Nitride semiconductor resonance tunneling diode oscillator and manufacturing method thereof

Abstract

The invention discloses a nitride semiconductor resonant tunneling diode oscillator and a manufacturing method thereof. The problems that an existing resonant tunneling diode oscillator is low in output power, large in material epitaxy difficulty, high in direct-current power consumption and large in circuit complexity, and resonant frequency drifts due to substrate coupling are mainly solved. The device comprises a resonant tunneling diode and a slot antenna, the resonant tunneling diode comprises a substrate, an emitter ohmic contact layer, a first isolation layer, a first barrier layer, a potential well layer, a second barrier layer, a second isolation layer and a collector ohmic contact layer from bottom to top, and all the layers are made of nitride materials; the slot antenna comprises a metal ground, a dielectric plate, a metal slot layer and an MIM capacitor from bottom to top. The whole nitride semiconductor resonance tunneling diode is located on one side of the metal gap layer and connected with the MIM capacitor. Influence of substrate coupling on resonant frequency is shielded, direct current power consumption and circuit complexity are low, output power is high, a material epitaxy process is simple, and the terahertz high-power radiation source can be applied to a terahertz on-chip high-power radiation source.

Description

Technical Field

[0001] The invention belongs to the technical field of microelectronic devices, and in particular relates to a nitride semiconductor resonant tunneling diode oscillator, which can be used for an on-chip high-power terahertz radiation source. Background Art

[0002] The resonant tunneling diode is a quantum effect device that relies on unipolar tunneling transport and has a unique differential negative resistance characteristic. The device has a small junction capacitance and an extremely short carrier transport time, and has a simple structure. The oscillation circuit prepared based on the resonant tunneling diode usually has an extremely high operating frequency and can achieve terahertz wave radiation at room temperature, which has important applications in on-chip terahertz radiation sources.

[0003] The core structure of the traditional on-chip resonant tunneling diode oscillator is a GaAs-based resonant tunneling diode. Due to the limitations of the GaAs material properties, the output power of the oscillation circuit of this device is obviously insufficient, which limits the practical application of compound semiconductor resonant tunneling diode oscillator circuits. In order to solve the problem of low output power of traditional GaAs semiconductor resonant tunneling diode oscillators, researchers have proposed the following solutions:

[0004] Masato Shiraishi et al. proposed a resonant tunneling diode oscillator circuit with integrated slot antenna in "High Output Power (~400μW) Oscillators ataround 550GHz Using Resonant Tunneling Diodes with Graded Emitter and ThinBarriers". Figure 1 As shown, it uses a three-stage emitter and a thin barrier resonant tunneling diode device as the core device of the oscillation circuit and is integrated with a slot antenna, such as Figure 1 As shown in a, an output power of about 400 μW is achieved at an oscillation frequency of 550 GHz. The resonant tunneling diode device structure is as follows Figure 1 As shown in b, it includes substrate, intrinsic InGaAs, emitter ohmic contact layer, n-InGaAs, In 0.51 Ga 0.49 As、In 0.49 Ga 0.51 As、In 0.47 Ga 0.53 As, AlAs barrier layer, InGaAs potential well layer, AlAs barrier layer, InGaAs isolation layer, collector ohmic contact layer. Although the oscillation circuit improves the output power to a certain extent, it has the following shortcomings:

[0005] First, the material growth of the tertiary emitter is difficult. The three-level emitter layer structure is 2.5nm In from bottom to top. 0.51 Ga 0.49 As, 2.5nm In 0.49 Ga 0.51 As, 2nm In 0.47 Ga 0.53 As, In and Ga components of the three-layer material are different and the difference is small, which is difficult to control precisely, which poses a technical challenge to the control of the epitaxial growth of the material.

[0006] Second, the slot antenna participates in the resonance as the load of the resonant tunneling diode. The electromagnetic waves on both sides of the slot will couple with each other through the substrate, causing the oscillation frequency to shift and be easily affected by the external environment.

[0007] Third, due to the limitation of the intrinsic narrow bandgap of GaAs material, the oscillator cannot be biased with too high an operating voltage, and its output power is still relatively low, which cannot meet the application requirements of high-power terahertz radiation sources.

[0008] Patent document with application number CN202410614915.5 discloses a resonant tunneling diode oscillator and a terahertz source device, which realizes power coupling of two resonant tunneling diodes through a U-shaped slot antenna and optimizes the radiation efficiency of the antenna. Although the oscillation circuit further improves the output power of the oscillator, the use of two resonant tunneling diodes increases the DC power consumption and circuit complexity of the circuit. At the same time, since the slot antenna is used as the load of the resonant tunneling diode to participate in the resonance, the electromagnetic waves on both sides of the slot will couple with each other through the substrate, resulting in oscillation frequency deviation and easy to be affected by the external environment, which cannot meet the application requirements of on-chip high-power terahertz radiation source. Summary of the invention

[0009] The purpose of the present invention is to address the shortcomings of the above-mentioned prior art and propose a nitride semiconductor resonant tunneling diode oscillator and a method for manufacturing the same, so as to improve the output power of the oscillation circuit, reduce the difficulty of material epitaxial control and DC power consumption, reduce circuit complexity, and shield the influence of substrate coupling on the oscillation frequency, so as to meet the application requirements of on-chip high-power terahertz radiation sources.

[0010] To achieve the above object, the implementation scheme of the present invention includes the following:

[0011] 1. A nitride semiconductor resonant tunneling diode oscillator, comprising a resonant tunneling diode and a slot antenna, wherein the resonant tunneling diode comprises, from bottom to top, a substrate, an emitter ohmic contact layer, a first isolation layer, a first barrier layer, a potential well layer, a second barrier layer, a second isolation layer, and a collector ohmic contact layer, characterized in that:

[0012] The slot antenna comprises a metal ground, a dielectric plate, a metal slot layer and a MIM capacitor;

[0013] The emitter ohmic contact layer, the first isolation layer, the first barrier layer, the potential well layer, the second barrier layer, the second isolation layer, and the collector ohmic contact layer are all made of nitride materials to increase output power. The entire resonant tunneling diode is located on one side of the metal gap layer and is connected to the MIM capacitor.

[0014] Furthermore, the metal gap layer is made of any one of gold, silver, copper and aluminum materials, with a thickness of 100nm-300nm, a gap width of 2μm-6μm, and a gap length determined by the required resonant frequency. The distance between the gap and its metal edges is 300μm-400μm.

[0015] Furthermore, the MIM capacitor includes a lower plate, a dielectric layer and an upper plate, which is located on the other side of the metal gap layer, and the lower plate and the metal gap layer share the same metal layer.

[0016] Furthermore, the collector ohmic contact layer and the emitter ohmic contact layer of the resonant tunneling diode are respectively connected to the upper plate of the MIM capacitor in the slot antenna and the metal slot layer in the slot antenna.

[0017] Furthermore, the thickness and material of each layer of the resonant tunneling diode are as follows:

[0018] The substrate is made of any one of sapphire material, silicon material, silicon carbide material, gallium nitride material, aluminum nitride material, boron nitride material, diamond material, and gallium oxide material;

[0019] The emitter ohmic contact layer and the collector ohmic contact layer are both 40nm-300nm thick and have a doping concentration of 1×10 19 cm -3 -2×10 20 cm -3 n-type GaN or n-type InGaN or n-type ScGaN or n-type YGaN or n-type BGaN material;

[0020] The first isolation layer and the second isolation layer are both 4nm-12nm thick and made of any one of GaN, InGaN, ScGaN, YGaN and BGaN;

[0021] The first barrier layer and the second barrier layer are both 1nm-3nm thick and made of any one of AlN, AlGaN, InAlN, ScAlN, YAlN, BAlN, AlPN and BPN;

[0022] The potential well layer has a thickness of 1nm-3nm, and the material is any one of GaN, InGaN, ScGaN, YGaN, and BGaN.

[0023] Furthermore, the metal ground of the slot antenna has a thickness of 100nm-300nm, and the material is any one of gold, silver, copper, and aluminum; the dielectric plate of the slot antenna has a thickness of 3μm-6μm, and the material is BCB dielectric; the MIM capacitor of the slot antenna has an upper plate thickness of 100nm-300nm, and the material is any one of gold, silver, copper, and aluminum; the dielectric layer thickness is 20nm-300nm, and the material is any one of SiN, Al2O3, HfO2, and SiO2.

