JP2006028005A - Magnesium oxide film and plasma display panel equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excellent magnesium oxide film whose electric discharge responsiveness hardly changes in a wide temperature range, and to provide a plasma display panel which is obtained by using the same and exhibits reduced flickering on itself and improved luminance and contrast. <P>SOLUTION: The magnesium oxide film has an oxygen deficient amount of 5.0×10<SP>15</SP>to 2.0×10<SP>17</SP>pieces/cm<SP>3</SP>, which is calculated from the total number of F-center and F<SP>+</SP>-center, and an oxygen deficient amount of 5.0×10<SP>15</SP>to 1.0×10<SP>17</SP>pieces/cm<SP>3</SP>, which is calculated from the total number of Fs-center and Fs<SP>+</SP>-center existing in the surface of the magnesium oxide film. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a magnesium oxide film and a plasma display panel (hereinafter referred to as “PDP”) provided with the magnesium oxide film as a protective film.

  In recent years, PDPs have come to be widely used in applications such as television images and computer monitors with the practical use of color screens. In such a surface discharge AC type PDP, a sustain electrode and a scan electrode are arranged in parallel in the horizontal direction of the screen of the front plate made of a glass substrate, and the vertical screen of the back plate is arranged. In the direction, an address electrode is arranged. The region where the effect of the electrode pair where the vertical and horizontal electrodes intersect is generally called a cell.

The sustain electrode and the scan electrode are covered and protected by a dielectric layer (for example, low melting point glass). A protective film having high sputtering resistance is provided on the surface of the dielectric layer in order to reduce ion bombardment caused by discharge gas during discharge.
The characteristics required for such a protective film are (1) low discharge voltage, (2) sputtering resistance during discharge, high light transmittance, (3) quick discharge response, and (4) insulation. In general, magnesium oxide is used as such a protective film material. Magnesium oxide is an insulator having excellent spatter resistance and a large secondary electron emission coefficient.

  However, when magnesium oxide is used as a protective film, there has been a problem that display disturbance called “black noise” has occurred in the past. “Black noise” is a disordered panel display in which a cell to be lit (selected cell) is not lit, and is known to be likely to occur at the boundary between a lit area and a non-lit area in the screen. This disorder phenomenon does not mean that all of the plurality of selected cells in one line or one column are not lit, and since the occurrence sites are scattered, black noise is caused by no address (writing) discharge. However, even if it occurs, it is considered that the address miss is insufficient.

  As a measure for solving the problem of “black noise”, a PDP provided with a magnesium oxide film containing silicon in a proportion in the range of 500 to 10000 mass ppm has been proposed. In order to form this magnesium oxide film, a pellet is used. The target is a material in which a magnesium oxide in the form of a pellet and an impurity compound in the form of pellets or powder are mixed (see, for example, Patent Document 1).

In general, with respect to driving of a matrix display type AC type PDP, a memory effect is used to maintain (sustain) a lighting state of a cell as a display element. At the time of display, first, the wall charge of the entire screen is erased and reset between the end of the sustain of one image and the addressing (writing) of the next image.
Next, line-sequential addressing (writing) is performed in which wall charges are further accumulated only in the cells to be lit (emitted).
Thereafter, a voltage (sustain voltage) lower than the discharge start voltage having an alternating polarity is applied to all the cells simultaneously. At this time, in the cell in which wall charges exist, the wall voltage is superimposed on the sustain voltage, so that the effective voltage applied to the cell exceeds the discharge start voltage and discharge occurs. By increasing the applied frequency of the sustain voltage, an apparently continuous lighting state is obtained.

In the addressing (writing), wall charges are accumulated by performing address discharge between the address electrodes on the back plate and the scan electrodes on the front plate. Therefore, when considering stable panel drive, it is extremely difficult to control the drive voltage sequentially while sensing the panel temperature, so the PDP must always have a constant discharge response within the guaranteed temperature range of the panel. Is desirable.
Japanese Patent No. 3247632

However, in the PDP according to Patent Document 1, although the image quality is evaluated, the temperature conditions at the time of evaluation are not particularly mentioned, and it is considered that the evaluation was performed under conditions near room temperature. The relationship with temperature was unknown.
Then, the present inventors evaluated the discharge response over a wide temperature range of −15 to 90 ° C., which is the guaranteed temperature range of the PDP, and found that the discharge response has temperature dependency.

