WO2005036244A1

WO2005036244A1 - Module for reflection liquid crystal display and its manufacturing method, and reflection liquid crystal display

Info

Publication number: WO2005036244A1
Application number: PCT/JP2003/012943
Authority: WO
Inventors: Toyoaki Sakai; Naoya Nakamura; Atsushi Kuwashima
Original assignee: Fujitsu Limited
Priority date: 2003-10-09
Filing date: 2003-10-09
Publication date: 2005-04-21

Abstract

A method for manufacturing a module for reflection liquid crystal displays, characterized by comprising the steps of forming a third interlayer insulating film (first insulating film) (26) over a silicon (semiconductor) substrate (1), forming an insulating film (second insulating film) (29) for a spacer on the third interlayer insulating film (26), forming an insulating spacer (29a) having an opening (29b) for each pixel by patterning the insulating film (29), forming a conductive film (30) on the insulating spacer (29a) and on the third interlayer insulating film (26) in the opening (29b), and polishing the conductive film (30) to an extent that the insulating spacer (29a) becomes exposed, thereby making the conductive film (30) left in the opening (29b) a reflection electrode (30a).

Description

Description Reflective liquid crystal display module, method of manufacturing the same, and reflective liquid crystal display

The present invention relates to a reflection type liquid crystal display device module, a method for manufacturing the same, and a reflection type liquid crystal display device. More specifically, the present invention relates to a reflective liquid crystal display module having good display quality, a method for manufacturing the same, and a reflective liquid crystal display device. Background art

In recent years, a reflection type liquid crystal display device called a silicon chip-based liquid crystal has been attracting attention as a head mounted display or a projection type display. Hereinafter, a method for manufacturing the reflection type liquid crystal display device according to the conventional example will be described.

1 This will be described with reference to (a) and (b).

First, steps required until a sectional structure shown in FIG. First, an interlayer insulating film 101 is formed above a silicon wafer (not shown) on which MOS transistors are formed on the surface, and then the first interlayer insulating film 101 is formed on the interlayer insulating film 101 by a photolithography method and an etching step. The second holes 101a and 101b are formed. Subsequently, the first and second conductive plugs 102 a and 102 b connected to the source / drain regions of the MOS transistor are connected to the first and second holes 101 a and 100 lb. Form within.

Next, after forming a metal film on the upper surface of each of the interlayer insulating film 101 and each of the conductive plugs 102a and 102b, the metal film is patterned to form each conductive plug. The first reflective electrode 103a and the second reflective electrode 103b are left on 102a and 102b.

After that, in order to fill the gap between the reflective electrodes 103a and 103b, an insulating film is formed on the entire surface, and the insulating film is polished by CMP method or etched back. , Gear between each reflective electrode 103a, 103b The insulating film remaining in the gap is a buried insulating film 104.

Through the steps so far, the LCOS (Liquid Crystal on Silicon) substrate 105 is completed.

Next, as shown in FIG. 1 (b), a liquid crystal panel 106 formed in another step is bonded onto the LCOS substrate 105 by a sealing material (not shown). In the liquid crystal panel 106, a liquid crystal layer 108 is sealed between the lower liquid crystal alignment layer 107 and the upper liquid crystal alignment layer 109, and a transparent liquid crystal is formed on the upper liquid crystal alignment layer 109. The common electrode 110 is formed, and the surface glass 111 for protecting the surface of the liquid crystal panel 106 from external impact is provided on the common electrode 110.

As described above, the basic structure of the reflective liquid crystal display device 115 according to the conventional example is completed.

In this reflective liquid crystal display device 115, pixels are defined by the first and second reflective electrodes 103a and 103b, and the voltage value of each reflective electrode 103a and 103b is not changed. The potential difference between the common electrode 110 and each of the reflective electrodes 103 a and 103 b is controlled by individually changing the MOS transistors shown in the figure, and the liquid crystal layer 106 is controlled according to the potential difference. Is controlled for each pixel.

Then, as shown in FIG. 2, light emitted from a light source 112 composed of light emitting diodes of three colors is polarized in one direction by a polarizer 113, and the obtained polarized light is reflected by a reflective liquid crystal display device 1. 1 Insert diagonally into 5. The incident light passes through the liquid crystal layer 108, is reflected by each of the reflective electrodes 103a and 103b, passes through the liquid crystal layer 108 again, and goes out. When the light passes through the liquid crystal layer 108, the polarization direction of the light is twisted according to the orientation of the liquid crystal layer 108. An image with a controlled light intensity can be obtained.

