CN102023436B - Liquid crystal on silicon panel and manufacturing method thereof - Google Patents

Abstract

The invention discloses a silicon-based liquid crystal on silicon (LCoS) panel and a manufacturing method thereof, wherein the LCoS panel comprises a substrate, wherein at least one metal oxide semiconductor transistor is arranged on the substrate; the pixel electrode array is arranged on the substrate; a plurality of color filters (color filters) with at least two different colors are arranged on the pixel electrode array, intervals (gaps) are arranged between the adjacent color filters, and at least two color filters are non-coplanar; the inorganic film is arranged on the color filter and in the plurality of intervals; and the organic film is arranged on the surface of the inorganic film in a full-face manner. By the planarization effect of the two layers of films, the invention can provide a lower cost and shorter time process than the conventional planarization step by chemical mechanical polishing, and can provide an LCoS panel with better optical characteristics under the condition of saving energy (such as no need of depositing inorganic films by high temperature thermal process), thereby improving the yield of subsequent packaging.

Description

Liquid crystal on silicon panel and manufacturing method thereof

technical field

The invention relates to a silicon-based liquid crystal display panel, in particular to a silicon-based liquid crystal display panel in which an inorganic thin film and an organic thin film are sequentially arranged on a color filter array.

Background technique

With the advent of the digital age, changes in the form of digital signal broadcasting and display technology have made various types of flat-panel displays different from traditional cathode ray tube (CRT) displays in recent years, such as liquid crystal displays (liquid crystal displays, LCD), field emission display (field emission display, FED), organic light emitting diode (organic light emitting diode, OLED) display, and plasma display panel (plasma display panel, PDP), etc. are widely used in daily life.

In addition, because the micro-display (micro-display) can optically magnify the image to exceed the size of the above-mentioned flat-panel display, it is more in line with the demand for super-large-size display. And the microdisplay can be applied to various types of displays, such as LCD or OLED display, for example, the microdisplay applied to LCD is called micro liquid crystal panel. Due to their different imaging methods, microdisplays can be divided into two categories: transmissive and reflective. The transmissive liquid crystal micro-display panel is mainly constructed on a glass substrate, and light passes through the display panel during operation; the reflective liquid crystal micro-panel is constructed on a silicon substrate, so it is also called liquid crystal on silicon (liquid crystal on silicon, LCoS) panel. LCoS panels use silicon wafers as substrates, and use metal oxide semiconductor transistors (MOS transistors) instead of thin film transistors. Unlike general LCD panels that use transparent conductive materials as pixel electrodes, LCoS panels use metal materials as pixel electrodes. The principle of imaging, so it is called a reflective liquid crystal micro panel.

Whether it is a transmissive or a reflective microdisplay, it is necessary to have a color filter array (color filter array) on the panel. The known method of making a color filter array is mainly to make color filters (color filters) for projecting different colors, and then cover a material layer made of tetraethoxysilane (tetraethoxysilane, TEOS) in the color filter array. The optical filter is placed on the optical filter, and the material layer is planarized by a chemical mechanical polishing (CMP) process. However, the planarization step of the color filter by chemical mechanical polishing still has the problem of height difference, so that the manufactured micro-display cannot present a perfect display picture, for example, color shift (discoloration) and Newton ring (Newton ring) and other phenomena.

Contents of the invention

Therefore, the present invention provides a liquid crystal-on-silicon panel and a manufacturing method thereof, so as to solve the above-mentioned problems caused by conventional panels.

A preferred embodiment of the present invention discloses a liquid crystal on silicon (LCoS) panel, which includes a substrate on which at least one metal oxide semiconductor transistor is arranged; a pixel electrode array is arranged on the substrate; a plurality of LEDs with at least two different colors A color filter is arranged on the pixel electrode array, there are gaps between adjacent color filters, and at least two color filters are non-coplanar; the inorganic thin film is arranged on On the color filter and in the plurality of intervals; and the organic thin film is completely arranged on the surface of the inorganic thin film.

