Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
  • G02F1/1362—Active matrix addressed cells
  • G02F1/136227—Through-hole connection of the pixel electrode to the active element through an insulation layer
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D30/00—Field-effect transistors [FET]
  • H10D30/60—Insulated-gate field-effect transistors [IGFET]
  • H10D30/67—Thin-film transistors [TFT]
  • H10D30/6729—Thin-film transistors [TFT] characterised by the electrodes
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D30/00—Field-effect transistors [FET]
  • H10D30/60—Insulated-gate field-effect transistors [IGFET]
  • H10D30/67—Thin-film transistors [TFT]
  • H10D30/6729—Thin-film transistors [TFT] characterised by the electrodes
  • H10D30/673—Thin-film transistors [TFT] characterised by the electrodes characterised by the shapes, relative sizes or dispositions of the gate electrodes
  • H10D30/6732—Bottom-gate only TFTs
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D30/00—Field-effect transistors [FET]
  • H10D30/60—Insulated-gate field-effect transistors [IGFET]
  • H10D30/67—Thin-film transistors [TFT]
  • H10D30/6729—Thin-film transistors [TFT] characterised by the electrodes
  • H10D30/6737—Thin-film transistors [TFT] characterised by the electrodes characterised by the electrode materials
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D30/00—Field-effect transistors [FET]
  • H10D30/60—Insulated-gate field-effect transistors [IGFET]
  • H10D30/67—Thin-film transistors [TFT]
  • H10D30/674—Thin-film transistors [TFT] characterised by the active materials
  • H10D30/6741—Group IV materials, e.g. germanium or silicon carbide
  • H10D30/6743—Silicon
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D30/00—Field-effect transistors [FET]
  • H10D30/60—Insulated-gate field-effect transistors [IGFET]
  • H10D30/67—Thin-film transistors [TFT]
  • H10D30/674—Thin-film transistors [TFT] characterised by the active materials
  • H10D30/6741—Group IV materials, e.g. germanium or silicon carbide
  • H10D30/6743—Silicon
  • H10D30/6746—Amorphous silicon
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
  • G02F1/1362—Active matrix addressed cells
  • G02F1/1368—Active matrix addressed cells in which the switching element is a three-electrode device

Definitions

• TFT substrate liquid crystal display device using the same, and method of manufacturing the same
• the present invention relates to a TFT substrate, a liquid crystal display device using the same, and a method for manufacturing the same.
• TFT substrates are used as driving switching elements.
• aluminum alloys dominate as low-resistance electrode and wiring materials.
• indium tin oxide (ITO) and indium zinc oxide (IZO) are mainly used as the material of the transparent electrode.
• ITO indium tin oxide
• IZO indium zinc oxide
• a transparent electrode is directly formed on an electrode made of an aluminum alloy through a through hole in an interlayer insulating film, aluminum acid occurs and a contact resistance occurs between the electrode and the transparent electrode. Therefore, it is known that a liquid crystal display device including a TFT substrate manufactured with such a material does not operate normally.
• the electrode made of aluminum alloy has a three-layer structure sandwiched by metals such as Mo, Ti, and Cr to prevent the aluminum alloy from directly contacting the transparent electrode, thereby reducing contact resistance. It is common practice to suppress the increase in
• An object of the present invention is to provide a TFT substrate and a liquid crystal display device that operate stably, and an efficient manufacturing method thereof.
• the present inventors have conducted intensive studies and found that the distance between the source and drain electrodes and the transparent electrode It has been found that the above object can be achieved by providing a metal thin film buffer layer on the substrate and preventing them from directly contacting each other. Disclosure of the invention
• a TFT substrate in which an insulating layer is interposed between a source / drain electrode and a transparent electrode, and the source / drain electrode and the transparent electrode are electrically connected by through holes formed in the insulating layer. Further, there is provided a TFT substrate having a source / drain electrode mainly composed of metal aluminum and a through-hole having a metal thin film buffer layer between the source / drain electrode and the transparent electrode.
