JPH10261361A - Manufacture of vacuum micro element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a vacuum micro element using diamond on its emitter. SOLUTION: A silicon board 102 is coated on its surface with an oxide film serving as a gate insulating layer 101 and further a molybdenum(Mo) film serving as a gate electrode layer 103 is formed. The insulating layer 101 and the electrode layer 103 is partly etched to form an opening, in which diamond is grown. The diamond is raised there into the shape of a circular cone so as to gradually close the opening. The diamond depositing on the Mo layer 103 is finally peeled off to finish a vacuum micro element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a vacuum micro device having a field emission type cold cathode and a manufacturing technique thereof.

[0002]

2. Description of the Related Art In recent years, field-emission vacuum microdevices have been active due to the possibility of high-speed response, the possibility of improving radiation resistance and high temperature resistance, and the possibility of high-definition, self-luminous display. R & D is ongoing. As the emitter material, a material having a small electron affinity is used.

In recent years, it has been found that the electron affinity of diamond is close to 0 (for example, J. Van et al., J. Vac. S.
ci. Technol. B, 10, 4, (199
2)), various methods for forming a vacuum micro device using diamond as an emitter material have been proposed. It is considered that diamond is more difficult to process in a semiconductor process than a semiconductor such as Si or a metal due to its properties. Therefore, methods for forming a diamond emitter include (1) coating a conductor (for example, Mo) having a conical structure, and (2) embedding and forming in a pointed mold formed on a Si substrate by anisotropic etching or the like. is there. However, the diamond formed by the method (1) is granular and adheres to the conductor at random, so that the stability of the characteristics as an emitter,
Low reproducibility. In the case of (2), the diamond emitter shape is formed with good reproducibility, but after the diamond emitter is formed, the Si substrate used for manufacturing the pointed mold must be completely removed to expose the diamond emitter. Therefore, from an industrial point of view, this is a factor that increases the manufacturing cost.

[0004]

According to the present invention, in view of the above-mentioned current situation of vacuum microdevices, when diamond is used as the emitter material, the stability and reproducibility of the diamond emitter are improved, and the cost is further reduced. We propose a new vacuum micro device fabrication method that enables

[0005]

The gist of the present invention is to form an oxide film serving as a gate insulating layer on a Si substrate and subsequently form molybdenum (Mo) serving as a gate electrode layer. A pinhole is formed by etching the gate insulating layer and the gate electrode layer, and diamond is grown. Utilizing that the diameter of the pinhole is closed as the diamond grows, the diamond grows conically in the pinhole. Diamond deposited on Mo can be easily peeled off due to very low adhesion with Mo. According to the present invention,
As in the conventional example, the stability of the diamond emitter shape,
The reproducibility is improved, and a significant reduction in manufacturing cost can be expected.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings. 1 to 7 are views showing a method for manufacturing a vacuum micro device according to an embodiment of the present invention.

First, as shown in FIG.
2. For example, an oxide film 10 serving as a gate insulating layer on a Si substrate
Form one. The oxide film may be either a thermal oxide film or an oxide film formed by a plasma CVD method. In this embodiment, the thermal oxide film is formed with a thickness of 2 μm. Next, as shown in FIG. 2, molybdenum (Mo) 103 serving as a gate electrode layer is formed on the oxide film 101 by a sputtering method or the like. In this embodiment, the film is formed with a thickness of 0.5 μm. A resist 104 is applied on the Mo by spin coating, subjected to general exposure and development as shown in FIG. 3, and patterned, for example, to obtain an opening 104a having a diameter of 3 μm, as shown in FIG. As described above, for example, the Mo layer 103 serving as a gate electrode layer and then the thermally oxidized SiO2 film 101 serving as a gate insulating layer are etched by a reactive ion etching method. After the etching, the resist 104 is removed.

