JPH03205786A - Manufacture of double insulating thin film electroluminescence device - Google Patents

Abstract

PURPOSE:To manufacture a device with high luminescence intensity and high reliability at a high yield by applying the annealing process so that the portions serving as interfaces between layers are not exposed to the outside, and changing the material of a back electrode. CONSTITUTION:The reform annealing process is applied after a transparent electrode 12, the first dielectric region 13, a luminous region 14, the second dielectric region 15, and a back electrode 16 are laminated in sequence, the luminous region 14 is pinched by two dielectric regions 13, 15, and the reform annealing process is applied so that the interfaces between the luminous region 14 and the dielectric regions 13, 15 are not exposed to the outside. No pollution or void is generated on these interfaces due to the annealing process. A material mainly made of a high-melting point metal or a silicide of the high-melting point metal is used for the back electrode 16, its heat resistance is high, and the deterioration of the back electrode 16 itself and the diffusion of the back electrode material and the alloying with a dielectric substance rarely occur in the reform annealing process to improve the luminescence characteristic. A device with high intensity and high reliability can be manufactured at a high yield.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a double-insulated thin film electroluminescent device. It is about technique.

[Background Art] Thin-film electroluminescent devices that exhibit an electroluminescent phenomenon upon application of an alternating current electric field are attracting attention as panels for thin display devices because of their high brightness, high resolution, and large display capacity.

This electroluminescent device 22 uses a double insulating thin film electroluminescent device with a structure in which both sides of the entire optical layer are sandwiched between dielectric materials in order to improve luminous efficiency by increasing breakdown voltage and preventing leakage current. A device is being developed. A method of manufacturing this double insulated thin film electroluminescence device will be described below with reference to FIG.

As shown in FIG. 3(a), an I T
A transparent electrode 2 is formed by vapor deposition of indium tin oxide (Indium Tin Oxide), and six first dielectric layers 3 and a light emitting layer N4 are sequentially laminated thereon. Here, the luminescence N4 is caused by manganese (Mn
) and other transition metals and terbium (Tb) and other additives are added.

After the formation of the rays N4, a 60%
Annealing treatment may be performed at a temperature of 0° C. for about 1 hour. This is done for the purpose of improving the light emitting characteristics of the light emitting layer.Next, the second dielectric layer 5 is formed as shown in FIG. 3(b), and then the second dielectric layer 5 is formed as shown in FIG. ), Af is evaporated onto the second dielectric layer 5 to cover the back electrode 6 .

[Problem to be solved by Yaomei] In the above-mentioned conventional method for manufacturing a double-insulated thin film electroluminescent device, the structure shown in FIG. During this annealing process, contaminants may adhere to the surface 4a of the light emitting layer 4, which is exposed to the outside, and pores may be generated.

These contaminants and vacancies cause defects etc. to occur at the interface of the second dielectric layer 5 that is subsequently formed, leading to deterioration in luminance and device life, as well as deterioration in characteristics between individual devices. This causes variations, resulting in a decrease in yield.

Therefore, the present invention is an attempt to solve the above-mentioned problems.The object of the present invention is to perform annealing treatment in a state where the interface between each layer is not exposed to the outside, and to change the material of the back electrode. By preventing deterioration of the interface condition between each layer in the device and deterioration of the back electrode during processing,
It is an object of the present invention to provide a method for manufacturing a double insulating film electroluminescent device with high yield while ensuring uniformity of the device and having high luminance and high reliability.

(Means for solving the problem) In order to solve the above problems, at least a transparent electrode,
In the method of manufacturing a double insulating thin film electroluminescent device having a structure in which a first dielectric region, a light emitting nozzle region, a second dielectric region and a back electrode are laminated in sequence, the measures taken by the present invention are as follows: The electrode is formed of a material whose main component is a high-melting point metal or a silicide of a high-melting point metal, and includes at least a transparent electrode, a first dielectric region, a transparent region, a second dielectric region, and a back electrode. After the laminated structure has been completed, a modification annealing treatment is performed on the light emitting nodule region.

In addition, materials whose main constituents are high-melting point metals or silicides of high-melting point metals have a melting point of 1000°C or higher and a specific resistance of 10-
It is desirable that the resistance is 3 ΩCm or less, and the modification annealing treatment is preferably performed in a temperature range of 400° C. to 700″C in a vacuum or an atmosphere of oxygen or inert gas.