By the way, in the method of manufacturing the LCOS substrate 105 shown in FIG. 1A, the buried insulating film 104 is left in the gap between the reflective electrodes 103a and 103b by the CMP method or the etch-back method. However, it is difficult to detect the end point of CMP or etch back on the insulating film in a systematic manner, so the buried insulating film 104 is excessively polished, and the upper surface of the buried insulating film 104 0 3 a, 1 0 3 It becomes easier to sink than the upper surface of b, and the flatness of the upper surface of the LCOS substrate 105 becomes worse.

However, when the liquid crystal panel 106 is bonded on the LCOS substrate 105 having such poor flatness, a gap 112 is formed between the buried insulating film 104 and the liquid crystal panel 106. When the incident light is scattered by the gaps 1 and 12, the color tone becomes poor, and when the contrast is lowered, some inconvenience is caused. Disclosure of the invention

An object of the present invention is to provide a reflection type liquid crystal display module capable of preventing a decrease in contrast and poor color tone, a method for manufacturing the same, and a reflection type liquid crystal display device.

According to one aspect of the present invention, a semiconductor substrate; an insulating film formed above the semiconductor substrate; an insulating spacer formed on the insulating film, having an opening for each pixel; A reflective electrode formed in the opening of the spacer and having a flat upper surface at the same height as the upper surface of the insulating spacer; and a module for a reflective liquid crystal display device, comprising: Is done.

According to another aspect of the present invention, a step of forming a first insulating film above a semiconductor substrate; a step of forming a second insulating film on the first insulating film; Forming an insulating spacer having an opening for each pixel by patterning the film; and forming the insulating spacer on the insulating spacer and in the opening in the opening.

1) a step of forming a conductive film on the insulating film, and a step of polishing the conductive film to such an extent that the insulating spacer is exposed, and using the conductive film remaining in the opening as a reflective electrode. A method for manufacturing a module for a reflection type liquid crystal display device, comprising:

Next, the operation of the present invention will be described.

According to the present invention, the conductive film is polished to such an extent that the insulating spacer is exposed, and the conductive film remaining in the opening of the insulating spacer is used as the reflective electrode, so that the upper surface of the reflective electrode is flat. And the upper surface is at the same height as the upper surface of the insulating spacer. Therefore, even if the liquid crystal panel is pasted on the reflective electrode, Since a gap is not formed between the insulating spacer and the insulating spacer as in the related art, scattering of incident light due to the gap is prevented. As a result, a combination of the liquid crystal panel and the liquid crystal panel realizes a reflection type liquid crystal display module in which the color tone is improved and the contrast is enhanced.

Further, by making the cross-sectional shape of the insulating spacer into a tapered shape, the interval between adjacent reflective electrodes becomes extremely short due to the narrow upper surface of the insulating spacer. As a result, the reflection electrodes are arranged at a very high density, so that the incident light scattered by the insulating spacer is reduced, and most of the incident light is reflected by the reflection electrode. The reflectance of the entire display module is improved.

In order to make the cross-sectional shape of the insulating spacer tapered as described above, for example, a resist pattern is formed on the second insulating film, and the etching gas and the flow rate are higher than the etching gas. Using a mixed gas with a large deposition gas as an etching gas, the second insulating film may be etched using the resist pattern as a mask.

Alternatively, instead of this, a resist pattern is formed on the second insulating film, and the resist pattern is heated and melted to break the cross-sectional shape of the resist pattern, and the resist pattern and the second insulating film Also, by etching simultaneously, an insulating spacer having a tapered cross section can be formed.

In the case where an aluminum film is formed as a conductive film serving as a reflective electrode, the aluminum film is formed by a sputtering method in which the substrate temperature is kept at a low temperature of room temperature (20 ° C.) to 350 ° C. However, since the grains of the aluminum film do not grow large, the irregularities on the surface of the aluminum film are reduced, and a reflective electrode having a high reflectance can be obtained. Brief Description of Drawings

FIGS. 1 (a) and 1 (b) are cross-sectional views for explaining a method of manufacturing a reflection type liquid crystal display device according to a conventional example;

Figure 2 shows a reflective liquid crystal display using silicon chip-based liquid crystal. It is a principle diagram schematically showing;

3 (a) and 3 (b) are cross-sectional views (part 1) showing a method of manufacturing a reflective liquid crystal display module according to the first embodiment of the present invention in the order of steps; FIG. 5 (a) and 5 (b) are cross-sectional views (part 2) showing a method of manufacturing the reflective liquid crystal display device module according to the first embodiment of the present invention in the order of steps; FIGS. FIGS. 6A and 6B are cross-sectional views showing a method of manufacturing a module for a reflection type liquid crystal display device according to the first embodiment of the present invention in the order of steps; FIGS. FIG. 7 is a cross-sectional view (part 4) showing a method for manufacturing a module for a reflective liquid crystal display device according to the first embodiment in the order of steps; FIG. 7 is a reflective liquid crystal display device according to the first embodiment of the present invention. Sectional drawing (No. 5) showing the manufacturing method of the module for use in the order of steps;