[0024] 2. A method for manufacturing a nitride semiconductor resonant tunneling diode oscillator, characterized in that it comprises the following steps:

[0025] 1) Using molecular beam epitaxy technology, a 40nm-300nm thick and 1×10 19 cm -3 -2×10 20 cm -3 The emitter ohmic contact layer;

[0026] 2) using molecular beam epitaxy technology to grow a first isolation layer (3) with a thickness of 4 nm to 12 nm on the emitter ohmic contact layer;

[0027] 3) growing a first barrier layer with a thickness of 1 nm to 3 nm on the first isolation layer using molecular beam epitaxy technology;

[0028] 4) using molecular beam epitaxy technology to grow a potential well layer with a thickness of 1nm-3nm on the first barrier layer;

[0029] 5) using molecular beam epitaxy technology to grow a second barrier layer with a thickness of 1 nm to 3 nm on the potential well layer;

[0030] 6) growing a second isolation layer with a thickness of 4 nm to 12 nm on the second barrier layer using molecular beam epitaxy technology;

[0031] 7) Using molecular beam epitaxy technology, a 40nm-300nm thick and doping concentration of 1×10 19 cm -3 -2×10 20 cm -3 The collector ohmic contact layer;

[0032] 8) using a photolithography process to form a mesa isolation pattern on the collector ohmic contact layer, and then using a photoresist as a mask and an inductively coupled plasma etching method to etch the collector ohmic contact layer to the upper part of the substrate to form a mesa isolation shallow groove with a depth of 3 μm-6 μm;

[0033] 9) Using photoresist as a mask, setting a collector region on the collector ohmic contact layer after the mesa isolation, and depositing metal Ti / Au / Ni in the region by electron beam evaporation process to form a resonant tunneling diode collector with a diameter of 0.1 μm-5 μm;

[0034] 10) Using the collector metal of the resonant tunneling diode as a mask, an inductively coupled plasma etching method is used to etch the collector ohmic contact layer after the mesa isolation to the upper surface of the emitter ohmic contact layer to form a resonant tunneling diode columnar mesa from the first isolation layer to the collector;

[0035] 11) using a photoresist as a mask, setting an emitter region on the emitter ohmic contact layer forming the columnar mesa of the resonant tunneling diode, and depositing metal Ti / Au / Ni in the region by electron beam evaporation process to form the emitter of the resonant tunneling diode;

[0036] 12) Using the photoresist as a mask, a metal ground region is set on the substrate, and a metal with a thickness of 100nm-300nm is deposited in the region by an electron beam evaporation process to form a metal ground of the slot antenna;

[0037] 13) Spin-coat a layer of AP3000 tackifier on the epitaxial wafer, and then spin-coat a layer of BCB dielectric with a thickness of 3 μm-6 μm to form a dielectric plate of the slot antenna;

[0038] 14) using a photolithography process to set an emitter through hole and a collector through hole region on the dielectric plate, using a photoresist as a mask, and using a reactive ion etching method to perform etching to form an emitter through hole and a collector through hole respectively;

[0039] 15) using a photolithography process to set a metal slot layer region on the dielectric plate, and using an electron beam evaporation process to deposit metal in the region to form a metal slot layer of the slot antenna;

[0040] 16) Depositing a dielectric layer with a thickness of 20 nm to 300 nm on the surface of the epitaxial wafer by plasma enhanced chemical vapor deposition or atomic layer deposition;

[0041] 17) using a photolithography process to set a dielectric layer region of the MIM capacitor on the dielectric layer, using a photoresist as a mask and using a reactive ion etching method to form the dielectric layer of the MIM capacitor;

[0042] 18) Using a photolithography process, an upper plate region is set on the dielectric layer of the MIM capacitor, and an electron beam evaporation process is used to deposit metal in the region to form an upper plate of the MIM capacitor of the slot antenna, thereby completing the preparation of the nitride semiconductor resonant tunneling diode oscillator.

[0043] Compared with the prior art, the present invention has the following advantages:

[0044] 1. Since the present invention uses a nitride semiconductor resonant tunneling diode as the core device of the oscillator, there is no need to perform special structural design on the emitter, and the material epitaxial growth process is simple.

[0045] 2. Since the present invention adds a metal ground in the slot antenna structure, the influence of substrate coupling on the oscillation frequency can be shielded, thereby improving the frequency stability of the oscillation circuit.

[0046] 3. Since the resonant tunneling diode of the present invention adopts nitride material with high breakdown field strength, the bias operating voltage of the diode can be increased to achieve high output power.

[0047] 4. Since there is only one resonant tunneling diode in the oscillator circuit of the present invention, the DC power consumption and circuit complexity of the oscillator are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a structural diagram of an existing resonant tunneling diode oscillator;

[0049] Figure 2 is a structural diagram of a nitride semiconductor resonant tunneling diode oscillator of the present invention;

[0050] Figure 3 yes Figure 2 A top view of

[0051] Figure 4 is a structural diagram of a nitride semiconductor resonant tunneling diode in the present invention;

[0052] Figure 5 It is a schematic diagram of the process of manufacturing a nitride semiconductor resonant tunneling diode oscillator according to the present invention. DETAILED DESCRIPTION

[0053] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0054] Reference Figure 2 and Figure 3 , the nitride semiconductor resonant tunneling diode oscillator of this embodiment includes a resonant tunneling diode and a slot antenna, wherein:

[0055] The slot antenna includes, from bottom to top, a metal ground 9, a dielectric plate 10, a metal slot layer 11 and a MIM capacitor 12, wherein the entire resonant tunneling diode is located on one side of the metal slot layer 11 and is connected to the MIM capacitor 12;

[0056] The metal ground 9 of the slot antenna has a thickness of 100nm-300nm and is made of any one of gold, silver, copper and aluminum;

[0057] The dielectric plate 10 of the slot antenna has a thickness of 3 μm-6 μm and is made of BCB dielectric;

[0058] The metal slot layer 11 of the slot antenna is made of any one of gold, silver, copper and aluminum materials, with a thickness of 100nm-300nm, a slot width of 2μm-6μm, and a slot length determined by the required resonant frequency. The distance between the slot and its metal edges is 300μm-400μm.

[0059] The MIM capacitor 12 of the slot antenna includes a lower plate 121, a dielectric layer 122 and an upper plate 123, which is located on the other side of the metal slot layer 11, and the lower plate 121 and the metal slot layer 11 share the same metal layer. The upper plate 123 has a thickness of 100nm-300nm, and the material is any one of gold, silver, copper and aluminum; the dielectric layer 122 has a thickness of 20nm-300nm, and the material is any one of SiN, Al2O3, HfO2 and SiO2.

[0060] Reference Figure 4 The nitride semiconductor resonant tunneling diode in the oscillator of this example includes a substrate 1, an emitter ohmic contact layer 2, a first isolation layer 3, a first barrier layer 4, a potential well layer 5, a second barrier layer 6, a second isolation layer 7, and a collector ohmic contact layer 8, wherein:

[0061] The substrate 1 is made of any one of sapphire material, silicon material, silicon carbide material, gallium nitride material, aluminum nitride material, boron nitride material, diamond material, and gallium oxide material;

[0062] The emitter ohmic contact layer 2 has a thickness of 40nm-300nm and a doping concentration of 1×10 19 cm -3 -2×10 20 cm -3 n-type GaN or n-type InGaN or n-type ScGaN or n-type YGaN or n-type BGaN material between them, which is located on the substrate 1;

[0063] The first isolation layer 3 has a thickness of 4nm-12nm and is made of any one of GaN, InGaN, ScGaN, YGaN and BGaN, and is located on the emitter ohmic contact layer 2;

[0064] The first barrier layer 4 has a thickness of 1 nm to 3 nm and is made of any one of AlN, AlGaN, InAlN, ScAlN, YAlN, BAlN, AlPN and BPN, and is located on the first isolation layer 3;

[0065] The potential well layer 5 has a thickness of 1nm-3nm and is made of any one of GaN, InGaN, ScGaN, YGaN and BGaN, and is located on the first barrier layer 4;

[0066] The second barrier layer 6 has a thickness of 1 nm to 3 nm and is made of any one of AlN, AlGaN, InAlN, ScAlN, YAlN, BAlN, AlPN and BPN, and is located on the potential well layer 5;

[0067] The second isolation layer 7 has a thickness of 4nm-12nm and is made of any one of GaN, InGaN, ScGaN, YGaN and BGaN, and is located on the second barrier layer 6;

[0068] The collector ohmic contact layer 8 has a thickness of 40nm-300nm and a doping concentration of 1×10 19 cm -3 -2×10 20 cm -3 The n-type GaN, n-type InGaN, n-type ScGaN, n-type YGaN or n-type BGaN material is located on the second isolation layer 7 .

[0069] Reference Figure 5 The present invention manufactures the above-mentioned nitride semiconductor resonant tunneling diode oscillator and provides the following three embodiments.

[0070] In the first embodiment, a nitride resonant tunneling diode oscillator is manufactured on a gallium nitride substrate 1, in which the first barrier layer 4 is made of AlN with a thickness of 1 nm, the potential well layer 5 is made of GaN with a thickness of 2 nm, the second barrier layer 6 is made of AlN with a thickness of 1 nm, and in the slot antenna, the metal ground 9 is made of Au with a thickness of 120 nm, the dielectric plate 10 is made of BCB with a thickness of 4 μm, and the metal slot layer 11 is made of Au with a thickness of 120 nm.

[0071] Step 1: epitaxially grow an n-type GaN emitter ohmic contact layer 2 on a gallium nitride substrate, such as Figure 5 (a).

[0072] The temperature was set to 650°C, the nitrogen flow rate to 3.2 sccm, and the gallium beam equilibrium vapor pressure to 9.5×10 -7 Torr, silicon beam equilibrium vapor pressure is 2.0×10 -8 Torr, and a nitrogen RF source power of 450W. Molecular beam epitaxy was used to grow epitaxial layers with a thickness of 300nm and a doping concentration of 1×10 19 cm -3 The n-type GaN emitter ohmic contact layer 2.

