Method to prevent static destruction of an active element comprised in a liquid crystal display device

Abstract

A liquid crystal display device which utilizes an active matrix substrate and its substrate, and which is provided with a novel method of manufacture which can reduce the manufacturing process of amorphous silicon thin film transistors of reverse stagger construction, and an electrostatic protection means which is created using this method of manufacture. In a thin film transistor manufacturing process, along with forming an aperture for connecting the contact hole and the external terminal in a manufacturing process for a thin film transistor, utilization is made of ITO film as the wiring. The electrostatic protection means is formed from a bidirectional diode (electrostatic protection element) which is composed utilizing an MOS transistor connected between the electrode (PAD) for connecting the external terminal, and the joint electric potential line. The electrostatic protection element is substantially a transistor, with great current capacity, and utilizing the TFT formation process of pixel components in their existent state, the process can be formed without any complications.

1 . A method of manufacturing a thin film element, comprising: 
 (A) forming a gate electrode layer and a gate electrode material layer which is formed of substantially the same material as the gate electrode layer, above a substrate;    (B) forming a gate insulation film on the gate electrode layer and the gate electrode material layer;    (C) forming a channel layer and an ohmic contact layer on the gate insulation film that overlaps with the gate electrode layer;    (D) forming a source electrode layer and a drain electrode layer that are connected to the ohmic contact layer;    (E) removing the ohmic contact layer and a surface of the channel layer from a region between the source electrode layer and the drain electrode layer by etching;    (F) forming a protective film to cover the source electrode layer, the drain electrode layer and the gate electrode material layer;    (G) forming a first aperture wherein a part of the gate insulation film and the protective film above the gate electrode material layer is selectively etched to expose a portion of a surface of the gate electrode material layer, and substantially simultaneously, forming a second aperture wherein a part of protective film on at least one of the source electrode layer and the drain electrode layer is selectively etched to expose a portion of a surface of at least one of the source electrode layer and the drain electrode layer; and    (H) forming an electrically conductive material layer on at least one of the first aperture and the second aperture.    
   
   
       2 . The method of manufacturing a thin film element of  claim 1 , the first aperture formed in step (G) being one of a contact hole to connect a wiring to the gate electrode material layer, and an aperture to connect an external terminal to the gate electrode material layer.  
   
   
       3 . The method of manufacturing a thin film element of  claim 1 , the electrically conductive material layer being formed of ITO (indium tin oxide).  
   
   
       4 . A method of manufacturing an active matrix substrate, comprising: 
 (A) forming a gate electrode layer, and a gate electrode material layer which is formed of substantially the same material as the gate electrode layer, above a substrate;    (B) forming a gate insulation film on the gate electrode layer and the gate electrode material layer;    (C) forming a channel layer on the gate insulation film that overlaps with the gate electrode layer;    (D) forming an ohmic contact layer on the channel layer;    (E) forming a source electrode layer and a drain electrode layer that are electrically connected to the channel layer;    (F) removing the ohmic contact layer and a surface of the channel layer from a region between the source electrode layer and the drain electrode layer by etching;    (G) forming a protective film to cover the source electrode layer, the drain electrode layer and the gate electrode material layer;    (H) forming a first aperture wherein a part of the gate insulation film and the protective film above the gate electrode material layer is selectively etched to expose a portion of a surface of the gate electrode material layer, and substantially simultaneously, forming a second aperture wherein a part of the protective film on at least one of the source electrode layer and the drain electrode layer is selectively etched to expose a portion of a surface of at least one of the source electrode layer and the drain electrode layer; and    (I) forming an electrically conductive material film on at least one of the first aperture and the second aperture.    
   
   
       5 . The method of manufacturing an active matrix substrate of  claim 4 , the electrically conductive material layer of the second aperture being a pixel electrode.  
   
   
       6 . The method of manufacturing an active matrix substrate of  claim 4 , the electrically conductive material layer being made of ITO (indium tin oxide).  
   
   
       7 . The method of manufacturing an active matrix substrate of  claim 4 , the electrically conductive material layer of the first aperture being an external connection terminal.  
   
   
       8 . The method of manufacturing an active matrix substrate of  claim 4 , the electrically conductive material layer formed an the second aperture being connected to an electrically conductive material layer formed on the first aperture.  
   
