JPH02139843A - Electric field radiational type three-polar element and its manufacture - Google Patents

Abstract

PURPOSE:To equip a three-polar element with stability, higher density, and high degree of integration by installing a cathode, anode, and gate of a three-polar element of electric field radiation type oriented transversely in the same plane on an insulative base board. CONSTITUTION:If a cathode (C) 4 is grounded and a positive potential of 5-10V is impressed to an anode (A) 8, an electric field with steep potential slope is generated in a space as narrow as 50Angstrom wide between the sharp point of an electron gun 6 of C4 and the A6, and electrons of C4 go from the gun 6 through a potential barrier with small width according to the tunnel effect of the quantum mechanics and undergo electric field emission to the outside to then reach A8. Thus an electron stream at a very high speed flows from C4 to A8. A gate (G) 10 installed as pinching the sharp point of the gun 6 controls the electron stream flowing from C4 to A8 according to the voltage impressed. This allows performing of transistorial operations very quickly to achieve high degree of integration of the elements, which are put in rows and columns in a great number, and high density is accomplished by it along with provision of C4, A8, G10 in transverse arrangement in the same plane on an insulation base board 2.

Description

[Detailed Description of the Invention] [Summary] Regarding the three major field emission type elements, particularly regarding the field emission type triode element suitable for integration, the cathode, gate, and anode are separated by an extremely small gap and each element is Field emission type 3, which can be uniformly formed to achieve stable characteristics and high density, as well as easy wiring between elements to achieve high integration.
The object of the present invention is to provide a pole element and a method for manufacturing the same, comprising: a cathode formed on an insulating substrate and having a pointed end whose orientation direction is substantially parallel to the surface of the insulating substrate; , an anode provided facing the tip of the cathode, and a gate formed on the insulating substrate between the cathode and the anode to control the flow of electrons from the cathode to the anode. Configure to have.

[Industrial Field of Application] The present invention is a field emission type 3N! The present invention relates to an element and a flattening method thereof, and particularly to a field emission type triode element suitable for integration and a method for manufacturing the same.

[Prior Art] Generally, when giving electrons energy greater than the potential barrier and emitting the electrons from a solid to the outside, the method is as follows:
These include thermionic radiation, photoelectron radiation, and field radiation.

Among these, field emission occurs when the electric field strength increases at the surface of the cathode (cathode), the width of the potential barrier becomes thinner, and electrons within the solid escape through the potential barrier due to quantum mechanical tunneling effect and are emitted to the outside. Electric field is radiated. Utilizing this field emission, elements that operate like transistors have been fabricated.

In the conventional device using electric field radiation, as shown in FIG. 4, the cathode 26 provided on the insulating substrate 24 is
It has an electron gun 28 whose tip is perpendicular to the insulating substrate 24. A gate 32 is provided on the flat part of the cathode 26 with an insulating layer 30 interposed therebetween, and surrounds the tip of the electron gun 28 of the cathode 26 . Further, an anode (anode) 34 is provided above the tip of the electron gun 28 of the cathode 26 with a certain space in between.

In this way, by arranging a large number of field emission type tripole elements each having three electrodes, the device is integrated.

However, in an integrated circuit in which a large number of such field emission type triode elements are arranged, the cathode 26, the gate 32, and the anode 34 are arranged perpendicularly to the insulating substrate 24. electron gun 2
The gate 32 around the apex of the device 8 and the anode 34 on the top surface had to be formed uniformly for each device with extremely small gaps between them, which was technically extremely difficult.

Furthermore, when configuring a multi-stage logic circuit using such field emission type three-pole elements, for example, a large number of signal lines must be wired between the anode 34 on the upper surface and the cathode 26 on the lower surface in the wiring between the elements. Not only was it time-consuming, but it was also technically difficult.

[Problems to be Solved by the Invention] As described above, in the above-mentioned conventional field emission type triode integrated circuit, the cathode on the bottom surface, the gate around the tip of the electron gun of this cathode, and the anode on the top surface. It is technically extremely difficult to form these with extremely small gaps in the direction perpendicular to the substrate and to form them uniformly for each element. In addition, in the wiring between the conventional field emission type triode elements described above, wiring a large number of signal lines between the anode 12 on the top surface and the cathode 6 on the bottom surface in a direction perpendicular to the substrate not only requires a lot of man-hours. , it was also technically difficult.

Therefore, the above-mentioned conventional field emission type triode element integrated circuit is as follows:
There has been a problem in that it is difficult to make the characteristics of all elements uniform and stable, and to achieve high density and high integration.

Therefore, the present invention realizes stable characteristics and high density by forming cathodes, gates, and anodes uniformly for each element with extremely small gaps between them, and also facilitates wiring between elements. It is an object of the present invention to provide a field emission type triode element that can achieve high integration and a method for manufacturing the same.

Further, a first step of forming a conductive layer on the insulating substrate,
a cathode formed by selectively etching the conductive layer and having a tip whose orientation direction is substantially parallel to the surface of the insulating substrate; an anode facing the tip of the cathode; and a gap between the cathode and the anode. and a second step of forming a gate disposed in the cathode to control the flow of electrons from the cathode to the anode.

[Means for Solving the Problems] The above-mentioned problems include: a cathode formed on an insulating substrate and having a tip whose orientation direction is substantially parallel to the surface of the insulating substrate; an anode provided facing the tip of the cathode; and a gate formed on the insulating substrate between the cathode and the anode to control the flow of electrons from the cathode to the anode. This is achieved by a field emission type triode element characterized by the following.

[Function] That is, the present invention arranges the cathode, anode, and gate of a field emission type triode element horizontally in the same plane on an insulating substrate, thereby allowing the cathode, gate, and anode to be spaced with extremely small gaps. It is possible to uniformly form each element with a distance between them, and also to easily perform wiring between elements.

[Example] The present invention will be specifically described below based on an illustrative example.

FIGS. 1(a) and 1(b) are a plan view showing a field emission type triode element according to an embodiment of the present invention, and FIG.
-A sectional view.

For example, the cathode 4 provided on the insulating substrate 2 made of silicon, GaAs, silicon oxide film on silicon, silicon oxide film, sapphire, etc. that does not contain many impurities, has an orientation direction that is similar to that of the insulating substrate 2. It has an electron gun 6 having a wedge-shaped tip that is substantially parallel to the plane. The wedge-shaped tip of the electron gun 6 serves as an electron emission part.
It is sharp with a radius of curvature of 100A or less.

Similarly, on the insulating substrate 2, an electron gun 6 of the cathode 4 is placed.
An anode 8 is provided with a space of width 50A separated from the tip in the direction of directivity of the tip. Furthermore, a gate 10 is provided on the same insulating substrate 2 between the cathode 4 and the anode 8 so as to sandwich the tip of the electron gun 6 of the cathode 4 .

And these cathode 4, anode 8 and gate 10
The three electrodes each consist of a 100-layer conductive layer,
For example, platinum (Pt), gold (Au), palladium (Pd)
It may be a metal layer made of a noble metal such as, a silicon layer to which an impurity is added, or a silicon layer coated with the noble metal film mentioned above on the silicon surface.

Further, an eraser 12 is formed on the surface of the insulating substrate 2 near the tip of the electron gun 6 of the cathode 4, and the electron I of the cathode 4 is
The tip of a6, the part of the anode 8 that is the shortest to the tip of the electron gun 6, and the edge of the gate 1o that is the shortest to the tip of the electron gun 6 are each at a constant 7 with respect to the insulating substrate 2. It is provided with a gap. This is to increase the radiation efficiency of electrons emitted from the tip of the electron gun 6 of the cathode 4.

Also, the space between the cathode 4, anode 8, and gate 10 is, for example, in a vacuum state, or
Alternatively, it is filled with an inert gas such as helium (He), argon (Ar), or neon (Ne).

This is to prevent the electrons emitted from the tip of the electron gun 6 of the cathode 4 from colliding with gas molecules in the space between the cathode 4 and anode 8, or to prevent the gas molecules from colliding even if they collide. This is to prevent ionization6;
In this way, the cathode 4 is kept in a state where it is not ionized by the electrons emitted from the tip of the electron gun 6.

Next, the operation will be described.

Now, when the cathode 4 is grounded and a positive voltage of 5 to 10 V is applied to the anode 8, in the extremely narrow space of 50 people in width between the sharp tip of the electron gun 6 of the cathode 4 and the anode 8, the potential An electric field with a steep gradient is generated, and the cathode 4
The electrons reach the cathode 4 due to mechanical tunneling effect.
The electron beam exits from the sharp tip of the electron gun 6 through the thin potential IIa wall, radiates an electric field to the outside, and reaches the anode 8. In this way, a very high speed electron current flows from the cathode 4 to the anode 8.