  Specifically, it has been found that when the discharge response time at a certain temperature exceeds a threshold, an address discharge failure occurs and the panel “flickers”. In addition, when the discharge response is poor, it is necessary to lengthen the address period. As a result, the sustain period is shortened, and sufficient brightness of the panel cannot be obtained. I found the problem of declining.

  An object of the present invention is to provide an excellent magnesium oxide film with little change in discharge responsiveness over a wide temperature range in view of the above-mentioned problems of the prior art.

  Another object of the present invention is to provide a plasma display panel using this magnesium oxide film, in which “flickering” of the panel is reduced and the brightness and contrast are improved.

To solve this problem,
The invention according to claim 1 is characterized in that the oxygen deficiency obtained from the total number of F centers and F ⁺ centers is 5.0 × 10 ^{15 to} 2.0 × 10 ¹⁷ pieces / cm ^3. It is a magnesium oxide film.

The invention according to claim 2 is the magnesium oxide film characterized in that the amount of oxygen deficiency obtained from the F center is 5.0 × 10 ^{15 to} 1.0 × 10 ¹⁷ pieces / cm ³ .

The invention according to claim 3 is the magnesium oxide film characterized in that the amount of oxygen deficiency obtained from the F ⁺ center is 5.0 × 10 ^{15 to} 1.0 × 10 ¹⁷ pieces / cm ³ .

In the invention according to claim 4, the oxygen deficiency obtained from the total number of Fs centers and Fs ⁺ centers existing on the surface of the magnesium oxide film is 5.0 × 10 ^{15 to} 1.0 × 10 ¹⁷ pieces / cm ^3. This is a magnesium oxide film.

The invention according to claim 5 is characterized in that the oxygen deficiency obtained from the Fs center existing on the surface of the magnesium oxide film is 5.0 × 10 ^{15 to} 5.0 × 10 ¹⁶ pieces / cm ^3. It is a magnesium film.

The invention according to claim 6 is characterized in that the oxygen deficiency obtained from the Fs ⁺ center existing on the surface of the magnesium oxide film is 5.0 × 10 ^{15 to} 5.0 × 10 ¹⁶ pieces / cm ^3. It is a magnesium oxide film.

  The invention according to claim 7 is characterized in that the change rate of the discharge response time of the plasma display panel at −15 to 90 ° C. is 1.1 to 100. This is a magnesium oxide film.

  The invention according to claim 8 is the plasma display panel characterized in that the magnesium oxide film according to any one of claims 1 to 7 is provided on a dielectric layer.

  Since the magnesium oxide film of the present invention has a small amount of oxygen deficient portion (oxygen deficiency) that is considered to function as an electron emission site in the film, the electron emission ability is less likely to change depending on the temperature. It is an excellent film that does not affect the discharge response time and has little change in discharge response over a wide temperature range.

In addition, since the plasma display panel provided with the magnesium oxide film of the present invention has a small amount of oxygen vacancies in the film, the change in discharge responsiveness over a wide temperature range can be reduced. In addition, the discharge response time does not exceed the threshold value in a wide temperature range, address discharge defects are reduced, and the “flickering” of the panel can be reduced in a wide temperature range.
In addition, since the discharge response is excellent, the address period can be shortened and the sustain period can be extended, and sufficient panel luminance can be obtained.
Further, since the discharge response is excellent, the dark luminance at the time of erasing discharge is lowered, and the contrast can be improved.
Further, since the address period can be shortened, the panel driver IC (address IC) can be reduced, and as a result, the module cost can be reduced.

