阅读说明：本技术 一种双环栅结构的纳米冷阴极电子源及其制作方法 (Nano cold cathode electron source with double-ring grid structure and manufacturing method thereof ) 是由 陈军 黄佳 邓少芝 许宁生 佘峻聪 于 2019-09-04 设计创作，主要内容包括：本发明公开了一种双环栅结构的纳米冷阴极电子源,包括衬底、绝缘层、底部阴极电极、底部分段环状栅极电极、刻蚀通孔、顶部阴极电极、顶部环状栅极电极、生长源薄膜、纳米线冷阴极,所述顶部环状栅极电极通过刻蚀通孔分别与底部分段环状栅极电极相连,还公开了一种双环栅结构的纳米冷阴极电子源的制备方法,包括以下步骤：制作底部阴极电极、底部分段环状栅极电极、绝缘层、刻蚀通孔、顶部阴极电极、顶部环状栅极电极,沉积生长源薄膜,热氧化生长纳米线冷阴极。该纳米冷阴极电子源具有强栅控电子发射能力且是具有可行列寻址双环栅结构。(The invention discloses a nanometer cold cathode electron source with a double-ring grid structure, which comprises a substrate, an insulating layer, a bottom cathode electrode, a bottom section annular grid electrode, an etching through hole, a top cathode electrode, a top annular grid electrode, a growth source film and a nanowire cold cathode, wherein the top annular grid electrode is respectively connected with the bottom section annular grid electrode through the etching through hole, and the invention also discloses a preparation method of the nanometer cold cathode electron source with the double-ring grid structure, which comprises the following steps: and manufacturing a bottom cathode electrode, a bottom section annular grid electrode, an insulating layer, an etched through hole, a top cathode electrode and a top annular grid electrode, depositing a growth source film, and growing a nanowire cold cathode by thermal oxidation. The nanometer cold cathode electron source has strong grid control electron emission capability and a double-ring grid structure capable of column addressing.)

1. A nanometer cold cathode electron source with a double-ring grid structure is characterized in that the structure of the nanometer cold cathode electron source comprises:

a substrate;

a bottom cathode electrode and a plurality of bottom segment ring gate electrodes fabricated on said substrate; the bottom part section annular grid electrodes are arranged around the bottom cathode electrode and are not connected with the bottom cathode electrode;

an insulating layer overlying the bottom segmented ring gate electrode and the bottom cathode electrode;

etching through holes which respectively expose partial parts of the bottom section annular grid electrode and the bottom cathode electrode in the insulating layer are manufactured, and at least one etching through hole is formed in the bottom section annular grid electrode;

a top cathode electrode and a top annular gate electrode formed on the insulating layer; the top cathode electrode is connected with the bottom cathode electrode through the etching through hole; the top annular grid electrode surrounds the top cathode electrode and is not connected with the top cathode electrode; the top annular grid electrode is respectively connected with the bottom section annular grid electrode through etching through holes, so that the bottom section annular grid electrodes are connected in series;

a growth source film is manufactured on the top cathode electrode;

and manufacturing a nanowire cold cathode on the growth source film.

2. The double-ring grid structure nanometer cold cathode electron source of claim 1, wherein the number of the bottom subsection ring-shaped grid electrodes is 3; the top annular grid electrode is respectively connected with the bottom section annular grid electrode through at least 3 etching through holes.

3. The nano cold cathode electron source with the double-ring grid structure of claim 1, wherein the nano wire cold cathode is a zinc oxide nano wire, a copper oxide nano wire, a tungsten oxide nano wire, a molybdenum oxide nano wire, an iron oxide nano wire, a titanium oxide nano wire or a tin oxide nano wire.

4. The double-ring grid structure nanometer cold cathode electron source of claim 1 or 2, wherein the thickness of the growth source thin film is in the range of 0.3 μm to 5 μm; the distance between the adjacent growth source films is 0.1-10 times of the diameter or the side length.

5. The double-ring grid structure nanometer cold cathode electron source of claim 1, wherein the growth source film is in a shape of a symmetrically operable pattern, and the diameter or side length of the growth source film is 5 μm-500 μm.

6. The double-ring grid structure nanometer cold cathode electron source of claim 1, wherein the bottom segment ring-shaped grid electrode, the bottom cathode electrode, the top ring-shaped grid electrode and the top cathode electrode are provided with conductive films, and the thickness of the conductive films ranges from 0.1 μm to 2 μm.

