Gallium nitride planar micro-nano vacuum triode based on trapezoidal gate structure

Abstract

The invention discloses a gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure. The triode comprises an anode, a cathode, a first grid electrode, a second grid electrode, an insulating layer and a base, the insulating layer is arranged on the upper surface of the base; the anode, the cathode, the first grid electrode and the second grid electrode are arranged on the upper surface of the insulating layer; the anode and the cathode are arranged on the same straight line of the insulating layer, and the first grid electrode and the second grid electrode are symmetrically arranged relative to the straight line; a gap is formed between the first grid electrode and the second grid electrode, and one end of the cathode extends into the gap. The triode improves the shielding of the grid electrode to the anode electric field, and has high grid control capability and low grid electrode leakage current.

Description

Technical Field

[0001] The present invention relates to the field of micro-nano vacuum electronic devices, and more specifically, to a gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure. Background Art

[0002] Micro-nano vacuum triodes are a type of electronic device that uses vacuum as a carrier transmission channel. Due to the advantages of high temperature resistance, high frequency, and radiation resistance, micro-nano vacuum triodes have a wide range of application scenarios in defense, aerospace and other fields.

[0003] With the continuous advancement of micro-nano processing technology, micro-nano vacuum triodes are developing in the direction of miniaturization and integration. However, when the electrode spacing of micro-nano vacuum triodes is reduced, the influence of the anode voltage on the electric field on the cathode tip surface is further strengthened, and the anode current is difficult to saturate. In addition, the reduction in electrode spacing also brings about the problem of increased gate leakage current, and the static power consumption of the device increases. Although increasing the electrode spacing can reduce the gate leakage current, it also weakens the gate control ability of the device.

[0004] The prior art discloses a side anode vacuum channel nanogap triode and a preparation method. The nanogap triode includes a cathode, an anode, a gate, and an oxide insulating layer; a gap of less than 300 nm is maintained between the cathode and the gate, and the anode is arranged in a direction perpendicular to one side of the cathode-gate connection line. By adjusting the gate and anode voltages, the electrons emitted by the cathode can be partially or completely hit on the anode under the action of the anode voltage, thereby forming a nanogap device triode structure in which the current can be controlled. However, the gate of this side anode structure does not shield the anode, and the distance between the anode and the cathode is small, resulting in a large effect of the anode on the electric field strength at the cathode tip, and the anode current is difficult to saturate. In addition, the distance between the cathode and the gate of the device is large, the gate has a small effect on the electric field strength at the cathode tip, and the gate control capability is poor. Summary of the invention

[0005] In view of the problem that the gate control capability of the device in the prior art is poor and no anode shielding is formed, the present invention provides a planar gallium nitride micro-nano vacuum triode based on a trapezoidal gate structure, with a trapezoidal gate structure, which covers the cathode tip area and reduces the influence of the anode voltage on the cathode tip electric field. Under the premise of not changing the gate spacing of the device, the gate control capability of the device is improved by adjusting the gate angle. Compared with directly reducing the gate spacing, adjusting the gate angle has less effect on the anode collection rate, which can improve the problem of high gate leakage current caused by high gate control capability.

[0006] The primary purpose of the present invention is to solve the above technical problems. The technical solution of the present invention is as follows:

[0007] A gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure, comprising an anode, a cathode, a first gate, a second gate, an insulating layer and a base;

[0008] The insulating layer is arranged on the upper surface of the base;

[0009] The anode, cathode, first grid and second grid are all arranged on the upper surface of the insulating layer;

[0010] The anode and cathode are arranged on the same straight line of the insulating layer, and the first grid and the second grid are arranged symmetrically about the straight line;

[0011] There is a gap between the first grid and the second grid, and one end of the cathode extends into the gap.

[0012] Furthermore, one end of the cathode close to the grid is a pointed cone tip, and one end of the anode close to the grid is a rectangular or pointed cone tip.

[0013] Furthermore, the curvature radius of the cathode tip is 20 nm.

[0014] Furthermore, one end of the first grid and the second grid close to the cathode is a single pointed end.

[0015] Furthermore, the tip angles of the first grid and the second grid are in a range of 30 degrees to 75 degrees.