[Magnesium oxide film]
In the magnesium oxide film of the present invention, the amount of oxygen deficiency determined from the total number of F centers and F ⁺ centers is 5.0 × 10 ^{15 to} 2.0 × 10 ¹⁷ / cm ³ , preferably Is 5.0 × 10 ^{15 to} 1.2 × 10 ¹⁷ pieces / cm ³ .
In the magnesium oxide film of the present invention, the amount of oxygen deficiency required from the F center is 5.0 × 10 ^{15 to} 1.0 × 10 ¹⁷ pieces / cm ³ , preferably 5.0 × 10. ^{15 to} 8.0 × 10 ¹⁶ pieces / cm ³ .
Further, the amount of oxygen vacancies is determined from ^{F +} center is 5.0 × ¹⁰ 15 ~1.0 × ^{10 17} atoms / cm ^3, preferably 5.0 × ¹⁰ 15 ~9.5 × ^{10 16} pieces / cm ³ , more preferably 5.0 × 10 ^{15 to} 8.0 × 10 ¹⁶ pieces / cm ³ .

Here, “F center” refers to an electron trap in which two electrons are captured in an oxygen deficient portion in the magnesium oxide film, and “F ⁺ center” refers to an electron trap in which one electron is captured. . Note that an oxygen deficient portion in which electrons are not captured (capture number is 0) is referred to as “F ⁺⁺ center”.
Therefore, theoretically, regarding the true oxygen deficiency in the magnesium oxide film,
True oxygen deficiency = F center amount + F ⁺ center amount + F ⁺⁺ center amount.

Since the F ⁺ center is paramagnetic, it can be measured by an electron spin resonance method (hereinafter referred to as “ESR”). However, since the F center is nonmagnetic, it is usually inactive with ESR.
However, when the magnesium oxide film is brought to a very low temperature and irradiated with ultraviolet rays, the F center is excited and converted to F ⁺ center. Therefore, the F ⁺ center concentration (F ⁺ center amount) can be determined from the ESR signal before ultraviolet irradiation, and the F center concentration (Fcenter amount) can be determined from the signal after ultraviolet irradiation.

A commercially available ultraviolet irradiation device can be used for irradiation of the magnesium oxide film with ultraviolet rays. The intensity of ultraviolet rays is preferably 50 to 200 μW / cm ² and the irradiation time is preferably 30 to 60 minutes.

In addition, since there is no electron at the F ⁺⁺ center, it cannot be measured by ESR, and it cannot be detected by ESR even when irradiated with ultraviolet rays. Therefore, since the concentration of the F ⁺⁺ center cannot be measured, the true oxygen deficiency cannot be accurately measured.
Therefore, in the present invention, the amount of oxygen vacancies in the film is determined by using the amount of oxygen vacancies obtained from the total number of F centers and F ⁺ centers and the amount of oxygen vacancies obtained from each of F centers and F ⁺ centers. It was decided to prescribe.

The amount of oxygen deficiency obtained from the total number of F centers and F ⁺ centers in the magnesium oxide film is 5.0 × 10 ^{15 to} 2.0 × 10 ¹⁷ pieces / cm ³ , and is 5.0 × 10 ¹⁵ to It is preferable that it is 1.2 × 10 ¹⁷ pieces / cm ³ . This is because if this value is less than 5.0 × 10 ¹⁵ pieces / cm ³ , it cannot be detected by ESR, whereas if it exceeds 2.0 × 10 ¹⁷ pieces / cm ³ , the amount of oxygen deficiency in the film This is because the temperature dependence of the degree of change in the discharge response time of the PDP cannot be reduced.
The degree of change in discharge response time refers to a value normalized by “maximum response time / minimum response time” within a specified temperature range.

Further, the amount of oxygen vacancies is determined from F centers in the magnesium oxide film is 5.0 × ¹⁰ 15 ~1.0 × ^{10 17} atoms ^{/ cm 3, 5.0 × 10 15} ~8.0 × 10 16 Preferably, the number per piece / cm ³ . Further, the amount of oxygen vacancies is determined from ^{F +} centers in the magnesium oxide film is 5.0 × ¹⁰ 15 ~1.0 × ^{10 17} atoms ^{/ cm 3, 5.0 × 10 15} ~9.5 × 10 is preferably from ¹⁶ / cm ^3, and more preferably 5.0 × ¹⁰ 15 ~8.0 × ^{10 16} atoms / cm ^3. This is because if these values are less than 5.0 × 10 ¹⁵ pieces / cm ³ , they cannot be detected by ESR, whereas if they exceed 1.0 × 10 ¹⁷ pieces / cm ³ , oxygen vacancies in the film This is because the amount is too large, and the temperature dependence of the degree of change in the PDP discharge response time cannot be reduced.

