JPS5978386A - Manufacture of electrooptic unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing an electro-optical device.

For more details, see Metal-Insulating Film-Metal (Metal-Insulating Film-Metal)
A nonlinear element with a sulator-Metal structure (
The present invention relates to a method of manufacturing an electro-optical device equipped with an M element (hereinafter referred to as an M element).

In recent years, the practical use of g-optical devices using liquid crystals has progressed, and they have been applied to many fields including wristwatches and calculators.

However, when considering application to other fields, such as display units in information terminals and small personal electronic devices, the advantages of small display unit volume, low voltage drive, and low power consumption are still lacking. First, the voltage-contrast characteristics of the drive 11J were not very good, and because multi-digit matrix driving was not possible, the amount of information that could be displayed was small.

Matrix driving using M1M elements has been considered as one method to eliminate the drawbacks of electro-optical devices using liquid crystals.

As shown in FIG. 1, the electro-optical device incorporating this MIM element has an M-process M element 1 and each M-process using metal forming one metal electrode of the M-process M element. A substrate 5 consisting of lead portions 2 for connecting the M elements in the column direction, terminal portions 5 for connection to the outside of the substrate, and pixel electrodes 4, and a counter substrate ( (not shown) is subjected to liquid crystal alignment treatment, resulting in several It m
After adhering with a gap of about 20 IL rn and encapsulating liquid crystal, it is made by laminating a polarizing plate.

Figure 2 is an enlarged view of one pixel, and Figure 3 is a diagram of Figure 2 Q-
FIG. 6 is a cross-sectional view of the 6' portion.

In the conventional manufacturing process, a valve metal such as Tσ, At, or Nb is used to connect one metal electrode 6 of the MIM element 1, the lead part 2 that connects the metal electrode 6 of each MUM element in the column direction, and the connection to the outside of the substrate. After the desired terminal portion 6 is formed, an oxide film 7 is formed on the surface of the metal electrode B by anodic oxidation to serve as an insulating film of the MIM element 1.

Furthermore, after forming the counter electrode 8 of the M element 1 and the connection part 9 with the pixel electrode 4 with metal such as NiCr/Au or Or/Au, S rI02 , In2 o3 or T is formed.

The pixel electrode 4 is formed using a transparent conductive thin film such as (N203-4-3nO2), and the substrate on the MIM element side is completed.

The equivalent circuit for one pixel when combined with the counter substrate and sealed with the liquid crystal is shown in Figure 4, with MIM element 1 having capacitance Q MIM and nonlinear resistance RMIM and capacitor 1JObc.
It can be considered that the liquid crystal portion 1o having the resistance Rho and the liquid crystal portion 1o are connected in series.

In this case, the operating principle is that the low resistance state of the MIM element 1 is utilized during the selection period of the IJ drive to accumulate charge in the capacitor Obc of the liquid crystal portion 10, and the high resistance state of the MIM element 1 is accumulated during the non-selection period. It can be said that display is performed by applying an electric field to the liquid crystal to control the alignment state of the liquid crystal by holding the above-mentioned charge using the state. In this case, the effective value applied to the liquid crystal is determined by the interrelationship between the nonlinearity of the M element 1 and the capacitance CLc and resistance RLc of the liquid crystal portion 10.

In the conventional manufacturing process described above, if the lead 2 and the pixel electrode 4 overlap due to dust on the substrate, dust in the photoresist, or other causes during the photoringraph process for forming the pixel electrode 4, as shown in FIG. The disadvantage is that there are essentially two M elements connected to the pixel electrode, and the electric characteristics of the M element and the liquid crystal part become mismatched, resulting in abnormal operation, resulting in a display defect as an electro-optical device. It had

In order to eliminate such defects, the present invention attempts to correct the abnormally shaped pixel electrode by an anodizing process.

Hereinafter, explanation will be given according to examples.

EXAMPLE A thin film of T(+2011 and Tα) is formed on a Pyrex glass substrate. Then, one metal electrode 6 of the M element
1) The leads 2 for connecting the metal electrodes 6 in the column direction and the terminal portions for electrically connecting the leads 2 to the outside of the substrate are patterned.

Next, a TO thin film is formed by sputtering, and the pixel electrode 4 is turned by a photolithography process. Furthermore, after applying a resist and performing a blank-hake process, exposure and development are performed again in the shape of the pixel electrode, followed by post-baking. Even if there is a pixel electrode 4 whose shape becomes abnormal due to dust or the like when patterning the pixel electrode 4, the dust has been removed by cleaning etc. associated with the normal 7 otolithography steps. The shape of the resist formed on the pixel electrode 4 which has become abnormal again rarely becomes abnormal again, for example, as shown in FIG. 6(a).
The resist 12 formed again on the patterned pixel electrode 4 has a normal shape as shown by the hatched area in FIG. 6(6).

In this state, when the lead part 2 and the metal electrode 6 part of one of the MT and M elements are anodized in a citric acid aqueous solution, the ITO of the pixel electrode 4 which overlaps with the lead part 2 and is not covered with the resist 12 is electrochemically oxidized. The shape of the pixel electrode 4 is corrected.

After removing the resist 12, a counter electrode 8 of the M element (Or) is deposited and patterned.

Further, a liquid crystal alignment process is performed, and a separately produced counter substrate which has also been subjected to a liquid crystal alignment process is adhered to maintain a gap of 10 μm to encapsulate the liquid crystal, and then a polarizing plate is attached to form an electro-optical device.

As described above, according to the present invention, it is possible to obtain an electro-optical device in which display defects caused by abnormal shapes of pixel electrodes are reduced.

[Brief explanation of drawings]

FIG. 1 is a plan view schematically showing a substrate provided with an M element. FIG. 2 is an enlarged view of one pixel in FIG. - Figure 3 is a sectional view taken along line aa' in Figure 2; Figure 4 shows one example of an electro-optical device using an MXM element and liquid crystal.
This is an equivalent circuit for pixels. FIG. 5 is a diagram showing an example of a pixel electrode that has an abnormal shape. FIG. 6 is a diagram illustrating modification of a pixel electrode in an embodiment of the present invention. Above Figure 1 Figure 2 Figure 4

Claims (1)

[Claims] A liquid crystal is sealed between two substrates, and at least one of the substrates is provided with a plurality of pixel electrodes arranged in rows and columns, and a nonlinear element having a metal-insulating film-metal structure coupled to the pixel electrodes. In the method for manufacturing an electro-optical device, the insulating film of the nonlinear element is obtained by anodizing one of the metals, and the pixel electrode is formed before the anodizing process and is protected by a resist during the anodizing process. A method for manufacturing an electro-optical device, characterized in that: