JPS60144722A - Production of solid state type electrochromic display element - Google Patents

Abstract

PURPOSE:To improve productivity and reproducibility by installing glass substrate on which a lower electrode and iridium hydroxide film are patterned in a reaction chamber and laminating successively a tantalum pentaoxide film, tungsten trioxide film and upper electrode by CVD on said substrate. CONSTITUTION:Ta2O5, WO3 and upper ITO electrode are continuously formed by a plasma CVD method on a substrate on which a lower ITO electrode and Ir(OH)n are preliminarily patterned. Ta(OC2H5)5 is introduced with gaseous H2 as a carrier gas into a vacuum chamber and a gaseous mixture composed of Ta(OC2H5)5-H2 and an equal amt. of gaseous O2 are introduced therein to form a Ta2O5 film. WCl6 is then introduced likewise with H2 as a carrier gas into the chamber to form WO3 by making the mixing ratio with O2 as 15SCCM (WCl6-H2):10SCCM(O2). A gaseous mixture composed of In(C2H5)3-H2 at 19 SCCM, a gaseous mixture composed of Sn(OCH3)4-H2 at 2SCCM and O2 at 15SCCM are introduced with H2 as a carrier gas into the chamber to form ITO. The film formation by such CVD method is excellent in productivity, reproducibility of element characteristics and ease of process automation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrochrominok (hereinafter abbreviated as EC) display element.

EC display elements are characterized by low viewing angle dependence and good visibility (bright display), and have recently attracted attention as display elements for watches and other fields. Among EC display elements, solid-state elements formed by laminating thin films have been actively researched due to their advantages in thinning and the like. The present invention relates to the production of this solid-state EC element by low-temperature CVD.

FIG. 1 shows a schematic cross-sectional view of the structure of a solid-state EC display element. Transparent conductive film 1 serving as a lower electrode on substrate glass 11
2 (indium-tin oxide (abbreviated as ITO)),
Iridium hydroxide (I r
'(01()n) 1 3, solid electrolyte tantalum pentoxide (Ta20s) 14, reduction colored EC material tungsten trioxide (WO3) 15, and upper I'l'0 electrode 16 in sequence. Formed by vacuum evaporation or ion plating method.

In this structure, WO3, which is a reduced colored EC substance, is represented by WO3+xi-1++x e -+ 1-1xW03, and is colored by double injection of roton (1-1+) and electron (e-). Ir(Of-1)n, which is an oxidized colored EC substance, is Ir(Otl)n -xl-1+ -xe -+ Ir
0x(01-1),.

It is colored by the double emission of protons (H'') and electrons (e-), which are shown by Heavy coloring is observed.

Conventionally, film formation of such solid-state EC elements has been carried out by vacuum evaporation or ion plating. However, these methods have a small effective film forming area compared to the equipment scale (
, which is disadvantageous for industrial production. 11) It is difficult to control the quality, and the reproducibility of the device characteristics tends to be poor.

Furthermore, there are many control parameters, and automation, which is an important key to industrial production, is difficult (1).

The present invention proposes a process that has high productivity and reproducibility and is easy to automate by forming a film by plasma CVD or photo-CVD. This will be explained below using examples.

Example 1 In order to separate the display section into segments, the lower IT
Ta2 o, , W O3 and upper part 11' on the substrate patterned with O electrode and I r (U H) n
Zero electrodes were continuously formed by plasma CVD.

The substrate temperature was 100°C, hydrogen (H2) gas was used as a carrier gas, and pentaethoxytantalum (Ta(QC2Hs)
)5) was introduced into the vacuum chamber (flow rate 20SCCM).

Ta (,0C21-1,), -1-1,, introduce the same amount of oxygen (02) gas as the mixed gas and make the total gas pressure 0.4'l.
"orr", and a Ta205 film was formed with a high frequency power of 100 W.

The film formation rate of Ta2O is 5X/sec and the film thickness is 1
It was μ.

