WO2000079556A1

WO2000079556A1 - Emitter, emitter fabricating method, and cold electron emitting device fabricating method

Info

Publication number: WO2000079556A1
Application number: PCT/JP2000/004114
Authority: WO
Inventors: Tetsuya Norikane; Koichi Hiranaka; Naoki Wada; Yasuyo Sato
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 1999-06-24
Filing date: 2000-06-23
Publication date: 2000-12-28
Also published as: TW469463B; CN1318203A; KR20010072923A; ID27523A

Abstract

A cold electron emitting device comprising an emitter fabricated by etching a columnar polycrystalline film (2) formed by growing columnar crystal grains (4) along the same crystal axis on a substrate (1). Even if multiple emitters are fabricated in such a cold electron emitting device, the uniformness of the shapes of the emitters is of good reproducibility, and the variation of electron emitting characteristic due to variation of the shapes of emitters is little, thereby fabricating a cold electron emitting device having a uniform emitting characteristic and formed on a large-area substrate.

Description

TECHNICAL FIELD The present invention relates to an emitter, a method of manufacturing an emitter, and a method of manufacturing a cold electron emitting device.

The present invention relates to a cold electron emission emitter used as an electron source for various electron beam utilizing devices such as a flat panel image display device, various sensors, a high frequency oscillator, an ultra-high speed device, an electron microscope, and an electron beam exposure device. And a method of manufacturing the same. Background art

Conventional electron sources for cold electrons, such as field emission display devices, use a large number of conical microemitters with a height and a bottom diameter of around 1 / m formed on the cathode side. Have been. The emitter emits an emission current by concentrating an electric field at its tip. This basic structure is known by a method proposed by CA Spint et al. (Journal of Applied Physics, Vol. 47, No. 12, p. 5248, 1976). . Since the electron emission characteristics fluctuate depending on the shape of the emitter tip, in order to make the electron emission characteristics equal in each emitter, the shape of many emitters, especially the tip shape, must be uniform. It is desired to be formed.

The biggest problem with this emitter is that the amount of electron emission fluctuates over time. The method of manufacturing an emitter to solve this problem is roughly divided into the following two methods.

One is to form a metal emitter on a glass substrate and connect a large electrical resistance in series with this emitter to stabilize the emission current. Another method is to form a transistor with an emitter using a semiconductor, and to actively control the amount of emission current using this transistor. Things. This method has low power consumption and high operating speed, and is expected to be developed in the future.

When an emitter is formed using the above semiconductor, the following three types of emitter material films can be considered. One is a single crystal film with no grain boundaries and the crystal orientation is aligned in a fixed direction in every part.Next, a polycrystalline film in which crystal grains with different crystal orientations are gathered, and an amorphous material without a crystal structure Membrane. Among the three types of cold electron emission element materials described above, if a transistor having excellent characteristics is to be formed, it is preferable to use a single crystal film or a polycrystalline film.

When a single crystal film is used, since there is no grain boundary and the crystal orientation is in a fixed direction, the isotropic or anisotropic etching rate of wet etching or reactive ion etching is uniform, It is possible to manufacture emisota with excellent uniformity. However, single crystal films are not practical because they cannot be fabricated on large-area substrates such as glass substrates with high manufacturing costs and low ids.

On the other hand, a polycrystalline film is less expensive to manufacture than a single crystal film, and can be manufactured on a large-scale tomb plate at a low temperature. Suitable for.

FIG. 10 is a cross-sectional view of the conventional polycrystalline film substrate. FIG. 11 is a cross-sectional view of an emitter manufactured using the polycrystalline film of FIG. is there. In FIG. 10, reference numeral 1 denotes a substrate made of, for example, glass or the like, on which a polycrystalline film 14 composed of fine crystal grains 13 having different crystal orientations and grains g is formed. In the polycrystalline film 14, countless grain boundaries exist because crystal grains 13 having various sizes and directions exist on the substrate 1.

An emitter 15 manufactured using the polycrystalline film 14 shown in FIG. 11 is made of a polycrystalline structure composed of fine crystal grains 13 having different crystal orientations and grain sizes on a substrate 1 such as glass. The film 14 can be formed by etching. As described above, in the above-described conventional technology, since the polycrystalline film 14 is formed on the substrate to manufacture the semiconductor device 15, the transistor and the cold electron-emitting device having good characteristics are manufactured at a low process temperature. Therefore, a large-area inexpensive glass substrate can be used. As a result, the manufacturing cost of the emitter 15 can be reduced.

However, the emitter 15 formed using the polycrystalline film 14 has a problem that the electron emission characteristics vary. This is because the crystal grain size of the polycrystalline film subjected to the etching process varies, and the crystal orientation and the crystal orientation plane of each crystal grain are greatly different. The isotropic or anisotropic etching rate differs from crystal grain to grain boundary.

That is, in the conventional polycrystalline film 14, since the isotropic or anisotropic etching speed differs for each crystal grain, as shown in FIG. Countless irregularities are formed, and as a result, the electron emission characteristics vary. Furthermore, reproducibility cannot be obtained in the formation of the emitter 15 by etching. Therefore, it is difficult to form a large number of uniform emitters 15 with good reproducibility on a large-area substrate with such an irregular polycrystalline film 14. Device manufacturing costs will also increase.