[0073] Step 2: epitaxially grow a GaN first isolation layer 3 on the n-type GaN emitter ohmic contact layer 2, such as Figure 5 (b).

[0074] The temperature was set to 650 °C, the nitrogen flow rate was 3.2 sccm, and the gallium beam equilibrium vapor pressure was 9.5 × 10 -7 Torr, and a nitrogen RF source power of 450 W. A GaN first isolation layer 3 with a thickness of 4 nm was epitaxially grown on the n-type GaN emitter ohmic contact layer 2 using a molecular beam epitaxy technique.

[0075] Step 3: epitaxially grow an AlN first barrier layer 4 on the GaN first isolation layer 3, such as Figure 5 (c).

[0076] The temperature was set to 650 °C, the nitrogen flow rate was 3.2 sccm, and the aluminum beam equilibrium vapor pressure was 3.2 × 10 -7 Torr, and a nitrogen RF source power of 450 W. The molecular beam epitaxy technology was used to grow an AlN first barrier layer 4 with a thickness of 1 nm on the GaN first isolation layer 3.

[0077] Step 4: epitaxially grow a GaN potential well layer 5 on the AlN first potential barrier layer 4, such as Figure 5 (d).

[0078] The temperature was set to 650 °C, the nitrogen flow rate was 3.2 sccm, and the gallium beam equilibrium vapor pressure was 9.5 × 10 -7 Torr, and a nitrogen RF source power of 450 W. A GaN potential well layer 5 with a thickness of 2 nm was epitaxially grown on the AlN first barrier layer 4 using a molecular beam epitaxy technique.

[0079] Step 5: epitaxially grow an AlN second barrier layer 6 on the GaN potential well layer 5, such as Figure 5 (e).

[0080] The temperature was set to 650 °C, the nitrogen flow rate was 3.2 sccm, and the aluminum beam equilibrium vapor pressure was 3.2 × 10 -7Torr, and a nitrogen RF source power of 450 W. The molecular beam epitaxy technique was used to grow an AlN second barrier layer 6 with a thickness of 1 nm on the GaN potential well layer 5.

[0081] Step 6: epitaxially grow a GaN second isolation layer 7 on the AlN second barrier layer 6, such as Figure 5 (f).

[0082] The temperature was set to 650 °C, the nitrogen flow rate was 3.2 sccm, and the gallium beam equilibrium vapor pressure was 9.5 × 10 -7 Torr, a nitrogen RF source power of 450 W, and a GaN second isolation layer 7 with a thickness of 4 nm were grown on the AlN second barrier layer 6 using a molecular beam epitaxy technique.

[0083] Step 7: epitaxially grow an n-type GaN collector ohmic contact layer 8 on the GaN second isolation layer 7, such as Figure 5 (g).

[0084] The temperature was set to 650 °C, the nitrogen flow rate was 3.2 sccm, and the gallium beam equilibrium vapor pressure was 9.5 × 10 -7 Torr, the silicon beam equilibrium vapor pressure is 2.0×10 -8 Torr, the nitrogen RF source power is 450W, and the molecular beam epitaxy technology is used to grow the GaN second isolation layer 7 with an epitaxial thickness of 300nm and a doping concentration of 1×10 19 cm -3 An n-type GaN collector ohmic contact layer 8 is provided.

[0085] Step eight, perform photoresist coating, photolithography, development, and etching on the n-type GaN collector ohmic contact layer 8 to form a mesa isolation shallow groove with a depth of 4 μm, such as Figure 5 (h).

[0086] 8.1) Using photolithography process to form a mesa isolation shallow groove pattern on the n-type GaN collector ohmic contact layer 8:

[0087] 8.1.1) Spin-coat AZ5214 photoresist on the n-type GaN collector ohmic contact layer 8 at a speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2 Spin coating at 30 s / min for 30 s; then bake at 95°C for 90 s;

[0088] 8.1.2) using conventional optical lithography to expose the AZ5214 photoresist on the n-type GaN collector ohmic contact layer 8;

[0089] 8.1.3) The photoresist after exposure is developed with RZX-3038 developer for 45 seconds to form a mesa isolation shallow groove pattern;

[0090] 8.2) Set the process conditions of Cl2 gas flow rate to 10 sccm, BCl3 gas flow rate to 30 sccm, and etching time to 1200 s, adopt inductively coupled plasma etching method, use photoresist as mask, and etch the n-type GaN collector ohmic contact layer 8 to the substrate according to the mesa isolation shallow groove pattern to form a mesa isolation shallow groove with a depth of 4 μm.

[0091] Step nine, use electron beam evaporation technology to make the collector of the resonant tunneling diode, such as Figure 5 (i).

[0092] 9.1) Spin-coat PMMAA4 photoresist on the n-type GaN collector ohmic contact layer 8 at a speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2 Spin coating at 100 °C / min for 30 s, followed by curing at 180 °C for 90 s.

[0093] 9.2) Using photolithography technology, setting the electron dose ratio to 750, and performing exposure treatment on PMMAA4 photoresist;

[0094] 9.3) Using a tetramethyl dipentyl ketone and isopropanol solution in a ratio of 3:1, the exposed photoresist was developed for 120 seconds, and then fixed with isopropanol for 30 seconds to form a circular collector pattern with a diameter of 2 μm;

[0095] 9.4) Using electron beam evaporation, the circular collector electrode pattern is formed according to Ti / Au / Ni metals with a thickness of 20 / 80 / 50 nm were evaporated at a rate and then soaked in acetone solution to form the collector of the resonant tunneling diode.

[0096] Step 10: using an inductively coupled plasma etching process, etching to form a resonant tunneling diode columnar table, such as Figure 5 (j).

[0097] The process conditions are set to 10 sccm for Cl2 gas flow, 25 sccm for BCl3 gas flow, and 150 s for etching time. The collector metal of the resonant tunneling diode is used as a mask and an inductively coupled plasma etching process is adopted to etch the n-type GaN collector ohmic contact layer 8 after the mesa isolation to the upper surface of the n-type GaN emitter ohmic contact layer 2 to form a resonant tunneling diode columnar mesa from the first isolation layer 3 to the collector.

[0098] Step 11, using electron beam evaporation technology to make the resonant tunneling diode emitter, such as Figure 5 (k).

[0099] 11.1) Spin-coat PMMAA4 photoresist on the n-type GaN emitter ohmic contact layer 2 at a speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2 Spin coating at 100 °C / min for 30 s, followed by baking at 180 °C for 90 s.

[0100] 11.2) Using photolithography technology, setting the electron dose ratio to 750, the PMMAA4 photoresist was exposed;

[0101] 11.3) Using a 3:1 solution of tetramethyl dipentyl ketone and isopropyl alcohol, the exposed photoresist is developed for 120 seconds, and then fixed with isopropyl alcohol for 30 seconds to form an emitter electrode pattern;

[0102] 11.4) Using electron beam evaporation, the emitter electrode pattern is formed according to Ti / Au / Ni metals with a thickness of 20 / 80 / 50 nm were evaporated at a rate of 1000 nm and then immersed in an acetone solution to form a resonant tunneling diode emitter to obtain a sample of a nitride resonant tunneling diode.

[0103] Step 12: Use electron beam evaporation technology to make the metal ground 9 of the slot antenna, such as Figure 5 (l).

[0104] 12.1) Spin-coat PMMAA4 photoresist on the nitride resonant tunneling diode sample at a speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2 Spin coating at 100 °C / min for 30 s, followed by baking at 180 °C for 90 s.

[0105] 12.2) Using photolithography technology, setting the electron dose ratio to 750, the PMMAA4 photoresist was exposed;

[0106] 12.3) Using a tetramethyl dipentyl ketone and isopropyl alcohol solution in a ratio of 3:1, the exposed photoresist is developed for 120 seconds, and then fixed with isopropyl alcohol for 30 seconds to form a metal ground 9 pattern on the substrate after etching the mesa isolation shallow groove;

[0107] 12.4) Using electron beam evaporation, the metal ground pattern is formed according to Au metal with a thickness of 100 nm is evaporated at a rate and then immersed in acetone solution to form the metal ground 9 of the slot antenna.

[0108] Step 13: Make the dielectric plate 10 of the slot antenna, such as Figure 5 (m).

[0109] 13.1) Spin coat AP3000 tackifier on the sample at a speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 5s; then spin-coat at a speed of 1600rad / min and an acceleration of 2000rad 2 Spin coating at 30 s / min;

[0110] 13.2) Spin-coat the BCB medium on the sample at a speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 5s; then spin-coat at a speed of 8000rad / min and an acceleration of 2000rad 2 / min for 30s; then heat-treat and bake to form a BCB dielectric with a thickness of 4 μm, forming a dielectric plate 10 of the slot antenna;

[0111] Step 14: Make the emitter through hole and the collector through hole of the resonant tunneling diode, such as Figure 5 (n).