The oxygen deficient part in the magnesium oxide film forms a level (oxygen deficient level) with higher electron energy than the valence band in the band gap of the insulator, chemically as a donor, and physically It seems to function as a site that emits electrons. The interaction (adsorption) between this oxygen vacancy and the acceptor gas such as O ₂ and NO remaining in the discharge space of the PDP becomes stronger as the temperature becomes lower. As a result, the electron emission site is blocked and the electron emission ability is reduced. This delays the PDP discharge response time. As a result, it is considered that the degree of change in the discharge response time within a wide temperature range increases as the amount of oxygen deficiency increases.

  Alternatively, only the F center plays a central role in the discharge response of the PDP, and the thermal stability of the F center is around 0 ° C. even when the interaction between the oxygen deficient portion and the residual gas is not taken into consideration. The oxygen deficiency (in particular, the F center) is known to be generally stabilized at higher temperatures (VM Orera, Y. Chen, Phys. Rev. B36, 6120 (1987)). If the existence probability) changes rapidly with temperature, the temperature dependence of the degree of change in the discharge response time is considered to change as well. As a result, in a film having a large amount of oxygen vacancies, the degree of change in discharge response time within a wide temperature range increases.

  From these facts, it can be seen that there is a correlation between the oxygen deficiency in the magnesium oxide film and the temperature dependence of the degree of change in the discharge response time of the PDP. When the amount of oxygen deficiency in the magnesium oxide film is small, the temperature dependence of the degree of change in the discharge response time of the PDP is improved.

In the magnesium oxide film of the present invention, the amount of oxygen deficiency obtained from the total number of Fs centers and Fs ⁺ centers existing on the surface of the magnesium oxide film is 5.0 × 10 ^{15 to} 1.0 × 10 ^17. / Cm ³ , preferably 5.0 × 10 ^{15 to} 8.0 × 10 ¹⁶ pieces / cm ³ .
Further, the amount of oxygen vacancies is determined from Fs centers present in the magnesium oxide film surface is 5.0 × ¹⁰ 15 ~5.0 × ^{10 16} atoms / cm ^3, preferably 5.0 × ¹⁰ 15 ~4. It is 0 × 10 ¹⁶ pieces / cm ³ .
Further, the amount of oxygen vacancies is determined from Fs ⁺ centers present in the magnesium oxide film surface is 5.0 × ¹⁰ 15 ~5.0 × ^{10 16} atoms / cm ^3, preferably 5.0 × ¹⁰ 15 to 4 0.5 × 10 ¹⁶ pieces / cm ³ , and more preferably 5.0 × 10 ^{15 to} 4.0 × 10 ¹⁶ pieces / cm ³ .

Here, the surface of the magnesium oxide film is the thickness of the film surface converted to Fs ⁺ center by exciting the Fs center by irradiating UV light of 255.5 nm at an intensity (I ₀ ) of 100 μW / cm ² for 30 minutes. Means.

When the magnesium oxide film is measured by ESR, two types of signals are observed at g = 2.0024 and g = 2.0003 before and after ultraviolet irradiation. The concentration obtained by adding these two types of signals becomes the concentration of F ⁺ center (before ultraviolet irradiation) or the concentration of F center (after ultraviolet irradiation) in the entire film. Among these, the signal of g = 2.003 can be identified as the Fs ⁺ center existing on the surface of the magnesium oxide film because the g value matches the value of the F ⁺ center existing on the surface of the magnesium oxide single crystal. . Therefore, the concentration of Fs ⁺ center existing on the film surface (before ultraviolet irradiation) or the concentration of Fs center (after ultraviolet irradiation) can be obtained from only the signal of g = 2.003.