   
       9 . A method of manufacturing an active matrix substrate, comprising: 
 (A) forming a pixel gate electrode layer and a protective element gate electrode layer which is formed of substantially the same material as the pixel gate electrode layer;    (B) forming a gate insulation film on the pixel gate electrode layer and the protective element gate electrode layer;    (C) forming a pixel channel layer on the gate insulation film that overlaps with the pixel gate electrode layer, and a protective element channel layer on the gate insulation film that overlaps with the protective element gate electrode layer;    (D) forming a pixel ohmic contact layer on the pixel channel layer and a protective element ohmic contact layer on the protective element channel layer;    (E) forming a pixel source electrode layer and a pixel drain electrode layer that are electrically connected to the pixel channel layer, and a protective element source electrode layer and a protective element drain electrode layer that are electrically connected to the protective element channel layer;    (F) removing the pixel ohmic contact layer and a surface of the pixel channel layer from a region between the pixel source electrode layer and the pixel drain electrode layer by etching, and the protective element ohmic contact layer and a surface of the protective element channel layer from a region between the protective element source electrode layer and the protective element drain electrode layer by etching;    (G) forming a protective film to cover the pixel source electrode layer, the pixel drain electrode layer, the protective element source electrode layer and the protective element drain electrode layer;    (H) forming a first aperture wherein a part of the protective film on at least one of the pixel source electrode layer and the pixel drain electrode layer is selectively etched to expose a portion of a surface of at least one of the pixel source electrode layer and the pixel drain electrode layer, and substantially simultaneously, forming a second aperture wherein a part of protective film on at least one of the protective element source electrode layer and the protective element drain electrode layer is selectively etched to expose a portion of a surface of at least one of the protective element source electrode layer and the protective element drain electrode layer; and    (I) forming an electrically conductive material layer on at least one of the first aperture and the second aperture.    
   
   
       10 . A method of manufacturing an active matrix substrate, comprising: 
 (A) forming a pixel gate electrode layer, a protective element gate electrode layer which is formed of substantially the same material as the pixel gate electrode layer, and a gate electrode material layer which is formed of substantially the same material as the pixel gate electrode layer above a substrate;    (B) forming a gate insulation film on the pixel gate electrode layer, the protective element gate electrode layer and the gate electrode material layer;    (C) forming a pixel channel layer on the gate insulation film that overlaps with the pixel gate electrode layer, and a protective element channel layer on the gate insulation film that overlaps with the protective element gate electrode layer;    (D) forming a pixel ohmic contact layer on the pixel channel layer and a protective element ohmic contact layer on the protective element channel layer;    (E) forming a pixel source electrode layer and a pixel drain electrode layer that are electrically connected to the pixel channel layer, and a protective element source electrode layer and a protective element drain electrode layer that are electrically connected to the protective element channel layer;    (F) removing the pixel ohmic contact layer and a surface of the pixel channel layer from a region between the pixel source electrode layer and the pixel drain electrode layer by etching, and the protective element ohmic contact layer and a surface of the protective element channel layer from a region between the protective element source electrode layer and the protective element drain electrode layer by etching;    (G) forming a protective film for covering the pixel source electrode layer, the pixel drain electrode layer, the protective element source electrode layer, the protective element drain electrode layer and the gate electrode material layer;    (H) forming a first aperture wherein a part of the protective film on at least one of the pixel source electrode layer and the pixel drain electrode layer is selectively etched to expose a portion of a surface of at least one of the pixel source electrode layer and the pixel drain electrode layer, substantially simultaneously, forming a second aperture wherein a part of protective film on at least one of the protective element source electrode layer and the protective element drain electrode layer is selectively etched to expose a portion of a surface of at least one of the protective element source electrode layer and the protective element drain electrode layer, and forming a third aperture wherein a part of the gate insulation film and the protective film above the gate electrode material layer is selectively etched to expose a portion of a surface of the gate electrode material layer; and    (I) forming an electrically conductive material layer on at least one of the first aperture, the second aperture and the third aperture.    
   