[0112] Using photoresist as a mask, setting process conditions of pressure of 1500mTorr, power of 200W, SF6 flow rate of 8sccm, O2 of 10sccm, and He flow rate of 150sccm, a reactive ion etching method is used to etch the dielectric plate 10 of the slot antenna to the metal surface of the emitter and collector of the resonant tunneling diode, forming the emitter through hole and the collector through hole of the resonant tunneling diode respectively.

[0113] Step 15: Make the metal slot layer 11 of the slot antenna, such as Figure 5 (o).

[0114] 15.1) Spin-coat PMMAA4 photoresist on the dielectric plate 10 of the slot antenna at a rotation speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2 Spin coating at 100 °C / min for 30 s, followed by curing at 180 °C for 90 s.

[0115] 15.2) Using photolithography technology, setting the electron dose ratio to 750, the PMMAA4 photoresist was exposed;

[0116] 15.3) using a tetramethyl dipentyl ketone and isopropyl alcohol solution in a ratio of 3:1 to develop the exposed photoresist for 120 seconds, and then fixing it with isopropyl alcohol for 30 seconds to form a pattern of the metal slot layer 11 of the slot antenna;

[0117] 15.4) Using electron beam evaporation method, on the metal gap layer 11 pattern according to Au metal with a thickness of 100 nm is evaporated at a rate of 1000 nm, and then immersed in acetone solution to form a metal gap layer 11, wherein the gap is 200 μm long and 4 μm wide, and the gap is 350 μm away from the metal edge. The metal gap layer is connected to the emitter of the resonant tunneling diode.

[0118] Step 16: deposit an Al2O3 dielectric layer using atomic layer deposition technology, such as Figure 5 (p).

[0119] The process conditions are set as time 40s, pressure 2000mTorr, temperature 300℃, Al(CH3)3 flow rate 850sccm, H2O flow rate 350sccm, and N2 flow rate 1000sccm, and an Al2O3 dielectric layer with a thickness of 200nm is deposited on the entire epitaxial wafer surface using an atomic layer deposition process.

[0120] Step 17: fabricate the dielectric layer 122 of the MIM capacitor, such as Figure 5 (q).

[0121] The process conditions are set to 1500mTorr pressure, 200W power, 8sccm SF6 flow, 10sccm CHF3, and 150sccm He flow. The Al2O3 dielectric layer is etched by reactive ion etching using photoresist as a mask to form the dielectric layer 122 of the MIM capacitor.

[0122] Step 18, making the upper plate 123 of the MIM capacitor, such as Figure 5 (r).

[0123] 18.1) Spin-coat PMMAA4 photoresist on the epitaxial wafer at a speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2 Spin coating at 100 °C / min for 30 s, followed by baking at 180 °C for 90 s.

[0124] 18.2) Using a photolithography process, setting the electron dose ratio to 750, the PMMAA4 photoresist was exposed;

[0125] 18.3) using a tetramethyl dipentyl ketone and isopropyl alcohol solution in a ratio of 3:1, developing the exposed photoresist for 120 seconds, and then fixing it with isopropyl alcohol for 30 seconds to form a pattern 123 of the upper plate of the MIM capacitor connected to the collector of the resonant tunneling diode;

[0126] 18.4) Using electron beam evaporation, the upper plate pattern is formed according to Au metal with a thickness of 200 nm is evaporated at a rate of , and then immersed in acetone solution to form the upper plate 123 of the MIM capacitor, thereby completing the preparation of the nitride resonant tunneling diode oscillator.

[0127] Embodiment 2: The material of the first barrier layer 4 in the nitride resonant tunneling diode is B. 0.18 Al 0.82 N, thickness is 2nm, potential well layer 5 material is B 0.15 Ga 0.85 N, thickness is 1nm, the material of the second barrier layer 6 is B 0.18 Al 0.82 N, with a thickness of 2nm, and a nitride resonant tunneling diode oscillator in which the metal ground 9 in the slot antenna is made of Al and has a thickness of 200nm, the dielectric plate 10 is made of BCB and has a thickness of 6μm, and the metal slot layer 11 is made of Al and has a thickness of 200nm.

[0128] Step 1: epitaxially grow n-type B on aluminum nitride substrate 1 0.15 Ga 0.85 N emitter ohmic contact layer 2, such as Figure 5 (a).

[0129] Using molecular beam epitaxy technology, an epitaxial layer with a thickness of 100 nm and a doping concentration of 5×10 19 cm -3 n-type B 0.15 Ga 0.85 N emitter ohmic contact layer 2.

[0130] The process conditions of molecular beam epitaxy are: temperature 800 °C, nitrogen flow rate 1.8 sccm, boron beam equilibrium vapor pressure 5.0×10 -8 Torr, the equilibrium vapor pressure of gallium beam is 4.5×10 -7 Torr, the equilibrium vapor pressure of silicon beam is 4.6×10 - 8 Torr, and the nitrogen RF source power is 380W.

[0131] Step 2, in n-type B 0.15 Ga 0.85 N emitter ohmic contact layer 2 epitaxial B 0.15 Ga0.85 N first isolation layer 3, such as Figure 5 (b).

[0132] Using molecular beam epitaxy, n-type B 0.15 Ga 0.85 The N emitter ohmic contact layer 2 has an epitaxial thickness of 8nm. 0.15 Ga 0.85 N first isolation layer 3.

[0133] The process conditions of molecular beam epitaxy are: temperature 800 °C, nitrogen flow rate 1.8 sccm, boron beam equilibrium vapor pressure 5.0×10 -8 Torr, the equilibrium vapor pressure of gallium beam is 4.5×10 -7 Torr, and the nitrogen RF source power is 380W.

[0134] Step 3, in B 0.15 Ga 0.85 N Epitaxial layer B on the first isolation layer 3 0.18 Al 0.82 N first barrier layer 4, such as Figure 5 (c).

[0135] Using molecular beam epitaxy, 0.15 Ga 0.85 N The first isolation layer 3 has an epitaxial thickness of 2nm B 0.18 Al 0.82 N first barrier layer 4 .

[0136] The process conditions of molecular beam epitaxy are: temperature 800 °C, nitrogen flow rate 1.8 sccm, boron beam equilibrium vapor pressure 5.0×10 -8 Torr, the equilibrium vapor pressure of aluminum beam is 5.2×10 -7 Torr, and the nitrogen RF source power is 380W.

[0137] Step 4, in B 0.18 Al 0.82 N first barrier layer 4 epitaxial B 0.15 Ga 0.85 N potential well layer 5, such as Figure 5 (d).

[0138] Using molecular beam epitaxy, 0.18 Al 0.82 N The first barrier layer 4 is epitaxially grown with a thickness of 1 nm. 0.15 Ga 0.85 N potential well layer 5.

[0139] The process conditions of molecular beam epitaxy are: temperature 800 °C, nitrogen flow rate 1.8 sccm, boron beam equilibrium vapor pressure 5.0×10-8 Torr, the equilibrium vapor pressure of gallium beam is 4.5×10 -7 Torr, and the nitrogen RF source power is 380W.

[0140] Step 5, in B 0.15 Ga 0.85 N potential well layer 5 epitaxial B 0.18 Al 0.82 N second barrier layer 6, such as Figure 5 (e).

[0141] Using molecular beam epitaxy, 0.15 Ga 0.85 The N potential well layer 5 is epitaxially grown with a thickness of 2 nm. 0.18 Al 0.82 N second barrier layer 6 .

[0142] The process conditions of molecular beam epitaxy are: temperature 800 °C, nitrogen flow rate 1.8 sccm, boron beam equilibrium vapor pressure 5.0×10 -8 Torr, the equilibrium vapor pressure of aluminum beam is 5.2×10 -7 Torr, and the nitrogen RF source power is 380W.

[0143] Step 6, in B 0.18 Al 0.82 N second barrier layer 6 epitaxial B 0.15 Ga 0.85 N second isolation layer 7, such as Figure 5 (f).

[0144] Using molecular beam epitaxy, 0.18 Al 0.82 N second barrier layer 6 is epitaxially grown with a thickness of 8 nm. 0.15 Ga 0.85 N second isolation layer 7.

[0145] The process conditions of molecular beam epitaxy are: temperature 800 °C, nitrogen flow rate 1.8 sccm, boron beam equilibrium vapor pressure 5.0×10 -8 Torr, the equilibrium vapor pressure of gallium beam is 4.5×10 -7 Torr, and the nitrogen RF source power is 380W.

[0146] Step 7, in B 0.15 Ga 0.85 N second isolation layer 7 epitaxial n-type B 0.15 Ga 0.85 N collector ohmic contact layer 8, such as Figure 5 (g).

[0147] Using molecular beam epitaxy,0.15 Ga 0.85 The epitaxial thickness of the second isolation layer 7 is 100 nm and the doping concentration is 5×10 19 cm -3 n-type B 0.15 Ga 0.85 N collector ohmic contact layer 8.

[0148] The process conditions of molecular beam epitaxy are: temperature 800 °C, nitrogen flow rate 1.8 sccm, boron beam equilibrium vapor pressure 5.0×10 -8 Torr, the equilibrium vapor pressure of gallium beam is 4.5×10 -7 Torr, the equilibrium vapor pressure of silicon beam is 4.6×10 - 8 Torr, and the nitrogen RF source power is 380W.