Another embodiment of the present invention discloses a method for manufacturing a liquid crystal on silicon panel, which includes the following steps. Firstly, a substrate is provided, and at least one metal oxide semiconductor transistor is arranged on the substrate, and then a pixel electrode and a plurality of color filters having at least two different colors are formed on the substrate, and the color filters adjacent to each other are formed There are intervals between them, and at least two color filters are non-coplanar. Next, an inorganic thin film is formed on the color filter and in the plurality of intervals, and an organic thin film is formed on the surface of the inorganic thin film.

Description of drawings

1 to 4 are schematic diagrams of fabricating a liquid crystal on silicon panel in a preferred embodiment of the present invention.

Explanation of reference signs

12 semiconductor substrate 14 pixel electrode layer

16 reflective layer 18 color filter

20 color filter array 22 intervals

24 Inorganic thin film 26 Organic thin film

28 lower alignment film 30 liquid crystal layer

32 upper substrate 34 substrate

36 transparent conductive layer 38 upper alignment film

40 pixel electrodes 42 metal oxide semiconductor transistor elements

44 inner dielectric layer

Detailed ways

Please refer to FIG. 1 to FIG. 4 . FIG. 1 to FIG. 4 are schematic diagrams of fabricating a liquid crystal on silicon panel according to a preferred embodiment of the present invention. As shown in FIG. 1, a semiconductor substrate 12, such as a silicon substrate, is first provided,

Then, an array-like pixel electrode layer 14 , a reflective layer 16 and a color filter array 20 composed of a plurality of color filters 18 are sequentially formed on the semiconductor substrate 12 . The semiconductor substrate 12 is provided with a plurality of metal-oxide-semiconductor (MOS) transistor elements 42 fabricated by standard semiconductor processes, such as complementary metal-oxide-semiconductor transistors, etc., and an interlayer dielectric layer 44 covers the MOS transistor elements. 42 for driving the pixel electrode 40 in the pixel electrode layer 14 . Wherein, each pixel electrode 40 is an independent aluminum metal layer, and the reflective layer 16 selectively provided can be a dielectric material layer with a high reflection coefficient covering the surface of each pixel electrode 40 in an all-round way, or a metal layer can be formed separately. Correspondingly arranged on the surface of each pixel electrode 40 to reflect the incident light filtered by the color filter 18 . The manufacture of the color filter array 20 can first form a single-color filter layer (not shown) on the semiconductor substrate 12, and then perform a pattern transfer process on the filter layer, such as patterning a photoresist layer to After the filter layer is etched, a color filter 18 is formed on the semiconductor substrate 12 . Then, the filter layer deposition and pattern transfer processes are repeated to form a plurality of color filter arrays 20 composed of color filters 18 of different wavelength ranges or containing dyes of different colors on the semiconductor substrate 12 . In this embodiment, the color filter 18 is an organic chemical substance with the function of filtering incident light, such as acrylic resin (acrylic resin) mixed with pigments and dyes of different colors. It is composed of dichroic filters composed of refractive index. The color filter 18 of the present invention preferably includes a combination of at least three colors such as a red filter, a green filter, and a blue filter, but the color of the color filter 18 is not limited thereto. In addition, the color filters 18 preferably form a plurality of gaps 22 between each color filter 18 after these pattern transfer processes, and at least two color filters 18 are not coplanar.

Then, as shown in FIG. 2 , an inorganic thin film 24 is formed to cover the color filters 18 and fill up the spaces 22 between the color filters 18 . In this embodiment, the inorganic thin film 24 is preferably formed by a spin coating process, but is not limited thereto, and may be formed by plasma-assisted chemical vapor deposition (PECVD) or the like according to process requirements. Secondly, the inorganic film 24 is selected from spin-on glass (spin on glass, SOG) film, field oxidation spin-on-glass (field oxidespin-on-glass, FOX SOG) film, plasma enhanced oxide layer (plasma enhanced oxide, At least one of materials such as PE-oxide) and tetraethoxysilane (tetraethoxysilane, TEOS) or any combination of the above materials, the thickness is mainly between 2100 angstrom to 3100 angstrom, and preferably 2600 angstrom.

