JP3239282B2 - Evaluation system for electron beam excited phosphor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam-excited phosphor evaluation apparatus for evaluating the emission characteristics of a phosphor sample which emits light by a slow electron beam.

[0002]

2. Description of the Related Art FIG. 8 shows an example of a conventional evaluation apparatus for evaluating the emission characteristics of a phosphor by a high-speed electron beam. In this figure, reference numeral 80 denotes a vacuum chamber for accommodating a cathode electrode 83, an anode electrode 81 and a phosphor sample 82 in a vacuum atmosphere, 81 denotes an anode electrode provided with the phosphor sample 82, and 82 denotes a phosphor sample to be evaluated. 83, a cathode electrode made of an oxide, 84, a focusing coil for focusing the electron beam emitted from the cathode electrode 83, 85, a cathode power supply for applying a voltage to the cathode electrode, and 86, a B power supply for applying a voltage to the anode electrode. .

[0003] In the evaluation apparatus shown in FIG. 8, a cathode electrode 83 having an oxide adhered to a substrate is heated by an applied cathode power supply 85 to emit electrons. The emitted electrons are pulled by the anode 81 to which the B power of 10 KV to 30 KV is applied. The electrons are focused by the focusing coil 84 provided in the middle thereof, and reach the anode 81 as a small spot. Therefore, a small spot of the electron beam is raster-scanned to excite a predetermined portion of the phosphor sample 82 provided on the front surface of the anode 81 to emit light. Then, the emitted phosphor sample 82
The light emission characteristics of the phosphor sample 82 are evaluated by measuring the brightness, color tone, spectrum, etc. As the cathode electrode used in this evaluation device, an impregnated oxide cathode electrode for CRT, a hairpin cathode made of tungsten, or the like is used.

[0004]

One of the devices using a phosphor is a fluorescent display tube that emits light by exciting the phosphor with a low-speed electron beam. For evaluation, it is necessary to lower the speed of the electron beam (acceleration voltage is 1 KV or less) from the necessity of evaluating the light emission characteristics of cathodoluminescence. However, in the evaluation apparatus shown in FIG. 8, if the electron beam is slowed down by lowering the voltage of the B power supply, the electron beam cannot be focused on a small spot, and the current density supplied to the phosphor sample becomes small. And the phosphor sample cannot emit light sufficiently.

[0005] Therefore, according to the above-described evaluation apparatus, it is possible to evaluate the emission characteristics of a phosphor excited by a high-speed electron beam, but to evaluate the emission characteristics of a phosphor excited by a low-speed electron beam to emit light. Can not. For this reason, conventionally, when evaluating a phosphor excited and emitted by a low-speed or medium-speed electron beam, as shown in FIG. 1 described below, an anode electrode provided with a phosphor sample on a cathode electrode is opposed to a vacuum chamber. The phosphor sample was made to emit light by a low-speed electron beam emitted by heating a cathode electrode made of an oxide, and the emission characteristics of the phosphor were evaluated.

However, in such a configuration, when the phosphor sample is replaced, the oxide cathode is exposed to the atmosphere, and the oxide cathode is significantly deteriorated. Therefore, the same oxide cathode is used only several times. Therefore, there has been a problem that the emission characteristics of the phosphor cannot be evaluated under the same conditions. An oxide filament cathode is generally used as the oxide cathode. The cathode 73 is provided for the anode electrode 71 as shown in FIG. That is, 71 is an anode electrode provided with a phosphor sample 72, 72 is a phosphor sample whose emission characteristics are evaluated, and 73 is a cathode of an oxide filament. By the way, in this case, the electrons emitted from the filament cathode 73 are emitted once around the filament 73 as shown in the figure, but are drawn to the anode electrode 71 in accordance with an electric field formed around the filament 73 to draw a parabola. To spread.