FIG. 8 is a cross-sectional view (part 6) illustrating a method for manufacturing a module for a reflective liquid crystal display device according to the first embodiment of the present invention in the order of steps;

FIG. 9 is a sectional view (No. 7) showing the method of manufacturing the module for the reflective liquid crystal display device according to the first embodiment of the present invention in the order of steps;

FIG. 10 is a sectional view (No. 8) showing a method for manufacturing a module for a reflective liquid crystal display device according to the first embodiment of the present invention in the order of steps;

FIG. 11 is a cross-sectional view (No. 9) showing a method for manufacturing a module for a reflective liquid crystal display device according to the first embodiment of the present invention in the order of steps;

FIG. 12 is a cross-sectional view (No. 10) showing a method of manufacturing a module for a reflective liquid crystal display device according to the first embodiment of the present invention in the order of steps;

FIG. 13 is a cross-sectional view (No. 11) showing a method for manufacturing a module for a reflective liquid crystal display device according to the first embodiment of the present invention in the order of steps;

FIG. 14 is a cross-sectional view illustrating the method of manufacturing the reflective liquid crystal display device according to the first embodiment of the present invention;

FIG. 15 is a perspective view (No. 1) showing the method of manufacturing the module for a reflective liquid crystal display device according to the first embodiment of the present invention;

FIG. 16 is a perspective view (part 2) showing the method of manufacturing the module for a reflective liquid crystal display device according to the first embodiment of the present invention;

FIG. 17 shows a module for a reflective liquid crystal display device according to the second embodiment of the present invention. FIG. 18 is a cross-sectional view (No. 1) showing a method of manufacturing a module in the order of steps; FIG. 18 is a cross-sectional view showing a method of manufacturing a module for a reflective liquid crystal display device according to the second embodiment of the present invention in the order of steps. (Part 2);

FIG. 19 is a cross-sectional view (No. 3) illustrating a method for manufacturing a module for a reflective liquid crystal display device according to the second embodiment of the present invention in the order of steps. BEST MODE FOR CARRYING OUT THE INVENTION

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

(First Embodiment)

3 to 13 are cross-sectional views illustrating a method of manufacturing a module for a reflective liquid crystal display device according to the present embodiment in the order of steps.

First, steps required until a sectional structure shown in FIG. First, an SiO ₂ film is formed as an element isolation insulating film 2 on a part of the surface of a p-type silicon (semiconductor) substrate 1 by a LOCOS (Local Oxidation of Silicon) method. As the element isolation insulating film 2, an element isolation structure other than LOCOS, for example, STI (Shallow Trench Isolation) may be adopted.

Next, a p-type impurity is introduced into the silicon substrate 1 exposed between the element isolation insulating films 2 to form a p-well 3, and then the exposed silicon substrate 1 is thermally oxidized to form a silicon oxide film 4. .

Next, steps required until a sectional structure shown in FIG. First, a polysilicon film is formed as the first conductive film 5 on the entire surface to a thickness of about 18 O nm by low-pressure CVD using silane (SiH ₄ ) gas at a substrate temperature of 62 ° C. I do.

Then, using a low pressure CVD method using an oxidizing agent and a silane gas such as N ₂ 0 as a reaction gas, under conditions of a substrate temperature of 8 0 0 ° C, the thickness of the Si0 ₂ film on the first conductive film 5 The dielectric film 6 is formed to a thickness of about 28 nm.

Furthermore, a polysilicon film is formed to a thickness of about 10 O nm as the second conductive film 7 on the dielectric film 6 by a low-pressure CVD method using silane gas at a substrate temperature of about 530. I do.

Next, as shown in Fig. 4 (a), the first register in the shape of the upper electrode After the strike pattern 8 is formed on the second conductive film 7, the second conductive film 7 is etched using the first resist pattern 8 as a mask, and the remaining second conductive film 7 is a. This etching is performed by, for example, RIE (Reactive Ion Etching) using a mixed gas of Cl ₂ and O ₂ as an etching gas.

After that, the first resist pattern 8 is removed.