As shown in FIG. 3 , the organic thin film 26 is coated on the surface of the inorganic thin film 24 comprehensively. In this embodiment, the organic thin film 26 is preferably made of a negative photoresist, for example, it can be selected from planar photoresist and buffer layer photoresist. At least one of the above materials or any combination of the above materials. In addition, the thickness of the organic film 26 is approximately five times that of the inorganic film 24 , for example, between 10000 angstroms and 12000 angstroms, and preferably 11000 angstroms. Subsequently, a lower alignment film 28 can be formed on the organic thin film 26 to complete the fabrication of the lower substrate of the LCD-on-Silicon panel. It is worth noting that, through the planarization effect brought by the inorganic film 24 and the organic film 26, the present invention can solve the shortcomings of the known planarization process of the film covering the color filter by chemical mechanical polishing, for example, it can greatly improve Discoloration and Newton rings are likely to occur on the display screen, thereby projecting a better display screen.

Then, as shown in FIG. 4 , carry out the post process of the liquid crystal on silicon panel, such as sequentially forming a liquid crystal layer 30 and an upper substrate 32 on the lower substrate provided with the color filter array 20, wherein the manufacture of the upper substrate 32 includes The substrate 34 , the transparent conductive layer 36 and the upper alignment film 38 are disposed on the lower surface of the substrate 34 . The substrate 34 is a transparent substrate that can transmit light, such as a glass substrate or a quartz substrate. The transparent conductive layer 36 is selected from transparent conductive materials, such as indium tin oxide (indium tin oxide, ITO), indium zinc oxide (indium zinc oxide, IZO), indium tin zinc oxide (ITZO), aluminum zinc oxide (aluminum zinc oxide, AZO), zirconium-zinc oxide ZZO (zirconium-zinc oxide) and gallium-doped zinc oxide (GZO) and other transparent conducting oxides (transparent conducting oxide, TCO). The function of the upper alignment film 38 and the lower alignment film 28 is to make the liquid crystal molecules of the liquid crystal layer 30 tilt toward a predetermined direction when not deflected by voltage, so as to precisely control the amount of light transmitted. So far, the fabrication of the LCoS panel of the preferred embodiment of the present invention is completed.

Please refer to FIG. 4 , which further discloses the liquid crystal on silicon (LCoS) panel structure of a preferred embodiment of the present invention. As shown in the figure, the liquid crystal on silicon panel mainly includes a substrate 12, a plurality of color filters 18 are arranged on the substrate 12 and there are a plurality of intervals 22 between the color filters 18, and an inorganic film 24 is comprehensively arranged on each color. The filter 18 fills the space 22, the organic thin film 26 is comprehensively arranged on the surface of the inorganic thin film 24, the lower alignment film 28 is arranged on the surface of the organic thin film 26, the liquid crystal layer 30 is arranged on the lower alignment film 28, and the upper substrate 32 is arranged on the on the liquid crystal layer 30. The upper substrate 32 includes a transparent substrate 34 made of glass or quartz, a transparent conductive layer 36 and an upper alignment film 38 .

Wherein, the color filter 18 may have dyes of different colors or different wavelength ranges, for example, include a red filter, a green filter and a blue filter. Inorganic film 24 is selected from spin-on glass (spin on glass, SOG) film, field oxide spin-on-glass (field oxide spin-on-glass, FOXSOG) film, plasma enhanced oxide layer (PE-oxide) and four Ethoxysilane (TEOS), and the organic film 26 is preferably made of a negative photoresist, for example, can be selected from planar photoresist (planar photoresist) and buffer layer photoresist ( buffer layer photoresist). In this embodiment, the thickness of the inorganic thin film 24 is between 2100 angstroms and 3100 angstroms, preferably 2600 angstroms, and the thickness of the organic thin film 26 is between 10000 angstroms and 12000 angstroms, preferably 11000 angstroms.