[0016] Furthermore, the first grid and the second grid are trapezoidal, wherein the lower base of the trapezoid is close to the anode.

[0017] Furthermore, the distance between the first gate and the second gate ranges from 100 nm to 550 nm.

[0018] Furthermore, the distance between the lower bottom edge of the trapezoid of the first gate or the second gate and the cathode tip in the direction of the symmetry axis is 100 nm to 150 nm.

[0019] Furthermore, the height of the trapezoid of the first gate or the second gate is 525 nm.

[0020] Furthermore, the gate, anode and cathode are made of gallium nitride, the insulating layer is made of aluminum nitride, and the base is made of sapphire.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention designs a gate with a trapezoidal structure to cover the cathode tip area, thereby increasing the influence of the gate on the electric field strength at the cathode tip, enhancing the gate control capability, and reducing the influence of the anode voltage on the electric field at the cathode tip; and, as a further technical solution of the present invention, by adjusting the gate spacing, the gate tip angle and the spacing between the bottom edge of the trapezoidal gate and the cathode tip in the direction of the symmetry axis, the high gate leakage current problem caused by the device under high gate control capability conditions is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural diagram of the gallium nitride planar micro-nano vacuum triode provided in Example 1.

[0024] Figure 2 A top view of the gallium nitride planar micro-nano vacuum triode provided in Example 1.

[0025] Figure 3 A top view of a gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure provided in Example 2.

[0026] Figure 4 A top view of the gallium nitride planar micro-nano vacuum triode based on a pointed cone-shaped gate provided in Example 3.

[0027] Figure 5 A top view of a gallium nitride planar micro-nano vacuum triode based on a rectangular gate provided in Example 4.

[0028] Figure 6 The potential diagram of the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate provided in Example 2.

[0029] Figure 7 The potential diagram of the gallium nitride planar micro-nano vacuum triode based on the pointed cone gate provided in Example 3.

[0030] Figure 8 The potential diagram of the gallium nitride planar micro-nano vacuum triode based on the rectangular gate structure provided in Example 4.

[0031] Fig. 9 The particle trajectory diagram of the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure provided in Example 5.

[0032] Fig.10 The particle trajectory diagram of the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure provided in Example 6.

[0033] Fig.11 The particle trajectory diagram of the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure provided in Example 7.

[0034] Fig.12 The particle trajectory diagram of the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure provided in Example 8.

[0035] Fig.13 A top view of a gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure provided in Example 9.

[0036] Fig.14A top view of a gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure provided in Example 7.

[0037] Fig.15 A top view of a gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure provided in Example 10.

[0038] Fig.16 A top view of a gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure provided in Example 11.

[0039] Fig.17 A top view of a gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure provided in Example 12.

[0040] Fig.18 A top view of a gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure provided in Example 13.

[0041] Fig.19 These are the structural parameters corresponding to devices with different gate structures.

[0042] Fig. 20 The electric field strength at the cathode tip and the anode collection rate corresponding to devices with different gate structures.

[0043] Fig.21 These are the structural parameters corresponding to devices with different gate spacings.

[0044] Fig. 22 The electric field strength at the cathode tip and the anode collection rate corresponding to devices with different gate spacings.

[0045] Fig.23 Structural parameters corresponding to the device with different distances between the bottom edge of the trapezoid and the cathode tip in the direction of the symmetry axis.

[0046] Fig.24 The electric field strength at the cathode tip and the anode collection rate of the device with different distances between the bottom edge of the trapezoid and the cathode tip in the direction of the symmetry axis.

[0047] Fig.25 Corresponding structural parameters of devices with different gate angles.

[0048] Fig.26 The electric field strength at the cathode tip and the anode collection rate corresponding to devices with different gate angles. DETAILED DESCRIPTION

[0049] The drawings are for illustrative purposes only and should not be construed as limiting the present patent;

[0050] In order to better illustrate the present embodiment, some parts in the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product;

[0051] It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0052] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0053] Example 1

[0054] like Figure 1 , Figure 2 As shown, a gallium nitride planar micro-nano vacuum triode comprises an anode, a cathode, a first gate, a second gate, an insulating layer and a base;

[0055] The insulating layer is arranged on the upper surface of the base;

[0056] The anode, cathode, first grid and second grid are all arranged on the upper surface of the insulating layer;

[0057] The anode and cathode are arranged on the same straight line of the insulating layer, and the first grid and the second grid are arranged symmetrically about the straight line;

[0058] There is a gap between the first grid and the second grid, and one end of the cathode extends into the gap.

[0059] Furthermore, the gate, anode and cathode are made of gallium nitride, the insulating layer is made of aluminum nitride, and the base is made of sapphire.

[0060] Furthermore, one end of the first grid and the second grid close to the cathode is a single pointed end.

[0061] Furthermore, one end of the cathode close to the grid is a pointed cone tip.

[0062] Furthermore, the curvature radius of the cathode tip is 20 nm.

[0063] The distance between the cathode and the anode is 600 nm.

[0064] It should be noted that when the anode voltage is set to 0V and the gate voltage is 40V, the electric field at the cathode tip is the gate electric field; when the anode voltage is set to 40V and the gate voltage is 0V, the electric field at the cathode tip is the anode electric field; the anode collection rate is set to the probability of electrons reaching the anode when the anode voltage is 40V and the gate voltage is 10V.

[0065] It should be noted that gallium nitride materials have a lower electron affinity; using gallium nitride materials to make the gate, anode, and cathode of the triode makes it easier for electrons to tunnel from the cathode tip surface, resulting in a larger field emission current. At the same time, gallium nitride has good thermal and chemical stability, and good field emission stability.

[0066] Example 2

[0067] Based on the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure described in Example 1, that is, this embodiment adopts the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure same as that in Example 1. Figure 3 As shown, the end of the anode close to the grid is rectangular.

[0068] Furthermore, the included angle between the tips of the first grid and the second grid is 60 degrees.

[0069] Furthermore, the first grid and the second grid are trapezoidal, wherein the lower base of the trapezoid is close to the anode.

[0070] Furthermore, the distance between the lower bottom edge of the trapezoid of the first gate or the second gate and the cathode tip in the direction of the symmetry axis is 125 nm.

[0071] Furthermore, the height of the trapezoid of the first gate or the second gate is 525 nm.

[0072] In a specific embodiment, the shortest distance between the first gate and the second gate is 550nm, and the anode width is 1μm. At this time, COMSOL is used for simulation calculation, and the gate electric field is 1.91×10 8 V / m, the anode electric field is 7.55×10 7 V / m, the ratio of the gate electric field to the anode electric field is 2.53. If the anode electric field is 40V and the gate electric field is 10V, the anode collection rate is 100%.

[0073] It should be noted that when the anode voltage is fixed at 0V, the effect of the gate voltage on the space potential is as follows: Figure 6 As shown in the figure, the trapezoidal gate has a great influence on the potential of the channel space between the cathode and the anode. Therefore, the performance of the triode is better.

[0074] Example 3

[0075] Based on the gallium nitride planar micro-nano vacuum triode described in Example 1, this embodiment uses the same gallium nitride planar micro-nano vacuum triode as in Example 1. Figure 4 As shown, the end of the anode close to the grid is rectangular.

[0076] The first gate and the second gate are single-pointed.

[0077] In a specific embodiment, the shortest distance between the first gate and the second gate is 550nm, the anode width is 1μm, the longitudinal distance between the gate and the cathode tip is 125nm, and the width of the first gate or the second gate is 525nm. At this time, COMSOL is used for simulation calculation, and the gate electric field is 2.10×10 8V / m, the anode electric field is 1.05×10 8 V / m, the ratio of the gate electric field to the anode electric field is 2. If the anode electric field is 40V and the gate electric field is 10V, the anode collection rate is 100%.

[0078] It should be noted that when the anode voltage is fixed at 0V, the effect of the gate voltage on the space potential is as follows: Figure 7 As shown in the figure, the pointed cone-shaped gate has a great influence on the potential of the channel space between the cathode and the anode. Therefore, the performance of the triode is better.