7. The preparation method of the nano cold cathode electron source with the double-ring grid structure as claimed in claim 1 is characterized by comprising the following steps:

s1, manufacturing a bottom cathode electrode and a bottom segment annular gate electrode on the substrate;

s2, covering an insulating layer on the bottom cathode electrode and the bottom section annular grid electrode;

s3, etching the insulating layer, and manufacturing etching through holes on the bottom cathode electrode and the bottom section annular grid electrode;

s4, manufacturing a top cathode electrode connected with the bottom cathode electrode strip on the etched through hole, and manufacturing a top annular grid electrode connected with the bottom section annular grid electrode;

s5, depositing a growth source film;

and S6, thermally oxidizing the growth source film to grow the nanowire cold cathode.

8. The method according to claim 7, wherein the thermal oxidation in step S6 includes a temperature rise process and a temperature maintenance process, and a temperature rise rate of the temperature rise process is 1 ℃/min to 30 ℃/min; the heat preservation temperature in the heat preservation process is 300-600 ℃, the heat preservation time is 1-600 min, and the natural cooling is carried out to the room temperature after the heat preservation is finished.

9. The method according to claim 8, wherein Ar and H are introduced during the temperature raising and maintaining steps of the thermal oxidation₂、N₂、O₂One or two or more of the combined gases.

10. A nano cold cathode electron source array with a double ring grid structure is characterized by being composed of the nano cold cathode electron source with the double ring grid structure according to any one of claims 1 to 6.

Technical Field

The invention relates to the technical field of vacuum microelectronic devices, in particular to a nano cold cathode electron source with a double-ring grid structure and a manufacturing method thereof.

Background

Chinese patent ZL201610542509.8, entitled nanowire cold cathode electron source array with self-aligned focusing structure and manufacturing method thereof, wherein a top cathode electrode and a top grid electrode film are prepared and deposited to form a film of electrodes, and are connected with a bottom cathode electrode strip and a bottom cathode grid strip through etching through holes; chinese patent ZL201711063201.6, entitled coplanar focusing nano cold cathode electron source array capable of addressing in rows and columns and its manufacturing method, discloses that bottom cathode electrode strips and bottom cathode grid strips are vertically arranged on a substrate, a focusing electrode and a control grid are manufactured on the same plane, and the manufactured device has the function of addressing in rows and columns by a through hole bridging method. However, the bottom gate electrode bars in the above two structures of the nano cold cathode electron source only play a role of electrical connection, so that only a single planar control gate structure is provided, and in practical application, the problems of poor gate control characteristics, low field emission current of the nano cold cathode, and high driving voltage exist. If the field emission current is further increased and the regulation and control effect on the cold cathode current is enhanced on the basis of the structure, a plurality of control grids need to be manufactured, and the problems of high manufacturing difficulty, high cost and incapability of large-area manufacturing exist.

Disclosure of Invention

The invention aims to provide a nano cold cathode electron source with a double-ring grid structure. The nanometer cold cathode electron source has strong grid control electron emission capability and a double-ring grid structure capable of column addressing. The top annular grid electrode and the bottom section annular grid electrode are connected by the etching through hole, a double-ring grid structure of the bottom annular grid electrode and the top annular grid electrode is realized, the grid control characteristic of the device is greatly improved, and therefore the field emission current is effectively increased, and the regulation and control effect on the cold cathode current is enhanced.

The invention also aims to provide a method for manufacturing the nano cold cathode electron source with the double-ring grid structure. The nanometer cold cathode electron source manufactured by the method realizes a double-ring grid structure, namely control of a plurality of grids, so that the double-ring grid structure is simple to manufacture, the cost is reduced, and large-area manufacturing is realized.

In order to solve the technical problems, the invention adopts the technical scheme that:

a nanometer cold cathode electron source with a double ring grid structure comprises the following components in part by weight:

a substrate; a bottom cathode electrode and a plurality of bottom segment ring gate electrodes fabricated on said substrate; the bottom part section annular grid electrodes are encircled around the bottom cathode electrode and are not connected with the bottom cathode electrode; an insulating layer overlying the bottom segmented ring gate electrode and the bottom cathode electrode; etching through holes which respectively expose partial bottom section annular grid electrodes and partial bottom cathode electrodes in the insulating layer are manufactured, and at least one etching through hole is respectively arranged on at least two bottom section annular grid electrodes; a top cathode electrode and a top annular gate electrode formed on the insulating layer; the top cathode electrode is connected with the bottom cathode electrode through the etching through hole; the top annular grid electrode surrounds the top cathode electrode and is not connected with the top cathode electrode; the top annular grid electrode is respectively connected with the bottom section annular grid electrode through etching through holes, so that the bottom section annular grid electrodes are connected in series; a growth source film is manufactured on the top cathode electrode; and manufacturing a nanowire cold cathode on the growth source film.