4. The oxygen deficiency obtained from the total number of Fs centers and Fs ⁺ centers present on the surface of the magnesium oxide film of the present invention is 5.0 × 10 ^{15 to} 1.0 × 10 ¹⁷ pieces / cm ³ . It is preferably 0 × 10 ^{15 to} 8.0 × 10 ¹⁶ pieces / cm ³ . This is because if this value is less than 5.0 × 10 ¹⁵ pieces / cm ³ , it cannot be detected by ESR, while if it exceeds 1.0 × 10 ¹⁷ pieces / cm ³ , oxygen present on the film surface This is because the amount of defects becomes excessive, and the temperature dependence of the degree of change in the PDP discharge response time cannot be reduced.

Moreover, the oxygen deficiency calculated | required from the Fs center which exists in the magnesium oxide film surface is 5.0 * 10 < ¹⁵ > -5.0 * 10 < ¹⁶ > piece / cm < ³ >, 5.0 * 10 < ¹⁵ > -4.0 *. It is preferably 10 ¹⁶ pieces / cm ³ . Moreover, the oxygen deficiency calculated | required from the Fs ⁺ center which exists in the magnesium oxide film surface is 5.0 * 10 < ¹⁵ > -5.0 * 10 < ¹⁶ > piece / cm < ³ >, 5.0 * 10 < ¹⁵ > -4.5. × is preferably ^{10 16} / cm ^3, and more preferably 5.0 × ¹⁰ 15 to 4.0 × ^{10 16} / cm ^3. This is because if these values are less than 5.0 × 10 ¹⁵ pieces / cm ³ , they cannot be detected by ESR, while if they exceed 5.0 × 10 ¹⁶ pieces / cm ³ , they exist on the film surface. This is because the amount of oxygen vacancies becomes excessive, and the temperature dependence of the degree of change in the PDP discharge response time cannot be reduced.

  Moreover, in the magnesium oxide film of this invention, it is preferable that the change degree of the discharge response time of PDP is 1.1-100 in 15-90 degreeC which is a guarantee temperature range of PDP, and is 2-90. More preferably. This is because it is difficult to produce a magnesium oxide film when the degree of change in the discharge response time of the PDP within the range of −15 to 90 ° C. is less than 1.1. This is because when the time exceeds the threshold value, “flickering” of the panel occurs, and the luminance and contrast decrease.

The thickness of the magnesium oxide film is preferably 0.5 to 1.5 μm, and more preferably 0.7 to 1.2 μm. If the film thickness is less than 0.5 μm, it is too thin to function as a protective film and the life of the PDP is insufficient. On the other hand, if it exceeds 1.5 μm, it takes a long film formation time. It is because it is too much.
The crystal orientation of the magnesium oxide film is preferably (111) plane single or (111) plane preferred orientation. This is because if the amount of orientation to the (111) plane is extremely reduced, the discharge response of the PDP is lowered.

  In the present invention, in order to reduce the amount of oxygen vacancies in the magnesium oxide film, (1) increase the amount of oxygen introduced into the film formation apparatus during film formation, (2) lower the electron beam output during film formation, and By suppressing the radiant heat of the substrate and suppressing the substrate temperature rise at the time of film formation, oxygen is efficiently taken into the film. (3) Water vapor with higher oxidizing ability is used as an oxygen source to the film formation apparatus at the time of film formation. A method such as introduction can be used.

[PDP]
The PDP of the present invention has a configuration in which the magnesium oxide film of the present invention is provided on a dielectric layer. In the PDP of the present invention, basically, a sustain electrode such as ITO and a scan electrode are provided on one side of a front plate made of a glass substrate, and a dielectric layer made of transparent low-melting glass or the like is provided thereon. Further, a magnesium oxide film as a protective film is further provided thereon.