• a gate electrode gate wiring
• a gate insulating film a first silicon layer, a channel protective layer, a second silicon layer, a source , A drain electrode, an interlayer insulating film, a metal thin film buffer layer, and a transparent electrode.
• the source and drain electrodes and the transparent electrode are electrically connected through the through holes in the interlayer insulating film.
• a type without a channel protection layer is also known.
• one layer of the metal thin film buffer is made of a material that can be etched with the same etchant as the transparent electrode.
• the etching step can be simplified.
• the metal thin film buffer layer has a main component of a metal which is more easily oxidized than aluminum.
• the contact resistance may be lower than when a metal that is hardly oxidized is used.
• the above-mentioned metal is preferably a metal exhibiting conductivity when oxidized, and more preferably a metal exhibiting transparency.
• the metal oxide is conductive, the contact resistance between the source and drain electrodes and the transparent electrode can be further reduced.
• the transparency of the entire metal thin film buffer is improved, and the transparency of the pixel portion is also improved.
• the metal thin film buffer layer is formed of at least one metal selected from Ag, Au, Pt, Rh, Pd, Cr, In, Ga, Zn, Mo, Ti and Sn. Or it is preferable to consist of an alloy.
• Such a metal or alloy has excellent film-forming properties. Also, the stability of the obtained thin film is excellent.
• one metal thin film buffer layer is made of one or more metals or alloys selected from Cr, In, Ga, Zn, Mo, Ti and Sn.
• one metal thin film buffer layer is made of one or more metals or alloys selected from In, Ga, Zn and Sn. Such a metal or alloy is more easily oxidized than aluminum, and the oxidized product is excellent in transparency and conductivity.
• the thickness of one metal thin film buffer is 30 to 30 OA.
• the film thickness be in such a range from the viewpoint of preventing an increase in contact resistance between the electrodes and the transparency of the metal thin film buffer layer.
• Another embodiment of the present invention is a liquid crystal display device including the above-mentioned TFT substrate.
• the liquid crystal display device can operate stably without deteriorating its performance.
• an insulating film is formed on the source and drain electrodes, a through hole is formed in the insulating film, and a metal buffer film and a transparent conductive film are formed on the insulating film and the through hole. Forming a metal buffer film and a transparent conductive film simultaneously to form a metal thin film buffer layer and a transparent electrode.
• the source and drain electrodes have a multilayer structure
• the metal buffer film and the transparent conductive film can be etched by the same etchant, there is no need to repeat etching, and a TFT substrate can be manufactured efficiently.
• the amount of material used is reduced, a TFT substrate can be manufactured at lower cost.
• FIG. 1 is a sectional view of a ⁇ -Si TFT substrate which is an embodiment of the TFT substrate of the present invention.
• the TFT substrate of the present invention a liquid crystal display device using the same, and a method for manufacturing the same will be described.
• the material of the source / drain electrodes is not particularly limited as long as the main component is metallic aluminum.
• Components other than aluminum metal and the amount thereof are not particularly limited.
• Examples of the component other than the metal alloy include metals such as Nd, Pt, Pd, Zn, and Ni.
• the metal thin film buffer layer is provided between the source / drain electrodes and the transparent electrode, and prevents an increase in contact resistance between these electrodes.
• the metal thin film buffer layer is conductive and may be easily oxidized or hardly oxidized.
• the oxide is preferably conductive, and more preferably transparent.
• the material of the metal thin film buffer layer is not particularly limited as long as the contact resistance between the electrodes can be prevented from increasing.
• Such examples include one or more metals or alloys selected from Ag, Au, Pt ;, Rh, Pd, and Cr.
• these metals or alloys can be etched with the same etchant as the transparent electrode. Further, those which are more easily oxidized than aluminum are preferable, and the metal oxide is more preferably transparent and conductive.
• the etchant include, but are not particularly limited to, oxalic acid aqueous solution, nitric acid monoacetic acid monophosphate aqueous solution, hydrochloric acid aqueous solution, hydrogen bromide aqueous solution, iron chloride-hydrochloric acid aqueous solution, aqua regia, and the like.