The present invention has been made to solve such a problem. Even when a large number of emitters are formed, the uniformity of the shape of the emitter can be obtained with good reproducibility, and the shape of the emitter can be improved. It is an object of the present invention to provide an emitter capable of suppressing variations in electron emission characteristics caused by fluctuations in electron emission, and a method for manufacturing the same. Disclosure of the invention

An emitter according to claim 1 of the present invention is characterized in that columnar crystal grains are formed on a substrate by etching a columnar polycrystalline film grown along the same crystal axis. It is assumed that. This allows Emi Even when a large number of emitters are formed, uniformity of the emitter shape can be obtained with good reproducibility, and variations in the electron emission characteristics due to variations in the emitter shape can be suppressed.

Next, the emitter according to claim 2 of the present invention forms a columnar polycrystalline film in which columnar crystal grains are grown along the same crystal axis on a substrate, and then forms the columnar polycrystalline film on the columnar polycrystalline film. The method is characterized in that the first insulating film is patterned, and the columnar polycrystalline film is etched using the patterned first insulating film. As a result, even when a large number of emitters are formed, uniformity of the emitter shape can be obtained with good reproducibility, and variations in the electron emission characteristics due to variations in the emitter shape can be suppressed.

Next, the emitter according to claim 3 of the present invention forms a second insulating film on the substrate, and grows columnar crystal grains on the second insulating film along the same crystal axis. After forming the columnar polycrystalline film, the first insulating film is patterned on the columnar polycrystalline film, and the columnar polycrystalline film is etched using the patterned first insulating film. It is characterized by forming by applying. As a result, even when a large number of emitters are formed, the uniformity of the emitter shape can be obtained with good reproducibility, and variations in the electron emission characteristics due to variations in the shape of the emitter can be suppressed. . Next, the emitter according to claim 4 of the present invention is the emitter according to any one of claims 1 to 3, wherein the columnar polycrystalline film is formed by: The constituent columnar crystal grains are characterized in that the crystal orientation and the crystal plane are aligned in a certain direction with respect to the substrate surface. As a result, even when a large number of emitters are formed, uniformity of the emitter shape can be obtained with good reproducibility, and variation in electron emission characteristics due to variations in the emitter shape can be suppressed. Can be.

Next, the EMI according to claim 5 of the present invention is the EMI according to any one of claims 1 to 4, wherein the columnar polycrystalline film has at least Both are characterized by containing silicon. this Thus, columnar polycrystals can be realized on a human area substrate by a low-temperature process of 500 ° C. or less. Therefore, columnar polycrystals can be etched in a uniform shape on a large-area substrate, and even when a large number of emitters are formed on a human-area substrate, uniformity of the emitter shape can be obtained with good reproducibility. Variations in the electron emission characteristics caused by variations in the shape of the light source can be suppressed.

Next, the EMI according to claim 6 of the present invention is the EMI according to any one of claims 1 to 5, wherein the orientation of the columnar polycrystalline film is The surface is characterized by being {1 1 0}. As a result, the crystal orientation and the crystal plane can be easily aligned, so that uniform etching can be performed, and the uniformity of the emitter shape can be obtained with good reproducibility. The variation in the electron emission characteristics.

Next, the emitter according to claim 7 of the present invention is the emitter according to any one of claims 1 to 5, wherein the columnar polycrystalline The orientation surface of the film is {100}. As a result, the crystal orientation and the crystal orientation can be easily aligned, so that uniform etching can be performed, the uniformity of the emitter shape can be obtained with good reproducibility, and the variation of the emitter shape can be caused. Variation in electron emission characteristics can be suppressed. Further, the barrier at the crystal grain boundaries can be suppressed: and the trap level formed at the interface with the insulating film can be further reduced. Therefore, the mobility of traveling electrons is increased, and efficient emission can be realized.

Next, the emitter according to claim 8 of the present invention is characterized in that, in the emitter according to any one of claims 1 to 7, the columnar polycrystalline film is etched. In this case, the radius of curvature of the tip of the formed emitter is 50 nm or less. As a result, the electric field concentration at the tip of the emitter can be increased, and electrons can be emitted at a low pressure.

Next, the emitter according to claim 9 of the present invention is the emitter according to any one of claims 1 to 8, The columnar crystal grains constituting the crystal film are characterized in that the shorter grain size of the columnar crystal grains is at least 100 nm or more. As a result, the number of crystal grain boundaries at the tip of the emitter, which may cause variations in etching, is reduced, uniform etching is possible, and uniformity of the emitter shape is obtained with good reproducibility. Variations in electron emission characteristics due to variations in the evening shape can be suppressed.

Next, the emitter according to claim 10 of the present invention is the emitter according to claim 9, wherein the angle formed by the columnar crystal grains and the substrate is 83 ° or more. It is characterized by the following. As a result, the number of crystal grain boundaries at the leading edge of the emitter, which may cause unevenness in etching, is reduced, etching with a more uniform shape is enabled, and uniformity of the emitter shape is obtained with good reproducibility. Variations in electron emission characteristics due to variations in the shape of the emitter can be suppressed.