  Next, the manufacturing method of the magnesium oxide film of this invention is demonstrated. The magnesium oxide film of the present invention can be formed by electron beam vapor deposition or ion plating using a polycrystalline magnesium oxide vapor deposition material as a target. By using polycrystalline magnesium oxide vapor deposition material instead of single crystal magnesium oxide, the vapor deposition material splash (splash) is prevented and the vapor deposition efficiency is improved, and the magnesium oxide film is uniformly formed on a large area dielectric layer The film can be formed to a thickness of In addition, according to the electron beam evaporation method, a film can be formed with a uniform film thickness on a large-area substrate.

Next, the case where this electron beam evaporation method is used is demonstrated concretely.
A “crucible” positioned at the bottom of the electron beam vapor deposition apparatus is filled with a polycrystalline magnesium oxide vapor deposition material, and a glass substrate serving as a front plate of the PDP is disposed at a position 400 to 800 mm above it. A dielectric layer or the like is already provided on the surface of the glass substrate facing the “crucible”. After evacuating the film forming chamber of the vapor deposition apparatus to 1.0 × 10 ^{−4 to} 1.0 × 10 ⁻⁵ Pa, oxygen gas partial pressure 1.0 × 10 ^{−2 to} 6.0 × 10 ⁻² Pa, water vapor Partial pressure 1.0 × 10 ⁻³ Pa or less, electron beam output 500 to 1500 W, deposition pressure 1.0 × 10 ^{−2 to} 6.0 × 10 ⁻² Pa, substrate set temperature 150 to 300 ° C., deposition rate 0 Film formation is performed at 5 to 15 nm / second.

The ESR is measured using a commercially available ESR apparatus at a central magnetic field of 337 mT, a frequency of 9.46 GHz, and a temperature of 20K. The detection limit is 5.0 × 10 ¹⁵ pieces / cm ³ .
In order to measure the concentration of the non-magnetic F center, first, the concentration of the original F ⁺ center is measured at 20K, and after irradiating the above-described ultraviolet rays at 20K, the ESR is measured. The concentration of the F ⁺ center excited by the ultraviolet light is defined as the F center concentration. Therefore, the F ⁺ center concentration (F ⁺ center amount) is determined from the ESR signal before ultraviolet irradiation, and the Fcenter concentration (Fcenter amount) is determined from the signal after ultraviolet irradiation. This concentration corresponds to the amount of oxygen deficiency.
Further, the concentration of the Fs ⁺ center existing on the surface of the magnesium oxide film is obtained from the signal of g = 2.003 before the ultraviolet irradiation. Further, the Fs center existing on the surface of the magnesium oxide film can be obtained from a signal of g = 2.003 after the ultraviolet irradiation.

  In the present invention, by forming the magnesium oxide film so as to reduce the amount of oxygen vacancies, the electron emission ability is less likely to change depending on the temperature, and does not affect the discharge response time of the PDP. An excellent magnesium oxide film with little change in discharge response can be obtained.

  Hereinafter, the present invention will be described in more detail by way of examples. The present invention is not limited to the following examples.

[Example 1]
<Production of magnesium oxide film>
The polycrystalline magnesium oxide vapor deposition material was produced in accordance with the production method disclosed in JP-A-10-297956. Using a polycrystalline magnesium oxide vapor deposition material having a purity of 99.98% and density of 98% obtained by sintering, a magnesium oxide film having a film thickness of 1 μm and a (111) crystal orientation is formed by an electron beam vapor deposition apparatus. It was. A “crucible” located at the bottom of the electron beam deposition apparatus was filled with a polycrystalline magnesium oxide deposition material, and a PDP front plate was placed above it. Regarding the film forming conditions, the ultimate vacuum is 1.0 × 10 ⁻⁴ Pa, the oxygen gas partial pressure is 3.0 × 10 ⁻² Pa, the water vapor partial pressure is less than 1.0 × 10 ⁻⁴ Pa, and the electron beam output Was 900 W, the deposition pressure was 3.0 × 10 ⁻² Pa, the substrate set temperature was 200 ° C., and the deposition rate was 1.5 nm / second.