To achieve the bottom segment ring gate, at least two of the bottom segment ring gate electrodes have at least one etched via.

Among the plurality of bottom segment ring gate electrodes, each bottom segment ring gate electrode corresponds to two or more etched vias to improve conductivity.

Etching the through hole by introducing the bottom section annular grid electrode to expose the bottom section annular grid electrode and the bottom cathode electrode partially; the top annular grid electrode is arranged on the insulating layer and surrounds the top cathode electrode and is not connected with the top cathode electrode, the top annular grid electrode and the bottom annular grid electrode are connected through the etching through hole, series connection of the bottom annular grid electrode is achieved, the bottom annular grid electrode is formed and connected into a circular ring, and a double-ring grid structure is achieved.

The principle is as follows: the cold cathode emits electrons from the tip through an external electric field, and voltage is applied to the bottom section annular grid electrode and the top section annular grid electrode. The top annular grid electrode and the bottom section annular grid electrode are connected through the etching through holes, so that a double-ring grid structure of the bottom annular grid electrode and the top annular grid electrode, namely a plurality of control grid electrodes, is realized, the grid control characteristic of the device is greatly improved, the field emission current is effectively increased, and the regulation and control effect on the cold cathode current is enhanced.

Further, the number of the bottom segment annular gate electrodes is 3; the top annular grid electrode is respectively connected with the bottom section annular grid electrode through at least 3 etching through holes.

Furthermore, a plurality of the growth source films are arranged on the top cathode electrode, and the nanowire cold cathode is a zinc oxide nanowire, a copper oxide nanowire, a tungsten oxide nanowire, a molybdenum oxide nanowire, an iron oxide nanowire, a titanium oxide nanowire or a tin oxide nanowire.

Further, a plurality of the growth source thin films are arranged on the top cathode electrode in an array form.

Further, the growth source film is prepared from any one of zinc, copper, tungsten, molybdenum, iron, titanium and tin, and the thickness of the growth source film ranges from 0.3 mu m to 5 mu m; the distance between the adjacent growth source films is 0.1-10 times of the diameter or the side length. Maintaining this distance facilitates subsequent thermal oxidation growth of the nanowires.

Further, the shape of the growth source thin film is a symmetrically operable pattern, the diameter or side length of the pattern is 5 μm-500 μm, and the shape can be circular, annular or polygonal. The symmetrical pattern facilitates experimental manufacture.

Further, the substrate is composed of one or more of silicon wafer, glass, quartz glass or ceramic substrate. Silicon wafers, glass, quartz glass or ceramic substrates are large-area materials.

Further, conductive thin films are arranged on the bottom part segmented annular grid electrode, the bottom cathode electrode, the top annular grid electrode and the top cathode electrode, the conductive thin films are prepared by one or more of Cr, Al, Ti, Cu, ITO, IZO, AZO, FTO and LTFO, and the thickness range of the conductive thin films is 0.1-2 μm. The conductive film is prepared by a magnetron sputtering method, ultraviolet photoetching and etching processes.

Further, the insulating layer is made of any one or a combination of silicon dioxide, silicon nitride or aluminum oxide, including silicon oxide, silicon nitride or aluminum oxide, and the thickness of the insulating layer is 1-5 μm.

The invention also aims to provide a preparation method of the nano cold cathode electron source with the double-ring grid structure, which comprises the following steps:

s1, manufacturing a bottom cathode electrode and a bottom segment annular gate electrode on the substrate; the thickness of the bottom cathode electrode and the bottom segment ring-shaped gate electrode is preferably 0.1 μm-2 μm.

S2, covering an insulating layer on the bottom cathode electrode and the bottom section annular grid electrode; the thickness of the insulating layer is preferably 1 μm to 5 μm.

S3, etching the insulating layer, and manufacturing etching through holes on the bottom cathode electrode and the bottom section annular grid electrode;

s4, manufacturing a top cathode electrode connected with the bottom cathode electrode strip on the etched through hole, and manufacturing a top annular grid electrode connected with the bottom section annular grid electrode; the thickness of the top cathode electrode and the top ring-shaped gate electrode is preferably 0.1 μm-2 μm.