Next, the emitter according to claim 11 of the present invention is the emitter according to claim 3, wherein the second insulating film is formed of at least oxygen or nitrogen. It is characterized by including. This suppresses the diffusion of impurities from the glass into the columnar polycrystal, provides a columnar polycrystal with excellent crystallinity, and achieves uniformity of the emitter shape with good reproducibility, as well as the emitter shape. Variations in electron emission characteristics due to fluctuations in electron emission characteristics can be suppressed.

Next, the emitter according to claim 12 of the present invention is the emitter according to claim 2 or claim 3, wherein the patterned first insulating film is used. Is characterized by having a circular shape. Thus, by etching the columnar polycrystalline film, a sharp-edged emitter can be easily realized.

Next, the emitter described in claim 13 of the present invention is the emitter described in claim 2 or claim 3, wherein The first insulating film has a polygonal shape. As a result, in addition to the effects of Claims 12 of the present invention, furthermore, The exposure accuracy of the lithography can be improved, and the cost of the exposure mask can be reduced.

Next, the method for manufacturing an emitter according to claim 14 of the present invention includes a step of forming a columnar polycrystalline film in which columnar crystal grains are grown along the same crystal axis on a substrate; And a column for etching the columnar polycrystalline film. As a result, even when a large number of emitters are formed, uniformity of the emitter shape can be obtained with good reproducibility, and variations in the electron emission characteristics due to variations in the emitter shape can be suppressed.

Next, the method for manufacturing an emitter according to claim 15 of the present invention includes a step of forming a columnar polycrystalline film in which columnar crystal grains are grown along the same crystal axis on a substrate; Patterning a first insulating film on the columnar polycrystalline film; and etching the columnar polycrystalline film using the patterned first insulating film. is there. As a result, even when a large number of emitters are formed, uniformity of the emitter shape can be obtained with good reproducibility, and variations in the electron emission characteristics due to variations in the emitter shape can be suppressed.

Next, in the method for producing an emitter according to claim 16 of the present invention, the step of forming a second insulating film on the substrate and the step of forming columnar crystal grains on the second insulating film in the same crystal Forming a columnar polycrystalline film grown along the axis, patterning a first insulating film on the columnar polycrystalline film, using the first insulating film that has been buttered. And etching the columnar polycrystalline film. As a result, even when a large number of emitters are formed, uniformity of the emitter shape can be obtained with good reproducibility, and variations in the electron emission characteristics due to variations in the emitter shape can be suppressed.

Next, the method for producing an emitter according to claim 17 of the present invention is a method for producing an emitter according to any one of claims 14 to 16 of the present invention. Wherein the columnar crystal grains constituting the columnar polycrystalline film correspond to the substrate surface. In addition, the crystal orientation and the crystal plane are aligned in a certain direction. As a result, even when a large number of emitters are formed, the uniformity of the emitter shape can be obtained with good reproducibility, and the variation in the mosquito discharge characteristics due to the variation in the emitter shape can be suppressed.

Next, the method for producing an emitter according to claim 18 of the present invention includes the method for producing an emitter according to any one of claims 14 to 17 and claim 17. In the method, the columnar polycrystalline film contains at least silicon. Thereby, columnar polycrystals are formed on a large area substrate at 500. It can be realized by a low temperature process of C or lower. Therefore, columnar polycrystals can be etched on a large-area substrate in a uniform shape, and even when many emitters are formed on a large-area substrate, uniformity of the emitter shape can be obtained with good reproducibility. Variations in the electron emission characteristics due to variations in the shape of the emitter can be suppressed.

Next, the method for producing an emitter according to claim 19 of the present invention is the method for producing an emitter according to any one of claims 14 to 18, The orientation plane of the columnar polycrystalline film is {110}. As a result, the crystal orientation and the crystal plane are easily aligned, so that uniform etching can be performed, the uniformity of the emitter shape can be obtained with good reproducibility, and the electron emission characteristics due to the fluctuation of the emitter shape can be improved. Variation can be suppressed.

Next, the method for manufacturing an emitter according to claim 20 of the present invention is the method for manufacturing an emitter according to any one of claims 14 to 18. The orientation plane of the columnar polycrystalline film is {100}. As a result, the crystal orientation and the crystal plane are easily aligned, so that uniform etching can be performed, the uniformity of the emitter shape can be obtained with good reproducibility, and the electron emission caused by the fluctuation of the emitter shape can be achieved. Variations in emission characteristics can be suppressed. In addition, obstacles at crystal grain boundaries can be suppressed, and trap levels formed at the interface of the insulating film can be reduced. Therefore, the mobility of the traveling electrons increases and the efficiency increases. It is possible to manufacture new emitters.

Next, the method for producing an emitter according to claim 21 of the present invention includes the method for producing an emitter according to any one of claims 14 to 20. The method is characterized in that the columnar polycrystalline film is etched so that the radius of curvature at the tip of the emitter is 50 nm or less. As a result, the field concentration at the tip of the emitter can be increased, and electrons can be emitted at a low voltage.

Next, the method for producing an emitter according to claim 22 of the present invention is the method for producing an emitter according to any one of claims 14 to 21. The columnar crystal grains in the columnar crystal film are characterized in that the shorter one of the columnar crystal grains has a particle size of at least 100 nm or more. As a result, the number of crystal grain boundaries at the tip of the emitter, which causes variations in etching, is reduced, uniform etching is possible, and uniformity of the emitter shape is obtained with good reproducibility. Variations in electron emission characteristics due to variations in shape can be suppressed.