Next, diamond layers 105 and 106 are formed on the substrate 101 as shown in FIG. In this embodiment, the diamond was formed by using a hot filament method. The diamond layers 105 and 106 have an H2 flow rate of 10
Using a mixed gas of 0 sccm and a flow rate of acetone of 0.5 sccm, the pressure was set to 150 Torr, and the substrate temperature was set to 800 ° C. As shown in FIG. 5, as the diamond 106 grows, the diamond 105 also grows on the surface of the Mo layer which is the gate electrode layer. The Mo layer diamond 106 grows to cover the oxide film layer serving as the gate insulating layer and the opening 107 of the gate electrode Mo layer. Therefore, the probability that the diamond growth species reach the Si substrate becomes lower with the passage of time. In addition, as the opening is closed, the spread of the grown species in the opening is reduced, and the diamond 106 inevitably grows in a conical or pyramid shape, and as shown in FIG. Growth ends.

The diamond 105 deposited on the surface of the Mo layer 103 serving as the gate electrode layer has very low adhesion to Mo and can be easily peeled off. In addition, since diamond hardly grows on an oxide film, the emitter 1 via the gate insulating layer 101 can be used without any special treatment.
06 and the gate electrode layer 103 are not electrically leaked. As shown in FIG. 7, when the diamond 106 is peeled off, a vacuum micro device using a diamond emitter according to an embodiment of the present invention is completed.

Next, a flat panel type image display device using a vacuum micro device according to the above embodiment will be described. As shown in FIG. 8, the flat panel type image display device of this embodiment has a Si substrate 102 on which a large number of pyramid-shaped emitters of vacuum micro-elements are formed in an array (here, a sectional view of a single emitter instead of a plurality of emitters). ) And a glass face plate 201 in which a phosphor layer 203 and a transparent electrode (anode electrode) layer 202 made of ITO are sequentially formed.
Are arranged opposite to each other with a predetermined space therebetween, and these constitute a vacuum housing. The Si substrate 10
The diamond micro-element formed in accordance with the method of manufacturing a vacuum micro-element described in the above-described embodiment is used as an emitter, and a Mo gate electrode is provided via an insulating layer 101 to form a vacuum micro-element 100. . That is, the vacuum micro element unit 100 is used as a part of a vacuum housing. As described above, when the vacuum micro device according to the embodiment of the present invention is applied to a flat panel display, improvement in stability and reproducibility of the emitter makes it possible to obtain a highly accurate and highly reliable image. . The present invention is not limited to the above embodiments, and can be implemented in various modifications without departing from the spirit of the present invention.

[0011]

As described above, by using the present invention,
The stability and reproducibility of the diamond emitter shape have been improved,
Further, it is possible to provide a vacuum micro device capable of significantly reducing the manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a manufacturing process of a vacuum micro device according to one embodiment of the present invention.

FIG. 2 is a sectional view showing a manufacturing process of the vacuum micro device according to one embodiment of the present invention.

FIG. 3 is a sectional view showing a manufacturing process of the vacuum micro device according to one embodiment of the present invention.

FIG. 4 is a sectional view showing a manufacturing process of the vacuum micro device according to one embodiment of the present invention.

FIG. 5 is a sectional view showing a manufacturing process of the vacuum micro device according to one embodiment of the present invention.

FIG. 6 is a sectional view showing a manufacturing process of the vacuum micro device according to one embodiment of the present invention.

FIG. 7 is a sectional view showing a manufacturing process of the vacuum micro device according to one embodiment of the present invention.

FIG. 8 is a sectional view showing a flat panel display according to an embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 vacuum micro element portion 101 silicon substrate 102 gate insulating oxide film layer 103 gate electrode Mo layer 104 resist 105 diamond layer 106 diamond emitter 107 face plate 202 transparent electrode (anode electrode) 203 phosphor layer

Claims (3)

[Claims] 1. A method of manufacturing a vacuum micro device having an emitter for field emission of electrons and a gate electrode for controlling the emission, wherein a step of laminating a gate insulating film and a gate electrode layer on a substrate; Opening a gate electrode layer and an insulating film in a region where a hole is to be formed, forming diamond on the entire surface, and forming a diamond emitter layer on the substrate by closing the opening with diamond formed on the gate electrode layer. And a method for manufacturing a vacuum micro device. 2. The method according to claim 1, wherein the diamond emitter layer has a pyramid shape or a conical shape. 3. The method according to claim 1, wherein a molybdenum layer is formed as a gate electrode layer.