JP2001155647A - Gas discharge display device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas discharge display device with enhanced light emitting efficiency and less variation per hour at a low cost. SOLUTION: In a gas discharge display device having a dielectric layer 17b which covers electrodes arranged in a row on a substrate and extending to the whole area of a display region, the dielectric layer is made as a laminate consisting of a first layer 171 composed of silicon dioxide and a second nitride layer 172 denser and thinner than the first layer, and the first layer is formed by chemical vapor deposition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to PDP, PALC
The present invention relates to a gas discharge display device having a group of electrodes for discharge such as, and a dielectric layer covering the same, and a method of manufacturing the same.

2. Description of the Related Art PDPs are becoming widespread as display devices for large-screen television images and computer outputs with the practical use of color display. The power consumption is increasing with the increase in size and definition, and countermeasures have become important.

[0003]

2. Description of the Related Art As a color display device, an AC type PDP having a three-electrode surface discharge structure has been commercialized. This is a matrix display in which a pair of main electrodes (first and second electrodes) for maintaining lighting are arranged for each row (line) of the matrix display, and an address electrode (third electrode) is arranged for each column. It is. AC
Since the display is of the type, the memory function of the dielectric layer covering the main electrode is used for display. That is, addressing for forming a charged state according to display contents is performed in a line scanning format, and thereafter, a lighting sustaining voltage Vs having an alternating polarity is simultaneously applied to all the main electrode pairs. As a result, the effective voltage (also referred to as cell voltage) is obtained only in the cell having the wall charge.
When Veff exceeds the discharge starting voltage Vf, surface discharge occurs along the substrate surface. By shortening the application period of the lighting sustaining voltage Vs, an apparently continuous lighting state can be obtained. In a surface-discharge type PDP, a phosphor layer for color display is provided on the other substrate opposite to the substrate on which the main electrode pair is arranged, so that deterioration of the phosphor layer due to ion bombardment during discharge is reduced. The service life can be extended.

In general, a dielectric layer for AC driving is formed by a thick film technique in which a low-melting glass paste is printed in a solid film shape and fired, and the thickness is selected to be about 30 to 50 μm.

[0005]

If a material having a lower dielectric constant than the low melting point glass is used for forming the dielectric layer, the driving voltage can be reduced by reducing the thickness of the layer. Further, since the capacity between the electrodes is reduced, wasteful power consumed for charging and discharging the capacity can be reduced and the luminous efficiency can be increased. Therefore, silicon dioxide (S
Attempts have been made to form a dielectric layer of iO ₂ ). The thickness of the dielectric layer made of silicon dioxide may be 1/3 or less of that of the low melting glass. In addition, the CVD method allows a more uniform layer to be formed than the thick film method.

[0006] As an introduction gas in the film formation of silicon dioxide by the plasma CVD method, [1] monosilane (SiH
Combinations of ₄ ) and nitrous oxide (nitrous oxide: N ₂ O) and [2] combinations of tetraethoxysilane (ethyl orthosilicate) and oxygen are widely known. However, tetraethoxysilane is much more expensive than monosilane, and is not suitable for manufacturing a display panel requiring a large-area film formation.

PDP having a 10 μm thick dielectric layer made of silicon dioxide using monosilane and dinitrogen monoxide
And an operation test was conducted. As a result, improvement in luminous efficiency was confirmed. However, it has been found that there is a problem that the change with time in which the luminance decreases is more remarkable than in the conventional example.

An object of the present invention is to provide an inexpensive display device having excellent luminous efficiency and little change over time.

[0009]

In the present invention, a dense layer made of a nitrogen compound and thinner than the first layer is laminated on the silicon dioxide layer (first layer), or a gas containing no nitrogen is used. Form a silicon dioxide layer.

The decrease in luminance in the prior art is particularly remarkable in blue and green cells, and the decrease in red cells is slight. As a result of investigating the cause, it has been found that a large amount of ammonia (NH ₃ ) is contained in the thick silicon dioxide layer as a thin film, and the ammonia released from the silicon dioxide layer deteriorates the phosphor. When there is no phosphor, it is considered that the discharge gas composition changes due to the precipitation of ammonia and the discharge characteristics become unstable.