Next, the method for producing an emitter according to claim 23 of the present invention is the method for producing an emitter according to claim ffl, wherein the angle between the columnar crystal grains and the substrate is Is characterized by being at least 83 °. As a result, the number of grain boundaries at the tip of the emitter, which may cause unevenness in etching, is reduced, the etching is made more uniform, and the uniformity of the emitter is obtained with good reproducibility. Variations in electron emission characteristics due to variations in the shape of the light can be suppressed.

Next, an emitter manufacturing method according to claim 24 of the present invention is the emitter manufacturing method according to claim 16, wherein the second insulating film is at least , Characterized by containing oxygen or nitrogen. This suppresses the diffusion of impurities from the glass into the columnar polycrystals, provides columnar polycrystals with excellent crystallinity, and achieves uniform emitter shape with good reproducibility and changes in emitter shape. It is possible to suppress the variation in the electron emission characteristics caused by this. Next, in the method for producing an emitter according to claim 25 of the present invention, the method for producing an emitter according to claim 15 or claim 16 is provided. The thinned first insulating film has a circular shape. Thus, by etching the columnar polycrystalline film, an emitter having a sharp tip can be easily realized.

Next, the method for manufacturing an emitter according to claim 26 of the present invention is the same as the method for manufacturing an emitter according to claim 15 or claim 16. The patterned first insulating film has a polygonal shape. Thereby, in addition to the effect of the present invention, the exposure accuracy of photolithography can be further increased, and the cost of the exposure mask can be reduced.

Next, a method for manufacturing a cold electron emitting device according to claim 27 of the present invention is provided by the method for manufacturing an emitter according to claim 15 or claim 16. Manufacturing a third insulating layer and an extraction gate electrode while leaving the first insulating film patterned on the columnar polycrystalline film; and Forming an opening by removing only the upper part of the first insulating film patterned in this manner. Thus, the extraction gate electrode can be easily formed without using a photolithography process, and the manufacturing cost of the cold electron emission device can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a columnar polycrystalline substrate according to Embodiment 1 of the present invention.

FIG. 2 is a process cross-sectional view of a method for manufacturing a cold electron emission wire using the columnar polycrystalline substrate shown in FIG.

FIG. 3 is a Raman spectrum of the columnar polycrystalline substrate according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view of a columnar polycrystalline substrate provided with an underlayer according to Embodiment 2 of the present invention. FIG. 5 is a cross-sectional view of a columnar polycrystalline substrate according to Embodiments 3 and 5 of the present invention, in which crystal orientations and crystal planes are aligned in a certain direction.

FIG. 6 is a cross-sectional view of a cold electron emission device according to Embodiment 4 of the present invention.

FIG. 7 is a diagram showing an amount of electrons emitted from a cold electron emission element due to a difference in film structure according to a sixth embodiment of the present invention.

FIG. 8 is an XRD spectrum of a {110} -oriented columnar polycrystalline silicon film.

FIG. 9 is a diagram illustrating the relationship between the electric field intensity applied to the emitter tip and the curvature half S of the emitter tip.

FIG. 10 is a sectional view of a polycrystalline film according to the prior art.

The first is a cross-sectional view of an emitter using a polycrystalline film according to the prior art. BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1)

Hereinafter, Embodiment 1 of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a cross-sectional view of a columnar polycrystalline substrate according to Embodiment 1 of the present invention, and FIG. 2 is a process cross-section of a method of manufacturing an emitter and a cold electron emitting device according to Embodiment 1 of the present invention. FIG.

In FIG. 1, reference numeral 1 denotes a substrate such as glass. 2 is a columnar polycrystalline film. 3 is a crystal grain boundary indicating a boundary between crystal grains. 4 is columnar crystal grains.

Hereinafter, formation of the columnar polycrystalline film 2 will be described. For example, a plasma chemical vapor deposition (PCVD) method using a 0.1% to 3% silane gas diluted with hydrogen gas as a material gas is formed on a substrate 1 such as a glass shown in FIG. Crystals at temperatures from 200 "C to 350 ° C, deposition pressures from 0.1 Pa to 5 Pa, and RF power from 300 W to 1 kW A columnar polycrystalline film 2 is formed, which is a columnar polycrystalline silicon film having a grain size of about 10 ° nm to about 140 nm having the same orientation and crystal plane. The film grown under these conditions is mainly a columnar polycrystalline film 2 having a {110} plane orientation. On a substrate 1 made of glass or the like shown in FIG. When manufactured under the conditions of 0 ° C, film formation pressure l OOP a to 170 Pa, and RF power 50 W to 500 W, a particle size having a {100} plane orientation is mainly about 250 nm. Thus, the columnar polycrystalline film 2 is obtained.

The columnar polycrystalline film 2 having the {110} plane orientation or the {100} plane orientation thus produced is a cold electron emitting element having a uniform-shaped emitter, which is an effect of the present invention. Can be realized.

Although the columnar polycrystalline film 2 includes an amorphous layer, a crystallization ratio which is a ratio included in a unit area of the polycrystal and the amorphous is required to form a uniform emitter. Is preferably 80% or more.