[0149] Step 8, in n-type B 0.15 Ga 0.85 The N collector ohmic contact layer 8 is coated, photolithographically, developed, and etched to form a mesa isolation shallow groove with a depth of 6 μm. Figure 5 (h).

[0150] 8a) Using photolithography process on n-type B 0.15 Ga 0.85 A mesa isolation shallow groove pattern is formed on the N collector ohmic contact layer 8:

[0151] The specific implementation of this step is the same as step 8.1) of Example 1;

[0152] 8b) Based on the mesa isolation shallow groove pattern, n-type B 0.15 Ga 0.85 The N collector ohmic contact layer 8 is etched to form a mesa isolation shallow groove:

[0153] Using the inductively coupled plasma etching method, the photoresist is used as a mask to etch the n-type B according to the mesa isolation shallow groove pattern. 0.15 Ga 0.85 The N collector ohmic contact layer 8 is connected to the substrate to form a mesa isolation shallow trench with a depth of 6 μm.

[0154] The process conditions adopted for inductively coupled plasma etching are: Cl2 gas flow rate is 10 sccm, and BCl3 gas flow rate is 25 sccm.

[0155] Step 9, using electron beam evaporation technology to make the collector of the resonant tunneling diode, such as Figure 5 (i).

[0156] 9a) In n-type B 0.15 Ga 0.85PMMAA4 photoresist is spin-coated on the N collector ohmic contact layer 8, and the rotation speed is 500 rad / min and the acceleration is 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2 Spin coating at 100 °C / min for 30 s, followed by curing at 180 °C for 90 s.

[0157] 9b) using a photolithography process, setting the electron dose ratio to 750, and performing an exposure treatment on the PMMAA4 photoresist;

[0158] 9c) The photoresist after exposure treatment is first developed with a tetramethyl dipentyl ketone and isopropyl alcohol solution in a ratio of 3:1 for 120 seconds, and then fixed with isopropyl alcohol for 30 seconds to form a circular collector pattern with a diameter of 5 μm;

[0159] 9d) Using electron beam evaporation method, on the collector pattern according to Ti / Au / Ni metals with a thickness of 20 / 80 / 50 nm were evaporated at a rate and then soaked in acetone solution to form the collector of the resonant tunneling diode.

[0160] Step 10, using an inductively coupled plasma etching process, etching to form a resonant tunneling diode columnar table, such as Figure 5 (j).

[0161] Using the inductively coupled plasma etching method, the collector metal of the resonant tunneling diode is used as a mask to etch the n-type B 0.15 Ga 0.85 N collector ohmic contact layer 8 to n-type B 0.15 Ga 0.85 On the upper surface of the N emitter ohmic contact layer 2, a resonant tunneling diode columnar mesa with a diameter of 5 μm is formed from the first isolation layer 3 to the collector.

[0162] The etching process conditions are: Cl2 gas flow rate is 10 sccm, BCl3 gas flow rate is 25 sccm, and etching time is 50 s.

[0163] Step 11, using electron beam evaporation technology to make a resonant tunneling diode emitter, such as Figure 5 (k).

[0164] 11a) In n-type B 0.15 Ga 0.85 PMMAA4 photoresist is spin-coated on the N emitter ohmic contact layer 2, and the rotation speed is 500 rad / min and the acceleration is 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2Spin coating at 100 °C / min for 30 s, followed by curing at 180 °C for 90 s.

[0165] 11b) using a photolithography process, setting the electron dose ratio to 750, and performing an exposure process on the PMMAA4 photoresist;

[0166] 11c) using a tetramethyl dipentyl ketone and isopropyl alcohol solution in a ratio of 3:1 to develop the exposed photoresist for 120 seconds, and then fixing it with isopropyl alcohol for 30 seconds to form an emitter electrode pattern;

[0167] 11d) Using electron beam evaporation method, on the emitter electrode pattern according to Ti / Au / Ni metals with a thickness of 20 / 80 / 50 nm were evaporated at a rate of 1000 nm and then immersed in an acetone solution to form an emitter of a resonant tunneling diode, thereby obtaining a sample of a nitride resonant tunneling diode.

[0168] Step 12, using electron beam evaporation technology to make the metal ground 9 of the slot antenna, such as Figure 5 (l).

[0169] 12a) Spin-coat PMMAA4 photoresist on the sample of nitride resonant tunneling diode at a rotation speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2 Spin coating at 100 °C / min for 30 s, followed by curing at 180 °C for 90 s.

[0170] 12b) using a photolithography process, setting the electron dose ratio to 750, and performing an exposure process on the PMMAA4 photoresist;

[0171] 12c) using a tetramethyl dipentyl ketone and isopropyl alcohol solution in a ratio of 3:1 to develop the exposed photoresist for 120 seconds, and then fixing it with isopropyl alcohol for 30 seconds to form a metal ground 9 pattern on the substrate after etching the mesa isolation shallow groove;

[0172] 12d) Using electron beam evaporation, the metal ground pattern is formed according to Al metal with a thickness of 200 nm is evaporated at a rate of , and then immersed in acetone solution to form a metal ground 9 of the slot antenna on the substrate after etching the mesa isolation shallow groove.

[0173] Step 13, making the dielectric plate 10 of the slot antenna, such as Figure 5 (m).

[0174] 13a) Spin coat AP3000 tackifier on the sample at a speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 5s; then spin-coat at a speed of 1600rad / min and an acceleration of 2000rad 2 Spin coating at 30 s / min;

[0175] 13b) Spin-coat the BCB medium onto the sample, first at a speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 5s; then spin-coat at a speed of 3000rad / min and an acceleration of 2000rad 2 / min for 30s; then heat-treat and bake to form a BCB dielectric with a thickness of 6 μm, forming a dielectric plate 10 of the slot antenna;

[0176] Step 14, making the emitter through hole and the collector through hole of the resonant tunneling diode, such as Figure 5 (n).

[0177] Using photoresist as a mask, setting the pressure to 1500mTorr, the power to 200W, the SF6 flow rate to 8sccm, the O2 flow rate to 10sccm, and the He flow rate to 150sccm, a reactive ion etching method is used to etch the dielectric plate 10 of the slot antenna to the metal surface of the emitter and collector of the resonant tunneling diode, forming the emitter through hole and the collector through hole of the resonant tunneling diode respectively.

[0178] Step 15, making the metal slot layer 11 of the slot antenna, such as Figure 5 (o).

[0179] 15a) Spin-coat PMMAA4 photoresist on the dielectric plate 10 of the slot antenna at a rotation speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2 Spin coating at 100 °C / min for 30 s, followed by curing at 180 °C for 90 s.

[0180] 15b) using a photolithography process, setting the electron dose ratio to 750, and performing an exposure process on the PMMAA4 photoresist;

[0181] 15c) using a tetramethyl dipentyl ketone and isopropyl alcohol solution in a ratio of 3:1 to develop the exposed photoresist for 120 seconds, and then fixing it with isopropyl alcohol for 30 seconds to form a pattern of the metal slot layer 11 of the slot antenna;

[0182] 15d) Using electron beam evaporation method, on the pattern of metal ground 11 according to Al metal with a thickness of 200 nm is evaporated at a rate of , and then immersed in acetone solution to form a metal gap layer 11. This metal layer is connected to the emitter of the resonant tunneling diode. The gap is 400 μm long and 4 μm wide, and the gap is 400 μm away from the metal edge.

[0183] Step 16, depositing a SiN dielectric layer, such as Figure 5 (p).

[0184] A SiN dielectric layer with a thickness of 300 nm is deposited on the entire surface of the epitaxial wafer using a plasma enhanced chemical vapor deposition method.

[0185] The plasma enhanced chemical vapor deposition process conditions are: pressure of 2200 mTorr, temperature of 350°C, SiH4 flow rate of 13.5 sccm, NH3 flow rate of 10 sccm, and N2 flow rate of 1000 sccm.

[0186] Step 17, making the dielectric layer 122 of the MIM capacitor, such as Figure 5 (q).

[0187] The SiN dielectric layer is etched using a reactive ion etching method with the photoresist as a mask to form a dielectric layer 122 of the MIM capacitor.

[0188] The process conditions of reactive ion etching are as follows: pressure of 1500 mTorr, power of 200 W, SF6 flow rate of 8 sccm, CHF3 of 10 sccm, and He flow rate of 150 sccm.

[0189] Step 18, making the upper plate 123 of the MIM capacitor, completing the preparation of the nitride semiconductor resonant tunneling diode oscillator, such as Figure 5 (r).

[0190] 18a) Spin-coat PMMAA4 photoresist on the epitaxial wafer at a speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2 Spin coating at 100 °C / min for 30 s, followed by baking at 180 °C for 90 s.

[0191] 18b) using a photolithography process, setting the electron dose ratio to 750, and performing exposure treatment on the PMMAA4 photoresist;

[0192] 18c) using a tetramethyl dipentyl ketone and isopropyl alcohol solution in a ratio of 3:1 to develop the exposed photoresist for 120 seconds, and then fixing it with isopropyl alcohol for 30 seconds to form a pattern of the upper plate 123 of the MIM capacitor connected to the collector of the resonant tunneling diode;

[0193] 18d) Using electron beam evaporation method, on the upper plate pattern according to Al metal with a thickness of 300 nm is evaporated at a rate of , and then immersed in acetone solution to form an upper plate 123 of the MIM capacitor, thereby completing the preparation of the nitride resonant tunneling diode oscillator.

[0194] Embodiment 3: The material of the first barrier layer 4 of the nitride resonant tunneling diode is In 0.17 Al 0.83 N, thickness is 3nm, the material of potential well layer 5 is In 0.1 Ga 0.9 N, thickness is 3nm, the material of the second barrier layer 6 is In 0.17 Al 0.83 N, with a thickness of 3nm, and a nitride resonant tunneling diode oscillator in which the metal ground 9 in the slot antenna is made of Cu and has a thickness of 300nm, the dielectric plate 10 is made of BCB and has a thickness of 3μm, and the metal slot layer 11 is made of Cu and has a thickness of 300nm.

[0195] Step A, growing n-type In on silicon substrate 1 0.1 Ga 0.9 N emitter ohmic contact layer 2, such as Figure 5 (a).

[0196] Using molecular beam epitaxy technology, at a temperature of 500°C, a nitrogen flow rate of 0.5 sccm, and an indium beam equilibrium vapor pressure of 2.3×10 -7 Torr, the equilibrium vapor pressure of gallium beam is 2.5×10 -7 Torr, the equilibrium vapor pressure of silicon beam is 6.5×10 -8 Torr, and the nitrogen RF source power is 300W. Under the process conditions, a 40nm thick and 2×10 20 cm -3 n-type In 0.1 Ga 0.9 N emitter ohmic contact layer 2.

[0197] Step B, in n-type In 0.1 Ga 0.9 In is grown on the N emitter ohmic contact layer 2 0.1 Ga 0.9 N first isolation layer 3, such as Figure 5 (b).

[0198] Using molecular beam epitaxy technology, at a temperature of 500°C, a nitrogen flow rate of 0.5 sccm, and an indium beam equilibrium vapor pressure of

[0199] 2.3×10 -7Torr, the equilibrium vapor pressure of gallium beam is 2.5×10 -7 Torr, under the process conditions of nitrogen RF source power of 300W, in n-type In 0.1 Ga 0.9 A 12 nm thick Indium layer is grown on the N emitter ohmic contact layer 2. 0.1 Ga 0.9 N first isolation layer 3.

[0200] Step C, In 0.1 Ga 0.9 In is grown on the N first isolation layer 3 0.17 Al 0.83 N first barrier layer 4, such as Figure 5 (c).

[0201] Using molecular beam epitaxy technology, at a temperature of 500°C, a nitrogen flow rate of 0.5 sccm, and an indium beam equilibrium vapor pressure of 2.3×10 -7 Torr, the equilibrium vapor pressure of aluminum beam is 0.3×10 -7 Torr, nitrogen RF source power of 300W, under the process conditions of In 0.1 Ga 0.9 The first isolation layer 3 is grown with a thickness of 3 nm. 0.17 Al 0.83 N first barrier layer 4 .

[0202] Step D, In 0.17 Al 0.83 In is grown on the N first barrier layer 4 0.1 Ga 0.9 N potential well layer 5, such as Figure 5 (d).

[0203] Using molecular beam epitaxy technology, at a temperature of 500°C, a nitrogen flow rate of 0.5 sccm, and an indium beam equilibrium vapor pressure of 2.3×10 -7 Torr, the equilibrium vapor pressure of gallium beam is 2.5×10 -7 Torr, nitrogen RF source power of 300W, under the process conditions of In 0.17 Al 0.83 The N first barrier layer 4 is grown with a thickness of 3 nm. 0.1 Ga 0.9 N potential well layer 5.

[0204] Step E, In 0.1 Ga 0.9 In is grown on the N potential well layer 5 0.17 Al 0.83 N second barrier layer 6, such as Figure 5 (e).

[0205] Using molecular beam epitaxy technology, at a temperature of 500°C, a nitrogen flow rate of 0.5 sccm, and an indium beam equilibrium vapor pressure of 2.3×10 -7 Torr, the equilibrium vapor pressure of aluminum beam is 0.3×10 -7 Torr, nitrogen RF source power of 300W, under the process conditions of In 0.1 Ga 0.9 An In layer with a thickness of 3 nm is grown on the N potential well layer 5. 0.17 Al 0.83 N second barrier layer 6 .

[0206] Step F, In 0.17 Al 0.83 In is grown on the N second barrier layer 6 0.1 Ga 0.9 N second isolation layer 7, such as Figure 5 (f).

[0207] Using molecular beam epitaxy technology, at a temperature of 500°C, a nitrogen flow rate of 0.5 sccm, and an indium beam equilibrium vapor pressure of 2.3×10 -7 Torr, the equilibrium vapor pressure of gallium beam is 2.5×10 -7 Torr, nitrogen RF source power of 300W, under the process conditions of In 0.17 Al 0.83 On the N second barrier layer 6, an In layer with a thickness of 12 nm is grown. 0.1 Ga 0.9 N second isolation layer 7.

[0208] Step G, In 0.1 Ga 0.9 N second isolation layer 7 is grown on n-type In 0.1 Ga 0.9 N collector ohmic contact layer 8, such as Figure 5 (g).

[0209] Using molecular beam epitaxy technology, at a temperature of 500°C, a nitrogen flow rate of 0.5 sccm, and an indium beam equilibrium vapor pressure of 2.3×10 -7 Torr, the equilibrium vapor pressure of gallium beam is 2.5×10 -7 Torr, the equilibrium vapor pressure of silicon beam is 6.5×10 -8 Torr, nitrogen RF source power of 300W, under the process conditions of In 0.1 Ga 0.9 The second isolation layer 7 is grown with a thickness of 40 nm and a doping concentration of 2×10 20 cm -3 n-type In 0.1 Ga 0.9N collector ohmic contact layer 8.

[0210] Step H, in n-type In 0.1 Ga 0.9 The N collector ohmic contact layer 8 is coated, photolithographically, developed, and etched to form a mesa isolation shallow groove with a depth of 3 μm. Figure 5 (h).

[0211] H1) Using photolithography process on n-type In 0.1 Ga 0.9 A mesa isolation shallow groove pattern is formed on the N collector ohmic contact layer 8:

[0212] The specific implementation of this step is the same as step 8.1) of Example 1.

[0213] H2) Based on the mesa isolation shallow groove pattern, n-type In 0.1 Ga 0.9 The N collector ohmic contact layer 8 is etched to form a mesa isolation shallow groove:

[0214] Using photoresist as a mask, using inductively coupled plasma etching method, under the process conditions of Cl2 gas flow rate of 10sccm, BCl3 gas flow rate of 25sccm, and etching time of 120s, the n-type In was etched according to the mesa isolation shallow groove pattern. 0.1 Ga 0.9 The N collector ohmic contact layer 8 is connected to the substrate to form a mesa isolation shallow trench with a depth of 3 μm.

[0215] Step I, using electron beam evaporation technology to make the collector of the resonant tunneling diode, such as Figure 5 (i).

[0216] I1) In n-type In 0.1 Ga 0.9 PMMAA4 photoresist is spin-coated on the N collector ohmic contact layer 8, and the rotation speed is 500 rad / min and the acceleration is 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2 Spin coating at 100 °C / min for 30 s, followed by baking at 180 °C for 90 s.

[0217] I2) using a photolithography process, setting the electron dose ratio to 750, and exposing the PMMAA4 photoresist;

[0218] I3) using a tetramethyl dipentyl ketone and isopropanol solution in a ratio of 3:1 to develop the exposed photoresist for 120 seconds, and then fixing it with isopropanol for 30 seconds to form a circular collector pattern with a diameter of 0.1 μm;

[0219] I4) Using electron beam evaporation method, on the collector pattern according to Ti / Au / Ni metals with a thickness of 20 / 80 / 50 nm were evaporated at a rate and then soaked in acetone solution to form the collector of the resonant tunneling diode.

[0220] Step J, using an inductively coupled plasma etching process, etching to form a resonant tunneling diode columnar mesa, such as Figure 5 (j).

[0221] Using the collector metal of the resonant tunneling diode as a mask, an inductively coupled plasma etching process was used to etch the n-type In film under the process conditions of Cl2 gas flow rate of 10 sccm, BCl3 gas flow rate of 25 sccm, and etching time of 20 s. 0.1 Ga 0.9 N collector ohmic contact layer 8 to n-type In 0.1 Ga 0.9 The N emitter ohmic contact layer 2 forms a resonant tunneling diode columnar mesa with a diameter of 0.1 μm from the first isolation layer 3 to the collector.

[0222] Step K, using electron beam evaporation technology to make a resonant tunneling diode emitter, such as Figure 5 (k).

[0223] K1) in n-type In 0.1 Ga 0.9 PMMAA4 photoresist is spin-coated on the N emitter ohmic contact layer 2, and the rotation speed is 500 rad / min and the acceleration is 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2 Spin coating at 100 °C / min for 30 s, followed by curing at 180 °C for 90 s.