   
       11 . A method of manufacturing a thin film element, comprising: 
 (A) forming a gate electrode layer and a gate electrode material layer which is formed of substantially the same material as the gate electrode layer, above a substrate;    (B) forming a gate insulation film on the gate electrode layer and the gate electrode material layer;    (C) forming a channel layer and an ohmic contact layer on the gate insulation film that overlaps with the gate electrode layer;    (D) forming a source electrode layer and a drain electrode layer that are connected to the ohmic contact layer by etching within a chamber of an etching device;    (E) removing the ohmic contact layer from a region between the source electrode layer and the drain electrode layer by etching within the same chamber of the same etching device;    (F) forming a protective film for covering the source electrode layer, the drain electrode layer and the gate electrode material layer;    (G) forming a first aperture wherein a part of the gate insulation film and the protective film above the gate electrode material layer is selectively etched to expose a portion of a surface of the gate electrode material layer, and substantially simultaneously, forming a second aperture wherein a part of protective film on at least one of the source electrode layer and the drain electrode layer is selectively etched to expose a portion of a surface of at least one of the source electrode layer and the drain electrode layer; and    (H) forming an electrically conductive material layer on at least one of the first aperture and the second aperture.    
   
   
       12 . The method of manufacturing a thin film element of  claim 11 , the first aperture formed in step (G) being one of a contact hole to connect a wiring to the gate electrode material layer, and an aperture to connect an external terminal to the gate electrode material layer.  
   
   
       13 . The method of manufacturing a thin film element of  claim 11 , step (E) including switching an etching gas to form the source electrode layer and the drain electrode layer to an etching gas to remove the ohmic contact layer.  
   
   
       14 . The method of manufacturing a thin film element of  claim 11 , step (E) including removing a surface of the channel layer.  
   
   
       15 . A method of manufacturing an active matrix substrate, comprising: 
 (A) forming a gate electrode layer, and a gate electrode material layer which is formed of substantially the same material as the gate electrode layer, above a substrate;    (B) forming a gate insulation film on the gate electrode layer and the gate electrode material layer;    (C) forming a channel layer on the gate insulation film that overlaps with the gate electrode layer;    (D) forming an ohmic contact layer on the channel layer;    (E) forming a source electrode layer and a drain electrode layer that are electrically connected to the channel layer by etching within a chamber of an etching device;    (F) removing the ohmic contact layer from a region between the source electrode layer and the drain electrode layer by etching within the same chamber of the same etching device;    (G) forming a protective film to cover the source electrode layer, the drain electrode layer and the gate electrode material layer;    (H) forming a first aperture wherein a part of the gate insulation film and the protective film above the gate electrode material layer is selectively etched to expose a portion of a surface of the gate electrode material layer, and substantially simultaneously, forming a second aperture wherein a part of the protective film on at least one of the source electrode layer and the drain electrode layer is selectively etched to expose a portion of a surface of at least one of the source electrode layer and the drain electrode layer; and    (I) forming an electrically conductive material film on at least one of the first aperture and the second aperture.    
   
   
       16 . The method of manufacturing an active matrix substrate of  claim 15 , the electrically conductive material layer of the second aperture being a pixel electrode.  
   
   
       17 . The method of manufacturing an active matrix substrate of  claim 15 , the electrically conductive material layer of the first aperture being an external connection terminal.  
   
   
       18 . The method of manufacturing an active matrix substrate of  claim 15 , the electrically conductive material layer formed on the second aperture being connected to an electrically conductive material layer formed on the first aperture.  
   
   
       19 . The method of manufacturing a thin film element of  claim 11 , step (F) including switching an etching gas to form the source electrode layer and the drain electrode layer to an etching gas to remove the ohmic contact layer.  
   
   
       20 . The method of manufacturing a thin film element of  claim 11 , step (F) including removing a surface of the channel layer.  
   
