JP2004206108A - Reflective liquid cystal display and method for manufacturing reflective liquid cystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a process of forming via holes in a reflective liquid crystal display by disposing at least two layers of metal light shielding films between a semiconductor substrate and a plurality of pixel electrodes for reflection. <P>SOLUTION: First and second metal light shielding films 28, 33 with insulating films 27, 32, 29 layered on and under each film are formed between a semiconductor substrate 11 and a plurality of reflective pixel electrodes 30 so as to prevent part of the readout light L entering a liquid crystal 40 from a transparent substrate 42 side through a counter electrode 41 from leaking to a switching element side 14 when the light intrudes from an opening 30a formed between the adjacent reflective pixel electrodes 30 into a third interlayer insulating film 29. The opening 30a formed between adjacent reflective pixel electrodes 30 is covered with one of the first and second metal light shielding films 28, 33, while one of the first and second metal light shielding films 28, 33 is electrically connected to one switching element 13, one reflective pixel 30 and storage capacitors C1 to C3 through a third via hole Via3. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  According to the present invention, in a reflective liquid crystal display device, a part of the readout light that has entered the liquid crystal from the transparent substrate side through the counter electrode passes from an opening formed between adjacent reflective pixel electrodes to the reflective pixel electrode. The present invention relates to a reflective liquid crystal display device capable of reducing a leak current generated in a switching element provided on a semiconductor substrate by a part of the readout light when it enters an adjacent insulating film and a method of manufacturing the reflective liquid crystal display device. It is.

  Recently, projection-type displays for displaying images on a large screen, such as displays for outdoor public use or traffic control services, and displays for displaying high-definition images typified by the HDTV broadcast standard and the SVGA standard of computer graphics. Liquid crystal display devices are widely used.

  This type of projection type liquid crystal display device is roughly classified into a transmission type liquid crystal display device using a transmission type and a reflection type liquid crystal display device using a reflection type, but in the case of the former transmission type liquid crystal display device. Has the disadvantage that the area of a TFT (Thin Film Transistor) provided in each pixel does not become a transmission area of a pixel that transmits light, so that the aperture ratio becomes small. -Type liquid crystal display devices are receiving attention.

  In general, in the above-mentioned reflection type liquid crystal display device, a plurality of switching elements are provided on a semiconductor substrate (Si substrate) in an electrically separated manner, and are stacked and formed above the plurality of switching elements. A plurality of reflective pixel electrodes corresponding to the plurality of switching elements are provided on the uppermost layer among the plurality of functional films, respectively, and one reflective pixel electrode and one switching element connected to one switching element are provided. A single pixel is formed by grouping a plurality of storage capacitors for use in a matrix, and a plurality of the pixels are arranged in a matrix on a semiconductor substrate, and are opposed to a plurality of reflective pixel electrodes, and are transparently opposed to all pixels. Electrodes are formed on the lower surface of a transparent substrate (glass substrate), and liquid crystal is sealed between a plurality of pixel electrodes for reflection and a counter electrode. The readout light is made to enter the liquid crystal through the counter electrode, and the switching element changes the potential difference between the counter electrode and each reflective pixel electrode for each reflective pixel electrode in accordance with the video signal, thereby aligning the liquid crystal. Is controlled to modulate the read light for the color image, and the read light for the color image reflected by each reflective pixel electrode is emitted from the transparent substrate.

FIG. 1 is a cross-sectional view schematically showing one pixel in a reflective liquid crystal display device of Conventional Example 1 in an enlarged scale.
FIG. 2A is a block diagram for explaining an active matrix driving circuit in the reflection type liquid crystal display device of Conventional Example 1, and FIG. 2B is a schematic diagram showing an enlarged portion X in FIG. is there.

The reflective liquid crystal display device 10A of Conventional Example 1 shown in FIG. 1 is configured so as to be applicable to a general reflective projector, and one of a plurality of pixels for displaying an image. When the semiconductor substrate 11 serving as a base is a p-type Si substrate (or an n-type Si substrate) such as single-crystal silicon, this semiconductor substrate (hereinafter referred to as a p-type Si substrate) is used. 1), one p ^- well region 12 is provided on the left side of the drawing 11 in a state of being electrically separated in pixel units by left and right field oxide films 13A and 13B. One switching element 14 is provided in one p ^- well region 12, and this switching element 14 is configured as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor).

Further, one switching element (hereinafter referred to as MOSFET) 14 has a gate G formed by forming a gate electrode 16 made of polysilicon on a gate oxide film 15 located substantially at the center of the p ^- well region 12. Is formed.

  A drain region 17 is formed on the left side of the gate G of the MOSFET 14 in the figure, and a drain electrode 18 is formed on the drain region 17 by aluminum wiring in the first via hole Via1, thereby forming a drain D. Have been.

  A source region 19 is formed on the right side of the gate G of the MOSFET 14 in the figure, and a source electrode 20 is formed on the source region 19 by aluminum wiring in the first via hole Via1, thereby forming the source S. Have been.

Further, on the p-type Si substrate 11, a diffusion capacitance electrode 21 implanted with ions is formed on the right side of the p ^- well region 12 in the figure, and the diffusion capacitance electrode 21 is also formed on the pixel unit by the left and right field oxide films 13B and 13C. , And a range from the field oxide film 13A to the field oxide film 13C corresponds to one pixel.

  Further, an insulating film 22 and a capacitor electrode 23 are sequentially formed on the diffusion capacitor electrode 21, and a capacitor electrode contact 24 is formed on the capacitor electrode 23 by aluminum wiring in the first via hole Via 1. Thus, a storage capacitor C corresponding to one MOSFET 14 is formed.

  Above the field oxide films 13A to 13C, the gate electrode 16, and the capacitor electrode 23, a first interlayer insulating film 25, a first metal film 26, a second interlayer insulating film 27, and a second metal film 28 , A third interlayer insulating film 29 and a third metal film 30 are stacked to form a plurality of functional films in the order described above.

At this time, the first, second, and third interlayer insulating films 25, 27, and 29 are formed using insulating SiO ₂ (silicon oxide) or the like.

  Further, the first, second, and third metal films 26, 28, and 30 are partitioned into a predetermined pattern shape for each pixel corresponding to one switching element 14 by conductive aluminum wiring or the like. Although the first, second, and third metal films 26, 28, and 30 are electrically connected to each other in the same pixel, the first, second, and third metal films 26 , 28, and 30 are formed between adjacent films, respectively, so that one first, second, and third metal films 26, 28, and 30 are electrically provided for each pixel, respectively. Are separated.

  In one pixel, the lowermost first metal film 26 is formed by forming an aluminum wiring in each first via hole Via1 in which the first interlayer insulating film 25 is etched. , And one of the switching elements 14 and the storage capacitor C via the capacitor electrode contact 24.

  Further, in one pixel, the second metal film 28 in the middle stage is formed by the MOSFET 14 on the p-type Si substrate 11 provided below a part of the readout light L incident from the transparent substrate 42 side described later disposed above. It is provided as a metal light shielding film for shielding light from the side. That is, the second metal film (metal light-shielding film) 28 covers the opening 30a so as to shield part of the readout light L that enters from the opening 30a formed between the upper adjacent third metal films 30. The aluminum wiring is formed in the second via hole Via2 in which the second interlayer insulating film 27 is etched, and is connected to the first metal film 26 at the lowermost stage.

  Further, in one pixel, the upper third metal film 30 is divided into a square shape by an opening 30a formed between the adjacent third metal films 30 corresponding to one pixel, and one reflection pixel is formed. It is provided as an electrode, and is connected to the second metal film 28 in the middle stage by forming an aluminum wiring in the third via hole Via3 in which the third interlayer insulating film 29 is etched.

  A liquid crystal 40 is sealed above a third metal film (hereinafter, referred to as a reflective pixel electrode) 30, and a transparent counter electrode 41 is formed on the lower surface of a transparent substrate (glass substrate) 42 via the liquid crystal 40. The film is formed by using ITO (Indium Tin Oxide) or the like as a common electrode for each of the reflective pixel electrodes 30 without being divided for each pixel.

  Next, in the reflection type liquid crystal display device 10A of the conventional example 1, an active matrix drive circuit in which a plurality of MOSFETs (switching elements) 14 are arranged in a matrix on the p-type Si substrate 11 is shown in FIG. This will be described with reference to FIG.

  As shown in FIGS. 2A and 2B, in the active matrix drive circuit 70 in the conventional reflective liquid crystal display device 10A, a plurality of MOSFETs (switching elements) 14 are provided on a p-type Si substrate (semiconductor substrate) 11. One pixel is formed by combining one reflection pixel electrode 30 connected to one MOSFET 14 and one storage capacitor C for the MOSFET, and one pixel is formed. A plurality are arranged in a matrix on the Si substrate 11.

  In order to specify one pixel among the plurality of pixels, a horizontal shift register circuit 71 and a vertical shift register circuit 75 are provided separately in a column direction and a row direction.

  First, on the side of the horizontal shift register circuit 71, a signal line 73 is wired in the vertical direction via a video switch 72 for each column of pixels. However, here, for convenience of illustration, one signal line 73 is provided. Only the state connected to the horizontal shift register circuit 71 is shown. A video line 74 is connected to a signal line 73 provided between the horizontal shift register circuit 71 and the video switch 72. One signal line 73 is connected to the drain electrodes 18 of the plurality of MOSFETs 14 arranged in one column.

  Next, on the side of the vertical shift register circuit 75, a gate line 76 is wired in the horizontal direction for each row of pixels, but here, for convenience of illustration, only one gate line 76 is used for the vertical shift register circuit. It is shown in a state connected to the 75 side. Further, one gate line 76 is connected to the gate electrodes 16 of the plurality of MOSFETs 14 arranged in one row.

  In addition, the source electrode 20 of each MOSFET 14 is connected to one reflection pixel electrode 30 and the capacitor electrode contact 24 and the capacitor electrode 23 of the storage capacitor C. At this time, the active matrix driving circuit 70 applies a well-known frame inversion driving method, and the video signal is inverted to a positive polarity and a negative polarity every frame period, that is, for example, the n-th frame period of the video signal is The positive write and the (n + 1) th frame period are negative write. Therefore, when a video signal is input from the signal line 73, the signal line 73 may be connected to either the drain electrode 18 of the MOSFET 14 or the source electrode 20, but here, as described above, 73 is connected to the drain electrode 18. When the signal line 73 is connected to the source electrode 20, one reflection pixel electrode 30 is connected to the drain electrode 18, and the capacitor electrode contact 24 and the capacitor electrode 23 of the storage capacitor C are connected. is there.