(Function) According to the above means, the modification annealing treatment is performed after completing the structure in which the transparent electrode, the first dielectric region, the light emitting nodule region, the second dielectric region and the back electrode are sequentially laminated. The light emitting nodule region is sandwiched between two dielectric regions, and the modification annealing treatment is performed in a state where the interface between the light emitting nodule region and the electric conductor region is not exposed to the outside.Therefore, the annealing treatment is performed on these interfaces. No contamination or porosity occurs.

In addition, since the back electrode is made of a material whose main component is a high-melting point metal or a silicide of a high-melting point metal, it has high heat resistance and undergoes a modification annealing process (generally 400°C to 70°C) to improve light emission characteristics. It is carried out within the range of 0 0 'C.

), deterioration of the back electrode itself, diffusion of the back electrode material, alloying with the dielectric, etc. are less likely to occur.

By the way, in order to solve the problems of conventional manufacturing methods,
As a means different from the above-mentioned means, it is also conceivable to perform annealing immediately after forming the second dielectric layer 5 as shown in FIG. 3(b), but in this case, the second dielectric layer 5 is Since the surface 5a of the dielectric layer 5 is exposed, the state of the interface between the second dielectric layer 5 and the back electrode 6 deteriorates. On the other hand, when annealing is performed in the state shown in FIG. 3(C) after forming the conventional back electrode 6 made of A2, it is considered that there is almost no deterioration of the interface state between each layer. However, in the device manufactured by this method, the luminance was actually lower than that of a device not subjected to annealing treatment. Curve B in Figure 2 shows the relationship between luminescence brightness and applied voltage without annealing, and curve A in Figure 2 shows the relationship between the luminance and applied voltage when annealing was performed in the state shown in Figure 3(c). It shows the case. The reason for this is that Al, the material of the back electrode, has a low melting point (melting point 660"C).
Therefore, it seems that this is because the back electrode itself deteriorates during the annealing process.

In the means of the present invention, based on such facts,
Since the modification annealing treatment is performed after the laminated structure is completed and a high melting point material is used for the back electrode, it is possible to simultaneously avoid deterioration of the interface condition and deterioration of the back electrode due to the modification annealing treatment. . Therefore, it is possible to fully bring out the annealing effect in the emission nodule region that is inherent in the modification annealing process. Therefore, the luminance of the double-insulated thin film electroluminescent device can be increased, and the reliability is also improved.

Furthermore, since it is difficult to control the reproducibility of the interface state and electrode deterioration itself, it is thought that the deterioration of the interfacial state and the deterioration of the back electrode due to the modification annealing process vary considerably between different types. Moreover, the light emitting characteristics of the device, ie, the light emission brightness and lifetime, are sensitive to deterioration of the interface state and deterioration of the back electrode. Therefore, by preventing the deterioration of the interface state and the deterioration of the back electrode, the cause of variations in the light emitting characteristics of each device is eliminated, and the yield of products is improved.

〔Example〕

Next, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows the structure of a double insulating thin film electroluminescent device. First, an ITO film with a thickness of 2000 was deposited on a glass substrate 11 by sputtering to form a transparent electrode 1.
Set it to 2. Next, as the first dielectric [13], a film thickness of 300
0 people's A I2 z○3 is formed by Y battering method. Then, a light-emitting layer 14 having a thickness of 5000 nm is formed using zinc sulfide containing 0.5% by weight of manganese by electron beam evaporation. Further, a second dielectric layer 15 is formed thereon.
As! 3000 thick A/! z O. @ Formed by sputtering method. Finally, a film is used as the back electrode 16. Chromium (Cr) with a thickness of 3000 mm is deposited by a spa sottering method. After completing the laminated structure shown in Figure 1 in this manner, an annealing treatment is performed at a temperature of 600 DEG C. for 1 hour in a vacuum (10-'T+rr).

According to the above manufacturing method, since the annealing process is performed after the laminated structure is completed, the interfaces between each region are closed from the outside world, and the annealing process prevents pores and contamination from forming at these interfaces. Therefore, the characteristics of the device will not be deteriorated. Also, the melting point of the back electrode 16 is 1 8 9
Since the back electrode 16 is made of chromium with a temperature of 0.0" C, the back electrode 16 itself does not deteriorate at the temperature of the annealing treatment. This is shown by curve C in Fig. 2. The luminance is approximately twice as high as that of luminescence characteristic curve B when no annealing treatment is performed.