[0079] Example 4

[0080] Based on the gallium nitride planar micro-nano vacuum triode described in Example 1, this embodiment uses the same gallium nitride planar micro-nano vacuum triode as in Example 1. Figure 5 As shown, the end of the anode close to the grid is rectangular.

[0081] The first gate and the second gate are rectangular.

[0082] In a specific embodiment, the shortest distance between the first gate and the second gate is 550nm, the width of the anode is 1μm, the longitudinal distance between the gate and the cathode tip is 125nm, and the width of the first gate or the second gate is 525nm. At this time, COMSOL is used for simulation calculation, and the gate electric field is 8.32×10 7 V / m, the anode electric field is 1.1×10 8 V / m, the ratio of the gate electric field to the anode electric field is 0.76. If the anode electric field is 40V and the gate electric field is 10V, the anode collection rate is 100%.

[0083] It should be noted that when the anode voltage is fixed at 0V, the effect of the gate voltage on the space potential is as follows: Figure 8 As shown in FIG. 1 , the rectangular gate has little effect on the potential of the channel space between the cathode and the anode. Therefore, the performance of the triode is poor.

[0084] It should be noted that the device structure parameters of Examples 2-4 are as follows Fig.19 , the grid electric field, anode electric field, grid-to-anode electric field ratio and anode collection efficiency of comparative examples 2-4 are as follows Fig. 20 As described in Examples 2 to 4, the electric field strengths of the pointed cone-shaped grid and the trapezoidal grid on the cathode are similar, but the electric field of the anode of the trapezoidal structure on the cathode is smaller, and thus has a better anode shielding effect.

[0085] Example 5

[0086] Based on the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure described in Example 1, that is, this embodiment adopts the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure same as that in Example 1. The particle trajectory of this embodiment is as follows Fig. 9 shown.

[0087] The shortest distance between the first gate and the second gate is 400nm;

[0088] The end of the anode close to the grid is a pointed conical tip, and the cathode tip and the anode tip are arranged opposite to each other; the pointed conical tip is located on the straight line.

[0089] The tip angle of the first grid and the second grid is 60 degrees.

[0090] Furthermore, the first grid and the second grid are trapezoidal, wherein the lower base of the trapezoid is close to the anode.

[0091] The distance between the lower bottom edge of the trapezoid of the first gate or the second gate and the cathode tip in the direction of the symmetry axis is 125 nm.

[0092] Furthermore, the height of the trapezoid of the first gate or the second gate is 525 nm.

[0093] In a specific embodiment, the anode width is 1 μm. At this time, COMSOL is used for simulation calculation, and the gate electric field is 2.37×10 8 V / m, the anode electric field is 4.35×10 7 V / m, the ratio of the gate electric field to the anode electric field is 5.45. If the anode electric field is 40V and the gate electric field is 10V, the anode collection rate is 100%.

[0094] Example 6

[0095] Based on the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure described in Example 1, that is, this embodiment adopts the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure same as that in Example 1. The particle trajectory of this embodiment is as follows Fig.10 shown.

[0096] The shortest distance between the first gate and the second gate is 300nm;

[0097] The end of the anode close to the grid is a pointed conical tip, and the cathode tip and the anode tip are arranged opposite to each other; the pointed conical tip is located on the straight line.

[0098] The tip angle of the first grid and the second grid is 60 degrees.

[0099] Furthermore, the first grid and the second grid are trapezoidal, wherein the lower base of the trapezoid is close to the anode.

[0100] The distance between the lower bottom edge of the trapezoid of the first gate or the second gate and the cathode tip in the direction of the symmetry axis is 125 nm.

[0101] Furthermore, the height of the trapezoid of the first gate or the second gate is 525 nm.

[0102] In a specific embodiment, the anode width is 1 μm. At this time, COMSOL is used for simulation calculation, and the gate electric field is 2.91×10 8 V / m, the anode electric field is 3.24×10 7 V / m, the ratio of the gate electric field to the anode electric field is 8.98. If the anode electric field is 40V and the gate electric field is 10V, the anode collection rate is 80.6%.

[0103] Example 7

[0104] Based on the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure described in Example 1, that is, this embodiment adopts the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure same as that in Example 1. The particle trajectory of this embodiment is as follows Fig.11 As shown, the structural diagram is as follows Fig.14 .