  Further, in the above-mentioned conventional reflective liquid crystal display device 10A, a well potential supplied to the MOSFET 14 and a COM (common) potential supplied to the storage capacitor C are required as fixed potentials.

That is, the well potential supplied to the MOSFET 14 is, for example, a fixed potential between the gate line 76 and a well potential contact on a p ⁺ region (not shown) formed in one p ⁻ well region 12 (FIG. 1). A voltage of 15 V is applied. When an n-type Si substrate is used, for example, 0 V may be applied as a well potential.

  On the other hand, the COM potential supplied to the storage capacitor C is, for example, 8.5 V as a fixed potential between the capacitor electrode 24 of the storage capacitor C and a COM (common) potential contact (not shown) on the diffusion capacitor electrode 22. Voltage is applied. At this time, although the COM potential may be basically any number of volts to form the storage capacitor section C, if the COM potential is set to the center value (for example, 8.5 V) of the video signal, the storage capacitor section C Is about half of the power supply voltage. That is, since the withstand voltage of the storage capacitor may be approximately half of the power supply voltage, it is possible to increase the capacitance by reducing only the thickness of the insulating film 22 of the storage capacitor C. Is large, the fluctuation of the potential of the reflective pixel electrode 30 can be reduced, which is advantageous for flicker and burn-in.

  The storage capacitor section C accumulates charges in accordance with the potential difference between the potential applied to one reflection pixel electrode 30 and the COM potential, and keeps the voltage even if one MOSFET 14 is turned off during the non-selection period. And the function of continuously applying the holding voltage to one reflection pixel electrode 30 is provided.

  Here, when one pixel is driven in the active matrix driving circuit 70 in the conventional reflection type liquid crystal display device 10A, a video signal input from the video line 74 at a sequentially shifted timing is transmitted via the video switch 72. One MOSFET 14 which is supplied to one signal line 73 arranged in the column direction and located at a position where this one signal line 73 intersects one gate line 76 arranged in the row direction is selected and turned on. .

  Then, when a video signal is input to the selected one of the reflective pixel electrodes 30 via the signal line 73, the video signal is written in the form of electric charges to the storage capacitor C, and the selected one of the reflective pixel electrodes 30 is A potential difference is generated between the liquid crystal 40 and the counter electrode 41 (FIG. 1) according to a video signal, and modulates the optical characteristics of the liquid crystal 40. As a result, the read light L (FIG. 1) for a color image, which is incident from the transparent substrate 42 side, is modulated for each pixel by the liquid crystal 40, reflected by the reflective pixel electrode 30, and emitted from the transparent substrate 42. Therefore, unlike the transmission method, the readout light L (FIG. 1) can be used close to 100%, and the projected image has a structure capable of achieving both high definition and high luminance.

  At this time, as shown in FIG. 1, a part of the color image readout light L incident from the transparent substrate 42 side is transmitted from the opening 30a formed between the adjacent reflective pixel electrodes 30 to the third interlayer insulating film. In the third interlayer insulating film 29, the lower surface of the reflective pixel electrode (third metal film) 30 formed by aluminum wiring and the upper surface of the metal light shielding film (second metal film) 28 formed by aluminum wiring. After that, a part of the readout light L enters the second interlayer insulating film 27 from the opening 28a where the metal light-shielding film 28 is not formed. The reflection between the lower surface of the metal light-shielding film 28 made of aluminum wiring and the upper surface of the first metal film 26 made of aluminum wiring is repeated, and the first interlayer insulating film 25 is removed from the opening 26a where the first metal film 26 is not formed. Invade. At this time, the opening 26a where the first metal film 26 is not formed is formed in a region above the gate electrode 16 of the MOSFET 14 or in a region above the capacitor electrode 23 of the storage capacitor C. Part of the readout light L that has entered the interlayer insulating film 25 reaches the gate electrode 16, the drain region 17, the source region 19 of the MOSFET 14 and the capacitance electrode 23 of the storage capacitor C.

Here, when a part of the readout light L enters the drain region 17 and the source region 19 of the MOSFET 14, the p ⁻ well region 12 and the drain region 17 and the source region 19 made of a high-concentration n ⁺ impurity layer in the MOSFET 14 Since a pn junction is formed, a photodiode function operates, and photocarriers are generated by a part of the readout light L to generate a leakage current, which may cause a change in the potential of the pixel electrode 30 for reflection. Since the fluctuation of the potential of the reflection pixel electrode 30 causes flicker or burn-in, it is necessary to minimize light leakage in the MOSFET 14 due to a part of the readout light L.

There is a liquid crystal display device that takes measures to suppress the occurrence of light leakage in the MOSFET 14 due to a part of the readout light L (for example, see Patent Document 1).
JP-A-2002-40482 (page 3-7, FIG. 1).

  FIG. 3 is a cross-sectional view schematically showing a liquid crystal display device of Conventional Example 2. The liquid crystal display device 100 of Conventional Example 2 shown in FIG. 3 is disclosed in the above-mentioned Patent Document 1 (Japanese Patent Application Laid-Open No. 2002-40482), and will be briefly described with reference to Patent Document 1. I do.

  As shown in FIG. 3, in the liquid crystal display device 100 of the second conventional example, a plurality of active elements 102 are provided on a first substrate (drive circuit substrate) 101. At this time, one active element 102 includes a gate electrode 103, a drain region 104 and a source region 105 provided on the left and right sides of the gate electrode 103, and one active element 102 is formed on the insulating film 106. The adjacent left and right field oxide films 107, 107 electrically isolate the adjacent active element 102.

  Above the active element 102, a first interlayer film 108, a first conductive film 109, a second interlayer film 110, a first light shielding film 111, a third interlayer film 112, A plurality of functional films each including a second light-shielding film 113, a fourth interlayer film 114, and a second conductive film (hereinafter, referred to as a reflective electrode) 115 serving as a reflective electrode are stacked in the order described above. Have been.

  At this time, the first conductive film 109, the first light-shielding film 111, the second light-shielding film 113, and the reflective electrode 115 are each provided with conductivity, and are partitioned in a predetermined pattern for each active element 102. I have.

  Further, the first conductive film 109 is connected to the drain region 104 and the source region 105 of one active element 102 via the first via hole Via1 formed in the first interlayer film 108. Further, the first light-shielding film 111 needs to form a second via hole Via2 shown by a virtual line outside the illustrated frame in order to apply a voltage as described later. The second light-shielding film 113 is connected to the first conductive film 109 via a third via hole Via3 formed in the second and third interlayer films 110 and 112. Further, the reflective electrode 115 is connected to the second light-shielding film 113 via a fourth via hole Via4 formed in the fourth interlayer film 114. Therefore, one reflection electrode 115 is connected to one active element 102 via the second light-shielding film 113 and the first conductive film 109.

  Further, an alignment film 116, a liquid crystal composition 117, an alignment film 118, an opposing electrode 119, and a second substrate (transparent substrate) 120 are provided above the reflective electrode (second conductive film) 115 in the above order. In addition, the inside of the liquid crystal composition 117 is divided into one reflective electrode 115 (one pixel) by the left and right spacers 121, 121.

  At this time, the above-mentioned spacer 121 is arranged on the opening 115 a formed between the adjacent reflecting electrodes 115, and the second light-shielding film 113 has substantially the same size as the reflecting electrode 115 so as to cover the opening 115 a. Further, since the first light-shielding film 111 is formed so as to cover the opening 113a formed between the adjacent second light-shielding films 113, the first light-shielding film 111 is made incident from the second substrate (transparent substrate) 120. Even if a part of the readout light L enters the fourth interlayer film 114 from the opening 115 a formed between the adjacent reflective electrodes 115, a part of the readout light L is removed from the first and second light-shielding films 111. , 113, and does not reach the active element 102 provided on the first substrate 101, so that the occurrence of light leakage in the active element 102 due to a part of the readout light L can be suppressed. Measures have been applied to so that.

  In the liquid crystal display device 100 of the second conventional example having the above configuration, a voltage is applied to the first light shielding film 111 and the first light shielding film 111, the third interlayer film 112, and the second light shielding film 113 are used. A capacitor is formed. When the voltage of the reflection electrode 115 is changed with respect to the counter electrode 119, the first capacitor including the reflection electrode 115, the liquid crystal composition 117, and the counter electrode 119, and the first light-shielding film 111 and the second A light-shielding film 113 and a second capacitor using the second light-shielding film 113 are used.

  Further, it is disclosed that the above configuration can prevent the incidence of unnecessary light generated on the liquid crystal display element, thereby realizing the liquid crystal display device 100 with high quality image quality and the liquid crystal projector using the same. .

  By the way, in the reflection type liquid crystal display device 10A of Conventional Example 1 shown in FIG. 1, as described above, a part of the color image readout light L incident from the transparent substrate 42 side is on the p-type Si substrate 11. Light leaks to reach the formed MOSFET 14 side.

  On the other hand, in the reflective liquid crystal display device 100 of Conventional Example 2 shown in FIG. 3, a second light shielding film 113 is provided below the reflective electrode 115 so as to cover the opening 115a formed between the adjacent reflective electrodes 115. Further, the second substrate (transparent substrate) 120 is provided by providing the second light-shielding film 113 below the second light-shielding film 113 so as to cover the opening 113a formed between the adjacent second light-shielding films 113. Although a part of the readout light L incident from the side does not reach the active element 102 formed on the first substrate 101, no light leakage occurs, but the first conductive film 109 is provided above the first substrate 101. , A second interlayer film 110, a first light shielding film 111, a third interlayer film 112, a second light shielding film 113, a fourth interlayer film 114, and a reflective electrode (a second conductive film). ) 115 are sequentially stacked. Forming a first via hole Via1 in the conductive film 109, forming a second via hole Via2 in the first light shielding film 111, and forming a third via hole Via3 in the second light shielding film 113 And a step of forming a fourth via hole Via4 in the reflective electrode (second conductive film) 115 must be performed. In particular, the additional step of forming the via hole increases the manufacturing of the liquid crystal display device 100. It takes time and the yield tends to be poor, which is a problem.

  Therefore, when minimizing light leakage in the switching element due to a part of the readout light L incident from the transparent substrate side, at least two or more metal light-shielding films are provided between the semiconductor substrate and the reflective pixel electrode. Can be reduced by one step compared to the conventional example 2, and the thickness of the light-shielding insulating film formed between the two metal light-shielding films can be reduced. A reflection type liquid crystal display device that can be set so as to obtain good characteristics with respect to reading light for a color image, and can set a larger storage capacitance value for one switching element provided on the semiconductor substrate; and There is a need for a method of manufacturing a reflection type liquid crystal display device.