As described above, by overlaying the second layer of the dense nitrogen compound on the first layer of silicon dioxide, the release of ammonia, which is an impurity gas contained in the first layer, is prevented by the second layer. As a result, the temporal change in the composition of the phosphor or the discharge gas is reduced. In addition, by forming a film using an introduction gas containing no nitrogen, encapsulation of ammonia itself can be eliminated.

A measure of compactness is the refractive index. The higher the refractive index, the more dense. A plurality of types of nitride compounds having different refractive indices were formed on a silicon dioxide layer having a thickness of 10 μm as a layer for suppressing outgassing (this is referred to as a cover layer), and degassing spectra were measured.

FIG. 1 is a graph showing the relationship between the refractive index of the cover layer and the amount of NH ₃ gas released. The cover layer has a refractive index n =
Refractive index n = 1.55 even with 1.95 silicon nitride (SiN)
Of silicon oxynitride (SiON) can also reduce NH ₃ gas emission.

FIG. 2 is a graph showing the relationship between the thickness of the cover layer and the amount of released NH ₃ gas. It can be seen that the larger the film thickness is, the smaller the release amount is, but the film thickness of 750 ° is sufficiently effective. In the structure in which the dielectric layer is provided on the front side of the discharge space, in consideration of the fact that the transmittance is reduced due to interference due to the difference in the refractive index between the silicon dioxide layer and the cover layer, the material of the cover layer and It is necessary to set the film thickness.

According to a first aspect of the present invention, there is provided a gas discharge display device having a dielectric layer having a surface provided with a magnesium oxide film covering electrodes arranged on a substrate, wherein the dielectric layer comprises: It is composed of a first layer made of silicon dioxide formed by a chemical vapor deposition method and a second layer made of a nitrogen compound thinner than the first layer.

In the gas discharge display device according to the present invention, the thickness of the first layer is 5 μm or more, and the thickness of the second layer is 1 μm or less. According to a third aspect of the present invention, there is provided a method for manufacturing a semiconductor device, comprising a dielectric layer having a surface provided with a magnesium oxide film covering electrodes arranged on a substrate, wherein the dielectric layer is formed by a chemical vapor deposition method. A method for manufacturing a gas discharge display device comprising a first layer made of silicon and a second layer made of a thinner nitrogen compound, comprising the steps of plasma chemical vapor deposition using monosilane and dinitrogen monoxide as an introduction gas. The first layer is formed by a method.

According to a fourth aspect of the present invention, there is provided an apparatus having a dielectric layer covering the electrodes arranged on the substrate and extending over the entire display area, wherein the dielectric layer is composed of monosilane and oxygen substantially free of nitrogen. This is a gas discharge display device that is a layer made of silicon dioxide formed by a plasma enhanced chemical vapor deposition method using a compound as an introduction gas.

In the gas discharge display device according to a fifth aspect of the present invention, the oxygen compound is carbon dioxide.

[0019]

FIG. 3 is an exploded perspective view showing a basic structure inside a PDP according to the present invention. Example PDP1
Has a three-electrode surface discharge structure in which a pair of first and second main electrodes X and Y are arranged in parallel, and in each cell C, the main electrodes X and Y intersect an address electrode A as a third electrode. AC
It is a mold and includes a pair of substrate structures 10 and 20. The main electrodes X and Y both extend in the row direction (horizontal direction) of the screen.
Is used as a scan electrode for selecting. The address electrode A extends in the column direction (vertical direction), and is used as a data electrode for selecting a cell C in a column unit. The area where the main electrode group and the address electrode group intersect on the substrate surface is the display area (screen) ES.