Next, as shown in FIG. 4 (b), a second resist pattern 9 having a capacitor dielectric film shape and covering the upper surface and side surfaces of the upper electrode 7a is formed, and the second resist pattern 9 is formed. the dielectric film 6 made of Si0 ₂ while using as a mask Uetsu preparative etched with HF (hydrofluoric acid) solution, the dielectric film 6 remaining below the upper electrode 7 a and the capacitor dielectric film 6 a. After this, the second resist pattern 9 is removed.

Subsequently, as shown in FIG. 5 (a), a third resist pattern 10 having a pattern covering the capacitor dielectric film 6a and the upper electrode 7a and a gate electrode-shaped pattern is formed as a first conductive film. Form on 5 Then, using the third resist pattern 10 as an etching mask, the first conductive film 5 is etched by, for example, RIE using a mixed gas of Cl ₂ and O ₂ as an etching gas.

As a result, the first conductive film 5 under the capacitor dielectric film 6a is left as the lower electrode 5a, and the capacitor formed by the lower electrode 5a, the capacitor dielectric film 6a, and the upper electrode 7a. Q is formed on the element isolation insulating film 2. Further, above the p-well 3, the first conductive film 5 remains as the gate electrode 5 b under the third resist pattern 10.

Next, using the gate electrode 5b as an etching mask, the silicon oxide film 4 is etched with an HF aqueous solution to leave the silicon oxide film 4 as a gate insulating film 4a under the gate electrode 5b.

Thereafter, the third resist pattern 10 is removed.

Subsequently, as shown in FIG. 5 (b), phosphorus is ion-implanted into the silicon substrate 1 through the window of the resist pattern (not shown), and the first and second p-wells 3 are formed on the sides of the gate electrode 5b. A second n-type impurity diffusion region 11a, lib is formed. That W

After that, the resist pattern used for ion implantation is removed.

Next, steps required until a sectional structure shown in FIG. First, formed by a CVD method using an oxidizing agent and a silane gas such as N ₂ 0 as a reaction gas, under conditions of a substrate temperature of 8 0 0 ° C, to about Si0 ₂ film having a thickness of about 1 0 O nm on the entire surface I do. Then, the Si0 ₂ film is anisotropically etched, leaving the Si0 ₂ film only on each side of the gate electrodes 5 b and the upper electrode 7 a, remaining the Si0 ₂ film first, second sidewall insulating films 1 and 13, respectively.

Further, the first and second n-type impurity diffusion regions 11 a and 11 b are LDD (lightly-lighted) by implanting phosphorus again into the p-well 3 using the first side wall insulating film 12 as a mask. Doped Drain) structure.

After that, a cobalt film is formed as a refractory metal film to a thickness of about 9 nm on the entire surface by sputtering. Then, in a N ₂ atmosphere, the cobalt film is annealed at a substrate temperature of 520 ° C. for about 30 seconds, so that the cobalt film reacts with silicon on the p-well 3, and the first and second n-types are formed. First and second cobalt silicide layers 14a and 14b are formed in the surface layer of the impurity diffusion regions 11a and 11b. Thereafter, the unreacted cobalt film is removed by etching.

As described above, the MOS transistor TR having the gate electrode 5b and the first and second impurity diffusion regions 11a and lib functioning as the source / drain regions is formed on the p-well 3.

Next, steps required until a sectional structure shown in FIG. First, the HDPCVD (Hig Density Plasma CVD) method using silane gas and Ar gas and 0 ₂ gas as the reaction gas, the MOS transistor TR and key Yapashi about 8 0 O nm evening thickness of Si0 ₂ film on the Q It is formed and used as a first buried insulating film 15.

In this HDPCVD, two types of AC power, high frequency (HF) and low frequency (LF), are used. The HF frequency is 13.56 MHz, and the noise power is 210 W. The frequency of the LF is 400 KHz and the power is 300 W. The flow rate of each gas, for example silane gas is 8 0 sccm, Ar gas is set to 4 4 O sccm, 0 ₂ force SI 1 5 sccm, the pressure during film formation is 1 0 mTorr, board temperature 3 5 Set to 0 ° C. The first buried insulating film 15 formed by such an HDPCVD method has an extremely good burying property, so that a narrow portion sandwiched between the MOS transistor TR, the capacitor Q, etc. can be formed without generating a void. Can be embedded, and its surface shape reflects the shape of the base.

Then, on the first buried insulating film 1 5 is formed on the Si0 approximately ₂ film thickness of about 8 0 O nm as the first sacrificial insulating film 1-6 by a plasma CVD method using TEOS as reactive gas.

Thereafter, the first sacrificial insulating film 16 is polished by a CMP (Chemical Mechanical Polishing) method to flatten its surface, and is composed of the first buried insulating film 15 and the first sacrificial insulating film 16. The thickness of the first interlayer insulating film 17 is set to about 100 O nm.