The present invention has been made in view of the above problems, and a first invention is to provide a plurality of switching elements on a semiconductor substrate, each of which is electrically separated from each other, and which is stacked above the plurality of switching elements. A plurality of reflective pixel electrodes corresponding to the plurality of switching elements are provided on the uppermost layer among the plurality of functional films formed by being electrically separated, and one of the plurality of functional films is connected to one switching element. A single pixel is formed by combining the reflective pixel electrode and the storage capacitor for the switching element, and a plurality of the pixels are arranged in a matrix. In a reflection type liquid crystal display device in which an electrode is formed on the lower surface of a transparent substrate and a liquid crystal is sealed between the plurality of reflection pixel electrodes and the counter electrode,
Part of the readout light that has entered the liquid crystal from the transparent substrate side through the counter electrode through the opening formed between the adjacent reflective pixel electrodes enters an insulating film adjacent to the reflective pixel electrode. In order to shield a part of the readout light from the switching element side when penetrating, at least two or more metal light-shielding films are vertically arranged between the semiconductor substrate and the plurality of reflective pixel electrodes. Provided with an insulating film interposed, the metal light-shielding film of each layer covers the opening formed between adjacent reflective pixel electrodes, and one metal light-shielding film is provided for each layer. After being electrically separated from the adjacent pixels, one of the metal light-shielding films of each layer was electrically connected to one of the switching elements, one of the reflection pixel electrodes, and the storage capacitor part via holes. A reflective liquid crystal display device according to claim.

According to a second aspect of the present invention, in the reflective liquid crystal display device according to the first aspect,
The storage capacitance value of the storage capacitance portion includes a storage capacitance value of a storage capacitance portion including a diffusion capacitance electrode, an insulating film, a capacitance electrode, and a contact for a capacitance electrode provided on the semiconductor substrate, and two metal light-shielding films. A reflection type liquid crystal display device, wherein a storage capacitance value of a storage capacitance portion formed by a light-shielding insulating film formed therebetween and the two metal light-shielding films is totaled.

According to a third aspect, in the reflection type liquid crystal display device according to the first aspect,
At least one of the two or more metal light-shielding films is formed of TiN or Ti or TiN / Ti in which TiN and Ti are stacked, and is a reflective liquid crystal display device. .

According to a fourth aspect of the present invention, a plurality of switching elements are provided on a semiconductor substrate so as to be electrically separated from each other, and the plurality of switching elements are stacked and formed above the plurality of switching elements. A plurality of reflective pixel electrodes corresponding to a plurality of the switching elements are provided in the upper layer in a state of being electrically separated from each other, and one reflective pixel electrode connected to one switching element and a storage capacitor for the switching element are provided. And forming a single pixel as a set, a plurality of the pixels are arranged in a matrix, and a transparent counter electrode facing the plurality of reflective pixel electrodes is formed on the lower surface of the transparent substrate, In a reflective liquid crystal display device in which liquid crystal is sealed between the plurality of reflective pixel electrodes and the counter electrode,
A part of the color image readout light that has entered the liquid crystal through the counter electrode from the transparent substrate side was adjacent to the reflective pixel electrode from an opening formed between the adjacent reflective pixel electrodes. At least two layers or more are provided between the semiconductor substrate and the plurality of reflective pixel electrodes in order to shield a part of the read light for the color image from the switching element side when penetrating into the insulating film. Metal light-shielding films are provided above and below each other with an insulating film interposed therebetween, and a light-shielding insulating film is formed between the two metal light-shielding films, and the thickness of the light-shielding insulating film is read out for the color image. A reflective liquid crystal display device characterized in that the wavelength is set to 400 nm or less corresponding to the wavelength of B (blue) light among the lights.

According to a fifth aspect of the present invention, a plurality of switching elements are provided on a semiconductor substrate so as to be electrically separated from each other, and among the plurality of functional films formed by stacking over the plurality of switching elements. A plurality of reflective pixel electrodes corresponding to a plurality of the switching elements are provided in the upper layer in a state of being electrically separated from each other, and one reflective pixel electrode connected to one switching element and a storage capacitor for the switching element are provided. And forming a single pixel as a set, a plurality of the pixels are arranged in a matrix, and a transparent counter electrode facing the plurality of reflective pixel electrodes is formed on the lower surface of the transparent substrate, In a reflective liquid crystal display device in which liquid crystal is sealed between the plurality of reflective pixel electrodes and the counter electrode,
A part of the color image readout light that has entered the liquid crystal through the counter electrode from the transparent substrate side was adjacent to the reflective pixel electrode from an opening formed between the adjacent reflective pixel electrodes. At least two layers or more are provided between the semiconductor substrate and the plurality of reflective pixel electrodes in order to shield a part of the read light for the color image from the switching element side when penetrating into the insulating film. A reflection type liquid crystal display device characterized in that a metal light shielding film is provided above and below with an insulating film interposed therebetween, and a light shielding insulating film is formed between the two metal light shielding films using SiN or SiON. It is.

Further, in a sixth aspect of the present invention, a single switching element and a storage capacitor portion for the switching element are assembled on a semiconductor substrate, and a plurality of the sets are provided electrically separated from each other. A plurality of interlayer insulating films and wiring metal films are alternately and repeatedly laminated above the switching element storage capacitor section, and the metal film of each layer is electrically connected to the plurality of switching elements for each layer. One metal film separated in each layer is connected to one switching element and a storage capacitor for the switching element through a via hole, and further separated into a plurality. A reflective liquid crystal display device in which liquid crystal is sealed between a plurality of pixel electrodes for reflection by the uppermost metal film and a transparent counter electrode formed on a transparent substrate. In the manufacturing method,
After forming an antireflection film for each layer on a plurality of layers of the metal film located below the plurality of reflection pixel electrodes, applying a photoresist on the antireflection film,
After forming an opening in the photoresist using a photolithography method, etching is performed from the antireflection film to the interlayer insulating film until the opening is wider than the opening in the antireflection film in the metal film. Forming the opening concentrically;
Removing all of the antireflection film formed on at least one layer or more of the metal film, or removing the antireflection film at an opening peripheral portion located around an opening of the metal film; and ,
Forming a metal light-shielding film above an at least one layer of the metal film and in an opening of the metal film via an insulating film. .

  In the reflective liquid crystal display device and the method of manufacturing the reflective liquid crystal display device according to the present invention described in detail above, according to the reflective liquid crystal display device of the first aspect, particularly, the liquid crystal inside the liquid crystal through the counter electrode from the transparent substrate side. When a part of the read light incident on the pixel enters the insulating film adjacent to the reflective pixel electrode from the opening formed between the adjacent reflective pixel electrodes, a part of the read light is transmitted to the switching element side. In order to shield light, at least two or more layers of metal light-shielding films are provided between the semiconductor substrate and the plurality of reflective pixel electrodes with insulating films interposed therebetween, and any one of the metal light-shielding films of each layer is provided. In addition to covering the opening formed between the adjacent reflective pixel electrodes, and electrically separating one metal light-shielding film for each layer from an adjacent pixel, one metal light-shielding film of each layer is Switching Since it is electrically connected to the pixel, one reflection pixel electrode, and the storage capacitor portion, the number of steps for forming a via hole can be reduced by one step compared to the conventional example 2 to be within the three steps of the first to third via holes. it can.

  According to the reflective liquid crystal display device of the second aspect, in the reflective liquid crystal display device of the first aspect, particularly, the storage capacitance value of the storage capacitance portion is determined by a diffusion capacitance electrode and an insulating film provided on the semiconductor substrate. , A capacitance electrode, and a capacitance electrode, and a capacitance value of a capacitance electrode, and a capacitance capacitance portion formed by a light-shielding insulating film formed between two metal light-shielding films and the two-layer metal light-shielding film. Since the total storage capacitance value can be set to a large value, the fluctuation in the potential of the reflective pixel electrode can be reduced, which is advantageous against flicker and burn-in.

  According to the reflective liquid crystal display device of the third aspect, in the reflective liquid crystal display device of the first aspect, at least one of the two or more metal light-shielding films is made of TiN or Ti or TiN. Since the film is formed using TiN / Ti in which Ti is laminated, the reflectance of the metal light-shielding film can be set low when a part of the reading light is absorbed by the metal light-shielding film. It is possible to absorb a part of the readout light that has entered through the opening formed therebetween.

  According to the reflection type liquid crystal display device of the present invention, in particular, a part of the readout light for a color image, which is made to enter the liquid crystal from the transparent substrate side via the counter electrode, is disposed between the adjacent reflection pixel electrodes. A semiconductor substrate and a plurality of reflective pixel electrodes are used to shield part of the readout light for a color image from the switching element side when entering the insulating film adjacent to the reflective pixel electrode from the formed opening. At least two metal light-shielding films are provided above and below each other with an insulating film interposed therebetween, and a light-shielding insulating film is formed between the two metal light-shielding films. Is set to 400 nm or less corresponding to the wavelength of B (blue) light or less in the color image readout light, so that the B (blue) light of wavelength 400 nm or less in the color image readout light L Because you do n’t have to use It can be highest light shielding effect of the shielding insulating film.

  According to the reflection type liquid crystal display device of the present invention, in particular, a part of the readout light for the color image which has entered the liquid crystal from the transparent substrate via the counter electrode is disposed between the adjacent reflection pixel electrodes. A semiconductor substrate and a plurality of reflective pixel electrodes are used to shield part of the readout light for a color image from the switching element side when entering the insulating film adjacent to the reflective pixel electrode from the formed opening. At least two metal light-shielding films are provided above and below each other with an insulating film interposed therebetween, and a light-shielding insulating film is formed between the two metal light-shielding films using SiN or SiON. Part of the readout light that has entered through the opening formed between the reflective pixel electrodes can be improved in light-shielding performance by SiN or SiON having a low reflectivity, and can be converted into SiN or SiON having a large dielectric constant. Ri can be increased retention capacitance value of the storage capacitor portion formed in a metal light-shielding film of the light shielding insulating film and said second layer was deposited between two layers of metal shielding film. Furthermore, the light-shielding effect can be further increased by combining a light-shielding insulating film made of SiN or SiON with a high refractive index and a metal light-shielding film having light absorbency.

  Further, according to the method of manufacturing a reflection type liquid crystal display device according to claim 6, in particular, after forming an anti-reflection film for each layer on a plurality of metal films located below the plurality of reflection pixel electrodes, After coating the photoresist on the anti-reflective film and forming an opening in the photoresist using photolithography, etching is performed from the anti-reflective film to the interlayer insulating film to prevent reflection in the metal film. A step of concentrically forming an opening wider than the opening in the film, and removing at least one antireflection film formed on the metal film of at least one layer or around the opening of the metal film And a step of forming a metal light-shielding film through an insulating film above an at least one metal film and in an opening of the metal film through a step of removing a part of the anti-reflection film located in LCD display Upon producing location, metal light-shielding film, phenomenon that a short circuit in contact with the metal film in the opening formed in the metal film is eliminated. As a result, the reflective pixel electrode and the COM potential are not short-circuited, and the storage capacitor portion can be formed normally between the metal light-shielding film and the metal film. Can be manufactured.