<Evaluation of discharge response>
In order to evaluate the discharge response, first, a PDP test substrate was fabricated. The rib height was 150 μm, the rib pitch was 360 μm, and 4 vol% xenon gas and the remaining neon gas were used as the discharge gas and sealed inside at a discharge gas pressure of 6.7 × 10 ⁴ Pa (500 Torr).
Using the PDP test substrate, a counter discharge test between two glass plates was performed as a pseudo address discharge test. In the test, the panel temperature was changed in the temperature range of 15 to 90 ° C. corresponding to the guaranteed temperature range of the PDP, and the applied voltage was 200 V and the frequency was 1 kHz. At that time, the near-infrared ray emitted by the discharge is detected using a photomultiplier tube, and the emission time from when the voltage is applied until the end of the latest emission is measured with the end of emission when the near-infrared ray is no longer detected. did. In order to evaluate statistical variation, measurements were repeated 3000 times at a certain measurement temperature, and the emission peak was overwritten. And the maximum response time and the minimum response time within the range of temperature -15-90 degreeC were calculated | required, and the maximum response time was divided | segmented by the minimum response time, and it was set as the change degree of the response time.
The degree of change in the obtained discharge response time was 75.

<ESR measurement pretreatment>
The magnesium oxide film produced on the P-type silicon substrate by the above-described method was vacuum degassed at 350 ° C. for 10 minutes, and helium gas was introduced and sealed in a glass tube. Then, when measuring F and Fs centers, ultraviolet rays with a wavelength of 255.5 nm were irradiated for 30 minutes at an intensity of 100 μW / cm ² using an ultraviolet irradiation device.

<Measurement of ESR>
The ESR device used was “ESP350E” manufactured by BRUKER, the microwave frequency counter used “HP5351B” manufactured by HEWLETT PACKARD, “ER035M” manufactured by BRUKER, and the cryostat used “ESR910” manufactured by OXFORD. .

The measurement conditions are
Measurement temperature 20K
Central magnetic field 3371G
Magnetic field sweep width 150G
Modulation 100KHz, 2.0G
Microwave 9.46GHz, 2.5μW
Sweep time 83.886s × 16time
Time constant 327.68ms
Data points 1024 points
Cavity TM ₁₁₀ , cylindrical.

F center amount (signals of g = 2.0024 and g = 2.0003 after UV irradiation), F ⁺ center amount (before UV irradiation, signals of g = 2.0024 and g = 2.0003), Fs center amount (After UV irradiation, g = 2.0003 signal) and Fs ⁺ center amount (before UV irradiation, g = 2.0003 signal) were determined.
Table 1 shows the film forming conditions, the degree of change in the discharge response time, the F center amount, the F ⁺ center amount, the Fs center amount, and the Fs ⁺ center amount.

[Example 2]
A magnesium oxide film and a PDP test substrate were produced in the same manner as in Example 1 except that the oxygen partial pressure during film formation was 1.0 × 10 ⁻² Pa, water vapor was not added, and the electron beam output was changed to 1000 W. . In the same manner as in Example 1, the degree of change in discharge response time and the F center amount, F ⁺ center amount, Fs center amount, and Fs ⁺ center amount were obtained.
Table 1 shows the film forming conditions, the degree of change in the discharge response time, the F center amount, the F ⁺ center amount, the Fs center amount, and the Fs ⁺ center amount.

[Example 3]
Example 1 except that the oxygen partial pressure during film formation was 1.0 × 10 ⁻² Pa, no water vapor was added, the electron beam output was 1000 W, and the film formation rate was changed to 3.5 nm / second. A magnesium oxide film and a PDP test substrate were produced. In the same manner as in Example 1, the degree of change in discharge response time and the F center amount, F ⁺ center amount, Fs center amount, and Fs ⁺ center amount were obtained.
Table 1 shows the film forming conditions, the degree of change in the discharge response time, the F center amount, the F ⁺ center amount, the Fs center amount, and the Fs ⁺ center amount.

[Example 4]
A magnesium oxide film and a PDP test substrate were prepared in the same manner as in Example 1 except that the oxygen partial pressure during film formation was changed to 1.0 × 10 ⁻² Pa and the water vapor partial pressure was changed to 1.0 × 10 ⁻³ Pa. did. In the same manner as in Example 1, the degree of change in discharge response time and the F center amount, F ⁺ center amount, Fs center amount, and Fs ⁺ center amount were obtained.
Table 1 shows the film forming conditions, the degree of change in the discharge response time, the F center amount, the F ⁺ center amount, the Fs center amount, and the Fs ⁺ center amount.