For this reason, the distribution of the diffused electrons on the phosphor sample 72 is not uniform due to the space charge effect as shown in the figure, and the light emission state of the phosphor sample 72 tends to be uneven. In some cases, a diffusion grid is inserted between the anode electrode 71 and the cathode 73. However, it is not possible to completely eliminate unevenness in the light emission state, and it is difficult to accurately measure the light emission characteristics of the phosphor sample 72. There was a point. Therefore, an object of the present invention is to provide an evaluation apparatus for an electron-beam-excited light-emitting phosphor using a cathode that does not deteriorate even when exposed to the atmosphere and can emit electrons in a uniform distribution.

[0008]

In order to achieve the above object, the present invention provides an apparatus for evaluating a low-speed electron-beam-excited light-emitting phosphor, in which an electron-emitting device utilizing field emission is miniaturized and integrated on a substrate. A planar electron-emitting device is used as a cathode, and the phosphor sample is caused to emit light by a low-speed electron beam emitted from the cathode.

[0009]

The evaluation apparatus for the electron-beam-excited light-emitting phosphor configured as described above has a planar cathode.
The distribution of electrons on the phosphor sample becomes uniform, and the emission characteristics can be accurately measured. In addition, since the cold cathode does not use an oxide, the cathode does not deteriorate even when exposed to air, and the same cathode can be used even if the vacuum chamber is opened and the phosphor sample is replaced, so that the same conditions can be used. Thus, the emission characteristics of a plurality of types of phosphor samples can be measured.

[0010]

EXAMPLE An applied electric field of 10 ⁹
At about [V / m], electrons pass through the barrier and emit electrons in a vacuum even at room temperature due to the tunnel effect. This is called field emission, and a cathode that emits electrons based on such a principle is called a field emission cathode. In recent years, making full use of semiconductor processing technology, micron-sized field emission cathodes (hereinafter
FEC).

FIG. 9 shows an example of the Spit (Spi).
1 shows a manufacturing process of a field emission cathode called an (ndt) type. In this figure, 111 is an N-type silicon substrate, 112 is SiO _{2 formed} by thermally oxidizing silicon.
Film, 113 is a niobium metal film to be a gate electrode deposited on SiO ₂ , 114 is a photoresist for selective etching, 115 is a metal film of aluminum or the like obliquely deposited on the niobium metal film 113, 116 is a film A deposited layer of molybdenum or the like deposited on a metal film 115 of aluminum or the like, 117 is a deposited layer of molybdenum or the like in a cone shape serving as an emitter deposited on the substrate 111, and 118 is a rotation axis for oblique rotation deposition. is there.

In FIG. 9A, an N-type silicon substrate 1
11 is thermally oxidized to form a SiO ₂ film on the surface, and a niobium 113 serving as a gate electrode is further deposited thereon. Next, after a photoresist 114 is applied in a niobium 113 shape, patterning is performed as shown in FIG. After patterning, etching is performed to make holes in the niobium 113 and the SiO ₂ film as shown in FIG.

Next, the photoresist is removed, and aluminum 115 is vapor-deposited from an oblique direction while rotating the substrate 111 about a rotation axis 118 shown in FIG. Then, aluminum 115 is selectively deposited only on the surface of niobium 113 without being deposited in the drilled hole. Further, when molybdenum 116 is deposited on the aluminum 115, the molybdenum 116 is deposited in a hole formed by etching as shown in FIG.
Accumulate in the form of a cone. Thereafter, when the aluminum 115 and molybdenum on the niobium 113 are removed by etching, an FEC having a shape as shown in FIG.

In the FEC shown in FIG. 9 (f), the distance between the emitter 117 on the cone and the gate electrode 113 can be made submicron.
By applying a voltage of several tens of volts between three, electrons can be emitted from the emitter 117.

FIG. 6A is a perspective view of a planar FEC array formed by integration in the manufacturing process shown in FIG.
In this figure, a gate electrode is provided on a silicon substrate via an SiO ₂ film, and a tip of a cone-shaped emitter provided in a round hole of the gate electrode faces from the hole of the gate. I have. The pitch between the emitters can be less than 10 microns and the FEC can be tens of thousands to
An FEC array in which ten thousand pieces are provided on one silicon substrate can be obtained.