The main electrodes X and Y are arranged in pairs on the inner surface of a glass substrate 11 which is the base material of the substrate structure 10 on the front side. A row is a horizontal cell column. Main electrode X,
Y is a transparent conductive film 41 and a metal film (bus conductor), respectively.
42, and is covered with a dielectric layer 17 having a thickness of about 10 μm. The surface of the dielectric layer 17 has magnesia (M
gO) protective film 18 having a thickness of several thousand angstroms.
Is provided. The address electrodes A are arranged on the inner surface of a glass substrate 21 which is the base material of the substrate structure 20 on the back side, and are covered with an insulator layer 24. On the insulator layer 24, one partition wall 29 having a height of 150 μm and having a linear band shape in plan view is provided between each address electrode A. These partition walls 29 divide the discharge space 30 in the row direction for each sub-pixel (unit light-emitting region), and define the gap size of the discharge space 30. Then, phosphor layers 28R, 28G, and 28B of three colors of R, G, and B for color display are provided so as to cover the inner surface on the back side including the upper side of the address electrode A and the side surface of the partition wall 29. ing. The discharge space 30 is filled with a discharge gas in which xenon is mixed with neon as a main component, and the phosphor layers 28R, 28
G and 28B are locally excited by ultraviolet rays emitted by xenon during discharge to emit light. One pixel (pixel) of display
Is composed of three sub-pixels arranged in the row direction. The structure within each sub-pixel is a cell (display element). Since the arrangement pattern of the partition walls 29 is a stripe pattern, a portion corresponding to each column in the discharge space 30 is continuous in the column direction across all rows.

FIG. 4 is a schematic view of a plasma CVD apparatus according to the present invention. The plasma CVD apparatus 100 is a parallel plate type. The substrate structure 10 'at the stage where the arrangement of the main electrodes X and Y has been completed is arranged in the vacuum chamber, and plasma is generated to deposit a predetermined substance on the base surface s. The lower ground surface s is an exposed surface of the main electrodes X and Y and the glass substrate 11. For example, monosilane (SiH ₄ ) is introduced as a source gas, and carbon dioxide (CO ₂ ) or carbon monoxide (CO) is introduced as a reaction gas to form a dielectric layer made of silicon dioxide (SiO ₂ ). The hydrocarbon-based gas generated as a by-product in this reaction system does not damage the phosphor.

FIG. 5 is a schematic view of the dielectric layer according to the first embodiment. In the figure, to facilitate understanding of the cross-sectional shape,
The front side of the PDP 1 is the lower side in the figure. As shown in FIG. 5, the metal film 42 is arranged near the end of the transparent conductive film 41 opposite to the surface discharge gap. The dielectric layer 17 is formed so as to cover such main electrodes X and Y isotropically, and has a compressive stress. Dielectric layer 17
, The unnecessary discharge is unlikely to occur above the metal film 42 far from the surface discharge gap. The generation of cracks is suppressed by the compressive stress.

The PDP 1 having the above-described structure is used for each glass substrate 1
Predetermined components are separately provided for the substrates 1 and 21 to produce the front and rear substrate structures 10 and 20, the two substrate structures 10 and 20 are overlapped to seal the periphery of the facing gap, and the internal exhaust is exhausted. And a series of steps for filling the discharge gas. At this time, the dielectric layer 17 which is a component of the substrate structure 10 is formed by a plasma CVD method which is a kind of a thin film forming method.

FIG. 6 is a schematic view of a dielectric layer according to the second embodiment. The dielectric layer 17b in FIG. 6 is a laminate of a first layer 171 made of silicon dioxide and a second layer (cover layer) 172 for suppressing gas emission from the first layer 171. Second layer 1
72 is made of silicon nitride or silicon oxynitride. Second layer 1
Since the first layer 171 is provided, inclusion of the impurity gas in the first layer 171 is allowed. That is, the degree of freedom in selecting a material in forming silicon dioxide is large. For the film formation by CVD, a combination of inexpensive and industrially proven monosilane and nitrous oxide can be employed. Example 1 A 10 μm-thick SiO ₂ film was formed on a soda-lime glass substrate on which main electrodes had been arranged under the following conditions using a parallel plate type plasma CVD apparatus 100.