[0224] K2) using a photolithography process, setting the electron dose ratio to 750, and exposing the PMMAA4 photoresist;

[0225] K3) using a tetramethyl dipentyl ketone and isopropyl alcohol solution in a ratio of 3:1 to develop the exposed photoresist for 120 seconds, and then fixing it with isopropyl alcohol for 30 seconds to form an emitter electrode pattern;

[0226] K4) Using electron beam evaporation method, on the emitter electrode pattern according to Ti / Au / Ni metals with a thickness of 20 / 80 / 50 nm were evaporated at a rate of 1000 nm and then immersed in an acetone solution to form an emitter of a resonant tunneling diode, thereby obtaining a sample of a nitride resonant tunneling diode.

[0227] Step L, using electron beam evaporation technology to make the metal ground 9 of the slot antenna, such as Figure 5 (l).

[0228] L1) Spin-coat PMMAA4 photoresist on a sample of a nitride resonant tunneling diode at a rotation speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2 Spin coating at 100 °C / min for 30 s, followed by curing at 180 °C for 90 s.

[0229] L2) using a photolithography process, setting the electron dose ratio to 750, and exposing the PMMAA4 photoresist;

[0230] L3) using a tetramethyl dipentyl ketone and isopropyl alcohol solution in a ratio of 3:1 to develop the exposed photoresist for 120 seconds, and then fixing it with isopropyl alcohol for 30 seconds to form a metal ground 9 pattern on the substrate after etching the mesa isolation shallow groove;

[0231] L4) Using electron beam evaporation method, the metal ground pattern is formed according to Cu metal with a thickness of 300 nm is evaporated at a rate of , and then immersed in acetone solution to form a metal ground 9 of the slot antenna on the substrate after etching the mesa isolation shallow groove.

[0232] Step M, making a dielectric plate 10 of a slot antenna, such as Figure 5 (m).

[0233] M1) Spin coat AP3000 adhesion promoter on the sample at a speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 5s; then spin-coat at a speed of 1600rad / min and an acceleration of 2000rad 2 Spin coating at 30 s / min;

[0234] M2) Spin-coat the BCB medium on the sample at a speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 5s; then spin-coat at a speed of 8000rad / min and an acceleration of 2000rad 2 / min for 60s; then heat-treat and bake to form a BCB dielectric with a thickness of 3μm, forming a dielectric plate 10 of the slot antenna;

[0235] Step N, making the emitter through hole and the collector through hole of the resonant tunneling diode, such as Figure 5 (n).

[0236] Using photoresist as a mask, setting the pressure to 1500mTorr, the power to 200W, the SF6 flow rate to 8sccm, the O2 flow rate to 10sccm, and the He flow rate to 150sccm, a reactive ion etching method is used to etch the dielectric plate 10 of the slot antenna to the metal surface of the emitter and collector of the resonant tunneling diode, forming the emitter through hole and the collector through hole of the resonant tunneling diode respectively.

[0237] Step O, making a metal slot layer 11 of the slot antenna, such as Figure 5 (o).

[0238] O1) Spin-coat PMMAA4 photoresist on the dielectric plate 10 of the slot antenna at a rotation speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2 Spin coating at 100 °C / min for 30 s, followed by baking at 180 °C for 90 s.

[0239] O2) using a photolithography process, setting the electron dose ratio to 750, and exposing the PMMAA4 photoresist;

[0240] O3) using a tetramethyl dipentyl ketone and isopropyl alcohol solution in a ratio of 3:1 to develop the exposed photoresist for 120 seconds, and then fixing it with isopropyl alcohol for 30 seconds to form a pattern of the metal slot layer 11 of the slot antenna;

[0241] O4) electron beam evaporation method is used to form a pattern on the metal ground 11 according to Cu metal with a thickness of 300nm is evaporated at a rate of 1.5 and then immersed in acetone solution to form a metal gap layer 11. This metal layer is connected to the emitter of the resonant tunneling diode. The gap is 10μm long and 2μm wide, and the gap is 300μm away from the metal edge.

[0242] Step P, depositing a HfO2 dielectric layer, such as Figure 5 (p).

[0243] Using an atomic layer deposition process, a 20 nm thick HfO2 dielectric layer was deposited on the entire epitaxial wafer surface under the process conditions of a time of 70 s, a temperature of 280°C, an ethylmethylamine hafnium flow rate of 1200 sccm, an H2O flow rate of 110 sccm, and an N2 flow rate of 1000 sccm.

[0244] Step Q, making the dielectric layer 122 of the MIM capacitor, such as Figure 5 (q).

[0245] Using the photoresist as a mask and a reactive ion etching method, the HfO2 dielectric layer is etched under the process conditions of a pressure of 1500mTorr, a power of 200W, a SF6 flow rate of 8sccm, a CHF3 flow rate of 10sccm, and a He flow rate of 150sccm to form a dielectric layer 122 of the MIM capacitor.

[0246] Step R, making the upper plate 123 of the MIM capacitor, completing the preparation of the nitride semiconductor resonant tunneling diode oscillator, such as Figure 5 (r).

[0247] R1) Spin-coat PMMAA4 photoresist on the epitaxial wafer at a speed of 500 rad / min and an acceleration of 1000 rad. 2 / min for 3s; then spin-coat at a speed of 4000rad / min and an acceleration of 2000rad 2 Spin coating at 100 °C / min for 30 s, followed by baking at 180 °C for 90 s.

[0248] R2) using a photolithography process, setting the electron dose ratio to 750, and exposing the PMMAA4 photoresist;

[0249] R3) using a tetramethyl dipentyl ketone and isopropyl alcohol solution in a ratio of 3:1 to develop the exposed photoresist for 120 seconds, and then fixing it with isopropyl alcohol for 30 seconds to form a pattern of an upper plate 123 of the MIM capacitor connected to the collector of the resonant tunneling diode;

[0250] R4) Using electron beam evaporation method, on the upper plate pattern according to A Cu metal with a thickness of 100 nm is evaporated at a rate of , and then immersed in an acetone solution to form an upper plate 123 of the MIM capacitor, thereby completing the preparation of the nitride resonant tunneling diode oscillator.

[0251] The above descriptions are only three specific examples of the present invention and do not constitute any limitation to the present invention. Obviously, after understanding the content and principle of the present invention, professionals in the field may make various modifications and changes in form and details without departing from the principle and structure of the present invention. For example, in addition to the gallium nitride material, aluminum nitride material, and silicon material that have been used, the substrate may also use any one of sapphire material, silicon carbide material, diamond material, boron nitride material, and gallium oxide material; in addition to the AlN, InAlN, and BAlN materials that have been used, the first and second barrier layers may also use any one of AlGaN, InAlGaN, YAlN, AlPN, ScAlN, and BPN materials; in addition to the GaN, InGaN, and BGaN materials that have been used, the potential well layer may also use any one of YGaN and ScGaN materials; the doping concentration of the ohmic contact layer may be 2×1020 cm -3 , 5×10 19 cm -3 , 1×10 19 cm -3 , can also be used in 1×10 19 cm -3 -2×10 20 cm -3 Any concentration between; In addition to the Au, Al, and Cu materials that have been used, silver materials can also be used for the metal ground, metal gap layer, and MIM capacitor upper plate. However, these modifications and changes based on the concept of the present invention are still within the scope of the claims of the present invention.

Claims

1. A nitride semiconductor resonant tunneling diode oscillator, comprising a resonant tunneling diode and a slot antenna, wherein the resonant tunneling diode comprises, from bottom to top, a substrate (1), an emitter ohmic contact layer (2), a first isolation layer (3), a first barrier layer (4), a potential well layer (5), a second barrier layer (6), a second isolation layer (7), and a collector ohmic contact layer (8), Features: The slot antenna comprises a metal ground (9), a dielectric plate (10), a metal slot layer (11) and a MIM capacitor (12); The emitter ohmic contact layer (2), the first isolation layer (3), the first barrier layer (4), the potential well layer (5), the second barrier layer (6), the second isolation layer (7), and the collector ohmic contact layer (8) are all made of nitride materials to increase output power. The entire resonant tunneling diode is located on one side of the metal gap layer (11) and is connected to the MIM capacitor (12).

2. The oscillator according to claim 1, Features: The metal gap layer (11) is made of any one of gold, silver, copper and aluminum materials, with a thickness of 100nm-300nm, a gap width of 2μm-6μm, and a gap length determined by the required resonance frequency. The distance between the gap and its metal edges is 300μm-400μm.

3. The oscillator according to claim 1, Features: The MIM capacitor (12) comprises a lower plate (121), a dielectric layer (122) and an upper plate (123), which is located on the other side of the metal gap layer (11), and the lower plate (121) and the metal gap layer (11) share the same metal layer.

4. The oscillator according to claim 1, Features: The collector ohmic contact layer (8) and the emitter ohmic contact layer (2) of the resonant tunneling diode are respectively connected to the upper plate (123) of the MIM capacitor (12) in the slot antenna and the metal slot layer (11) in the slot antenna.