[0105] The shortest distance between the first gate and the second gate is 200nm;

[0106] The end of the anode close to the grid is a pointed conical tip, and the cathode tip and the anode tip are arranged opposite to each other; the pointed conical tip is located on the straight line.

[0107] The tip angle of the first grid and the second grid is 60 degrees.

[0108] Furthermore, the first grid and the second grid are trapezoidal, wherein the lower base of the trapezoid is close to the anode.

[0109] The distance between the lower bottom edge of the trapezoid of the first gate or the second gate and the cathode tip in the direction of the symmetry axis is 125 nm.

[0110] Furthermore, the height of the trapezoid of the first gate or the second gate is 525 nm.

[0111] In a specific embodiment, the anode width is 1 μm. At this time, COMSOL is used for simulation calculation, and the gate electric field is 3.85×10 8 V / m, the anode electric field is 1.27×10 7 V / m, the ratio of the gate electric field to the anode electric field is 30.3. If the anode electric field is 40V and the gate electric field is 10V, the anode collection rate is 63.5%.

[0112] Example 8

[0113] Based on the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure described in Example 1, that is, this embodiment adopts the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure same as that in Example 1. The particle trajectory of this embodiment is as follows Fig.12 shown.

[0114] The shortest distance between the first gate and the second gate is 100 nm;

[0115] The end of the anode close to the grid is a pointed conical tip, and the cathode tip and the anode tip are arranged opposite to each other; the pointed conical tip is located on the straight line.

[0116] The tip angle of the first grid and the second grid is 60 degrees.

[0117] Furthermore, the first grid and the second grid are trapezoidal, wherein the lower base of the trapezoid is close to the anode.

[0118] The distance between the lower bottom edge of the trapezoid of the first gate or the second gate and the cathode tip in the direction of the symmetry axis is 125 nm.

[0119] Furthermore, the height of the trapezoid of the first gate or the second gate is 525 nm.

[0120] In a specific embodiment, the anode width is 1 μm. At this time, COMSOL is used for simulation calculation, and the gate electric field is 5.07×10 8 V / m, the anode electric field is 6.24×10 6 V / m, the ratio of the gate electric field to the anode electric field is 81.3. If the anode electric field is 40V and the gate electric field is 10V, the anode collection rate is 40.9%.

[0121] It should be noted that the device structure parameters of Examples 5-8 are as follows Fig.21 , the grid electric field, anode electric field, grid-to-anode electric field ratio and anode collection efficiency of comparative examples 5-8 are as follows Fig. 22 As described in Examples 5-8, when other conditions remain unchanged, the smaller the gate spacing, the greater the influence of the gate on the tip electric field, but at this time the anode collection rate decreases greatly and the gate leakage current increases significantly.

[0122] Example 9

[0123] Based on the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure described in Example 1, that is, this embodiment adopts the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure same as that in Example 1. Fig.13 As shown, the shortest distance between the first gate and the second gate is 200 nm.

[0124] The end of the anode close to the grid is a pointed conical tip, and the cathode tip and the anode tip are arranged opposite to each other; the pointed conical tip is located on the straight line.

[0125] Furthermore, the included angle between the tips of the first grid and the second grid is 60 degrees.

[0126] Furthermore, the first grid and the second grid are trapezoidal, wherein the lower base of the trapezoid is close to the anode.

[0127] Furthermore, the distance between the lower bottom edge of the trapezoid of the first gate or the second gate and the cathode tip in the direction of the symmetry axis is 150 nm.

[0128] Furthermore, the height of the trapezoid of the first gate or the second gate is 525 nm.

[0129] In a specific embodiment, the simulation calculation using COMSOL shows that the anode width is 1 μm. At this time, the gate electric field is 3.69×10 8 V / m, the anode electric field is 9.62×10 6 V / m, the ratio of the gate electric field to the anode electric field is 38.4. If the anode electric field is 40V and the gate electric field is 10V, the anode collection rate is 60.3%.