  Hereinafter, one embodiment of the reflective liquid crystal display device and the method of manufacturing the reflective liquid crystal display device according to the present invention will be described in detail in the order of Embodiments 1 to 3 with reference to FIGS.

FIG. 4 is a cross-sectional view schematically showing one pixel in a reflection type liquid crystal display device of Embodiment 1 according to the present invention,
FIG. 5 illustrates the first metal light-shielding film (second metal film) and the third via hole for electrically connecting the second metal light-shielding film and the reflective pixel electrode (third metal film) shown in FIG. FIGS. 4A and 4B are cross-sectional views partially enlarged for the sake of clarity. FIG. 5A shows a case where the inside of a third via hole is formed of tungsten, and FIG. 6B shows a case where the inside of the third via hole is formed of aluminum wiring. Figure,
FIG. 6 is a plan view showing the reflection pixel electrode (third metal film), the second metal light shielding film, and the third via hole shown in FIG.
7A and 7B are cross-sectional views for explaining formation of a storage capacitor for one switching element in the reflection type liquid crystal display device of Example 1 according to the present invention. FIG. 7A shows a case of Conventional Example 1 as a comparative example. (B) is a diagram showing the case of the present invention,
FIG. 8 is a view for explaining the reflectance of the light-shielding insulating film formed on the first metal light-shielding film (second metal film) / antireflection film in the reflection type liquid crystal display device according to the first embodiment of the present invention. FIG.

  The structure of the reflective liquid crystal display device 10B of Example 1 according to the present invention shown in FIG. 4 is different from the structure of the reflective liquid crystal display device 10A of Conventional Example 1 described above with reference to FIG. This is a partial application of the technical concept of light leakage prevention measures in the liquid crystal display device 100 of Conventional Example 2 described above with reference to FIG. 3, in which case at least between the semiconductor substrate and the reflective pixel electrode. Even if two or more metal light-shielding films are provided above and below each other with an insulating film interposed therebetween, the number of steps for forming a via hole is reduced by one in comparison with the conventional example 2, and the two metal light-shielding films are formed between the two layers. The thickness of the light-shielding insulating film may be set so as to obtain good characteristics with respect to read light for a color image, and the holding capacitance value for one switching element provided on the semiconductor substrate may be set to be larger. What you can configure A.

  For convenience of explanation, the same components as those of the reflection type liquid crystal display device 10A of the conventional example 1 described above are denoted by the same reference numerals, and the same components are appropriately designated as necessary. In the following, components different from those of the first conventional example will be denoted by new reference numerals, and the description will be focused on points different from the first conventional example.

As shown in FIG. 4, in the reflective liquid crystal display device 10B according to the first embodiment of the present invention, one of a plurality of pixels for displaying an image is enlarged and described. As the substrate 11, a p-type Si substrate (or an n-type Si substrate may be used) as in the case of the reflective liquid crystal display device 10 </ b> A of Conventional Example 1 described above with reference to FIG. , One p ^- well region 12 is provided in a pixel unit by a left and right field oxide films 13A and 13B in a state of being electrically separated. A low-voltage drive type MOSFET is provided as one switching element 14 in one p ^- well region 12. The switching element (hereinafter referred to as MOSFET) 14 includes a gate G having a gate electrode 16 formed on a gate oxide film 15, a drain D having a drain electrode 18 formed on a drain region 17, and a source D having a drain electrode 18 formed on a drain region 17. And a source S on which a source electrode 20 is formed, and is configured to be driven at a low voltage of about 7V.

Further, on the p-type Si substrate 11, a storage capacitor portion C1 including a diffusion capacitor electrode 21, an insulating film 22, a capacitor electrode 23, and a capacitor electrode contact 24 is formed to the right of the p ^- well region 12 in the figure. The capacitance section C1 is electrically separated for each pixel by left and right field oxide films 13B and 13C.

  Further, a plurality of reflective pixel electrodes 30 corresponding to the respective MOSFETs 14 are respectively formed on the uppermost layer among a plurality of functional films stacked and formed above the field oxide films 13A to 13C, the gate electrode 16, and the capacitor electrode 23. When they are provided separately from each other, the layers from the first interlayer insulating film 25 to the first metal film 26, the second interlayer insulating film 27, and the second metal film 28 are formed in the same manner as in the conventional example 1, and The first metal film 26 formed by the wiring is connected to one switching element 14 and the storage capacitor C1 via the drain electrode 18, the source electrode 20, and the capacitor electrode contact 24 made of aluminum wiring in the first via hole Via1. ing. Further, one second metal film 28 is electrically separated by an opening 28a formed between adjacent second metal films 28 and connected to the first metal film 26 by aluminum wiring in the second via hole Via2. This is also the same as the conventional example 1.

  Here, the point different from the conventional example 1 will be described. The second metal film 28 is an opening formed between adjacent reflective pixel electrodes 30 among a plurality of reflective pixel electrodes 30 formed thereon. The first metal light-shielding film is formed so as to cover the opening 30a in order to shield a part of the readout light L for a color image which enters from the part 30a toward the p-type Si substrate 11 side. is there.

  5A or 5B, an anti-reflection film 31 and a predetermined film are provided above a second metal film (hereinafter, referred to as a first metal light shielding film) 28. A second metal light-shielding film 33 is formed in order with a light-shielding insulating film 32 having a thickness of 400 nm or less, and an opening formed between the adjacent first metal light-shielding films 28 by the second metal light-shielding film 33. Portion 28a (FIG. 4). Further, as described later, the second metal light-shielding film 33 is electrically separated for each pixel, similarly to the reflective pixel electrode (third metal film) 30.

  Further, a third interlayer insulating film 29 is formed on the second metal light-shielding film 33, and a reflective pixel electrode (third metal film) 30 is formed on the third interlayer insulating film 29 via an antireflection film 34. Is formed. The anti-reflection films 31 and 34 are not shown in FIG. 4 but are shown only in FIG. 5A or FIG. 5B for convenience of illustration.

  At this time, the antireflection film 31 formed on the upper surface of the first metal light shielding film (second metal film) 28 and the antireflection film 34 formed on the lower surface of the pixel electrode for reflection (third metal film) 30 The read light L for a color image that has entered the third interlayer insulating film 29 from the opening 30a (FIG. 4) formed between the adjacent reflective pixel electrodes 30 using both conductive TiN (titanium nitride). It is provided to prevent reflection on a part.

Here, the above-mentioned light-shielding insulating film 32 constitutes a part of the main part of the present invention, and SiO ₂ (silicon oxide) is formed on the first metal light-shielding film (second metal film) 28 / anti-reflection film 31. ) Is usually formed using an oxide film, but need not be an oxide film, and other than the oxide film, such as SiN (silicon nitride) or SiON (silicon nitride oxide) having a higher dielectric constant than SiO _2. Can be used.

  The thickness of the light-shielding insulating film 32 is preferably 400 nm or less, and more preferably, about 300 nm. Explaining the reason, the reflective liquid crystal display device 10B reflects the readout light L for a color image having a wavelength of 400 nm to 700 nm in the visible light region on the reflective pixel electrode 30 to perform color display. Along with this, it is not necessary to use B (blue) light having a wavelength of 400 nm or less among the read light L for a color image, so that it is not necessary to make light having a wavelength of 400 nm or less incident on the transparent substrate 42.

  Accordingly, if the thickness of the light-shielding insulating film 32 is set to 400 nm or less corresponding to the wavelength of B (blue) light or less in the read light L for a color image, the adjacent second metal light-shielding film 33 is formed. Part of the color image readout light L that has entered the light-shielding insulating film 32 from the opening 33a formed between the first metal light-shielding film 28 formed below and above the light-shielding insulating film 32 In addition, since the light is absorbed or reflected by the second metal light shielding film 33, the light shielding effect of the light shielding insulating film 32 can be maximized.

  Further, since the light-shielding insulating film 32 is formed by a chemical vapor deposition method (CVD method: Chemical Vapor Deposition), the light-shielding insulating film 32 is excellent in in-plane variation of the wafer as is known. Accordingly, the thickness of the light-shielding insulating film 32 formed between the first metal light-shielding film 28 and the second metal light-shielding film 33 can be relatively uniformly set to 400 nm or less. Variations in the light blocking effect of the film 32 can also be reduced.

  Next, the second metal light-shielding film 33 formed on the light-shielding insulating film 32 also constitutes a part of the essential part of the present invention. In order to absorb a part of the reading light L for a color image that has entered the third interlayer insulating film 29 from the opening 30a formed therebetween, it is important to form the film using a metal having a low reflectance. Specifically, the second metal light-shielding film 33 is formed using TiN (titanium nitride: titanium nitride), Ti (titanium), TiN / Ti in which TiN and Ti are laminated, or the like within a range of 50 nm to 200 nm. It is formed with a film thickness. Thereby, when the second metal light-shielding film 33 absorbs a part of the readout light L, the reflectance of the second metal light-shielding film 33 can be set low, so that the second metal light-shielding film 33 is formed between the adjacent reflection pixel electrodes 30. Part of the readout light L that has entered through the opening 30a can be absorbed.

  Further, when forming a third via hole Via3 for connecting one reflection pixel electrode (third metal film) 30 to one first metal light-shielding film (second metal film) 28 formed below the same. Since the second metal light-shielding film 33 is a light-absorbing metal film that can be etched at the same time as the third interlayer insulating film 29, the second and first metal light-shielding films 33 are provided below the reflective pixel electrode 30. , 28, the number of steps for forming via holes can be reduced by one step compared to the conventional example 2, and can be included in the three steps of the first to third via holes Via1 to Via3.

  At this time, although the second metal light-shielding film 33 has a higher resistance value than the first to third metal films 26, 28, and 30 using aluminum wiring, the second metal light-shielding film 33 is a light-shielding storage capacitor. Since it is intended for forming, it does not need a function as a wiring for flowing a current, so that it is not necessary to lower the resistance value, thereby not affecting the electrical characteristics, and It works well for

  Further, as shown in FIG. 6, the shape of the second metal light-shielding film 33 is formed in a square shape slightly smaller than the pixel electrode for reflection (third metal film) 30 formed in a square shape. In addition, like the pixel electrode 30 for reflection, it is electrically separated for each pixel. At this time, when the second metal light-shielding film 33 is separated for each pixel, an opening 33a is formed between the adjacent second metal light-shielding films 33 as shown in FIG. 4, but as described above, Since the first metal light-shielding film 28 covers the opening 30a formed between the adjacent reflection pixel electrodes 30, the opening 33a formed between the second metal light-shielding films 33 is formed between the adjacent reflection pixel electrodes 30. Even if the upper and lower openings substantially coincide with the opening 30a formed in the above, no trouble occurs.