The source gas and flow rate: SiO _4/1000 SCCM reactive gas and flow rate: CO ₂ / 5000SCCM frequency output: 2.0 kW substrate temperature: 350 ° C. vacuum: 1.0 Torr and a film forming time was 7 minutes. 0.5μ thickness on SiO ₂ film
mO was formed by a vapor deposition method, and the obtained substrate structure was bonded to a separately prepared rear substrate structure to complete a PDP. The measurement result of the luminous efficiency is 1.5
[Lm / W]. Example 2 A 10 μm-thick SiO ₂ film was formed on a soda lime glass substrate on which main electrodes had been arranged under the following conditions using a parallel plate type plasma CVD apparatus 100.

The source gas and the flow rate: SiH _4/1000 SCCM reactive gas and flow rate: CO ₂ / 10000SCCM frequency output: 3.0 kW substrate temperature: 400 ° C. vacuum: 2.5 Torr deposition time was 10 minutes. 0.5 thickness on SiO ₂ film
A film of MgO having a thickness of μm was formed by a vapor deposition method, and a substrate structure obtained thereby and a separately prepared rear surface substrate structure were bonded to complete a PDP. The measurement result of the luminous efficiency is 1.4.
It was 5 [lm / W]. Example 3 A 10 μm-thick SiO ₂ film was formed on a soda-lime glass substrate on which main electrodes had been arranged under the following conditions using a parallel plate type plasma CVD apparatus 100.

The source gas and the flow rate: SiH _4/1000 SCCM reaction gas and flow: N ₂ O / 10000SCCM frequency output: 2.0 kW substrate temperature: 350 ° C. vacuum: 1.5 Torr and a film forming time was 7 minutes. Subsequently, a 0.5 μm thick SiN film was formed as a cover layer on the SiO ₂ film under the following conditions.

The source gas and the flow rate: SiH ₄ / 500SCCM reaction gas and flow: N _2/8000 sccm RF output: 2.0 kW substrate temperature: 350 ° C. vacuum: 2.0 Torr deposition time was 2 minutes. 0.5μm thickness on SiN film
Was formed by a vapor deposition method, and a substrate structure obtained thereby and a separately prepared rear substrate structure were bonded to complete a PDP. The measurement result of the luminous efficiency was 1.4 [l
m / W]. Example 4 A 10 μm-thick SiO ₂ film was formed on a soda-lime glass substrate on which main electrodes had been arranged under the following conditions using a parallel plate type plasma CVD apparatus 100.

The source gas and the flow rate: SiH _4/1000 SCCM reaction gas and flow: N ₂ O / 10000SCCM frequency output: 2.0 kW substrate temperature: 350 ° C. vacuum: 1.5 Torr and a film forming time was 7 minutes. Subsequently, a 0.5 μm thick SiON film was formed as a cover layer on the SiO ₂ film under the following conditions.

[0030] The film formation time was 1 minute and 30 seconds. A 0.5 μm-thick MgO film was formed on the SiON film by a vapor deposition method, and the obtained substrate structure was bonded to a separately prepared rear substrate structure to complete a PDP. The measurement result of the luminous efficiency was 1.4 [lm / W]. [Example 5] (Two-layer structure of SiON and SiN as a cover layer) Using a parallel plate type plasma CVD apparatus 100, a soda lime glass substrate having a main electrode arrayed thereon was SiO ₂ having a thickness of 10 µm under the following conditions. A film was formed.

The source gas and the flow rate: SiH _4/1000 SCCM reaction gas and flow: N ₂ O / 10000SCCM frequency output: 2.0 kW substrate temperature: 350 ° C. vacuum: 1.5 Torr and a film forming time was 7 minutes. Subsequently, a SiON film having a thickness of 0.25 μm was formed on the SiO ₂ film, and a SiN film having a thickness of 0.25 μm was further formed. The film forming conditions are as follows.