S5, depositing a growth source film; the growth source film can be deposited by magnetron sputtering, vacuum thermal evaporation, electron beam evaporation or chemical vapor deposition. The thickness of the growth source film is preferably 0.3-5 μm;

and S6, thermally oxidizing the growth source film to grow the nanowire cold cathode.

The bottom cathode electrode forms electrodes arranged in a column direction, the bottom section annular grid electrode forms electrodes arranged in a row direction under the connecting action of the top annular grid electrode, and the bottom cathode electrode and the bottom section annular grid electrode can be perpendicular to each other on the same plane through the sectional design of the bottom annular grid electrode, so that an electron source array formed by the electron sources has row and column addressing capability.

Further, the thermal oxidation method in the step S6 includes a temperature rise process and a heat preservation process, wherein a temperature rise rate of the temperature rise process is 1 ℃/min to 30 ℃/min; the heat preservation temperature in the heat preservation process is 300-600 ℃, the heat preservation time is 1-600 min, and the product is naturally cooled to the room temperature after the heat preservation is finished.

The process of growing the nanowire cold cathode by the thermal oxidation method is carried out in a box furnace or a tube furnace.

Further, Ar and H are introduced in the temperature rise process and the heat preservation process of the thermal oxidation₂、N₂、O₂One or two or more of the combined gases. The growth of the nanowires such as zinc oxide, copper oxide, tungsten oxide, molybdenum oxide, iron oxide, titanium oxide or tin oxide is related to the oxygen concentration, so that the growth of the nanowires can be controlled by introducing gas to change the oxygen concentration.

Compared with the prior art, the invention has the beneficial effects that:

according to the nanometer cold cathode electron source, the bottom annular grid electrode and the top annular grid electrode are connected through the top annular grid electrode and the etching through hole, so that a double-ring grid structure of the bottom annular grid electrode and the top annular grid electrode is realized, the grid control characteristic of the device is greatly improved, the field emission current is effectively increased, the regulation and control effect on the cold cathode current is enhanced, and the purposes of reducing the driving voltage and increasing the emission current are achieved.

In addition, as the grid electrodes and the cathode electrode leads are arranged on the bottom layer in a staggered manner, the addressing function of the device is realized, the complicated electrode lead arrangement on the top layer is obviously reduced, the possibility of electrode edge discharge is reduced, the stable work of the device is facilitated, and the application of the device in a field emission flat panel display and a flat panel X-ray source is widened.

According to the invention, the bottom section ring grids are connected into a circular ring through the matching of the top grid electrode and the etched through hole, and the nano cold cathode electron source manufactured by the method realizes a double-ring grid structure while ensuring the electrical connection, so that the double-ring grid structure is simple to manufacture, the cost is reduced, and the large-area manufacture is realized.

The invention is a passive device, only needs to be controlled by an electric field, does not need an additional external power supply for power supply, and has simpler structure and convenient manufacture.

Drawings

FIG. 1 is a schematic cross-sectional view of a nano cold cathode electron source with double ring grid structure according to the present invention;

FIG. 2 is a schematic diagram of the bottom electrode arrangement of the nano cold cathode electron source with three etched through holes according to the present invention;

FIG. 3 is a schematic structural diagram of a nano cold cathode electron source with a double ring grid structure according to the present invention;

FIGS. 4(a) - (f) are flow charts of the manufacturing process of the double-ring grid structure nano cold cathode electron source;

FIG. 5 is a schematic diagram of the bottom electrode arrangement of the nano-scale cold cathode electron source array with three etched through holes according to the present invention;

FIG. 6 is a schematic structural diagram of a nano cold cathode electron source array with a double ring grid structure according to the present invention;

FIG. 7 is a schematic diagram of the arrangement of the bottom electrodes of the nano-scale cold cathode electron source in the comparative example;

description of the reference numerals

The structure comprises a substrate 1, a bottom section annular gate electrode 2, a bottom cathode electrode 3, an insulating layer 4, an etched through hole 5, a top annular gate electrode 6, a top cathode electrode 7, a growth source film 8, a nanowire cold cathode 9, a gate electrode connecting line 10, a cathode electrode connecting line 11, a focusing electrode 81, a bottom gate electrode strip 21 and a top gate electrode 61.

Detailed Description

The present invention will be further described with reference to the following embodiments.