As described above, in this example, the light emitting characteristics are significantly improved compared to the double insulating thin film electroluminescent device formed by the conventional manufacturing method. Furthermore, since there is no deterioration of the unstable interface state or deterioration of the back electrode, variations between devices are reduced and product yield is improved.

As the back electrode in the present invention, it is desirable to use a material having a melting point of 1000° C. or higher and a specific resistance of 10 −3 Ωcm or lower. For example, Ti, Mo, Ta, W, Cr
High melting point metals such as Tisi2, MoSi2, Ta, which are silicides of these high melting point metals, etc.
Siz, WSi2, CrSi2, etc. are equal to a minute.

In addition, in the annealing treatment, 400 to 70
It is preferable to carry out the process within a temperature range of 0'C, preferably in a vacuum or in an atmosphere of oxygen or inert gas.

Note that the first dielectric layer and the second dielectric layer may be a combination of various highly insulating dielectrics.

〔Effect of the invention〕

The present invention provides a method for manufacturing a double edge thin film electroluminescent device, in which the back electrode is formed of a material whose main component is a refractory metal or a silicide of a refractory metal, and a transparent electrode and a tenth dielectric region are provided. The present invention is characterized in that, after the laminated structure consisting of the light emitting nodule region, the second dielectric region, and the back electrode is fully formed, the modification annealing treatment of the light emitting nodule region is performed, so that the following effects are achieved.

In other words, since the modification annealing treatment is performed after the formation of the product N structure, the modification annealing treatment is performed while the interfaces between each region are enclosed inside, so there is no possibility of contaminant adhesion or vacancies at these interfaces. If this occurs, it will not adversely affect the luminous properties of the double insulating thin film electroluminescent device 1 or the device life. Further, since the back electrode is made of a material whose main component is a high melting point metal or a silicide of a high melting point metal, the back electrode does not deteriorate during the modification annealing process.

In this way, by removing the negative effects of the modification annealing process that conventionally occurred, it is possible to effectively bring out the improvement effect of the original luminescent properties of the modification annealing process, resulting in high brightness and high reliability. Heavy insulating '4 membrane electroluminescent devices can be manufactured.

In addition, by reliably preventing deterioration of the interface condition and deterioration of the back electrode during annealing treatment, it is possible to reduce variations in light emission characteristics between devices compared to conventional devices, and to improve the performance of double-insulated thin-film electroluminescent devices. It can be manufactured with good yield.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a double-insulated thin film electroluminescent device fabricated in accordance with an embodiment of the present invention. FIG. 2 shows the relationship (curve C) between the luminance brightness and the applied voltage of a double-insulated thin film electroluminescent device manufactured by the manufacturing method according to the embodiment of the present invention, in the case of a device equipped with an AI2 back electrode. (Curve A) and a case where no annealing treatment is performed (Curve B). FIG. 3(a) is a cross-sectional view showing the structure after forming the light emitting layer in the conventional manufacturing method, and FIG. 3(b) is the second dielectric layer type, 5
! FIG. 3(C) is a sectional view showing the structure after the rear electrode type of Af. (Explanation of symbols) 12...Transparent electrode 13...Lth dielectric layer 14...Light emitting layer 15...Second dielectric layer 1 Figure 150 200 250 Voltage (V) 300 Figure 2

Claims (2)

[Claims] (1) A method for manufacturing a double insulated thin film electroluminescent device having a structure in which at least a transparent electrode, a first dielectric region, a light emitting region, a second dielectric region and a back electrode are sequentially laminated, comprising: the back surface; The electrode is formed of a material whose main component is a high melting point metal or a silicide of a high melting point metal, and after the laminated structure is completed, a modification annealing treatment is performed on the light emitting nodule region. A method for manufacturing a thin film electroluminescent device. (2) The material whose main component is a high melting point metal or a silicide of a high melting point metal has a melting point of 1000°C or higher and a specific resistance of 1
0^-^3 Ωcm or less, and the modification annealing treatment is performed at 40 Ω in vacuum or in an atmosphere of oxygen or inert gas.
2. The method of manufacturing a double constant-green thin film electroluminescent device according to claim 1, characterized in that the process is carried out within a temperature range of 0°C to 700°C.