[0130] Example 10

[0131] Based on the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure described in Example 1, that is, this embodiment adopts the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure same as that in Example 1. Fig.15 As shown, the shortest distance between the first gate and the second gate is 200 nm.

[0132] The end of the anode close to the grid is a pointed conical tip, and the cathode tip and the anode tip are arranged opposite to each other; the pointed conical tip is located on the straight line.

[0133] Furthermore, the included angle between the tips of the first grid and the second grid is 60 degrees.

[0134] Furthermore, the first grid and the second grid are trapezoidal, wherein the lower base of the trapezoid is close to the anode.

[0135] The distance between the lower bottom edge of the trapezoid of the first grid or the second grid and the cathode tip in the direction of the symmetry axis is 100 nm.

[0136] Furthermore, the height of the trapezoid of the first gate or the second gate is 525 nm.

[0137] In a specific embodiment, the anode width is 1 μm. At this time, COMSOL is used for simulation calculation, and the gate electric field is 3.95×10 8 V / m, the anode electric field is 1.71×10 7 V / m, the ratio of the gate electric field to the anode electric field is 23.1. If the anode electric field is 40V and the gate electric field is 10V, the anode collection rate is 72.9%.

[0138] It should be noted that the device structure parameters of Examples 7, 9-10 are as follows Fig.23 , comparing the gate electric field, anode electric field, ratio of gate-to-anode electric field and anode collection efficiency of Experimental Examples 7, 9-10. Fig.24 As described in Experimental Examples 7 and 9-10, the larger the distance between the bottom edge of the trapezoidal grid and the cathode tip in the direction of the symmetry axis, the lower the grid and anode electric fields are, the greater the decrease in the anode electric field is, and thus the grid-to-anode electric field ratio is, but the anode collection rate also decreases as the distance increases.

[0139] Embodiment 11

[0140] Based on the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure described in Example 1, that is, this embodiment adopts the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure same as that in Example 1. Fig.16 As shown, the shortest distance between the first gate and the second gate is 200 nm.

[0141] The end of the anode close to the grid is a pointed conical tip, and the cathode tip and the anode tip are arranged opposite to each other; the pointed conical tip is located on the straight line.

[0142] The tip angle of the first grid and the second grid is 30 degrees.

[0143] Furthermore, the first grid and the second grid are trapezoidal, wherein the lower base of the trapezoid is close to the anode.

[0144] The distance between the lower bottom edge of the trapezoid of the first grid or the second grid and the cathode tip in the direction of the symmetry axis is 150 nm.

[0145] Furthermore, the height of the trapezoid of the first gate or the second gate is 525 nm.

[0146] In a specific embodiment, the anode width is 1 μm. At this time, COMSOL is used for simulation calculation, and the gate electric field is 3.19×10 8 V / m, the anode electric field is 1.07×10 7 V / m, the ratio of the gate electric field to the anode electric field is 29.8. If the anode electric field is 40V and the gate electric field is 10V, the anode collection rate is 65.2%.

[0147] Example 12

[0148] Based on the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure described in Example 1, that is, this embodiment adopts the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure same as that in Example 1. Fig.17 As shown, the shortest distance between the first gate and the second gate is 200 nm.

[0149] The end of the anode close to the grid is a pointed conical tip, and the cathode tip and the anode tip are arranged opposite to each other; the pointed conical tip is located on the straight line.

[0150] The tip angle of the first grid and the second grid is 45 degrees.

[0151] Furthermore, the first grid and the second grid are trapezoidal, wherein the lower base of the trapezoid is close to the anode.

[0152] The distance between the lower bottom edge of the trapezoid of the first grid or the second grid and the cathode tip in the direction of the symmetry axis is 150 nm.

[0153] Furthermore, the height of the trapezoid of the first gate or the second gate is 525 nm.

[0154] In a specific embodiment, the anode width is 1 μm. At this time, COMSOL is used for simulation calculation, and the gate electric field is 3.38×10 8 V / m, the anode electric field is 1.03×10 7 V / m, the ratio of the gate electric field to the anode electric field is 32.8. If the anode electric field is 40V and the gate electric field is 10V, the anode collection rate is 63.8%.