This crystallization ratio can be measured by, for example, Raman spectroscopy. The intensity I (520) of the Raman shift amount of the crystalline phase of about 520 cm- ¹ by Raman spectroscopy and the Raman shift amount of the amorphous phase of 480 The crystallization ratio I (520) / {1 (520) +1 (480)} is shown in relation to the intensity I (480 ⁾ of cm— ^] (see FIG. 3).

Note that, in this embodiment, typical growth conditions are specified, and a specific flow rate, a gas mixture ratio, a substrate temperature, a film forming pressure, an RF power, and the like are specified using a mixed gas containing silicon. The columnar polycrystalline film 2 can be obtained under the growth conditions having the range described above, and the grain size and size can be changed according to the growth conditions.

For example, Fig. 8 shows a plasma chemical vapor deposition (PCVD) method using a mixed gas of silane and hydrogen under the conditions of a substrate temperature of 300 ° C, a deposition pressure of 2 Pa, and an RF power of 300 W. The X-ray diffraction (XRD) spectrum of a representative columnar polycrystalline silicon film is shown. Deposited under the above conditions In the film, a strong beak of 26 was obtained at about 47.4 °, and it was found that the film was oriented in the (2 0 0) plane.

The columnar polycrystalline film 2 oriented on the {100} plane was formed by a PCVD method using a mixed gas of silane gas and silicon tetrafluoride gas at a substrate temperature of 300 ^nC and a film forming pressure of 100 ^nm. FPower: obtained when the film is formed under the condition of FP power 300 W, and a beak of (400) is obtained when the 2β of the XRD spectrum is about 63.2 ° (not shown). ) Appears.

Next, an emitter manufactured using the above-described columnar polycrystalline film 2 and a method for manufacturing a cold electron emitting device will be described with reference to FIG.

After the columnar polycrystalline film 2 is formed on the substrate 1 as described above (FIG. 2 (a)), as shown in FIG. 2 (b), a PCVD method, a sputtering method, an evaporation method, or the like is used. a first insulating film 5, such as S i 0 _2, on the columnar polycrystalline film, each dot is Pas evening-learning so that the circular or polygonal shape. In this patterning, for example, an insulating film is deposited to a thickness of about 200 nm, and the insulating film is processed into a circular or polygonal dot pattern having a diameter of about 1 Aim by a photolithography process. .

After forming the first insulating film 5 having a circular or polygonal shape, the columnar polycrystalline film 2 is processed by reactive ion etching (RIE) as shown in FIG. Evening get 6. As an etching gas, a halogen gas, such as SF _s gas is used if e example.

And have梡, as shown in 2 (d) Fig., To form a drawer gate one Bok electrode 8 such as S i 0 gate one gate insulating layer 7, such as ₂ and N b by vapor deposition or the like. By controlling the thickness of the gate insulating layer 7, the distance between the tip of the emitter 6 and the extraction gate electrode 8 is easily changed, and the electric field is efficiently concentrated on the tip of the emitter 6. As a result, a cold electron-emitting device having good electron emission efficiency can be obtained.

Finally, as shown in FIG. 2 (e), an upper portion is removed from the first insulating film 5 processed into the above-mentioned circular or polygonal dot pattern by a lift-off method, and an opening is formed. In the first embodiment, the default Although the gate insulating layer 7 and the extraction electrode 8 are removed to form the open U portion by the フ method, it can also be formed by the etch back method.

As described above, according to the first embodiment, since the emitter 6 is manufactured by performing etching using the columnar polycrystalline film 2, the crystal orientation and the crystal plane in each columnar crystal grain 4 are formed. Is the same, the isotropic or anisotropic etching rate when wet or reactive ion etching is performed can be made equal in all parts except on the crystal grain boundary 3. Therefore, the emitter 6 can be manufactured with high reproducibility, and uniformity of the shape can be obtained in the emitter 6 formed in a large number over a wide range.

Further, the columnar polycrystalline film 2 contains at least silicon (silicon), specifically, a polycrystalline silicon film or polycrystalline silicon germanium. A columnar polycrystalline film can be formed on an area substrate by a low-temperature process of 500 ° C. or less. Therefore, columnar polycrystals can be etched in a uniform shape on a large-area substrate, and even when a large number of emitters are formed on a large-area substrate, the uniformity of the emitter shape can be obtained with good reproducibility, and Variations in the electron emission characteristics due to variations in the shape of the electron beam can be suppressed.

(Embodiment 2)

Hereinafter, Embodiment 2 of the present invention will be described with reference to FIG. FIG. 4 is a sectional view of a columnar polycrystalline substrate according to Embodiment 2 of the present invention. In addition, the cold-emitting device according to the second embodiment forms a columnar polycrystalline film 2 in which columnar crystal grains are grown along the same crystal axis after forming an insulating film on a substrate. It differs from the cold electron-emitting device according to the first embodiment in which the columnar polycrystalline film 2 is formed without coating the substrate with an insulating film only in the production of the emitter and the cold electron-emitting device. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In FIG. 4, a second insulating film 9 is formed on a glass substrate 1. The process of forming the second insulating film 9 on the glass substrate 1 is performed, for example, by using silane gas and N ₂₀ gas as a material gas, or a mixed gas of TEOS and oxygen. The substrate temperature was from 200 ° C to 300, the deposition pressure was 0.1 Pa to 10 Pa, and the RF power was 300 W to 500 W by PCVD method. _n still deposited 1 0 0 0 nm of the silicon dioxide film S i 0 ₂ from nm, the process of the second insulating film 9 formed later is the same as the above-described first embodiment will be omitted.