• Examples of the material that can be simultaneously etched include, for example, one or more metals selected from Ag, Au, Pt, Rh, Pd, Cr, In, Ga, Zn, Mo, Ti, and Sn. Alloys.
• One or more metals or alloys may be selected.
• the thickness of one metal thin film buffer is preferably 30 to 30 OA. The reason for this is that if the film thickness is less than 3 OA, the thin film may be too thin and the effect of one metal thin film buffer may not be exhibited. On the other hand, if the film thickness exceeds 300, the transparency may be poor.
• the transparency can be improved, and the film thickness can be increased.
• the film thickness should be 30 to 100 A. The reason for this is that if the film thickness is less than 3 OA, the thin film is too thin and aluminum in the source / drain electrodes may be oxidized, increasing the contact resistance with the transparent electrode. On the other hand, if the film thickness exceeds 10 OA, the light transmittance may decrease.
• the thickness is preferably 30 to 30 OA.
• the film thickness is less than 3 OA, the effect of preventing an increase in contact resistance may not be exhibited because the thin film is too thin.
• the film thickness is 30 OA or more, the degree of oxidation is low, and the transparency may decrease.
• Examples of the material of the transparent electrode include oxides such as indium tin oxide (ITO) and indium zinc oxide (IZO).
• components other than the above, such as the substrate and the gate electrode, are particularly limited. It is not specified, and commonly used configurations and materials can be used.
• components other than the TFT substrate are not particularly limited, and a commonly used configuration and material can be used.
• the metal buffer film and the transparent conductive film are simultaneously etched using the same etchant to form a metal thin film buffer layer and a transparent electrode.
• each component of the TFT substrate including the metal thin film buffer layer and the transparent electrode is not particularly limited.
• a vacuum deposition method or a 'sputtering' method can be used as a film forming method for each component.
• the method and apparatus for vacuum deposition and sputtering are not particularly limited.
• the vacuum deposition method include an electron beam method, an ion plating method, and a resistance heating method.
• Examples of the sputtering method include a high-frequency sputtering method, a DC sputtering method, an RF sputtering method, a DC magnetron sputtering method, an RF magnetron sputtering method, an ECR plasma sputtering method, and an ion beam sputtering method. No.
• the means for patterning the metal thin film formed by these methods into a desired electrode shape and the means for forming a through hole are not particularly limited, and the method can be carried out using a general photolithography method or the like.
• FIG. 1 is a sectional view of a Hi-Si TFT substrate which is an embodiment of the TFT substrate of the present invention.
• Metal A 1 resistivity: 5 n ⁇ ⁇ cm
• a gate electrode 4 and a gate wiring having desired shapes were formed on this layer by a photoetching method using a nitric acid-acetic acid-monophosphate aqueous solution as an etching solution.
• a gate insulating film 6 made of a first silicon nitride (Si Nx) film was deposited to a thickness of 3,000 A using a SiH 4 —NH 3 —N 2 system gas as a discharge gas. .
• a discharge gas S i H 4 - with N 2 -based mixed gas, a- S i: and the H (i) film (first silicon layer) 8 is deposited in a thickness of 3, 50 OA .
• S i H 4 - NH 3 - with N 2 containing gas was deposited a second silicon nitride (S i Nx) film thickness 70 OA.
• This second S i Nx film was formed a desired channel protective layer 10 by dry etching using CF 4 gas.
• a—Si: H (n) film (second silicon layer) 12 was deposited to a thickness of 1,00 OA using a SiH 4 —H 2 III- based mixed gas.
• the gate insulating film 6, the Hi-Si: H (i) film 8, the channel protective layer 10, and the ⁇ 1-Si: H (n) film 12 were deposited by a glow discharge CVD method.
• A1 containing 1 at% of Nd (resistivity: 5 ⁇ ⁇ ⁇ ) was deposited thereon to a thickness of 0.3 m by vacuum evaporation or sputtering.