  In the first embodiment, the opening 30a formed between the adjacent reflective pixel electrodes 30 is covered by the first metal light-shielding film 28. However, one of the first and second metal light-shielding films 28 and 33 is used. Thus, the opening 30a formed between the adjacent reflective pixel electrodes 30 may be covered. Accordingly, the positions of the first and second metal light-shielding films 28 and 33 with respect to the reflective pixel electrode 30 are slightly different from those illustrated, and the positions of the second and third via holes Via2 and Via3 are slightly different from those illustrated. It is possible that it may deviate.

  As described above, by providing the first and second metal light-shielding films 28 and 33 between the p-type Si substrate 11 and the pixel electrode 30 for reflection, the read light L for a color image incident from the transparent substrate 42 side is provided. Even if a part of the readout light L enters the third interlayer insulating film 29 from the opening 30a formed between the adjacent reflective pixel electrodes 30, a part of this readout light L Only reflection and absorption are repeated by the reflection pixel electrode 30 and the second metal light-shielding film 33 provided above and below in the three interlayer insulating film 29, and a part of the readout light L is applied to the MOSFET 14 provided on the p-type Si substrate 11. Since the light does not reach the side, the occurrence of light leakage in the MOSFET 14 due to a part of the readout light L can be suppressed.

As shown in FIGS. 5A and 6, one reflection pixel electrode (third metal film) 30 and one first metal light shielding film (second metal film) 28 are electrically connected. In the case of connection, the third interlayer insulating film 29 formed using SiO ₂ is etched from a position corresponding to a substantially central portion of the reflective pixel electrode 30, and furthermore, conductive TiN or Ti or TiN / TiN A second metal light-shielding film 33 formed by using, a light-shielding insulating film 32 formed by using SiO _2, SiN or SiON, and an antireflection film 31 formed by using conductive TiN. At the same time, the third via hole Via3 is formed by etching. Then, a conductive tungsten 35 is deposited and buried in the third via hole Via3 by the CVD method so that the lower end of the tungsten 35 is electrically connected to one first metal light shielding film (second metal film) 28. The second metal light-shielding film 33 is electrically connected to an intermediate portion of the tungsten 35, and further, an anti-reflection film 34 whose upper end is formed using conductive TiN is formed. The pixel electrode 30 is electrically connected to the pixel electrode 30 for reflection.

  At this time, usually, an oxide film etching apparatus (not shown) aims at etching only the oxide film, and therefore has a low etching rate with respect to Al (aluminum) and aims at selective etching. . However, simultaneously with the etching of the third via hole Via3, it is possible to easily etch TiN or Ti or TiN / Ti used for the second metal light shielding film 33 by the above-described oxide film etching apparatus.

  When the third via hole Via3 is formed, the tungsten 35 does not have to be buried in the third via hole Via3. In this case, as shown in FIG. The third interlayer insulating film 29 is etched from a position corresponding to the portion, and further, the second metal light-shielding film 33, the light-shielding insulating film 32, and the antireflection film 31 are simultaneously etched to form a third via hole Via3. After that, if the anti-reflection film 34 of TiN and the reflection pixel electrode 30 of aluminum wiring are formed in the third via hole Via3 by normal sputtering, the reflection pixel electrode 30, the second metal light shielding film 33, One metal light shielding film 28 is electrically connected.

  Therefore, the third via hole Via3 serves to electrically connect the pixel electrode for reflection (third metal film) 30, the second metal light shielding film 33, and the first metal light shielding film (second metal film). Have. Accordingly, the second metal light-shielding film 33 does not need to provide a dedicated via hole, and thus simplification of the process such as lithography and etching is possible.

  Next, the formation of the storage capacitor for one MOSFET 14 will be described with reference to FIGS. 7A and 7B in the case of Conventional Example 1 as a comparative example and the case of the present invention.

  As shown in FIG. 7A, in the case of Conventional Example 1 which is a comparative example, the diffusion capacitor electrode 21 and the insulating film are formed on the p-type Si substrate 11 with respect to the MOSFET 14 provided on the p-type Si substrate 11. In this case, only one storage capacitor portion C including the capacitor electrode 22, the capacitor electrode 23, and the capacitor electrode contact 24 is formed.

  On the other hand, in the present invention, as shown in FIG. 7 (b), the storage capacitor C1 including the diffusion capacitor electrode 21, the insulating film 22, the capacitor electrode 23, and the capacitor electrode contact 24 on the p-type Si substrate 11. And a second metal light-shielding film 33 is formed on the first metal light-shielding film (second metal film) 28 / antireflection film 31 (FIG. 5) with a light-shielding insulating film 32 interposed therebetween. Since the space between the first metal light-shielding film (second metal film) 28 and the second metal light-shielding film 33 also functions as a storage capacitor, the storage capacitor portions C2 and C3 are separated between the left and right of the third via hole Via3 between them. Is formed. The pixel electrode for reflection (third metal film) 30, the second metal light-shielding film 33, and the first metal light-shielding film (second metal film) 28 are electrically connected to one MOSFET 14 and the storage capacitors C1 to C3. Have been.

At this time, if SiN or SiON having a large dielectric constant is used as the light-shielding insulating film 32, the storage capacitance values of the storage capacitance portions C2 and C3 can be further increased. For example, in the case of using SiN as the light shielding insulating film 32 is the dielectric constant of the SiN 9, on the other hand, in the case of using SiO ₂ as a light-shielding insulating film 32 is a dielectric constant of SiO ₂ is 4.2 it is therefore, in the case of using SiN as the light shielding insulating film 32 can be increased more than twice the holding capacitance value than with the SiO _2.

  Thus, in the present invention, the total storage capacitance value of the three locations can be set larger than that of the first conventional example by the total three storage capacitance portions C1 to C3, and the reflection pixel electrode 30 due to light leakage current or the like can be set. Can be reduced, and display defects such as flicker and burn-in can be reduced. Further, even when the pixel is miniaturized, stable display characteristics can be obtained by forming the storage capacitor portions C1 to C3 at three locations.

Further, as shown in FIG. 8, each of the cases where SiN or SiO ₂ is formed as the light shielding insulating film 32 on the first metal light shielding film (second metal film) 28 / antireflection film 31 (FIG. 5). And the reflectance of only the first metal light shielding film (second metal film) 28 made of aluminum wiring is shown as a reference example. As shown in the figure, when SiN is used as the light-shielding insulating film 32, the reflectance can be suppressed lower than when SiO ₂ is used. Therefore, the light-shielding insulating film 32 is made of SiN or SiON instead of SiO _2. The light shielding effect can be increased by using. Further, while the refractive index of SiO ₂ is 1.45, the refractive index of SiN is approximately 2.0, and since the refractive index of SiON is about 1.8 higher than SiO _2. By combining such a high-refractive-index light-shielding insulating film 32 and the above-described light-absorbing second metal light-shielding film 33, the light-shielding effect can be further increased.

  The operation of the reflection-type liquid crystal display device 10B according to the first embodiment of the present invention configured as described above is similar to that of the reflection-type liquid crystal display of the first conventional example described above with reference to FIGS. Although the operation is substantially the same as the operation of the device 10A, detailed description thereof will be omitted here. However, in the present invention, three storage capacitor portions C1 to C3 are provided on the source electrode 20 (or the drain electrode 18) of the MOSFET (switching element) 14. The difference is that a total storage capacitance value obtained by adding the storage capacitance values of the three storage capacitance portions C1 to C3 is added between the source electrode 20 (or the drain electrode 18) and the COM potential for connection. .

  Next, a method for manufacturing the reflective liquid crystal display device 10B according to the first embodiment of the present invention configured as described above will be described with reference to FIGS. 9A to 9D and FIGS. 10A to 10C. Description will be made in the order of steps.

FIGS. 9A to 9D are cross-sectional views sequentially showing first to fourth steps in the method of manufacturing the reflective liquid crystal display device according to the first embodiment of the present invention.
FIGS. 10A to 10C are cross-sectional views sequentially showing the fifth to seventh steps in the method of manufacturing the reflective liquid crystal display device according to the first embodiment of the present invention.

  First, in a first step shown in FIG. 9A, a MOSFET (switching element) 14, a storage capacitor C1, field oxide films 13A to 13C are formed on a p-type Si substrate (semiconductor substrate) 11 by a known method. Are formed thereon, and a first interlayer insulating film 25, a first metal film 26, a second interlayer insulating film 27, a first metal light shielding film (second metal film) 28 / an anti-reflection film 31 (only shown in FIG. 5) ) Are sequentially formed. At this time, the first metal film 26 is electrically connected to the MOSFET 14 and the storage capacitor C1 by the aluminum wiring in the first via hole Via1, and the first metal light-shielding film (second metal film) 28 is in the second via hole Via2. It is electrically connected to the first metal film 26 by aluminum wiring. Further, an opening 28a is formed between the adjacent first metal light-shielding film (second metal film) 28 / anti-reflection film 31 (FIG. 5) by lithography with a predetermined patterning and etching to form one first metal. The light-shielding film (second metal film) 28 is electrically separated from the adjacent one.

Next, in a second step shown in FIG. 9B, a light-shielding insulating film 32 is formed on the first metal light-shielding film (second metal film) 28 / anti-reflection film 31 (FIG. 5) by using SiO ₂ or SiN or A film is formed with a thickness of, for example, 300 nm from SiON by a CVD method.

  Next, in a third step shown in FIG. 9C, a second metal light-shielding film 33 is formed on the light-shielding insulating film 32 by sputtering with TiN or Ti or TiN / Ti to a thickness of, for example, 70 nm. In addition, an opening 33a is formed between adjacent first metal light-shielding films 33 by predetermined patterning and etching by lithography, and one second metal light-shielding film 33 is electrically separated from an adjacent pixel.

Next, in a fourth step shown in FIG. 9D, a third interlayer insulating film 29 is formed on the second metal light shielding film 33 with a thickness of, for example, 700 nm from SiO ₂ , and the third interlayer insulating film is formed. 29 is flattened by chemical mechanical polishing (CMP).