[Comparative Example 1]
A magnesium oxide film and a PDP test substrate were produced in the same manner as in Example 1 except that the oxygen partial pressure during film formation was 1.0 × 10 ⁻² Pa and water vapor was not added. In the same manner as in Example 1, the degree of change in discharge response time and the F center amount, F ⁺ center amount, Fs center amount, and Fs ⁺ center amount were obtained.
Table 1 shows the film forming conditions, the degree of change in the discharge response time, the F center amount, the F ⁺ center amount, the Fs center amount, and the Fs ⁺ center amount.

[Comparative Example 2]
A magnesium oxide film and a PDP test substrate were produced in the same manner as in Example 1 except that the oxygen partial pressure during film formation was 1.0 × 10 ⁻² Pa, no water vapor was added, and the electron beam output was changed to 750 W. . In the same manner as in Example 1, the degree of change in discharge response time and the F center amount, F ⁺ center amount, Fs center amount, and Fs ⁺ center amount were obtained.
Table 1 shows the film forming conditions, the degree of change in the discharge response time, the F center amount, the F ⁺ center amount, the Fs center amount, and the Fs ⁺ center amount.

When Examples 1 to 4 were compared with Comparative Examples 1 and 2, the degree of change in the discharge response time in Examples 1 to 4 was as small as 100 or less. On the other hand, in Comparative Examples 1 and 2, the degree of change in discharge response time exceeded 100.
Further, the F center amount, the F ⁺ center amount, the Fs center amount, and the Fs ⁺ center amount were generally smaller in Examples 1 to 4 than those in Comparative Examples 1 and 2.

From the above results, since the magnesium oxide films of Examples 1 to 4 have a small amount of F center, F ⁺ center, Fs center, and Fs ⁺ center, the oxygen deficiency of the magnesium oxide film is small and a wide temperature range. It was confirmed that the film was an excellent film with little change in discharge response.
Further, when the 42-inch PDP using the magnesium oxide film of Examples 1 to 4 is manufactured and driven, the panel “flickering” due to defective writing discharge (writing error due to insufficient writing or erroneous writing) is reduced. A PDP with improved contrast was obtained.

Claims (8)

The amount of oxygen deficiency calculated from the total number of F centers and F ⁺ centers is
A magnesium oxide film having a density of 5.0 × 10 ^{15 to} 2.0 × 10 ¹⁷ / cm ³ . The amount of oxygen deficiency required from the F center is
A magnesium oxide film having a density of 5.0 × 10 ^{15 to} 1.0 × 10 ¹⁷ pieces / cm ³ . The amount of oxygen deficiency required from the F ⁺ center is
A magnesium oxide film having a density of 5.0 × 10 ^{15 to} 1.0 × 10 ¹⁷ pieces / cm ³ . The amount of oxygen deficiency obtained from the total number of Fs centers and Fs ⁺ centers existing on the surface of the magnesium oxide film is
A magnesium oxide film having a density of 5.0 × 10 ^{15 to} 1.0 × 10 ¹⁷ pieces / cm ³ . The amount of oxygen deficiency calculated from the Fs center existing on the surface of the magnesium oxide film is
A magnesium oxide film having a density of 5.0 × 10 ^{15 to} 5.0 × 10 ¹⁶ / cm ³ . The amount of oxygen deficiency calculated from the Fs ⁺ center existing on the surface of the magnesium oxide film is
A magnesium oxide film having a density of 5.0 × 10 ^{15 to} 5.0 × 10 ¹⁶ / cm ³ . The change rate of the discharge response time of the plasma display panel at −15 to 90 ° C.
It is 1.1-100, The magnesium oxide film as described in any one of Claims 1-6 characterized by the above-mentioned.   A plasma display panel comprising the magnesium oxide film according to claim 1 on a dielectric layer.