hydrogen by irradiating the surface of the diamond substrate 1100 with hydrogen radicals, and a surface layer 1102 containing hydrogen is formed. Next, the surface layer 1102 is exposed to the atmosphere, whereby the first adsorption layer 1104 made of molecules containing any of hydrogen, nitrogen, and oxygen is formed on the surface layer 1102. Next, the sample is set in a stainless steel chamber, and NO ₂ gas having a concentration of 2% diluted with N ₂ gas is introduced for 30 minutes, so that the second adsorption composed of NO ₂ molecules is formed on the first adsorption layer 1104. Layer 1106 is formed. Next, a metal film to be the source electrode 1108 and a metal film to be the drain electrode 1110 are formed over the second adsorption layer 1106 in a spatially separated region. The gold thin film is formed by resistance heating vapor deposition. Next, the gate electrode 1112 is formed between the source electrode 1108 and the drain electrode 1110 and on the second adsorption layer 1106. Finally, Al ₂ O ₃ is formed as a protective layer 1114 as a compound containing oxygen.

  In the creation process of the present embodiment, the processes from (a) to (d) in the embodiment shown in FIG. 8 are the same, but the third embodiment is that a protective layer is formed after the gate electrode is formed. And different.

In the diamond field effect transistor according to this embodiment, when the protective layer is Al ₂ O ₃ and the growth method is ALD, the maximum drain current is 1100 mA / mm and Tc is 540 ° C. The maximum drain current is the same as in the third embodiment. Compared with the third embodiment, Tc is 10% lower than that of the third embodiment because there is no protective layer between the gate electrode and the second adsorption layer, but much more than with the conventional method (100 mA / mm, 300 ° C). To rise.

100 Diamond substrate 102 Surface layer 104 Adsorption layer 106 Source electrode 108 Drain electrode 110 Gate electrode

400 Diamond substrate 402 Surface layer 404 First adsorption layer 406 Source electrode 408 Drain electrode 410 Second adsorption layer 412 Protective layer 414 Gate electrode

700 Diamond substrate 702 Surface layer 704 First adsorption layer 706 Source electrode 708 Drain electrode 710 Second adsorption layer 712 Gate electrode 714 Protective layer

800 Diamond substrate 802 Surface layer 804 First adsorption layer 806 Second adsorption layer 808 Source electrode 810 Drain electrode 812 Protective layer 814 Gate electrode

1100 Diamond substrate 1102 Surface layer 1104 First adsorption layer 1106 Second adsorption layer 1108 Source electrode 1110 Drain electrode 1112 Gate electrode 1114 Protective layer

Claims (6)

A diamond substrate;
A surface layer formed by terminating the surface of the diamond substrate with hydrogen atoms;
A first adsorption layer made of molecules in the atmosphere formed on the surface layer by exposing the surface layer to the atmosphere ;
Formed spaced apart from each other in the first adsorption layer, a source electrode and a drain electrode,
Exposed between the source electrode and the front Symbol drain electrode, which is formed so as to cover the entire upper portion of the first adsorption layer, and a second adsorbent layer consisting of NO ₂ molecules,
A protective layer made of a compound containing oxygen, formed on the second adsorption layer;
Wherein on the protective layer, the formed spaced apart between the source electrode and the drain electrode, the diamond field effect transistor comprising the gate electrode. A diamond substrate;
A surface layer formed by terminating the surface of the diamond substrate with hydrogen atoms;
A first adsorption layer made of molecules in the atmosphere formed on the surface layer by exposing the surface layer to the atmosphere;
A source electrode and a drain electrode formed on the first adsorption layer so as to be spaced apart from each other;
The formed to cover the entire top of the exposed said first adsorption layer between the source electrode and the drain electrode, and the second adsorption layer consisting of NO ₂ molecules,
A gate electrode formed on the second adsorption layer and spaced apart from the source electrode and the drain electrode;
Exposed between the source electrode and the drain electrode, the second is formed to cover the adsorbent layer and the gate electrodes, and a protective layer made of a compound containing oxygen
Features and to holder Iyamondo field effect transistor further comprising a. A diamond substrate;
A surface layer formed by terminating the surface of the diamond substrate with hydrogen atoms;
A first adsorption layer made of molecules in the atmosphere formed on the surface layer by exposing the surface layer to the atmosphere ;
Formed in said first adsorption layer, and the second adsorption layer consisting of NO ₂ molecules,
The formed apart from each other in the second adsorbent layer, and a source conductive Goku及 beauty drain electrode,
A protective layer made of a compound containing oxygen and formed between the source electrode and the drain electrode so as to cover the entire upper part of the second adsorption layer;
A diamond field effect transistor comprising: a gate electrode formed on the protective layer and spaced apart from the source electrode and the drain electrode . A diamond substrate;
A surface layer formed by terminating the surface of the diamond substrate with hydrogen atoms;
A first adsorption layer made of molecules in the atmosphere formed on the surface layer by exposing the surface layer to the atmosphere;
A second adsorption layer made of NO ₂ molecules formed on the first adsorption layer;
A source electrode and a drain electrode formed on the second adsorption layer so as to be spaced apart from each other;
A gate electrode formed on the second adsorption layer so as to be separated between the source electrode and the drain electrode;
A compound containing oxygen formed so as to cover the entire upper part of the second adsorbing layer exposed between the source electrode and the gate electrode and between the gate electrode and the drain electrode, and the gate electrode. A protective layer consisting of
Features and to holder Iyamondo field effect transistor further comprising a. Forming a surface layer by terminating the diamond substrate surface with hydrogen atoms;
Forming a first adsorption layer composed of molecules in the atmosphere on the surface layer by exposing the surface layer to the atmosphere ;
Forming a source electrode and a drain electrode spaced apart from each other on the first adsorption layer;
So as to cover the first adsorption layer exposed between the source electrode and the front Symbol drain electrode, and forming a second adsorption layer consisting of NO ₂ molecules,
Forming a protective layer made of a compound containing oxygen on the second adsorption layer;
And forming a gate electrode on the second adsorption layer so as to be spaced between the source electrode and the drain electrode. Forming a surface layer by terminating the diamond substrate surface with hydrogen atoms;
Forming a first adsorption layer composed of molecules in the atmosphere on the surface layer by exposing the surface layer to the atmosphere ;
The first adsorption layer, and forming a second adsorption layer consisting of NO ₂ molecules,
Forming a source electrode and a drain electrode spaced apart from each other on the second adsorption layer;
Forming a protective layer made of a compound containing oxygen so as to cover the second adsorption layer exposed between the source electrode and the drain electrode ;
Wherein the second adsorbent layer, the diamond field effect transistor forming method characterized by comprising the steps of forming a gate electrode spaced between the drain electrode and the source electrode.

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