  Next, in a fifth step shown in FIG. 10A, predetermined patterning is performed on the third interlayer insulating film 29 by lithography, and a third via hole Via3 is formed by etching. At this time, the second metal light-shielding film 33 and the light-shielding insulating film 32 are simultaneously etched and are etched until the first metal light-shielding film (second metal film) 28 is reached. Since the second metal light-shielding film 33 is formed using TiN or Ti or TiN / Ti as described above, the second metal light-shielding film 33 can be easily etched even in an oxide film etching apparatus (not shown).

  Next, in a sixth step shown in FIG. 10B, a tungsten 35 is formed in the third via hole Via3 from above the third interlayer insulating film 29 by the CVD method, and tungsten is formed by etch-back or CMP. Embed 35. Note that aluminum may be sputtered into the third via hole Via3 and etched back to embed the aluminum. Thereby, one second metal light shielding film 33 and one first metal light shielding film (second metal film) 28 are electrically connected to tungsten 35 or aluminum.

  Next, in a sixth step shown in FIG. 10C, an antireflection film 34 (only FIG. 5 is shown) / reflection pixel electrode (third metal film) is formed on the third interlayer insulating film 29 by a known method. 30 is formed by sputtering aluminum, and an opening 30a is formed between adjacent reflective pixel electrodes 30 by performing predetermined patterning by lithography and etching to form one reflective pixel electrode 30. It is electrically separated from adjacent pixels. At this time, the tungsten 35 or aluminum in the third via hole Via3 is electrically connected to one antireflection film 34 (FIG. 5) / reflection pixel electrode (third metal film) 30. Then, the formation of various functional films on the p-type Si substrate 11 is completed.

  As described above, compared with the structure of the first conventional example, the structure is more resistant to light leakage in the MOSFET 14, so that the pixels can be miniaturized. For example, more pixels are packed than the first conventional example for the same screen area. And high definition can be realized.

  Further, as compared with the structure of the conventional example 2, first and second metal light-shielding films 28 and 33 are provided between the p-type Si substrate 11 and the reflective pixel electrode 30 with insulating films 27, 32 and 29 interposed therebetween. Even when the via holes are formed, the number of via hole forming steps can be reduced by one in comparison with the conventional example 2, and the first and second metal films 26 and 28 in which the second metal light-shielding films 33 are formed above and below the via holes when forming the via holes. Can be connected to one MOSFET 14, one of the storage capacitor units C <b> 1 to C <b> 3, and one reflection pixel electrode 30, and the storage capacitance value for one MOSFET 14 can be set large.

  FIG. 11 is a cross-sectional view schematically showing one pixel in a reflective liquid crystal display device according to a second embodiment of the present invention in an enlarged manner.

  The position of the first and second metal light shielding films in the reflective liquid crystal display device 10B according to the first embodiment of the present invention described above is different from the reflective liquid crystal display device 10C according to the second embodiment of the present invention illustrated in FIG. Is partially modified, and only the differences from the first embodiment will be briefly described here.

  In the second embodiment, the second metal light-shielding film is formed on the first metal film 26 via the light-shielding insulating film 36 without forming the metal light-shielding film above the first metal light-shielding film (second metal film) 28. The film 37 is formed. Accordingly, a first metal light-shielding film 28 is formed on the second metal light-shielding film 37 with the second interlayer insulating film 27 interposed therebetween, and the first metal light-shielding films 28 are provided adjacent to each other. The opening 30a formed between the reflective pixel electrodes 30 is covered.

  Note that the first and second metal light-shielding films 28 and 37 are not named in the order of film formation, but the same reference numerals are assigned to the first metal light-shielding films corresponding to the same positions as in the first embodiment.

  In the second embodiment, since the metal light-shielding film is not formed above the first metal light-shielding film (the second metal film) 28, the storage capacitor C is the same as the conventional one described with reference to FIG. As in Example 1, there is only one location provided on the p-type Si substrate 11.

At this time, the light-shielding insulating film 36 is formed using SiO _2, SiN, or SiON to a thickness of 400 nm or less. Further, the above-mentioned second metal light-shielding film 37 is formed using TiN or Ti or TiN / Ti or the like having a low reflectance with a thickness in the range of 50 nm to 200 nm.

  In the second embodiment, when the second via hole Via2 for connecting the first metal light-shielding film (second metal film) 28 to the first metal film 26 is formed, tungsten or aluminum in the second via hole Via2 is used. The first metal light shielding film 28, the second metal light shielding film 37, and the first metal film 26 are electrically connected. Therefore, also in the second embodiment, the number of steps for forming the via hole can be reduced by one step compared to the conventional example 2, and can be included in the three steps of the first to third via holes Via1 to Via3.

  In the case where the reflective liquid crystal display device 10C according to the second embodiment is configured as described above, a part of the color image readout light L incident from the transparent substrate 42 side is formed between the adjacent reflective pixel electrodes 30. From the opening 30a thus formed into the third interlayer insulating film 29, and between the lower surface of the reflective pixel electrode 30 made of aluminum wiring and the upper surface of the first metal light shielding film 28 made of aluminum wiring within the third interlayer insulating film 29. After that, a part of the readout light L enters the second interlayer insulating film 27 from the opening 28a formed between the adjacent first metal light-shielding films 28. Partly, as shown by the dotted line in FIG. 11, the first metal light-shielding film 28 and the second metal light-shielding film 37 provided above and below in the second interlayer insulating film 27 only repeat reflection and absorption, and the read light L Is partially on the p-type Si substrate 11 In order not to reach the MOSFET14 side provided, it is possible to suppress the generation of light leakage in the MOSFET14 by part of the read light L.

  FIG. 12 is a cross-sectional view schematically showing one pixel in a reflective liquid crystal display device according to a third embodiment of the present invention in an enlarged manner.

  The reflective liquid crystal display device 10D according to the third embodiment of the present invention illustrated in FIG. 12 combines the metal light shielding films of the reflective liquid crystal display devices 10B and 10C according to the first and second embodiments according to the present invention described above. Here, only the differences from the first and second embodiments will be briefly described.

  In the third embodiment, the second metal light-shielding film 37 is formed on the first metal film 26 via the light-shielding insulating film 36 in the same manner as in the second embodiment, and the first metal light-shielding film 37 is formed in the same manner as in the first embodiment. A third metal light-shielding film 39 is formed on the light-shielding film (second metal film) 28 via a light-shielding insulating film 38, and is formed between the adjacent first metal light-shielding films 28 by the third metal light-shielding film 39. Cover 28a.

  The first, second, and third metal light-shielding films 28, 37, and 39 are not named in the order of film formation, but are the same as the first and second metal light-shielding films corresponding to the same positions as in the first and second embodiments. The reference numerals are assigned, and different reference numerals are assigned to the third metal light shielding films corresponding to the same positions as in the first embodiment.

At this time, the light-shielding insulating film 36 and the light-shielding insulating film 38 are formed to a thickness of 400 nm or less using SiO _2, SiN, or SiON. Further, the above-mentioned second metal light-shielding film 37 and third metal light-shielding film 39 are formed using TiN or Ti or TiN / Ti having a low reflectance in a thickness in the range of 50 nm to 200 nm.

  In the third embodiment, when the second via hole Via2 for connecting the first metal light-shielding film (second metal film) 28 to the first metal film 26 is formed, tungsten or aluminum in the second via hole Via2 is used. The first metal light-shielding film 28, the second metal light-shielding film 37, and the first metal film 26 are electrically connected, and the pixel electrode for reflection (third metal film) 30 is connected to the first metal light-shielding film (second metal light-shielding film). When the third via hole Via3 for connection to the metal film 28 is formed, the reflective pixel electrode 30, the third metal light shielding film 39, and the first metal light shielding film 28 are electrically connected by tungsten or aluminum in the third via hole Via3. Connected to Therefore, also in the third embodiment, the number of steps for forming the via holes can be reduced by one step compared to the conventional example 2, and the number of the steps can be reduced to three steps of the first to third via holes Via1 to Via3.

  As described above, it is possible to further suppress the occurrence of light leakage in the MOSFET 14 due to a part of the reading light L for a color image as compared with the first and second embodiments. Of course, also in the third embodiment, similarly to the first embodiment, in addition to the storage capacitor portion C1 formed on the p-type Si substrate 11, a first metal light shielding film (second metal film) 28 and a third metal light shielding film The storage capacitor portions C2 and C3 are formed between the left and right sides of the third via hole Via3 so as to function as a storage capacitor also between the third via hole Via3. This makes it possible to set the total storage capacitance value of the three locations larger than that of the conventional example 1 by using the three storage capacitance parts C1 to C3 in total, thereby reducing the fluctuation of the potential of the reflective pixel electrode 30. This is advantageous for flicker and burn-in.

  According to the first to third embodiments, at least two or more metal light-shielding films may be provided between the p-type Si substrate 11 and the reflective pixel electrode 30 with insulating films interposed between the upper and lower layers. The number of forming steps can be reduced by one compared with the conventional example 2, and one MOSFET 14 and one of the storage capacitor parts C1 to C3 (or C1) and one In addition to being able to be connected to the reflection pixel electrode 30, the storage capacitance value for one MOSFET 14 can be set large.

  Here, in the first embodiment described with reference to FIGS. 4 and 5A and 5B, the first metal light-shielding film (second metal film) 28 When the two-metal light-shielding film 33 is formed, or in the second embodiment described above with reference to FIG. 11, a second metal light-shielding film 37 is formed above the first metal film 26 via the light-shielding insulating film 36. In the case where the second metal light shielding film 37 is formed via the light shielding insulating film 36 above the first metal film 26 in the third embodiment described with reference to FIG. When the third metal light-shielding film 39 is formed above the film (second metal film) 28 via the light-shielding insulating film 38, the second metal light-shielding film 33, the second metal light-shielding film 37, or the third metal light-shielding film 37 is formed. In some cases, the metal light-shielding film 39 may cause a film formation failure. It has been found that a phenomenon as shown in FIG. 13 below has occurred, and by taking measures against it as shown in FIG. 14 or FIG. The film formation failure of the third metal light-shielding film 33 or the third metal light-shielding film 39 could be solved.

FIG. 13 is a diagram schematically showing a case where a metal light-shielding film has a film formation failure when a metal light-shielding film is formed above a metal film via a light-shielding insulating film.
FIG. 14 is a diagram schematically showing one embodiment in which a film formation defect of a metal light-shielding film formed over a metal film via a light-shielding insulating film is improved.
FIG. 15 is a diagram schematically showing another embodiment in which the film formation defect of the metal light-shielding film formed above the metal film via the light-shielding insulating film is improved.

  For example, in the first embodiment, the first metal light-shielding film (second metal film) 28 and the first metal film 26 located below the reflective pixel electrode (third metal film) 30 described above with reference to FIG. In forming the openings 28a and 26a for electrical isolation corresponding to one reflection pixel electrode 30 in each of the films 28 and 26, as described later, the resolution at the time of exposure in photolithography is increased. In order to improve the surface reflectance, an antireflection film for reducing the surface reflectance is formed using TiN (titanium nitride).