[0032] The film forming times were 45 seconds and 1 minute, respectively. A 0.5 μm-thick MgO film was formed on the SiN film by a vapor deposition method, and the obtained substrate structure was bonded to a separately manufactured rear substrate structure to complete a PDP. The measurement result of the luminous efficiency was 1.45 [lm / W]. Comparative Example 1 A 10 μm-thick SiO ₂ film was formed on a soda-lime glass substrate on which main electrodes had been arranged under the same conditions as in Example 3 using a parallel plate type plasma CVD apparatus 100. The film formation time was 7 minutes. S without cover layer
A 0.5 μm-thick MgO film was formed on the iO ₂ film by a vapor deposition method, and the obtained substrate structure was bonded to a separately prepared rear substrate structure to complete a PDP. The measurement result of the luminous efficiency was 1.0 [lm / W].

As is clear from the comparison of the luminous efficiencies in Examples 1 to 5 and Comparative Example 1, according to the present invention, the luminance at the initial stage can be increased as compared with the conventional example.

[0034]

According to the first to fifth aspects, it is possible to realize an inexpensive display device having excellent luminous efficiency and little change with time.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the refractive index of a cover layer and the amount of NH ₃ gas released.

FIG. 2 is a graph showing the relationship between the thickness of a cover layer and the amount of NH ₃ gas released.

FIG. 3 is an exploded perspective view showing a basic structure inside a PDP according to the present invention.

FIG. 4 is a schematic view of a plasma CVD apparatus according to the present invention.

FIG. 5 is a schematic diagram of a dielectric layer according to the first embodiment.

FIG. 6 is a schematic diagram of a dielectric layer according to a second embodiment.

[Explanation of symbols]

 Reference Signs List 1 PDP (gas discharge display device) 11 Glass substrate X, Y main electrode ES screen (display area) 17, 17b Dielectric layer 171 First layer 172 Second layer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideki Harada 3-2-1, Sakado, Takatsu-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Hitachi Plasma Display Limited In-house (72) Inventor Takeshi Furukawa 4 Kamikadanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Chome 1-1 Fujitsu Limited (72) Inventor William Reed Hashburger 3101 Scott Boulevard, San Taclara, California, USA Inside KT America Inc. (72) Inventor Masao Kakimoto Toyonaka, Osaka Prefecture 5-133, Hattori-cho, Hattori-shi, Ichiku Co., Ltd. (72) Naoko Takehara, Inventor 3101 Scott Boulevard, San Taclara, California, USA AK America, Inc. The internal F-term (reference) 4K030 AA01 AA06 AA14 BA40 BA42 BA44 BB12 CA06 EA03 EA11 FA01 KA23 KA30 LA01 LA18 5C027 AA07 5C040 FA01 GD02 GD07 GD09 JA07 KA03 KA04 KB19 MA03 MA10

Claims (5)

[Claims] 1. A gas discharge display device having a dielectric layer provided with a magnesium oxide film on a surface covering electrodes arranged on a substrate, wherein the dielectric layer is formed by a chemical vapor deposition method. A gas discharge display device comprising a first layer made of silicon dioxide and a second layer made of a thinner nitrogen compound. 2. The gas discharge display device according to claim 1, wherein the thickness of the first layer is 5 μm or more, and the thickness of the second layer is 1 μm or less. 3. The method for manufacturing a gas discharge display device according to claim 1, wherein said first layer is formed by a plasma enhanced chemical vapor deposition method using monosilane and dinitrogen monoxide as an introduction gas. Of manufacturing a gas discharge display device. 4. A gas discharge display device having a dielectric layer extending over the entire display area over electrodes arranged on a substrate, wherein the dielectric layer is substantially free of monosilane and nitrogen. A gas discharge display device comprising a layer made of silicon dioxide formed by a plasma enhanced chemical vapor deposition method using an oxygen compound as an introduction gas. 5. The gas discharge display device according to claim 4, wherein said oxygen compound is carbon dioxide.