[0155] Example 13

[0156] Based on the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure described in Example 1, that is, this embodiment adopts the gallium nitride planar micro-nano vacuum triode based on the trapezoidal gate structure same as that in Example 1. Fig.18 As shown, the shortest distance between the first gate and the second gate is 200 nm.

[0157] The end of the anode close to the grid is a pointed conical tip, and the cathode tip and the anode tip are arranged opposite to each other; the pointed conical tip is located on the straight line.

[0158] The tip angle of the first grid and the second grid is 75 degrees.

[0159] Furthermore, the first grid and the second grid are trapezoidal, wherein the lower base of the trapezoid is close to the anode.

[0160] The distance between the lower bottom edge of the trapezoid of the first grid or the second grid and the cathode tip in the direction of the symmetry axis is 150 nm.

[0161] Furthermore, the height of the trapezoid of the first gate or the second gate is 525 nm.

[0162] In a specific embodiment, the anode width is 1 μm. At this time, COMSOL is used for simulation calculation, and the gate electric field is 4.15×10 8 V / m, the anode electric field is 8.66×10 6 V / m, the ratio of the gate electric field to the anode electric field is 47.9. If the anode electric field is 40V and the gate electric field is 10V, the anode collection rate is 52.6%.

[0163] It should be noted that the device structure parameters of Examples 9, 11-13 are as follows: Fig.25 , comparing the gate electric field, anode electric field, ratio of gate-to-anode electric field and anode collection efficiency of Experimental Examples 9, 11-13. Fig.26 As described in Examples 9 and 11-13, as the gate tip angle increases, the ratio of the device gate-to-anodal electric field increases monotonically, reaching a maximum value at an angle of 75 degrees. The anode collection rate decreases slowly in the range of 30-60 degrees, but when the angle reaches 75 degrees, the anode collection rate decreases significantly.

[0164] It should be noted that, as described in Examples 5-13, the device of Example 9 has a larger gate-to-anode electric field ratio (38.4) and a higher anode collection rate (60.3%), achieving a balance between high gate control capability and low gate leakage current, which is the optimal parameter condition.

[0165] The same or similar reference numerals correspond to the same or similar components;

[0166] The terms used in the drawings to describe positional relationships are only used for illustrative purposes and should not be construed as limiting this patent;

[0167] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. Gallium nitride planar micro-nano vacuum triode based on trapezoidal gate structure, characterized in that: It includes an anode, a cathode, a first grid, a second grid, an insulating layer and a base; The insulating layer is arranged on the upper surface of the base; The anode, cathode, first grid and second grid are all arranged on the upper surface of the insulating layer; The anode and cathode are arranged on the same straight line of the insulating layer, and the first grid and the second grid are arranged symmetrically about the straight line; There is a gap between the first grid and the second grid, and one end of the cathode extends into the gap.

2. The gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure according to claim 1, characterized in that: The end of the cathode close to the grid is a pointed cone tip, and the end of the anode close to the grid is a rectangular or pointed cone tip.

3. The gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure according to claim 2, characterized in that: The curvature radius of the cathode tip is 20 nm.

4. The gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure according to claim 1, characterized in that: One end of the first grid and the second grid close to the cathode is a single tip.

5. The gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure according to claim 4, characterized in that: The tip angles of the first grid and the second grid are in a range of 30 degrees to 75 degrees.

6. The gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure according to claim 5, characterized in that: The first grid and the second grid are in a trapezoidal shape, wherein the lower bottom edge of the trapezoid is close to the anode.

7. The gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure according to claim 6, characterized in that: The distance between the first gate and the second gate ranges from 100 nm to 550 nm.

8. The gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure according to claim 6, characterized in that: The distance between the lower bottom edge of the trapezoid of the first grid or the second grid and the cathode tip in the direction of the symmetry axis is 100 nm to 150 nm.

9. The gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure according to claim 6, characterized in that: The height of the trapezoid of the first gate or the second gate is 525 nm.

10. The gallium nitride planar micro-nano vacuum triode based on a trapezoidal gate structure according to claim 1, characterized in that: The gate, anode and cathode are made of gallium nitride, the insulating layer is made of aluminum nitride, and the base is made of sapphire.

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