It should also be noted that although the present invention preferably fabricates the color filter array 20 composed of a plurality of color filters 18 on the semiconductor substrate 12, it is not limited to this design, and the color filter array 20 and the The inorganic thin film 24 and the organic thin film 26 thereon are fabricated on the lower surface of the upper substrate 32, that is, formed on the surface of a transparent substrate such as a glass substrate or a quartz substrate, and are not fabricated on a silicon substrate including MOS transistor elements and pixel electrodes. , this embodiment also falls within the scope of the present invention.

In summary, the present invention mainly covers the surface of the color filter used to form the color filter array and the interval between each color filter with the spin coating process of the inorganic thin film, and then fully coats the organic thin film. The film is on the surface of the inorganic film. Through the planarization effect brought by these two layers of films, the present invention can provide a process with lower cost and shorter time than the known planarization step with chemical mechanical polishing, and can save energy (such as without high temperature Thermal process to deposit inorganic thin film) to provide LCoS panels with better optical characteristics, thereby improving the yield of subsequent packaging.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the present invention.

Claims (15)

1. a silica-based liquid crystal panel, comprises:

Substrate, this substrate is provided with at least one metal oxide semiconductor transistor;

Pixel electrode array is located in this substrate;

Multiple colored filters with at least two kinds of different colors are located on this pixel electrode array, between adjacent the plurality of colored filter, all have interval, and at least two colored filters are non-copline;

Inorganic thin film is located on the plurality of colored filter and is filled in the plurality of interval; And

Comprehensive this inorganic thin film surface of being located at of organic film.

2. silica-based liquid crystal panel as claimed in claim 1, wherein the plurality of colored filter comprises Red lightscreening plate, green color filter or blue color filter.

3. silica-based liquid crystal panel as claimed in claim 1, wherein this inorganic thin film is to be selected from spin-on glasses film, an oxidation spin-on glasses film, plasma enhanced oxidation layer and tetraethoxysilane.

4. silica-based liquid crystal panel as claimed in claim 1, wherein this organic film is to be selected from planarization photoresist and buffering laminar photoresist.

5. silica-based liquid crystal panel as claimed in claim 1, wherein this organic film comprises negative type photoresist.

6. silica-based liquid crystal panel as claimed in claim 1, wherein the thickness of this inorganic thin film is between 2100 dust to 3100 dusts.

7. silica-based liquid crystal panel as claimed in claim 1, wherein the thickness of this organic film is between 10000 dust to 12000 dusts.

8. a method of making silica-based liquid crystal panel, comprises:

Substrate is provided, and this substrate is provided with at least one metal oxide semiconductor transistor;

Form pixel electrode array in this substrate;

Form multiple colored filters with at least two kinds of different colors on this pixel electrode array, between adjacent the plurality of colored filter, all there is interval, and at least two colored filters are non-copline;

Form inorganic thin film on the plurality of colored filter and be filled in the plurality of interval; And

Form organic film in this inorganic thin film surface.

9. method as claimed in claim 8, wherein the plurality of colored filter comprises Red lightscreening plate, green color filter or blue color filter.

10. method as claimed in claim 8, separately comprises and utilizes spin coating process to form this inorganic thin film.

11. methods as claimed in claim 8, wherein this inorganic thin film is to be selected from spin-on glasses film, an oxidation spin-on glasses film, plasma enhanced oxidation layer and tetraethoxysilane.

12. methods as claimed in claim 8, wherein this organic film is to be selected from planarization photoresist and buffering laminar photoresist.

13. methods as claimed in claim 8, wherein this organic film comprises negative type photoresist.

14. methods as claimed in claim 8, wherein the thickness of this inorganic thin film is between 2100 dust to 3100 dusts.

15. methods as claimed in claim 8, wherein the thickness of this organic film is between 10000 dust to 12000 dusts.

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