FIG. 6B is a perspective view of an FEC array having another shape. In the FEC array shown in this figure, a gate electrode is vapor-deposited on a silicon substrate so as to be elongated, and an emitter electrode is formed of SiO 2 in opposition to the gate electrode.
It is formed in a rectangular shape on the _two films. In this FEC array, the distance between the gate electrode and the emitter electrode can be made smaller than that in the FEC array shown in FIG. 1A, so that even at a lower emitter-gate voltage, electrons are emitted from the tip of the emitter electrode facing the gate electrode. Can be released. FIG. 1 shows an electron beam excited phosphor evaluation apparatus using such an FEC array as a cathode electrode.

In FIG. 1, reference numeral 1 denotes a vacuum chamber for accommodating a pair of a cathode electrode 2 and an anode electrode 3 provided with a phosphor sample 4 in a vacuum atmosphere, 2 denotes a cathode electrode formed of an FEC array, and 3 denotes a cathode electrode. An anode electrode on which the phosphor sample 4 is provided, 4 is a phosphor sample whose emission characteristics are measured, 5 is a lead lead-out portion for leading a lead wire between the cathode electrode 2 and the anode electrode, and 6 is a sight provided in the vacuum chamber 1. A window, 7 is a sensor facing the viewing window 6, 8 is a power supply for emitting electrons from the cathode electrode 2, 9 is a power supply applied to the anode electrode 3 for capturing electrons emitted from the cathode electrode 2. is there.

In the electron beam excited luminescent phosphor evaluation apparatus shown in FIG. 1, a cathode electrode 2 is provided in a vacuum chamber 1 and an anode electrode 3 provided with a phosphor sample 4 to be measured is opposed to the cathode electrode 2. set. Then, after the inside of the vacuum chamber 1 is evacuated, the power source 8 and the power source 9 are applied to the cathode electrode 2 and the anode electrode 3, and the electrons emitted from the cathode electrode 2 cause the phosphor sample 4 to emit light.

The light emission state of the phosphor sample 4 can be observed from a viewing window 6 provided in the vacuum chamber 1 through a light transmitting portion provided in the cathode 2 as described later. Then, the sensor 7 is made to face the viewing window 6 to measure the light emission characteristics such as luminance, color tone, spectrum and the like.

FIG. 7B shows the distribution of electrons emitted from the cathode electrode 2 at this time. As shown in this figure,
Since the cathode electrode 2 is formed by the planar FEC array, the distribution of electrons emitted from the cathode electrode 2 becomes uniform. For this reason, the distribution of electrons on the phosphor sample 4 becomes uniform, and the phosphor is excited and emitted by the uniform electrons, so that accurate emission characteristics of the phosphor sample 4 can be measured. become.

Hereinafter, an example of the structure of the cathode electrode applied to the present invention will be described with reference to FIGS. In FIG. 2, reference numeral 20 denotes a glass substrate constituting a cathode electrode, 21 denotes a ring-shaped outer deflection electrode for deflecting electrons emitted from the FEC array 22, and 22 denotes an FEC array integrated and formed on the glass substrate 20. , 23 are FEC arrays 22
A ring-shaped inner deflecting electrode 24 for deflecting the electrons emitted from the light source 24 is a light-transmitting portion for observing the emitted phosphor sample. In the cathode electrode shown in this figure, an FEC array 22 is formed on a glass substrate 20 by a manufacturing process shown in FIG. 9, and a ring-shaped inner deflection electrode 23 is formed inside the FEC array 22 and a ring-shaped outer deflection electrode 21 is formed outside by deposition. Is formed. Further, a light transmitting portion 24 is provided at the center of the glass substrate 20.

A bonding wire is connected to the FEC array 22 of the cathode electrode, and a lead wire is drawn out.
Electrons are emitted from the FEC array 22 by applying a voltage to the lead wires. The electron beam is deflected to the center by the ring-shaped inner deflection electrode 23 and the outer deflection electrode 21 to emit light from the phosphor sample provided on the anode electrode. The emission state of the emitted phosphor sample is observed from the light transmitting section 24 provided at the center.

FIG. 3 shows another example of the cathode electrode. In the cathode electrode shown in this figure, an FEC array 32 is formed on a silicon substrate 30 by a manufacturing process shown in FIG. 9, and a light-transmitting window 34 is opened at the center by etching or the like.
The inner deflecting electrode 33 and the outer deflecting electrode 31 are formed by vapor deposition so as to sandwich the light transmitting window. A bonding wire is connected to the FEC array 32 of the cathode electrode, a lead wire is drawn out, and electrons are emitted from the FEC array 32 by applying a voltage to the lead wire. This electron beam is deflected to the center by the inner deflection electrode 33 and the outer deflection electrode 31 to which a deflection voltage is applied via a lead wire (not shown), and causes the phosphor sample provided on the anode electrode to emit light. The light emission state of the phosphor sample that emits light is observed from the light transmitting part 34 provided at the center. Alternatively, the cathode electrode shown in FIG. 3 may be configured by fixing a chip of an FEC array formed by integrating the substrate 30 as a glass substrate thereon.

FIG. 4 shows still another example of the cathode electrode. In this figure, reference numeral 40 denotes a glass substrate provided with an emitter stripe 42 and a gate stripe 44 constituting an FEC array, 41 denotes an emitter line connected to the emitter stripe 42, and 42 denotes a linear line for emitting electrons. An emitter stripe, 43 is a gate line connected to a gate stripe 44, 44 is a linear gate stripe facing the linear emitter, and 45 is a light transmitting portion between the FEC arrays.

The cathode electrode shown in FIG.
The gate and the emitter are formed in stripes because the FEC having the structure shown in FIG. A predetermined voltage is applied between a gate line 43 connected to the stripe-shaped gate 44 and the emitter 42 and the emitter line 41 to emit an electron beam from the stripe 42 of the emitter. The phosphor sample provided on the anode electrode is caused to emit light by the electron beam, and this light emission state is observed from the light transmitting portion 45 between the stripes 42 and 44. It should be noted that the cathode electrode shown in FIG. 4 may be constituted by an FEC array having a cone-shaped emitter shown in FIG. In this case, the gate stripe may be provided via the SiO ₂ film so as to overlap the emitter stripe. In addition, a diffusion grid may be provided between the cathode electrode and the anode electrode to increase the diffusion or uniformity of electrons.

The emission characteristics of the phosphor are measured by using the cathode electrode having the structure shown in FIGS. 2 to 4 in an electron-beam-excited light-emitting phosphor evaluation device having the structure shown in FIG. In this case, it is necessary to measure the anode voltage substantially equal to the anode voltage of the phosphor device to be used. FIG. 5 schematically shows a circuit for applying the cathode voltage and the anode voltage in this case.

In this figure, 51 is an emitter electrode, 5
2 is a cone-shaped emitter, 53 is a gate electrode, 54 is an anode electrode, 55 is a phosphor sample provided on the anode electrode, 56 is a power supply applied to the cathode electrode, 57 is a power supply applied to the anode electrode, 58 is a mesh Grid,
Reference numeral 59 denotes a power supply applied to the grid. In the circuit shown in FIG. 5A, electrons cannot be stably emitted unless a voltage of 60 to 120 volts is normally applied between the gate electrode 53 and the emitter electrode 51 of the FEC. The voltage is about 60 to 120 volts, and the voltage of the anode power supply 57 is about 2 to 2 depending on the apparatus using the phosphor.
It is between 00 and 600 volts.