Next, steps required until a sectional structure shown in FIG.

First, by photolithography and subsequent etching, the first and second contact holes 17a and 17b, which reach the first and second n-type impurity diffusion regions 1 la and lib, are first interlayer insulating. A third contact hole 17c having a depth reaching the upper electrode 7a is formed on the capacitor Q while being formed on the film 17.

Next, a ΉΝ film is formed to a thickness of about 5 O nm as a glue film on the inner surfaces of the contact holes 17 a to 17 c and the upper surface of the first interlayer insulating film 17 by sputtering. Subsequently, a tungsten film is formed on the glue film by a CVD method using tungsten hexafluoride gas, and the contact holes 17a to 17c are completely filled with the tungsten film. After that, the excess glue film and the tungsten film formed on the upper surface of the first interlayer insulating film 17 are removed by the CMP method, and the dull film remaining in each of the contact holes 17a to 17c is removed. And the tungsten film are referred to as first to third conductive plugs 18a to 18c.

Of the conductive plugs 18a to 18c, the first and second conductive plugs 18a and 18b are electrically connected to the first and second n-type impurity diffusion regions 11a and lib. The third conductive plug 18 c is electrically connected to the upper electrode 7 a of the capacitor Q.

Next, steps required until a sectional structure shown in FIG. First, a metal laminated film is formed on the first interlayer insulating film 17 and the first to third conductive plugs 18a to 18c by a sputtering method. The metal laminated film includes, for example, a Ti film having a thickness of 40 nm, a TiN film having a thickness of 30 nm, an Al film containing Cu having a thickness of 500 nm, a Ti film having a thickness of 5 nm, and a thickness of 5 nm. It is formed by laminating 100 nm TiN films in this order.

Thereafter, the metal laminated film is patterned to form first and second metal wirings 19a and 19b. Among them, the second metal wiring 19 b is formed on the second and third conductive plugs 18 b and 18 c, and the upper electrode 7 a of the capacitor Q and the second n-type impurity diffusion region 1 Functions to electrically connect 1b. Then, in order to fill the narrow space between the metal wirings 19a and 19b with an insulating film, using the HDPCVD method with good embedding property, the metal wirings 19a and 19b are formed on the metal wirings 19a and 19b. A SiO ₂ film is formed on the interlayer insulating film 17 to a thickness of about 80 O nm, and is used as a second buried insulating film 20. The conditions for forming the second buried insulating film 20 are the same as those for forming the first buried insulating film 15.

Next, a SiO ₂ film having a thickness of about 13 was formed as a second sacrificial insulating film 21 on the second buried insulating film 20 by the same plasma CVD method as used for forming the first sacrificial insulating film 16. Form at 0 O nm. Then, the second sacrificial insulating film 21 is polished by the CMP method, and the second interlayer insulating film 22 composed of the insulating films 20 and 21 is formed on the metal wirings 19 a and 19 b. The thickness is about 100 O nm.

Next, steps required until a sectional structure shown in FIG.

First, a metal laminated film is formed on the second interlayer insulating film 22 by a sputtering method, and the metal laminated film is patterned to form a light shielding film 23. Constructing the light shielding film 23 · As the metal laminated film, for example, an aluminum film is adopted.

Then, using a HDPCVD process, form the shading film 2 3 and on the third buried insulating film 2 4 as Si0 ₂ forms film to a thickness of about 8 0 O nm on the second interlayer insulating film 2 2 above, The space between the adjacent light shielding films 23 is buried by the third buried insulating film 24. As the film forming conditions for the third buried insulating film 24, the same film forming conditions as for the first buried insulating film 17 are employed.

Next, by a plasma CVD method under the same film forming conditions as the first sacrificial insulating film 16, a SiO ₂ film is formed on the third buried insulating film 24 to a thickness of about 130 nm, This is referred to as a third sacrificial insulating film 25.

Then, the third interlayer insulating film (first insulating film) 26 composed of the insulating films 24 and 25 is polished by the CMP method, and the thickness of the third interlayer insulating film 26 on the light shielding film 23 is increased. To about 95 O nm.

Next, steps required until a sectional structure shown in FIG.

First, a hole 27 having a depth reaching the second metal wiring 19 b is formed in the second and third interlayer insulating films 22 and 26, and the inner surface of the hole 27 and the third interlayer insulating film 26 are formed. A TiN film with a thickness of about 5 O nm is formed on the upper surface as a glue film. Next, a tungsten film having a thickness completely burying the hole 27 is formed on the glue film by a CVD method, and then an excess dull film and a tungsten film formed on the upper surface of the third interlayer insulating film 26 are formed. Are removed by polishing by a CMP method, and the glue film and the tungsten film remaining in the hole 27 are used as a fourth conductive plug 28. The fourth conductive plug 28 is electrically connected to the second metal wiring 19b.