Next, tungsten chloride (WO6,) was introduced with 112 as a carrier gas, and the mixing ratio with 02 was set to 15SCC.
M (wcla-H2): 10 SCCM ((J
), a total gas pressure of 0.25 Torr, and high frequency power SOW to form WO3. The film formation rate of WO3 is ], OX /
IIM J'l was 6500λ in sec. Next, using H2 as a carrier gas, triethylindium (I
n (C21-1,)3)-1-12 mixed gas at 1.9
SCCM, tetramethoxytin (S n (ocl),
)4. ) I-'s mixed gas 2 SCCM, 02
was introduced at 15 SCCM, and ITO was formed at a total gas pressure of 0.35 Torr and a high frequency power of 65 W. The ITO film formation rate was IA/sec and the film thickness was 1000A. The coloring characteristics of the solid-state EC element thus formed were as follows.

Coloring efficiency is a parameter used to evaluate coloring properties.

It represents how much the 6-person charge contributes to coloring. The coloring rate of devices formed by conventional high-frequency ion preniting is 60 ffl/c (633 nm l
-1e-Ne laser measurement), the coloring efficiency of the element formed by the high frequency plasma CVD method of the present invention was 95a4/C, which was a significant improvement.

Example 2 I'a20. , WO3 and the upper ITO electrode were successively formed by the CVD method.

The substrate temperature was set to 100°C, Ta (QC2H,)5 was introduced into the vacuum chamber at a flow rate of 40 SCCM using 1 (2 gas) as a carrier gas. 0□ gas at a flow rate of 20 SCCM was introduced,
The total gas pressure was set to Q, 5 T' o r r. The temperature of the mercury in the reactor is 40°G, and the ultraviolet rays (power 50
0W, wavelength 2537X) was irradiated to form Ta2O.

The deposition rate of Ta2O is 0.5X/sec and 11
-The film thickness was 3000 Å. Next, WC & I
]2 is introduced as a carrier gas, and the mixing ratio with 02 is 5
0SCCM (WCA6-H2): 20 SCCM (
(J2), Hg reactor was introduced and ultraviolet irradiation was performed at a total gas pressure of 07'L' o r r to form WO3. The film formation rate of WOl was 0.7 A/sec, and the film thickness was 3000 A. Furthermore, using 1-12 as a carrier gas, I n (C,, I-1,) 3-1-12 mixed gas was added at 30 SCCM, 5n (OCI-1,) 4-1-
3 SCCM of 12 mixed gas and 22 SCCM of 02 were introduced, the total gas pressure was 0.55 Torr, I-(g IJ actor) was introduced and ultraviolet irradiation was performed to form I'I'O. is 0.3 A/s
The film thickness was 100OA using EC. Like this) C
The charge efficiency of the solid-state type 1C element formed by the VI) method was 907/c, which was superior to 60αlt/c of the conventional high-frequency ion blating forming element.

In this way, plasma CVD or photo CV1 of the present invention
．． ) formation, it was revealed that a solid-state EC element with excellent characteristics could be manufactured. Furthermore, these CVD methods are superior to conventional vacuum evaporation methods and ion blating methods in terms of productivity (larger effective area in the formation tank), reproducibility of device characteristics, and ease of process automation. I think it's a very effective method.

11...Substrate glass, 12...Lower electrode 1
6...Iridium hydroxide film, 14...
Tantalum pentoxide film, 15...Tungsten trioxide film, 16...
...Top electrode.

Claims (1)

[Claims] An indium-tin oxide film as a lower electrode on the substrate glass, an iridium hydroxide film as an oxidized colored EC substance,
Solid electrolyte: tantalum pentoxide membrane, reduction colored EC
In a method for manufacturing a solid-state electrochromic display element in which a tungsten trioxide film as a material and an indium-tin oxide film as an upper electrode are sequentially laminated, the lower electrode and the iridium hydroxide film are patterned and provided in advance. A method for manufacturing a solid-state electrochromic display element, characterized in that a glass substrate is placed in a reaction chamber and sequentially layered with a tantalum pentoxide film, a tungsten trioxide deleaded film, and an upper electrode (CV I).