Further, a gate 10 provided between the cathode 4 and the anode 8 so as to sandwich the tip of the electron gun 6 of the cathode 4 allows the electron flow to flow from the cathode 4 to the anode 8 by a voltage applied to the gate 10. control.

In this way, the three electrodes of cathode 4, anode 8, and gate 10 can perform transistor-like operations at extremely high speed.

Furthermore, by arranging a large number of such field emission type triode elements, it is possible to form, for example, an integrated circuit constituting a multi-stage logic circuit. At this time, in the field emission type triode element according to this embodiment, since the cathode 4, anode 8, and gate 10 are arranged horizontally in the same plane on the insulating substrate 2, complicated wiring between the elements can be easily performed. can be done.

Next, a method of manufacturing a field emission type triode element according to an embodiment of the present invention will be explained using the process diagram shown in FIG.

Form the eraser 14 at a predetermined location on the insulating substrate 2 (second
Figure (see a>). Subsequently, a filler 16 such as aluminum (Aj), for example, is filled into the tube 14 so that the insulating substrate 2 and the filler 1.6 form one flat surface. Note that this filler 16 is AJ! Any material may be used as long as it has the strength to form a conductive layer thereon in a later step and can be easily removed without damaging the conductive layer (see Figure 2).
b)).

Then, on the insulating substrate 2 and the filler 16, a layer with a thickness of 10
After forming a conductive layer 18 to 0 (see FIG. 2(C)) and then coating a resist 20 on this conductive layer 18,
It is patterned into a predetermined shape by phosphorography using an electron beam.

The pattern of this resist 20 is similar to that of the cathode formed in a later step, as shown in the plan view of FIG. 1(a).
This pattern corresponds to the shape and arrangement of the anode and gate (see FIG. 2(d)).

Next, the conductive layer 18 is etched using the resist 20 as a mask to form the cathode 4, anode 8, and gate 10. At this time, the cathode 4 has an electron gun 6 having a sharp tip with a radius of curvature of 300A or less, and the width between the tip of the electron gun 6 of the cathode 4 and the anode 8 located in the pointing direction of this tip. 50 people, and gate 10 has cathode 4 between cathode 4 and anode 8.
are arranged so as to sandwich the tip of the electron gun 6. Furthermore, the tip of the electron gun 6 of the cathode 4, a part of the anode 8 that is the shortest to the tip of the electron gun 6, and the end of the gate 10 that is the shortest to the tip of the electron gun 6 are filled with filler. 1
6 (see FIG. 2(e)).

Next, the filler 16 is removed and the column 12 is formed again.

This groove 12 allows the tip of the electron gun 6 of the cathode 4 to
A part of the shortest anode 8 at the tip of the electron gun 6,
And the end of the gate 10 that is the shortest to the tip of the electron gun 6 is
Each of them is provided with a certain gap from the insulating substrate 2 (see FIG. 2(f)).

Next, although not shown, a large number of field emission types 3 are arranged.
Complex wiring between elements of a pole element can be easily performed to form an integrated circuit constituting, for example, a multi-stage logic circuit. Then, the space between the cathode 4, anode 8, and gate 10 is ionized by electrons emitted from the tip of the electron gun 6 of the cathode 4, for example, by making it a vacuum state or filling it with an inert gas. will not be kept confidential.

As described above, according to the method for manufacturing a field emission type triode element according to this embodiment, since the phosphorography technique using an electron beam is used, the electron gun 6 of the cathode 4 has a tip with an extremely small radius of curvature. The dimensions of the electron gun 6 and the minute width between the tip of the electron gun 6 of the cathode 4 and the anode 8 can be made fine and precise, and these dimensions can be made uniform among the elements. Therefore, the field emission type 3Igi that operates at ultra-high speed! It is possible to realize higher density of the element and to stabilize the characteristics.

Further, since the cathode 4, anode 8, and gate 10 are horizontally arranged and formed in the same plane on the insulating substrate 2, complicated wiring between elements can be easily performed.

Therefore, the integrated circuit of the field emission type triode element can be highly integrated.

In the method for manufacturing a field emission type triode element according to this embodiment, a filler 16 is filled in a groove 14 formed on an insulating substrate 2, and a cathode 4, an anode 8, and a gate 10 are formed thereon. After that, the filler 16 is removed again to form the filler 12, but after forming the cathode 4, anode 8, and gate 10 on the insulating substrate 2 without forming the first filler 14. , resist coating and buttering are performed, and the cathode 4 and anode 8 are
, a method may be used in which etching is performed using the gate 10 and this resist as a mask to form the gate 12.