As described above, by forming the second insulating film 9 on the substrate 1, diffusion of impurities contained in the substrate 1, for example, boron (poron) or sodium, can be suppressed, and the crystal of the columnar polycrystalline film 2 can be suppressed. Performance can be improved.

Note that the second insulating film 9 is minimum, oxygen or nitrogen is also to a long path and often contains, for example, in addition to the silicon dioxide film S i 0 _2, or or a nitride film S i N _x, nitrous oxide nitride film Alternatively, _n the same effect by using these composite films are obtained

(Embodiment 3)

Hereinafter, Embodiment 3 of the present invention will be described with reference to FIG. FIG. 5 is a cross-sectional view of a columnar polycrystalline film substrate aligned in a certain direction according to Embodiment 3 of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In FIG. 5, the columnar polycrystalline grains 4 are aligned such that the crystal orientation and the crystal plane are in a certain direction with respect to one surface of a certain plate. Reference numeral 10 denotes a crystal orientation indicating the direction of each crystal grain. The crystal ώ is perpendicular to the crystal orientation 10, and a layer having {110} is oriented as で ί Ο.

The alignment of the columnar polycrystalline grains of the columnar polycrystalline film column can be obtained even if the columnar polycrystalline film 2 contains an amorphous phase, if the crystallization ratio is desirably 80% or more. Note that the processes after the formation of the columnar polycrystalline film substrate composed of the columnar polycrystalline grains 4 having the uniform shape are the same as those in Embodiment 1 described above, and a description thereof will be omitted.

As described above, according to the third embodiment, the columnar crystal grains 4 in the columnar crystal film 2 have a structure in which the crystal orientation and the crystal plane are aligned in a certain direction with respect to the substrate 1. , Not only within the same crystal grain, but also The etching isotropic or anisotropic etching speed can be made equal in all the crystal grain regions. Therefore, the emitter can be manufactured with good reproducibility, and the uniformity of the shape can be obtained in a large number of emitters.

(Embodiment 4)

Hereinafter, Embodiment 4 of the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view of an emitter part of a cold electron-emitting device manufactured using columnar polycrystalline film 2 according to Embodiment 4 of the present invention. In FIG. 6, 11 indicates the shorter particle size of the columnar crystal grains. 6 is the emitter, and 12 is the tip of the emitter. In FIG. 6, the same components as those in Embodiment 1 described above are denoted by the same reference numerals, and description thereof will be omitted. Generally, when the radius of curvature of the emitter tip 12 is 50 nm or more, the emitter tip 12 of the emitter gate electrode 8 (see FIG. 2 (e) above) is used. electric field concentration to is not performed efficiently, in order to obtain the electric field intensity 1 0 ⁶ V / mm required for electron emission in the case of silicon, to apply a high voltage of more than 50 V to the extraction gate one preparative electrodes 8 There is a need. Since the drive circuit desirably has a gate voltage of 50 V or less, it is desirable that the radius of curvature of the emitter tip 12 be 50 nm or less.

In general, the field strength of the field emission of silicon is needed more than 1 0 ⁶ V / mm, pull-out applies positive voltage V (V) with respect to E Mi Tsu evening and E Mi jitter and the gate electrode Assuming that the distance to is d and the radius of curvature at the tip of the emitter is r, the electric field strength at the tip of the emitter is expressed by equation (1).

F = 2 V / rLn (2 d / r) (V / mm)-(1) In the above (1), for example, d = 0.5 X 10 0 ¹⁶ (m), V = 60, 80, FIG. 9 shows the relationship between the field intensity F and the radius of curvature of the radius of curvature Emi at the tip of 100 (V). In the figure, the condition of V> 80 V and _r <50 nm must be satisfied to obtain F of 10 ^G V / mm or more. So For, the larger r is, in order to make a 1 0 ⁶ V / mm or more electric field emitter Tsu evening tip, requires extra voltage, conversely, r is small lever, the voltage is low Help me. When a high voltage is required, the driving circuit for controlling the emitter becomes complicated, and the breakdown voltage of the insulating layer below the extraction gate electrode also becomes a problem, resulting in a high cost cold electron emission device. Therefore, an inexpensive low-voltage drive circuit can be provided by setting the tip curvature to 50 nm or less.

By the way, the radius of curvature of the emitter tip 12 can be extremely reduced to 50 nm or less, for example, several nm or less according to reactive etching using ordinary halogen gas or wet etching including hydrofluoric acid. It is very difficult to make the shape as sharp as this, usually about 50 nm. Therefore, by forming the shorter grain size 11 of the columnar crystal grains to be 100 nm or more, a cold electron emitting device having a uniform-shaped emitter can be realized.