Then, using the plasma CVD method, it is formed on the fourth conductive plug 2 8 and on the third interlayer insulating film 2 6 above and the Si0 ₂ film thickness of about 3 0 O nm, scan it page Insulating film for substrate (second insulating film) 29.

Thereafter, a photoresist is applied on the insulating film for spacer 29, and is exposed and developed to form a fourth resist pattern 37. The fourth resist pattern 37 is formed along the boundary between adjacent pixels, and has a width W of about 0.5 m.

Next, steps required until a sectional structure shown in FIG.

First, a silicon substrate 1 in a chamber (not shown) for performing plasma etching is placed, and a deposition CHF ₃ gas and an etching CF ₄ gas are supplied as etching gases into the chamber. Note that the etching gas, 0 ₂ is also added. The flow rate of the etching gas is adjusted so that the deposition gas is higher than the etching gas.For example, the flow rate of the CHF ₃ gas is more than 1 and less than twice the flow rate of the CF ₄ gas. . In this embodiment, the flow rate of CHF ₃ gas to about 1 0 O sccm, the co-when the flow rate of CF ₄ gas is about 5 0 sccm, the substrate temperature was at a 1 0~ 3 0 ° C, the pressure in the chamber Approx. 100-900 Set to Torr. Further, 0 ₂ flow rate 5 0~: ί to 0 0 sccm.

By maintaining such a state for a predetermined time, the spacer insulating film 29 is isotropically etched as shown in FIG. As a result, the spacer insulating film 29 is left under the fourth resist pattern 37 as an insulating spacer 29 a having a tapered cross section. Thereafter, the fourth register pattern 37 is removed.

An enlarged perspective view after the completion of this step is as shown in FIG. 15, and FIG. 11 corresponds to a cross-sectional view taken along the line II of FIG. As shown in FIG. 15, the insulating spacer 29a has an opening 29b for each pixel, and the upper surface of the fourth conductive plug 28 is exposed in the opening 29b.

Next, as shown in FIG. 12, an aluminum film is formed as a third conductive film 30 on the third interlayer insulating film 26 in the opening 29 b and on the insulating spacer 29 a by a sputtering method. The opening 29 b of the spacer 29 is filled with the third conductive film 30.

As described above, the third conductive film 30 is formed by aluminum sputter. However, if the substrate temperature during sputtering is high, the aluminum grain size increases, and the third conductive film 30 becomes a reflective electrode later. (3) The reflectance of the conductive film 30 is reduced.

Therefore, the substrate temperature during the formation of the third conductive film 30 is preferably set as low as possible. In the present embodiment, the substrate temperature is set at room temperature (20 ° C.) to 350 ° C., preferably. Is 260 ° C.

Next, the third conductive film 30 was polished by the CMP method to the extent that the insulating spacer 29a was exposed, using SSW2000 (trade name, manufactured by CABOT) as a slurry. As shown, the third conductive film 30 is left as the reflective electrode 30a in the opening 29b. In this CMP, your polishing rate of the third conductive film 3 0 and the insulating spacer 2 9 a have the same value of about 300 _n m / min Both the third conductive film 3 0 and the insulating spacer 2 Either one of 9a will not be polished excessively more than the other. The polishing amount of the CMP is controlled by time.

The LCOS substrate according to the present embodiment (reflective liquid crystal display) Module for device) 40 basic structure is completed. An enlarged perspective view of the LCOS substrate 40 is as shown in FIG. 16, and FIG. 13 corresponds to a cross-sectional view taken along a line II-III of FIG.

Thereafter, the process proceeds to a step of attaching the liquid crystal panel manufactured in a different process from the above to the LCOS substrate 40.

As shown in FIG. 14, the liquid crystal panel 31 is adhered to the LCOS substrate 40 by a sealing material (not shown), and is provided between the lower liquid crystal alignment film 32 and the upper liquid crystal alignment film 34. It has a liquid crystal layer 33 arranged. Then, a common electrode 35 made of a transparent conductive material such as ITO (Indium Titan Oxide) is formed on the upper liquid crystal alignment film 34, and the liquid crystal layer 33 is formed on the common electrode 35 from external impact. Is provided with a surface glass for protecting the glass.

As described above, the basic structure of the reflective liquid crystal display device according to the present embodiment is completed.