   
       21 . A method of manufacturing an active matrix substrate, comprising: 
 (A) forming a pixel gate electrode layer and a protective element gate electrode layer which is formed of substantially the same material as the pixel gate electrode layer;    (B) forming a gate insulation film on the pixel gate electrode layer and the protective element gate electrode layer;    (C) forming a pixel channel layer on the gate insulation film that overlaps with the pixel gate electrode layer, and a protective element channel layer on the gate insulation film that overlaps with the protective element gate electrode layer;    (D) forming a pixel ohmic contact layer on the pixel channel layer and a protective element ohmic contact layer on the protective element channel layer;    (E) forming a pixel source electrode layer and a pixel drain electrode layer that are electrically connected to the pixel channel layer, and a protective element source electrode layer and a protective element drain electrode layer that are electrically connected to the protective element channel layer, by etching within a chamber of an etching device;    (F) removing the pixel ohmic contact layer from a region between the pixel source electrode layer and the pixel drain electrode layer, and the protective element ohmic contact layer from a region between the protective element source electrode layer and the protective element drain electrode layer, by etching within the same chamber of the same etching device;    (G) forming a protective film to cover the pixel source electrode layer, the pixel drain electrode layer, the protective element source electrode layer and the protective element drain electrode layer;    (H) forming a first aperture wherein a part of the protective film on at least one of the pixel source electrode layer and the pixel drain electrode layer is selectively etched to expose a portion of a surface of at least one of the pixel source electrode layer and the pixel drain electrode layer, and substantially simultaneously, forming a second aperture wherein a part of protective film on at least one of the protective element source electrode layer and the protective element drain electrode layer is selectively etched to expose a portion of a surface of at least one of the protective element source electrode layer and the protective element drain electrode layer; and    (I) forming an electrically conductive material layer on at least one of the first aperture and the second aperture.    
   
   
       22 . The method of manufacturing a thin film element of  claim 21 , step (F) including switching an etching gas to form the source electrode layer and the drain electrode layer to an etching gas to remove the ohmic contact layer.  
   
   
       23 . The method of manufacturing a thin film element of  claim 21 , step (F) including removing a surface of the channel layer.  
   
   
       24 . A method of manufacturing an active matrix substrate, comprising: 
 (A) forming a pixel gate electrode layer, a protective element gate electrode layer which is formed of substantially the same material as the pixel gate electrode layer, and a gate electrode material layer which is formed of substantially the same material as the pixel gate electrode layer above a substrate;    (B) forming a gate insulation film on the pixel gate electrode layer, the protective element gate electrode layer anal the gate electrode material layer;    (C) forming a pixel channel layer on the gate insulation film that overlaps with the pixel gate electrode layer, and a protective element channel layer on the gate insulation film that overlaps with the protective element gate electrode layer;    (D) forming a pixel ohmic contact layer on the pixel channel layer and a protective element ohmic contact layer on the protective element channel layer;    (E) forming a pixel source electrode layer and a pixel drain electrode layer that are electrically connected to the pixel channel layer, and a protective element source electrode layer and a protective element drain electrode layer that are electrically connected to the protective element channel layer, by etching within a chamber of an etching device;    (F) removing the pixel ohmic contact layer from a region between the pixel source electrode layer and the pixel drain electrode layer, and the protective element ohmic contact layer from a region between the protective element source electrode layer and the protective element drain electrode layer, by etching within the same chamber of the same etching device;    (G) forming a protective film for covering the pixel source electrode layer, the pixel drain electrode layer, the protective element source electrode layer, the protective element drain electrode layer and the gate electrode material layer;    (H) forming a first aperture wherein a part of the protective film on at least one of the pixel source electrode layer and the pixel drain electrode layer is selectively etched to expose a portion of a surface of at least one of the pixel source electrode layer and the pixel drain electrode layer, substantially simultaneously, forming a second aperture wherein a part of protective film on at least one of the protective element source electrode layer and the protective element drain electrode layer is selectively etched to expose a portion of a surface of at least one of the protective element source electrode layer and the protective element drain electrode layer, and forming a third aperture wherein a part of the gate insulation film and the protective film above the gate electrode material layer is selectively etched to expose a portion of a surface of the gate electrode material layer; and    (I) forming an electrically conductive material layer on at least one of the first aperture, the second aperture and the third aperture.    
   
   
       25 . The method of manufacturing a thin film element of  claim 24 , step (F) including switching an etching gas to form the source electrode layer and the drain electrode layer to an etching gas to remove the ohmic contact layer.  
   
   
       26 . The method of manufacturing a thin film element of  claim 24 , step (F) including removing a surface of the channel layer.