  More specifically, as described above with reference to FIGS. 5A and 5B, the first metal light-shielding film (second metal film) 28 is formed between the pixel electrodes 30 for reflection. A second metal light-shielding film 33 is formed via the light-shielding insulating film 32 to shield part of the color image readout light L that has entered the third interlayer insulating film 29 from the opening 30a (FIG. 4). At this time, an anti-reflection film 31 is formed on the first metal light shielding film (second metal film) 28 using TiN (titanium nitride) with a thickness of about 30 nm.

  Here, the reason for forming the anti-reflection film 31 on the first metal light-shielding film (second metal film) 28 as shown in FIG. 13 will be described. This is necessary for forming the opening 28a in the metal light shielding film 28 with high dimensional accuracy.

  In a normal case, a photoresist (not shown) is applied on the first metal light-shielding film 28 without forming the antireflection film 31 on the first metal light-shielding film (second metal film) 28. A photomask is placed on the resist, and exposure and development are performed from above the photomask by using a photolithography method to form a photoresist pattern (opening) on the photoresist. Thereafter, when dry etching is performed from the first metal light-shielding film 28 exposed from the photoresist pattern (opening) to reach the second interlayer insulating film 27, an opening 28a is formed in the first metal light-shielding film 28. . At this time, the exposure light is transmitted in the thickness direction of the photoresist pattern and reaches the first metal light-shielding film 28, and irregular reflection occurs at the first metal light-shielding film 28, so that the exposure area is increased. For this reason, a photoresist pattern with good dimensional accuracy cannot be formed. Accordingly, the opening 28a in the first metal light shielding film 28 has poor dimensional accuracy.

  Therefore, as a countermeasure, the opening 28a in the first metal light shielding film (second metal film) 28 was formed as follows.

  First, a photoresist is applied on the antireflection film 31 formed on the first metal light shielding film 28.

  Next, a photomask is placed on the photoresist, and exposure and development are performed from above the photomask using a photolithography method to form a photoresist pattern (opening) on the photoresist.

  Next, when dry etching is performed from the anti-reflection film 31 exposed from the photoresist pattern (opening) to the second interlayer insulating film 27 via the first metal light-shielding film 28, the light is reflected in the first metal light-shielding film 28. An opening 28a wider than the opening 31a in the prevention film 31 is formed concentrically.

  The above-described dry etching is performed by applying a microwave power with chlorine and boron chloride serving as etching gases in a vacuum atmosphere to generate plasma. At this time, since the above-mentioned photoresist is also etched at the same time, hydrocarbon and chlorine, which are the main components of the photoresist, are applied to the antireflection film 31 and the first metal light shielding film (second metal film) 28 to be etched. The attachment enables anisotropic etching, and a fine wiring pattern can be formed.

  From the above, when the anti-reflection film 31 is formed on the first metal light-shielding film (second metal film) 28, since the exposure light can suppress irregular reflection by the anti-reflection film 31, only the exposure region is exposed. In order to form a patterned photoresist pattern (opening), the opening 31a in the anti-reflection film 31 and the opening 28a in the first metal light shielding film 28, which are etched using the photoresist pattern as a mask, have dimensional accuracy. Will be good.

  However, in the above-described dry etching process, the anti-reflection film 31 using TiN (titanium nitride) and the first metal light-shielding film (second metal film) 28 using aluminum are different in the gas to be etched, The cross-sectional shape of the opening 28a formed in the first metal light-shielding film 28 after etching is as shown in the drawing, that is, the anti-reflection film 31 is located at an upper part in the opening 28a formed in the first metal light-shielding film 28. It will remain in a state protruding "eave-like".

Thereafter, a light-shielding insulating film 32 having a thickness of 400 nm or less is formed on the anti-reflection film 31 using SiO ₂ , and further, TiN (titanium nitride) and / or Ti (titanium) is formed on the light-shielding insulating film 32. When the second metal light-shielding film 33 is formed by using the above-described method, the second metal light-shielding film 33 is formed substantially along the inside of the opening 28a formed in the first metal light-shielding film 28 via the light-shielding insulating film 32. At this time, the “lower part of the eaves” of the anti-reflection film 31 protruding “eave-like” in the upper part in the above-mentioned opening part 28a becomes a shadow, so that the light-shielding insulating material in the above-mentioned opening part 28a Since the film 32 and the second metal light-shielding film 33 are not formed normally, the second metal light-shielding film 33 comes into contact with the first metal light-shielding film 28 in the opening 28a to cause a short circuit. As a result, defects such as short-circuiting between adjacent reflective pixel electrodes 30 (FIG. 4) or difficulty in forming the storage capacitor portions C2 and C3 described above with reference to FIG. It has been found that this can happen.

  Therefore, as shown in FIG. 14, a photoresist is applied on an antireflection film 31 'formed on the first metal light-shielding film (second metal film) 28, and the photoresist is applied on the photoresist using a photolithography method. After the photoresist pattern (opening) is formed, dry etching is performed from the anti-reflection film 31 ′ to the second interlayer insulating film 27 via the first metal light-shielding film 28, and the case of FIG. Similarly to the above, after the dry etching, the antireflection film 31 ′ protrudes in an “eave-like shape” above the opening 28 a formed in the first metal light shielding film (second metal film) 28, After the etching is completed, the entire anti-reflection film 31 'formed on the first metal light-shielding film 28 is removed. At this time, even if all of the antireflection film 31 ′ is removed, a part of the readout light L can be shielded by the second metal light-shielding film 33 formed thereon via the light-shielding insulating film 32. Does not cause any trouble.

Here, when removing the antireflection film 31 ′ using TiN (titanium nitride) by dry etching, a gas of CF ₄ and O ₂ is introduced in a vacuum atmosphere to generate RF plasma. At this time, the film thickness of the anti-reflection film 31 ′ is approximately 30 nm as described above, and is formed below the first metal light shielding film 28 and faces the opening 28 a formed in the first metal light shielding film 28. The thickness of the second interlayer insulating film 27 is about 1000 nm, and the etching rates of the antireflection film 31 ′ and the second interlayer insulating film 27 are substantially the same. At the time of etching, even if the second interlayer insulating film 27 facing the opening 28a is etched by about 30 nm, the thickness is only about 970 nm, so that no problem is caused.

Thereafter, a light-shielding insulating film 32 having a thickness of 400 nm or less is formed using SiO ₂ on the first metal light-shielding film 28 from which the antireflection film 31 ′ is completely removed. When the second metal light-shielding film 33 is formed using TiN (titanium nitride) and / or Ti (titanium), the second metal light-shielding film 33 is formed in the first metal light-shielding film 28 via the light-shielding insulating film 32. The film is normally formed substantially along the inside of the opening 28a formed in the above. Thereafter, the second metal light-shielding film 33 is electrically separated into a plurality corresponding to the plurality of pixel electrodes for reflection (third metal film) 30, and one separated second metal light-shielding film 33 is illustrated first. As described with reference to FIG. 5 (a) or FIG. 5 (b), a via hole Via3 formed in one reflective pixel electrode 30 which is electrically separated above the third interlayer insulating film 29 above the conductive film is formed. Connected.

  As a result, the phenomenon in which the second metal light-shielding film 33 is short-circuited by contact with the first metal light-shielding film 28 in the opening 28a formed in the first metal light-shielding film (second metal film) 28 is eliminated. As a result, the reflective pixel electrode 30 (FIG. 4) and the COM voltage do not short-circuit, and the second metal light-shielding film 33 and the first metal light-shield as described with reference to FIG. The storage capacitor portions C2 and C3 can also be formed normally between the film (second metal film) 28.

  In the first embodiment, since the metal light-shielding film is not formed above the first metal film 26 as shown in FIG. It is not necessary to remove the formed reflection film prevention (not shown).

  As described above, in the case of forming the second metal light-shielding film 37 above the first metal film 26 via the light-shielding insulating film 36 in the second embodiment described with reference to FIG. In the third embodiment described above, the second metal light-shielding film 37 is formed above the first metal film 26 via the light-shielding insulating film 36 and the first metal light-shielding film (second metal film) 28 is formed. The third metal light-shielding film 39 may be formed via the light-shielding insulating film 38 in the same manner as in the first embodiment.

  When the antireflection film 31 ″ formed on the first metal light-shielding film (second metal film) 28 is desired to be left, the anti-reflection film 31 ″ is formed in the first metal light-shielding film 28 as shown in FIG. If the anti-reflection film 31 ″ of the opening peripheral portion 31b located around the opening 28a is patterned with a photoresist and only the opening peripheral portion 31b of the anti-reflection film 31 ″ is removed by the above-mentioned dry etching, the second The metal light-shielding film 33 is normally formed substantially along the inside of the opening 28a formed in the first metal light-shielding film 28 via the light-shielding insulating film 32. Thereafter, the second metal light-shielding film 33 is electrically separated into a plurality corresponding to the plurality of pixel electrodes for reflection (third metal film) 30, and one separated second metal light-shielding film 33 is illustrated first. As described with reference to FIG. 5 (a) or FIG. 5 (b), the via hole Via3 formed in the reflective pixel electrode 30 which is electrically separated above and via the third interlayer insulating film 29 is electrically connected to the via hole Via3. Connected.

  As a result, the phenomenon in which the second metal light-shielding film 33 is short-circuited by contact with the first metal light-shielding film 28 in the opening 28a formed in the first metal light-shielding film (second metal film) 28 is eliminated. As a result, the reflective pixel electrode 30 (FIG. 4) and the COM voltage do not short-circuit, and the second metal light-shielding film 33 and the first metal light-shield as described with reference to FIG. The storage capacitor portions C2 and C3 can be formed normally between the film (the second metal film) 28 and, in this case, a masking step for the antireflection film 31 '' is added to the case shown in FIG. However, the antireflection film 31 ″ other than the removed portion can maintain the antireflection function for a part of the readout light L with respect to the intrusion light.

  The manufacturing process in the case shown in FIG. 14 or FIG. 15 will be briefly described. The anti-reflection film 31 is provided for each layer on a plurality of metal films 28 (26) located below the plurality of reflective pixel electrodes 30. Forming a film of '(31' '), applying a photoresist on the anti-reflection film 31' (31 ''), forming an opening in the photoresist using photolithography, and then forming an anti-reflection film Etching is performed from the film 31 ′ (31 ″) to the interlayer insulating film 27 (25), and the metal film 28 (26) is wider than the opening 31a in the antireflection film 31 ′ (31 ″). A step of forming the openings 28a (26a) concentrically, and removing all the antireflection films 31 'formed on at least one or more metal films 28 (26); ) Opening 28 (26a) A step of removing the antireflection film 31 ″ of the peripheral portion 31b of the opening located in the periphery, the upper portion of at least one metal film 28 (26) and the opening 28 (26a) of the metal film 28 (26); The reflective liquid crystal display device 10B (10C, 10D) can be favorably manufactured by forming the metal light-shielding film 33 (37, 39) through the insulating film 32 (36, 38).