In addition, when the radius of curvature of the emitter tip 12 is about 50 nrn, if the shorter grain size 11 of the columnar crystal grains is smaller than 100 nm, the grain boundary The probability (possible) that 3 is located at the emitter tip becomes higher, and the emitter tip 12 having a radius of curvature of about 50 nm will not be formed with good reproducibility due to grain boundaries. .

Furthermore, the crystal grain boundary 3 has many defects, and if the defect is located at the tip 12 of the emitter, the amount of emitted electrons decreases. For the above reasons, the shorter grain size 11 of the columnar crystal grains is preferably formed to be 100 nm or more.

As described above, according to the fourth embodiment, since the shorter particle size 11 of the columnar crystal grains is at least 100 nm or more, the etching is performed at the tip 12 of the emitter. Since there are no crystal grain boundaries having different velocities, it becomes possible to form the emitter end 11 with good reproducibility.

(Embodiment 5)

Hereinafter, the fifth embodiment of the present invention will be described with reference to FIGS. 5 and 2 (e). In FIG. 5, the same components as those in the above-described third embodiment are denoted by the same reference numerals, and description thereof is omitted. In FIG. 5, 10 is a crystal orientation indicating the direction of each crystal grain. Each crystal grain 4 is formed at an angle of 83 ° or more with respect to substrate 1. In order to form an emitter, the thickness of the columnar polycrystalline film 2 having a grain size of at least 0.1 Aim must be at least about 0.8 μm. In order to prevent the existence of crystal grain boundaries having different etching rates as near as possible, tan ' ¹ (0.8 / 0.1) = 83 ° is required. Also, as shown in FIG. 2 (e), when the field is concentrated on the emitter tip 12 and the electrons are extracted, the electrons flow almost perpendicularly to the substrate 1. If the crystal grain is 8 3 against the substrate 1. Below, electrons have to flow to the emitter tip, traversing the grain boundary. On the other hand, when the temperature is 83 ° or more, electrons can flow through the same crystal grain to the tip of the emitter, and do not need to cross a grain boundary with many defects, thereby reducing the emission current.

As described above, according to the fifth embodiment, since each crystal grain 4 is formed at an angle of not less than 83 ° with respect to substrate 1, crystal grains having different etching speeds are formed at the tip of the emitter. There is no field, and the emitter tip 11 can be formed with good reproducibility. Further, a cold electron-emitting device having excellent electron emission characteristics can be obtained.

(Embodiment 6)

Hereinafter, Embodiment 6 of the present invention will be described with reference to FIGS. 1 and 7. In addition, since FIG. 1 has been described in the first embodiment, the description of each component will be omitted.

The crystal plane of the columnar crystal grain 4 was {110} or {100} plane oriented. The {110} plane orientation is achieved by setting the orientation plane of the columnar polycrystalline film 2 to {110} so that the crystal orientation and the crystal plane can be easily aligned, and therefore, a uniform shape etching can be performed. This realizes a cold electron-emitting device having an emitter with excellent uniformity on a large-area substrate.

Furthermore, by setting the orientation plane to {110} or {100} plane orientation, the electrons in the columnar polycrystalline film 2 are transported by the grain boundaries when traveling through the semiconductor layer. The energy barrier of the child motion can be reduced, the mobility can be increased, and as a result, the amount of emitted electrons can be increased and a fast response can be realized.

Also, the {100} plane orientation is used to lower the crystal grain boundary barrier and facilitate the flow of electrons as compared with the {110} plane orientation. This is because the number of carrier traps at the interface between the gate insulating layer and the surface of the semiconducting insulator is smaller than in the {110} plane orientation, and electrons at the interface between the conductor and the insulating layer are more likely to flow. As a result, the mobility is further increased, and as a result, the amount of emitted electrons can be increased and a fast response can be realized.

FIG. 7 shows the measured amount of electrons emitted from an emitter of 1,000 chips due to the difference in crystal structure, which was implemented in the present invention. However, the voltage applied to the extraction gate electrode is the same. In Fig. 7, when the emitter is formed with the {110} columnar polycrystalline film 2, the amount of emitted electrons is more than twice as large as that of amorphous silicon. I have. The amount of emitted electrons is related to the luminance of light emitted from the phosphor, and the luminance is proportional to the amount of emitted electrons. In other words, when the emitter is formed of the {100} columnar polycrystalline film 2 to obtain the same emitted electrons S (emission brightness), the extraction gate electrode is lower than that of amorphous silicon. Therefore, the voltage can be reduced.

Furthermore, the amount of current from the cold electron-emitting device is higher in the oriented plane {100} than in the case of the oriented plane {110} columnar polycrystalline film, and the voltage must be reduced. Can be.

As described above, according to Embodiment 6 ′, if the crystal plane of the columnar crystal grains is oriented in {110} or {100} plane, the amount of emitted electrons is increased, An efficient cold electron emitting element can be formed. Industrial applicability

The emitter and the method of manufacturing an emitter according to the present invention are characterized in that etching is performed on a columnar polycrystalline film formed by growing columnar crystal grains on a substrate along the same crystal rod, whereby the tip shape is obtained. A well-formed emitter can be formed with good reproducibility. Therefore, even when a large number of emitters are formed on a large-area substrate, uniformity of the emitter shape can be obtained. As a result, it is possible to suppress variations in the electron emission characteristics of the cold electron emitter due to variations in the shape of the emitter, such as a flat panel dual image display device, various sensors, a high-frequency oscillator, an ultra-high-speed device, and an electron microscope. It can be used as an electron source for various electron beam utilizing devices such as an electron beam exposure device.