When measuring the light emission characteristics of a phosphor applied to a fluorescent display tube, the voltage of the anode power supply 57 is set to 50 volts because the anode voltage of a general phosphor display tube is about 10 to 50 volts. It is necessary to However, since the voltage of the gate electrode 53 is 60 to 120 volts, the voltage of the anode electrode 54 is
Unless the voltage is higher than the above, 10 to 50 volts cannot be obtained because electrons do not reach the anode. Therefore, FIG.
As shown in (b), a mesh grid 58 is provided between the gate electrode 53 and the anode electrode 54 to form a grid 5.
The voltage of the power supply 59 applied to the power supply 8 may be set to about 120 volts, and the voltage of the anode power supply 57 may be set to 10 to 50 volts. Note that, in the above-described embodiment, an example in which light emission of the phosphor sample is observed from the cathode electrode side is shown. However, as a display type, light emission is observed through the anode electrode by making the anode electrode translucent. In this case, if the emission of the phosphor sample is observed from the anode electrode side,
An evaluation similar to the actual display state can be performed.

The apparatus for evaluating an electron-beam-excited light-emitting phosphor of the present invention is configured as described above, so that an electron beam with a uniform distribution is supplied from a planar cathode onto a phosphor sample to be measured. Thus, the emission characteristics of the phosphor sample can be accurately measured. In addition, it is a cold cathode that does not use oxides, and the cathode deteriorates almost even when exposed to air.
Therefore , always supply a constant electron beam even if the phosphor sample is replaced by opening the vacuum chamber of the evaluation device.
Can be. Therefore, the emission characteristics of a plurality of types of phosphor samples can be accurately measured under the same conditions. Also cathode
Since the light transmitting portion is provided in a part of the electrode, the light transmitting portion is provided.
It is easy to observe the state of light emission through
This has the effect of reducing

[Brief description of the drawings]

FIG. 1 is an electron beam excited luminescence evaluation apparatus of the present invention.

FIG. 2 is a diagram showing a configuration of a cathode electrode.

FIG. 3 is a diagram showing another embodiment of the configuration of the cathode electrode.

FIG. 4 is a diagram showing still another embodiment of the configuration of the cathode electrode.

FIG. 5 is a diagram schematically showing a power supply circuit of the electron beam excited luminescence evaluation apparatus.

FIG. 6 is a perspective view of an FEC array.

FIG. 7 is a diagram showing a distribution of electrons emitted from a cathode.

FIG. 8 is a view showing a conventional electron beam excited luminescence evaluation apparatus.

FIG. 9 is a diagram showing a manufacturing process of the FEC.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2 Cathode electrode 3 Anode electrode 4 Phosphor sample 5 Lead extraction part 6 Lookout window 7 Sensor 8 Cathode power supply 9 Anode power supply 20, 40 Glass substrate 21, 31 Outer deflection electrode 22, 32 FEC array 23, 33 Inner deflection electrode 24, 34 Light-transmitting window 41 Emitter line 42 Emitter stripe 43 Gate line 44 Gate stripe 45 Light-transmitting portion 51 Emitter electrode 52 Emitter 53 Gate electrode 54, 71 Anode electrode 55, 72 Phosphor sample 56 Cathode power supply 57 Anode power supply 58 Grid 59 Grid power supply 73 Filament 74 FEC 80 Vacuum chamber 81 Anode electrode 82 Phosphor sample 83 Oxide cathode electrode 84 Focusing coil 85 Cathode power supply 86 Anode power supply 111 N-type silicon 112 iO ₂ film 113 metal film 114 photoresist 115 aluminum film 116 molybdenum deposited layer

Claims (2)

(57) [Claims] 1. A cathode electrode which is provided in a vacuum chamber and has a field emission type cathode integrated with a planar substrate and which is capable of surface emission. An anode electrode for capturing an electron beam emitted from an electrode, and a phosphor sample provided on the surface of the anode electrode , a light-transmitting portion provided on a part of the cathode electrode, the output electron beam by emitting the phosphor sample, the light transmitting portion of the emission characteristics
Evaluation device of an electron beam excited light-emitting phosphor and evaluating the more the phosphor sample to be observed through. 2. A light transmitting part is provided in a part of the cathode electrode,
2. The apparatus for evaluating an electron-beam-excited light-emitting phosphor according to claim 1, wherein the light-emitting state of the phosphor sample is observed from the side of the cathode electrode through the light-transmitting portion.