5. The oscillator according to claim 1, It is characterized in that The thickness and material of each layer of the resonant tunneling diode are as follows: The substrate (1) is made of any one of sapphire material, silicon material, silicon carbide material, gallium nitride material, aluminum nitride material, boron nitride material, diamond material, and gallium oxide material; The emitter ohmic contact layer (2) and the collector ohmic contact layer (8) are both 40nm-300nm thick and have a doping concentration of 1×10 19 cm -3 -2×10 20 cm -3 n-type GaN or n-type InGaN or n-type ScGaN or n-type YGaN or n-type BGaN material; The first isolation layer (3) and the second isolation layer (7) are both 4nm-12nm thick and made of any one of GaN, InGaN, ScGaN, YGaN and BGaN; The first barrier layer (4) and the second barrier layer (6) are both 1 nm to 3 nm thick and are made of any one of AlN, AlGaN, InAlN, ScAlN, YAlN, BAlN, AlPN and BPN; The potential well layer (5) has a thickness of 1nm-3nm and is made of any one of GaN, InGaN, ScGaN, YGaN and BGaN.

6. The oscillator according to claim 1, Features: The metal ground (9) of the slot antenna has a thickness of 100nm-300nm and is made of any one of gold, silver, copper and aluminum; The dielectric plate (10) of the slot antenna has a thickness of 3 μm-6 μm and is made of BCB dielectric; The MIM capacitor (12) of the slot antenna has an upper plate (123) with a thickness of 100nm-300nm and a material selected from any one of gold, silver, copper and aluminum; and a dielectric layer (122) with a thickness of 20nm-300nm and a material selected from SiN, Al 2 O 3 , HfO 2 、SiO 2 Any one of .

7. A method for manufacturing a nitride semiconductor resonant tunneling diode oscillator, It is characterized in that The steps include: 1) Using molecular beam epitaxy technology, a 40nm-300nm thick and doping concentration of 1×10 19 cm -3 -2×10 20 cm -3 An emitter ohmic contact layer (2); 2) using molecular beam epitaxy technology to grow a first isolation layer (3) with a thickness of 4 nm to 12 nm on the emitter ohmic contact layer (2); 3) growing a first barrier layer (4) with a thickness of 1 nm to 3 nm on the first isolation layer (3) using a molecular beam epitaxy technique; 4) using molecular beam epitaxy technology to grow a potential well layer (5) with a thickness of 1 nm to 3 nm on the first potential barrier layer (4); 5) using molecular beam epitaxy technology to grow a second barrier layer (6) with a thickness of 1 nm to 3 nm on the potential well layer (5); 6) growing a second isolation layer (7) with a thickness of 4 nm to 12 nm on the second barrier layer (6) using a molecular beam epitaxy technique; 7) Using molecular beam epitaxy technology, a layer with a thickness of 40 nm to 300 nm and a doping concentration of 1×10 19 cm -3 -2×10 20 cm -3 A collector ohmic contact layer (8); 8) using a photolithography process to form a mesa isolation pattern on the collector ohmic contact layer (8), and then using a photoresist as a mask and an inductively coupled plasma etching method to etch the collector ohmic contact layer (8) to the upper part of the substrate (1), forming a mesa isolation shallow groove with a depth of 3 μm-6 μm; 9) using a photoresist as a mask, setting a collector region on the collector ohmic contact layer (8) after the mesa isolation, and using an electron beam evaporation process to deposit metal Ti / Au / Ni in the region to form a resonant tunneling diode collector with a diameter of 0.1 μm-5 μm; 10) using the collector metal of the resonant tunneling diode as a mask, and using an inductively coupled plasma etching method, etching the collector ohmic contact layer (8) after the mesa isolation to the upper surface of the emitter ohmic contact layer (2), so as to form a resonant tunneling diode columnar mesa from the first isolation layer (3) to the collector; 11) using a photoresist as a mask, setting an emitter region on the emitter ohmic contact layer (2) forming the columnar mesa of the resonant tunneling diode, and depositing metal Ti / Au / Ni in the region by electron beam evaporation process to form the emitter of the resonant tunneling diode; 12) Using the photoresist as a mask, a metal ground (9) region is set on the substrate, and a metal with a thickness of 100 nm to 300 nm is deposited in the region by an electron beam evaporation process to form a metal ground (9) of the slot antenna; 13) Spin-coating a layer of AP3000 adhesion promoter on the epitaxial wafer, and then spin-coating a layer of BCB dielectric with a thickness of 3 μm-6 μm to form a dielectric plate (10) of the slot antenna; 14) using a photolithography process to set an emitter through hole and a collector through hole region on the dielectric plate (10), using a photoresist as a mask and using a reactive ion etching method to perform etching to form an emitter through hole and a collector through hole respectively; 15) using a photolithography process to set a metal slot layer region on the dielectric plate (10), and using an electron beam evaporation process to deposit metal in the region to form a metal slot layer (11) of the slot antenna; 16) Depositing a dielectric layer with a thickness of 20 nm to 300 nm on the surface of the epitaxial wafer by plasma enhanced chemical vapor deposition or atomic layer deposition; 17) using a photolithography process to set a dielectric layer region of the MIM capacitor on the dielectric layer, using a photoresist as a mask and using a reactive ion etching method to form a dielectric layer (122) of the MIM capacitor; 18) Using a photolithography process, an upper plate (123) region is set on the dielectric layer of the MIM capacitor (12), and metal is deposited in the region using an electron beam evaporation process to form an upper plate (123) of the MIM capacitor of the slot antenna, thereby completing the preparation of the nitride semiconductor resonant tunneling diode oscillator.

8. The method according to claim 7, It is characterized in that The molecular beam epitaxy technology used in step 1) and step 7) has the following process conditions: The temperature is 500℃-800℃; The nitrogen flow rate is 0.5sccm-3.2sccm; The equilibrium vapor pressure of gallium beam is 2.5×10 -7 Torr-9.5×10 -7 Torr; The equilibrium vapor pressure of indium beam is 0.6×10 -7 Torr-2.3×10 -7 Torr; The equilibrium vapor pressure of scandium beam is 1.0×10 -8 Torr-7.0×10 -8 Torr; The equilibrium vapor pressure of yttrium beam is 1.0×10 -8 Torr-6.0×10 -8 Torr; The equilibrium vapor pressure of silicon beam is 2.0×10 -8 Torr-6.5×10 -8 Torr; The equilibrium vapor pressure of boron beam is 1.0×10 -8 Torr-5.0×10 -8 Torr; The power of nitrogen RF source is 300W-450W.

9. The method according to claim 7, It is characterized in that The molecular beam epitaxy technology used in step 2), step 4) and step 6) has the following process conditions: The temperature is 500℃-800℃; The nitrogen flow rate is 0.5sccm-3.2sccm; The equilibrium vapor pressure of gallium beam is 2.5×10 -7 Torr-9.5×10 -7 Torr; The equilibrium vapor pressure of indium beam is 0.6×10 -7 Torr-2.3×10 -7 Torr; The equilibrium vapor pressure of scandium beam is 1.0×10 -8 Torr-7.0×10 -8 Torr; The equilibrium vapor pressure of yttrium beam is 1.0×10 -8 Torr-6.0×10 -8 Torr; The equilibrium vapor pressure of boron beam is 1.0×10 -8 Torr-5.0×10 -8 Torr; The power of nitrogen RF source is 300W-450W.

10. The method according to claim 7, It is characterized in that The molecular beam epitaxy technology used in step 3) and step 5) has the following process conditions: The nitrogen flow rate is 0.5sccm-3.2sccm; The equilibrium vapor pressure of gallium beam is 2.5×10 -7 Torr-9.5×10 -7 Torr; The equilibrium vapor pressure of aluminum beam is 0.3×10 -7 Torr-5.2×10 -7 Torr; The equilibrium vapor pressure of indium beam is 0.6×10 -7 Torr-2.3×10 -7 Torr; The equilibrium vapor pressure of scandium beam is 1.0×10 -8 Torr-7.0×10 -8 Torr; The equilibrium vapor pressure of yttrium beam is 1.0×10 -8 Torr-6.0×10 -8 Torr; The equilibrium vapor pressure of boron beam is 1.0×10 -8 Torr-5.0×10 -8 Torr; The equilibrium vapor pressure of phosphorus beam is 1.0×10 -8 Torr-4.0×10 -8 Torr; The power of nitrogen RF source is 300W-450W.

11. The method according to claim 7, Features: The inductively coupled plasma etching method in step 10) has the following process conditions: Cl 2 Gas flow rate is 5sccm-25sccm, BCl 3 Gas flow rate is 20sccm-70sccm; The plasma enhanced chemical vapor deposition method in step 16) has the following process conditions: pressure of 2000mTorr-2200mTorr, temperature of 350°C, SiH 4 The flow rate is 12sccm-15sccm, NH 3 The flow rate is 9sccm-14sccm, N 2 Flow rate is 900sccm-1200sccm; The atomic layer deposition method in step 16) has the following process conditions: pressure of 2000mTorr-2300mTorr, temperature of 280°C-300°C, flow rate of ethylmethylamine hafnium of 1000sccm-1300sccm, H 2 O flow rate is 110sccm-850sccm, Al(CH 3 ) 3 Flow rate is 300sccm-870sccm, N 2 The flow rate is 800sccm-1200sccm.

Images