FIG. 9 is a cross-sectional view schematically showing one pixel in a reflective liquid crystal display device of Conventional Example 1 in an enlarged manner. (A) is a block diagram for explaining an active matrix drive circuit in the reflection type liquid crystal display device of Conventional Example 1, and (b) is a schematic diagram showing an enlarged X portion in (a). FIG. 9 is a cross-sectional view schematically illustrating a liquid crystal display device of Conventional Example 2. FIG. 2 is a cross-sectional view schematically showing one pixel in a reflective liquid crystal display device according to a first embodiment of the present invention in an enlarged manner. In order to explain the first metal light-shielding film (second metal film) and the third via hole for electrically connecting the second metal light-shielding film and the reflective pixel electrode (third metal film) shown in FIG. It is the sectional view which expanded and showed a part, (a) shows the case where the inside of the 3rd via hole was formed with tungsten, and (b) is the figure which showed the case where the inside of the 3rd via hole was formed with aluminum wiring. . FIG. 5 is a plan view schematically showing a reflection pixel electrode (third metal film), a second metal light-shielding film, and a third via hole shown in FIG. 4. FIG. 9 is a cross-sectional view for explaining formation of a storage capacitor for one switching element in the reflection type liquid crystal display device of Example 1 according to the present invention, and FIG. (B) is a diagram showing the case of the present invention. FIG. 4 is a diagram for explaining the reflectance of a light-shielding insulating film formed on a first metal light-shielding film (second metal film) / anti-reflection film in the reflective liquid crystal display device according to the first embodiment of the present invention. . (A)-(d) is sectional drawing which showed the 1st process-the 4th process in order in the manufacturing method of the reflective liquid crystal display device of Example 1 which concerns on this invention. (A)-(c) is sectional drawing which showed 5th-7th process in order in the manufacturing method of the reflective liquid crystal display device of Example 1 which concerns on this invention. FIG. 6 is a cross-sectional view schematically showing one pixel in a reflective liquid crystal display device according to a second embodiment of the present invention in an enlarged manner. FIG. 13 is a cross-sectional view schematically showing one pixel in a reflective liquid crystal display device according to a third embodiment of the present invention in an enlarged manner. FIG. 5 is a diagram schematically illustrating a case where a metal light-shielding film has a film formation failure when the metal light-shielding film is formed above the metal film via a light-shielding insulating film. FIG. 4 is a diagram schematically showing one embodiment in which a film formation defect of a metal light shielding film formed above a metal film via a light shielding insulating film is improved. FIG. 9 is a view schematically showing another embodiment in which a defective film formation of a metal light-shielding film formed above a metal film via a light-shielding insulating film is improved.

Explanation of reference numerals

10B... The reflective liquid crystal display device of Example 1 according to the present invention,
10C: a reflective liquid crystal display device according to a second embodiment of the present invention;
10D: a reflective liquid crystal display device according to a third embodiment of the present invention;
11: semiconductor substrate (p-type Si substrate), 12: p ^- well region,
13A to 13C: Field oxide film,
14 switching element (MOSFET), 15 gate oxide film,
16 gate electrode, 17 drain region, 18 drain electrode,
19: source region, 20: source electrode,
21: diffusion capacitance electrode, 22: insulating film, 23: capacitance electrode,
24 ... Capacitor electrode contact,
25: first interlayer insulating film, 26: first metal film, 27: second interlayer insulating film,
28: first metal light-shielding film (second metal film) of Examples 1 to 3, 28a: opening,
29: third interlayer insulating film,
30 ... Reflection pixel electrode (third metal film),
31: an anti-reflection film, 31a: an opening, 31b: a part around the opening,
32 ... light-shielding insulating film,
33, 33 ′, 33 ″: the second metal light-shielding film of Example 1,
34: anti-reflection film, 35: tungsten,
36: a light-shielding insulating film; 37: a second metal light-shielding film of the second and third embodiments;
38: a light-shielding insulating film; 39: a third metal light-shielding film of Example 3;
41: liquid crystal, 42: transparent counter electrode, 43: transparent substrate (glass substrate),
70: Active matrix drive circuit,
71: horizontal shift register circuit, 72: video switch, 73: signal line,
74 video line, 75 vertical shift register circuit, 76 gate line,
C1 to C3: storage capacity unit,
D: drain, G: gate, S: source,
Via1 to Via3 ... First to third via holes.

Claims (6)

A plurality of switching elements are provided on a semiconductor substrate, each being electrically separated, and a plurality of the switching elements are formed in the uppermost layer among a plurality of functional films formed by stacking over the plurality of switching elements. A plurality of corresponding reflection pixel electrodes are provided electrically separated from each other, and one reflection pixel electrode connected to one switching element and a storage capacitor unit for the switching element are paired to form one A pixel is formed, and a plurality of the pixels are arranged in a matrix, and a transparent counter electrode facing the plurality of reflective pixel electrodes is formed on a lower surface of a transparent substrate. In a reflective liquid crystal display device in which liquid crystal is sealed between the counter electrode and
Part of the readout light that has entered the liquid crystal from the transparent substrate side through the counter electrode through the opening formed between the adjacent reflective pixel electrodes enters an insulating film adjacent to the reflective pixel electrode. In order to shield a part of the readout light from the switching element side when penetrating, at least two or more metal light-shielding films are vertically arranged between the semiconductor substrate and the plurality of reflective pixel electrodes. Provided with an insulating film interposed, the metal light-shielding film of each layer covers the opening formed between adjacent reflective pixel electrodes, and one metal light-shielding film is provided for each layer. After being electrically separated from the adjacent pixels, one of the metal light-shielding films of each layer was electrically connected to one of the switching elements, one of the reflection pixel electrodes, and the storage capacitor part via holes. Reflection type liquid crystal display device according to claim. The reflective liquid crystal display device according to claim 1,
The storage capacitance value of the storage capacitance portion includes a storage capacitance value of a storage capacitance portion including a diffusion capacitance electrode, an insulating film, a capacitance electrode, and a contact for a capacitance electrode provided on the semiconductor substrate, and two metal light-shielding films. A reflection type liquid crystal display device, wherein a storage capacitance value of a storage capacitance portion formed by a light shielding insulating film formed therebetween and the two metal light shielding films is totaled. The reflective liquid crystal display device according to claim 1,
A reflective liquid crystal display device, wherein at least one of the two or more metal light-shielding films is formed using TiN or Ti or TiN / Ti obtained by laminating the TiN and the Ti. A plurality of switching elements are provided on a semiconductor substrate, each being electrically separated, and a plurality of the switching elements are formed in the uppermost layer among a plurality of functional films formed by stacking over the plurality of switching elements. A plurality of corresponding reflection pixel electrodes are provided electrically separated from each other, and one reflection pixel electrode connected to one switching element and a storage capacitor unit for the switching element are paired to form one A pixel is formed, and a plurality of the pixels are arranged in a matrix, and a transparent counter electrode facing the plurality of reflective pixel electrodes is formed on a lower surface of a transparent substrate. In a reflective liquid crystal display device in which liquid crystal is sealed between the counter electrode and
A part of the color image readout light that has entered the liquid crystal through the counter electrode from the transparent substrate side was adjacent to the reflective pixel electrode from an opening formed between the adjacent reflective pixel electrodes. At least two layers or more are provided between the semiconductor substrate and the plurality of reflective pixel electrodes in order to shield a part of the read light for the color image from the switching element side when penetrating into the insulating film. Metal light-shielding films are provided above and below each other with an insulating film interposed therebetween, and a light-shielding insulating film is formed between the two metal light-shielding films, and the thickness of the light-shielding insulating film is read out for the color image. A reflection type liquid crystal display device, wherein the wavelength is set to 400 nm or less corresponding to the wavelength of B (blue) light among the lights. A plurality of switching elements are provided on a semiconductor substrate, each being electrically separated, and a plurality of the switching elements are formed in the uppermost layer among a plurality of functional films formed by stacking over the plurality of switching elements. A plurality of corresponding reflection pixel electrodes are provided electrically separated from each other, and one reflection pixel electrode connected to one switching element and a storage capacitor unit for the switching element are paired to form one A pixel is formed, and a plurality of the pixels are arranged in a matrix, and a transparent counter electrode facing the plurality of reflective pixel electrodes is formed on a lower surface of a transparent substrate. In a reflective liquid crystal display device in which liquid crystal is sealed between the counter electrode and
A part of the color image readout light that has entered the liquid crystal through the counter electrode from the transparent substrate side was adjacent to the reflective pixel electrode from an opening formed between the adjacent reflective pixel electrodes. At least two layers or more are provided between the semiconductor substrate and the plurality of reflective pixel electrodes in order to shield a part of the read light for the color image from the switching element side when penetrating into the insulating film. A reflection type liquid crystal display device characterized in that a metal light shielding film is provided above and below with an insulating film interposed therebetween, and a light shielding insulating film is formed between the two metal light shielding films using SiN or SiON. . A single switching element and a storage capacitor portion for the switching element are formed as a set on the semiconductor substrate, and a plurality of the sets are provided electrically separated from each other, and a plurality of the switching elements and the storage capacitor section for the switching element are provided. A plurality of interlayer insulating films and wiring metal films are alternately and repeatedly stacked above, and the metal films of each layer are electrically separated into a plurality corresponding to the plurality of switching elements for each layer. A single metal film separated in each layer is connected to one switching element and a storage capacitor for the switching element via a via hole; In a method of manufacturing a reflective liquid crystal display device in which liquid crystal is sealed between a reflective pixel electrode and a transparent counter electrode formed on a transparent substrate,
After forming an antireflection film for each layer on a plurality of layers of the metal film located below the plurality of reflection pixel electrodes, applying a photoresist on the antireflection film,
After forming an opening in the photoresist using a photolithography method, etching is performed from the antireflection film to the interlayer insulating film until the opening is wider than the opening in the antireflection film in the metal film. Forming the opening concentrically;
Removing all of the antireflection film formed on at least one layer or more of the metal film, or removing the antireflection film at an opening peripheral portion located around an opening of the metal film; and ,
Forming a metal light-shielding film above an at least one layer of the metal film and in an opening of the metal film via an insulating film.

Images