Claims

The scope of the claims

1. An emitter characterized by forming columnar crystal grains on a substrate by etching a columnar polycrystalline film grown along the same crystallographic axis.

2. After forming a columnar polycrystalline film in which columnar crystal grains are grown along the same crystal axis on the substrate, a first insulating film is patterned on the columnar polycrystalline film,

An emitter formed by performing etching on the columnar polycrystalline film using the patterned first insulating film.

3. A second insulating film is formed on the substrate, and a columnar polycrystalline film is formed on the second insulating film by growing columnar crystal grains along the same crystal axis. Patterning the first insulating film on the crystal film,

An emitter formed by etching the columnar polycrystalline film using the patterned first insulating film.

4. In the emitter described in any one of claims 1 to 3,

An emitter characterized in that the columnar crystal grains constituting the columnar polycrystalline film have crystal orientations and crystal axes aligned in a certain direction with respect to the substrate surface.

5. In the emitter according to any one of claims 1 to 4,

An emitter, wherein the columnar polycrystalline film contains at least silicon.

6. In the emitter set forth in any one of claims 1 to 5,

An emitter, wherein the orientation の of the columnar polycrystalline film is {110}.

7. In the emitter set forth in any one of claims 1 to 5, An emitter characterized in that the orientation plane of the columnar polycrystalline film is {100}.

8. In the emitter set forth in any one of claims 1 to 7,

An emitter characterized in that the radius of curvature at the tip of the emitter formed by etching the columnar polycrystalline film is 50 nm or less.

9. In the emitter according to any one of claims 1 to 8,

The columnar crystal grains constituting the columnar crystal film, wherein the shorter one of the columnar crystal grains is at least 100 nm or more.

10. In the case of the emissions set forth in claim 9,

The angle between the columnar crystal grains and the substrate is 83. Emit evening characterized by the above.

1 1. In the emitter described in claim 3,

The emitter, wherein the second insulating film contains at least oxygen or nitrogen.

1 2. In the event set forth in Claim 2 or Claim 3,

The above-mentioned patterned first insulating film has a circular shape.

1 3. In the emitter according to claim 2 or claim 3,

The above-mentioned patterned first insulating film has a polygonal shape.

14. a step of growing columnar crystal grains on the substrate along the same crystal axis to form a columnar polycrystalline film;

Performing a step of etching the columnar polycrystalline film.

1 5. Growing columnar crystal grains along the same crystal axis on the substrate Forming a crystalline film;

Patterning a first insulating film on the columnar polycrystalline film; and etching the columnar polycrystalline film using the patterned first insulating film.

A process for producing an emitter.

16. A step of forming a second insulating film on the substrate;

Forming a columnar polycrystalline film in which columnar crystal grains are grown along the same crystal axis on the second insulating film;

Patterning a first insulating film on the columnar polycrystalline film; and etching the columnar polycrystalline film using the patterned first insulating film. Emitter manufacturing method.

17. The method for producing an EMI according to any one of claims 14 to 16,

An emitter manufacturing method, characterized in that the columnar crystal grains constituting the columnar polycrystalline film have crystal orientations and crystal planes in a certain range from I to J with respect to the substrate surface.

18. The method for manufacturing an emitter according to any one of claims 14 to 17

The method for manufacturing an emitter, wherein the columnar multiple product film contains at least silicon.

19. The method for manufacturing an emitter according to any one of claims 14 to 18,

A method for manufacturing an emitter, wherein the orientation plane of the columnar polycrystalline film is {110}.

20. The method for manufacturing an Emi device according to any one of claims 14 to 18

An emitter manufacturing method, wherein the orientation plane of the columnar polycrystalline film is {100}.

21. The method of manufacturing an emitter according to any one of claims 14 to 20. A method for producing an emitter, comprising etching the columnar polycrystalline film so that the radius of curvature at the tip of the emitter is 50 nm or less.

22. The emitter manufacturing method according to any one of claims 14 to 21.

The columnar crystal grains in the columnar crystal film, wherein the shorter one of the columnar crystal grains has a particle size of at least 100 nm or more.

2 3. In Emi Tsu evening production method according to the second item 2 claims, the angle of the punch-like grains and the substrate, an emitter fabrication method, characterized in that at 8 3 ⁰ or more.

24. The method for manufacturing an emitter according to claim 16, wherein the second insulating film contains at least oxygen or nitrogen.

25. In the method of manufacturing an EMI lamp according to claim 15 or claim 16,

The method for manufacturing an emitter according to claim 1, wherein the patterned first insulating film has a circular shape.

26. In the method for producing an emitter according to claim 15 or claim 16,

The method for manufacturing an emitter, wherein the first insulating film formed in the above-mentioned manner has a polygonal shape.

27. A step of producing an emitter by the method for producing an emitter according to claim 15 or claim 16,

Forming a third insulating layer and an extraction gate electrode while leaving the first insulating film patterned on the columnar polycrystalline film;

Removing only the upper part of the first insulating film patterned on the columnar polycrystalline film to form an opening.