In this reflective liquid crystal display device, the transistor TR is turned on, and the voltage of the first metal wiring 19a is applied to the reflective electrode 30a, so that a pixel is formed on the liquid crystal layer 33 on the reflective electrode 30a. A voltage is applied every time. Then, the incident light obliquely incident from the surface glass 36 is polarized in a predetermined direction according to the voltage value of the reflective electrode 30a, and is reflected by the reflective electrode 30a and emitted to the outside again. A predetermined display is provided to the user by passing through an analyzer 114 as shown in FIG.

Further, since the voltage applied to the reflective electrode 30a is also held in the capacitor Q, the display screen does not change even if the transistor TR is turned off, and the display state can be held.

As described above, according to this embodiment, as shown in FIGS. 12 and 13, the third conductive film 30 is formed on the insulating spacer 29 a and in the opening 29 b. Then, the third conductive film 30 is polished by the CMP method and left as the reflective electrode 30a in the opening 28b, so that the upper surface of the reflective electrode 30a becomes flat, and the upper surface becomes an insulating spacer. It is the same height as the upper surface of 29a. As a result, as shown in FIG. 14, even when the liquid crystal panel 31 is attached on the reflective electrode 30a, a gap is formed between the liquid crystal panel 31 and the insulating spacer 29a. Because it is not Thus, it is possible to provide a reflection type liquid crystal display device in which scattering of incident light is prevented, color tone is good, and contrast is enhanced.

Moreover, as shown in FIG. 13, the cross-sectional shape of the insulating spacer 29a is tapered, so that the upper surface where the width of the insulating spacer 29a is narrow allows adjacent reflections. The distance d between the electrodes 30a is extremely short. Therefore, the reflection electrodes 30a are arranged at a very high density, so that the incident light scattered by the insulating spacer 29a is reduced, and most of the incident light is reflected by the reflection electrodes 30a. Reflected by a, the reflectance of the entire LCOS substrate 40 is improved, and the contrast is improved.

Further, when the aluminum film forming the reflective electrode 30a is formed by sputtering, the substrate temperature is kept at a low temperature of about room temperature to about 350 ° C., so that the grains of the aluminum film do not grow significantly. Irregularities on the surface of the aluminum film are reduced, and the reflectance of the reflective electrode 30a itself can be improved.

(Second embodiment)

This embodiment is different from the first embodiment in a method of forming a tapered insulating spacer 29a, and is otherwise the same as the first embodiment. 17 to 19 are cross-sectional views illustrating a method of manufacturing the module for a reflective liquid crystal display device according to the present embodiment in the order of steps. In these drawings, members already described in the first embodiment are denoted by the same reference numerals as in the first embodiment.

First, after forming the structure shown in FIG. 10 according to the first embodiment, the silicon substrate 1 is placed on a hot plate, and the substrate temperature is set to 120 ° C. to 130 ° C. in an atmosphere of N ₂ ( : The silicon substrate 1 is heated so as to become: When the silicon substrate 1 is heated in this way, the fourth resist pattern 37 is melted by heat and its shape collapses, as shown in FIG.

Next, steps required until a sectional structure shown in FIG.

First, Si0 a scan Bae one sub insulating film 2-9 composed of _2, the etch rate of the fourth resist pattern 3 7 1: under conditions such that 1, for spacer insulating film 2 9 and the fourth The resist pattern 37 is etched. Such Etsuchin grayed is, CHF ₃ to a mixed gas of gas and CF ₄ gas, the mixed flow rate is not multi than gas 0 _2, for example about 5 0 0 sccm flow rate of 0 ₂ etching gas obtained by adding Can be performed by using plasma etching.

As a result, the cross-sectional shape of the tapered fourth resist pattern 37 is transferred to the spacer insulating film 29, and an insulating spacer 29a having a tapered cross section is formed. As in the first embodiment, the insulating spacer 29a has an opening 29b for each pixel, and the upper surface of the fourth conductive plug 28 is formed from the opening 29b. Exposed.

Thereafter, by performing the above-described steps of FIGS. 12 to 13, as shown in FIG. 19, the reflection made of the aluminum film in the opening 29 b of the insulating spacer 29 a is performed. An electrode 30a is formed.

According to the above-described embodiment, as shown in FIG. 18, the fourth resist pattern 37 is etched and removed at the same time as the formation of the insulating spacer 29a. The step of removing the fourth resist pattern 37 again as in the embodiment is not required, so that the manufacturing process of the LCOS substrate can be simplified, and the manufacturing cost of the LCOS substrate can be reduced. As described above, according to the present invention, since the conductive film is polished into the reflective electrode, the upper surfaces of the reflective electrode and the insulating spacer have the same height. Therefore, even if the liquid crystal panel is attached on the reflective electrode, no gap is formed between the liquid crystal panel and the insulating spacer, so that a reflective liquid crystal display module with good color tone and high contrast is provided. Can be realized.