• This A1 layer was patterned by photoetching using a nitric acid-monoacetic acid-monophosphoric acid aqueous solution based on the desired source-drain electrodes 14, 15 and source-drain wiring (not shown). .
• a source-drain insulating film (interlayer insulating film) 16 as a third silicon nitride (SiNx) film was deposited to a thickness of 3,000 by glow discharge CVD.
• a SiH 4 —NH 3 _N 2 system gas was used as the discharge gas for the third SiNx film.
• a photo-etching method using a dry etching method using CF gas was adopted.
• a gate electrode outlet 24, a source electrode outlet (not shown), a desired through hole 22 as an electrical contact point between the source / drain electrode 15 and the transparent electrode (pixel electrode) 20 are formed. did.
• a metal In was formed to a thickness of 100 A by a vacuum evaporation method or a sputtering method. Then, an amorphous transparent conductive film containing indium oxide and zinc oxide as main components was deposited thereon by a sputtering method.
• a sputtering target an In 2 ⁇ 3 —Zn ⁇ sintered body in which the atomic ratio [In / (I + Zn)] of 111 and 211 was adjusted to 0.83 was placed in a planar magnetron-type cascade.
• a transparent conductive film was deposited to a thickness of 1,000 A using pure argon or an argon gas mixed with a small amount of oxygen gas of about 1 Vo 1% as a discharge gas.
• the In 2 ⁇ 3 —Zn ⁇ film When analyzed by X-ray diffraction, the In 2 ⁇ 3 —Zn ⁇ film was amorphous with no peaks observed.
• the metal buffer film and the thin film of the transparent conductive film are patterned into the desired metal thin film buffer layer 18, the transparent electrode 20, and the extraction electrode by a photoetching method.
• -SiTFTT substrate 1 was completed.
• Example 2 After a TF ⁇ -LCD flat panel display was manufactured using this substrate, the display performance was confirmed by inputting a video signal, and the display performance was good.
• Example 2 After a TF ⁇ -LCD flat panel display was manufactured using this substrate, the display performance was confirmed by inputting a video signal, and the display performance was good.
• the metal thin film buffer layer 18 of Example 1 was changed to a metal Ag having a thickness of 50 mm from the metal I ⁇ having a film thickness of 10 OA, and the etchant of the metal thin film buffer layer 18 and the transparent electrode 20 was prepared from an aqueous solution of 3.4 wt% oxalic acid
• a TFT-LCD type flat display was manufactured in the same manner as in Example 1 except that the aqueous solution of a nitric acid / acetic acid / monophosphate system was used. When a video signal was input to the obtained liquid crystal display device and the display performance was confirmed, the display performance was good. Comparative Example 1
• a TFT-LCD flat panel display was manufactured in the same manner as in Example 1, except that the step of forming the metal thin film puffer layer 18 of Example 1 was omitted.
• Liquid crystal table obtained When a video signal was input to the display device and the display performance was checked, no signal could be input, and the display performance was poor.
• substrate which operates stably, a liquid crystal display device, and its efficient manufacturing method can be provided.

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• Physics & Mathematics (AREA)
• Nonlinear Science (AREA)
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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Microelectronics & Electronic Packaging (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Thin Film Transistor (AREA)
• Liquid Crystal (AREA)
• Electrodes Of Semiconductors (AREA)
• Devices For Indicating Variable Information By Combining Individual Elements (AREA)
• Internal Circuitry In Semiconductor Integrated Circuit Devices (AREA)

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• 2001
  • 2001-07-02 JP JP2001200710A patent/JP2003017706A/ja not_active Withdrawn
• 2002
  • 2002-05-24 KR KR10-2003-7017295A patent/KR20040016908A/ko not_active Ceased
  • 2002-05-24 WO PCT/JP2002/005057 patent/WO2003005453A1/ja not_active Ceased
  • 2002-05-24 CN CNB028132793A patent/CN1279623C/zh not_active Expired - Fee Related
  • 2002-06-04 TW TW091112014A patent/TWI293208B/zh active

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