Next, a field emission type triode element according to another embodiment of the present invention and a method for manufacturing the same will be described with reference to FIG.

FIGS. 3(a) and 3(b) are a plan view and a sectional view taken along the line B--B of a field emission type triode element according to another embodiment of the present invention, respectively.

A silicon layer doped with impurities and having a crystal axis <100> is used as the conductive layer 18 in the above embodiment shown in FIG. When forming the cathode, anode, and gate, the cathode is first formed into an island-like square silicon layer.
When etched with an anisotropic alkaline etching solution containing OH, the (111) plane is exposed on the side surface of the square silicon layer, forming a truncated pyramidal silicon layer, as shown in FIG. The bottom corner of the truncated pyramid of this silicon layer is used as the tip of the cathode electron gun.

That is, in FIG. 3, a cathode 22 made of a truncated pyramid-shaped silicon layer provided on an insulating substrate 2 has an electron gun whose tip is the corner of the bottom surface of the truncated pyramid. An anode 8 is provided in the pointing direction of the tip of the electron gun of the cathode 22, separated from the tip by a space of width 50A,
Further, between the cathode 22 and the anode 8, the cathode 22
A gate 10 is provided to sandwich the tip of the electron gun.

In such a field emission type triode element, since the tip of the electron gun of the cathode 22 is pointed in the shape of a triangular pyramid, the tip of the electron gun 6 of the cathode 4 in the above embodiment is pointed in the shape of a wedge. The radiation efficiency of electrons emitted from the tip of the electron gun of the cathode 22 is higher than that of the above embodiment.

In this embodiment, a silicon layer is used as the cathode 22, but the surface of this silicon is coated with Pt, Al, etc.
A material coated with a noble metal film such as u or Pd may also be used.

[Effects of the Invention] As described above, according to the present invention, by arranging the cathode, the anode, and the gate of the field emission type 3N2 element laterally within the same plane on the insulating substrate, the cathode, the gate, and the anode can be formed with extremely small gaps between them, and wiring between elements can be easily performed.

This makes it possible to stabilize the characteristics of the field emission type triode element that operates at ultra-high speed, and to achieve higher density and higher integration.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a field emission type triode element according to an embodiment of the present invention, FIG. 2 is a process diagram showing a method for manufacturing a field emission type triode element according to an embodiment of the present invention, and FIG. FIG. 4 is a diagram showing a field emission type triode element according to another embodiment of the present invention. FIG. 4 is a diagram showing a conventional field emission type triode element. 8.34... Anode, 10.32... Gate, 12, 14... Groove, 16... Filler, 18... Conductive layer, 20...Resist, 30...Insulating layer. In the figure, 2.24...Insulating substrate, 4.22.26...Cathode, 6.28...
...An example of an electron gun, z book x Ming! 1. Thickening showing a field emission type three-pole element 1 Figure 12' Figure 3 showing a field emission type three-layer element according to another embodiment of the present invention. figure

Claims (1)

[Scope of Claims] 1. A cathode formed on an insulating substrate and having a pointed end whose orientation direction is substantially parallel to the surface of the insulating substrate; and a pointed end of the cathode formed on the insulating substrate. and a gate formed on the insulating substrate between the cathode and the anode to control the flow of electrons from the cathode to the anode. Field emission type triode element. 2. In the device according to claim 1, a groove is formed in the insulating substrate below the tip of the cathode, and the tip of the cathode is provided with a predetermined gap from the insulating substrate. A three-pole element characterized by 3. The device according to claim 1 or 2, characterized in that a space between the cathode, the anode, and the gate is kept confidential so that it is not ionized by electrons emitted from the cathode. type three-pole element. 4. A first step of forming a conductive layer on an insulating substrate; selectively etching the conductive layer to form a cathode having a tip whose orientation direction is substantially parallel to the surface of the insulating substrate; A second step of forming an anode facing the tip of the cathode and a gate disposed between the cathode and the anode to control the flow of electrons from the cathode to the anode. A method for manufacturing a field emission type triode element. 5. The method of manufacturing a field emission type triode element according to claim 4, further comprising the step of forming a groove in the insulating substrate below the tip of the cathode.