In addition, since the cross-sectional shape of the insulating spacer is tapered, the reflection electrodes can be arranged at a high density, and the reflectance of the entire reflection type liquid crystal display module can be increased.

In addition, since the aluminum film is used as a reflective electrode and the aluminum film is formed by a sputtering method at a low substrate temperature of room temperature or higher and 350 ° C or lower, the grain size of the aluminum film is reduced, and the reflection of the reflective electrode is reduced. Rates can be higher.

Claims

The scope of the claims

1. a semiconductor substrate;

An insulating film formed above the semiconductor substrate;

An insulating spacer formed on the insulating film and having an opening for each pixel; and a flat surface formed in the opening of the insulating spacer and having the same height as the upper surface of the insulating spacer. A reflective electrode having an upper surface,

A module for a reflection type liquid crystal display device, comprising:

2. The reflective liquid crystal display module according to claim 1, wherein a cross-sectional shape of the insulating spacer is tapered.

3. The reflective liquid crystal display module according to claim 1, wherein the insulating spacer is made of silicon dioxide.

4. The reflective liquid crystal display module according to claim 1, wherein the reflective electrode is made of aluminum.

5. forming a first insulating film above the semiconductor substrate;

Forming a second insulating film on the first insulating film;

A step of forming an insulating spacer having an opening for each pixel by patterning the second insulating film;

Forming a conductive film on the insulating spacer and on the first insulating film in the opening;

Polishing the conductive film to the extent that the insulating spacer is exposed, and using the conductive film remaining in the opening as a reflective electrode;

A method for manufacturing a module for a reflection type liquid crystal display device, comprising: '

6. The cross-sectional shape of the insulating spacer is tapered. A method for manufacturing a module for a reflective liquid crystal display device according to claim 5.

7. The step of forming the insulating spacer includes:

Forming a resist pattern on the second insulating film;

Using a mixed gas of an etching gas and a deposition gas having a larger flow rate than the etching gas as an etching gas, etching the second insulating film while using the resist pattern as a mask;

7. The method for producing a reflective liquid crystal display device module according to claim 6, wherein the method is performed by the following.

8. The use of CF ₄ gas as an etching gas, the manufacturing method of the reflection-type liquid crystal Display device module according to claim 7, wherein the use of CHF ₃ gas to said deposition gas.

9. The reflective liquid crystal display module according to claim 8, wherein the flow rate of the CHF ₃ gas is set to be more than 1 and not more than twice the flow rate of the CF ₄ gas. Method.

10. The step of forming the insulating spacer comprises:

Forming a resist pattern on the second insulating film;

Heating and melting the resist pattern to break the cross-sectional shape of the resist pattern;

After heating the resist pattern, simultaneously etching the resist pattern and the second insulating film;

7. The method for producing a reflective liquid crystal display device module according to claim 6, wherein the method is performed by:

11. The manufacturing method of the reflective liquid crystal display module according to claim 10, wherein the resist pattern is heated at a substrate temperature of 120 ° C. or more and 130 ° C. or less. Method.

1 2. The resist pattern and the second insulating film are simultaneously etched to that process, CHF ₃ to a mixed gas of gas and CF ₄ gas, a gas obtained by adding 0 ₂ flow rate is greater than the mixed gas 11. The method for manufacturing a reflective liquid crystal display module according to claim 10, wherein the etching is performed by plasma etching using a gas as an etching gas.

13. The method for manufacturing a reflective liquid crystal display module according to claim 5, wherein a silicon dioxide film is formed as the second insulating film.

14. The method for manufacturing a reflective liquid crystal display module according to claim 5, wherein an aluminum film is formed as the conductive film.

15. The manufacturing method for a reflective liquid crystal display module according to claim 14, wherein the aluminum film is formed by a sputtering method at a substrate temperature of room temperature or higher and 350 ° C. or lower. Method.

1 6. The semiconductor substrate,

An insulating film formed above the semiconductor substrate;

An insulating spacer formed on the insulating film and having an opening for each pixel; and a flat formed in the opening of the insulating spacer and having the same height as the upper surface of the insulating spacer. A plurality of reflective electrodes having a top surface,

A common electrode provided to face the plurality of reflective electrodes,

Liquid crystal sealed between the reflective electrode and the common electrode,

A reflective liquid crystal display device comprising:

17. The reflective liquid crystal display device according to claim 16, wherein a cross-sectional shape of the insulating spacer is tapered.