Thin film transistor substrate and method of manufacturing the same

A thin film transistor substrate comprising:

• semiconductor layers formed on or above an insulating substrate;
• gate insulating films formed on the semiconductor layers;
• and
• a one conductivity type channel transistor and a opposite conductivity type channel transistor respectively including gate electrodes formed on the gate insulating films,
• wherein the semiconductor layer for the one conductivity type channel transistor includes a channel region under the gate electrode, an LDD region, a source region and a drain region, and the gate insulating film for the one conductivity type channel transistor is patterned and formed on the channel region and the LDD region, and
• the semiconductor layer for the opposite conductivity type channel transistor includes a channel region under the gate electrode, a source region and a drain region, and the gate insulating film for the opposite conductivity type channel transistor is formed so as to cover the semiconductor layer for the opposite conductivity type channel transistor except for a predetermined portions on the source and drain regions of the opposite conductivity type channel transistor.

A method of manufacturing a thin film transistor substrate comprising the steps of:

• forming a pattern of a semiconductor layer on or above an insulating substrate;
• forming a gate insulating film on the semiconductor layer;
• forming a gate electrode on the gate insulating film;
• introducing impurities into portions of the semiconductor layer, which are to be a source region and a drain region;
• forming an interlayer insulating film including a plurality of insulating films with mutually different dielectric constants on the semiconductor layer and the gate electrode;
• forming contact holes in portions of the interlayer insulating film, the portions being at least on the source region and the drain region;
• forming a transparent conductive film on the interlayer insulating film and inner surfaces of the contact holes;
• forming a metal film on the transparent conductive film;
• forming a interconnection electrode in a portion including the contact hole of the drain region by patterning the metal film while using the transparent conductive film as an etch stop layer;
• and
• forming a pixel electrode connected to the source region through the contact hole and forming the interconnection electrode connected to the drain region through the transparent conductive film in the contact hole by patterning the transparent conductive film.

A method of manufacturing a thin film transistor substrate comprising the steps of:

• forming a pattern of a semiconductor layer on or above an insulating substrate;
• forming a gate insulating film on the semiconductor layer;
• forming a gate electrode on the gate insulating film;
• introducing impurities into portions of the semiconductor layer, which are to be a source region and a drain region;
• forming an interlayer insulating film including a plurality of insulating films with mutually different dielectric constants on the semiconductor layer and the gate electrode;
• forming contact holes in portions of the interlayer insulating film, the portions being at least on the source region and the drain region;
• forming a transparent conductive film on the interlayer insulating film and inner surfaces of the contact holes;
• forming a metal film on the transparent conductive film;
• forming a pattern of a resist film on the metal film so that a thickness of a portion for a formation of a pixel electrode connected with the source region is thinner than a thickness of a portion for a formation of a interconnection electrode connected with the drain region;
• forming the interconnection electrode by etching the metal film and the transparent conductive film while using the resist film as a mask;
• selectively removing the portion of the resist film for the formation of the pixel electrode and leaving the portion of the resist film for the formation of the interconnection electrode;
• and
• forming the pixel electrode by etching a portion of the metal film where the pixel electrode is formed while using the portion of the resist film for the formation of the interconnection electrode as a mask and using the transparent conductive film as an etch stop layer.

A method of manufacturing a thin film transistor substrate, comprising the steps of:

• forming patterns of a semiconductor layer for a one conductivity type channel transistor and a semiconductor layer for a opposite conductivity type channel transistor on or above an insulating substrate;
• forming a gate insulating film on the semiconductor layers;
• forming a conductive film, which is to be gate electrodes, on the gate insulating film;
• forming a structure in which a gate insulating film for the opposite conductivity type channel transistor and the gate electrode for the opposite conductivity type channel transistor, the gate electrode having a narrower width than a width of the gate insulating film for the opposite conductivity type channel transistor, are stacked from bottom to top on the semiconductor layer for the opposite conductivity type channel transistor, and forming a pattern of a covering film stack in which a gate insulating film and a conductive film are stacked, the covering film stack covering the semiconductor layer for the one conductivity type channel transistor, by patterning the conductive film and the gate insulating film,;
• forming predetermined source and drain regions for the opposite conductivity type channel transistor by introducing impurities of the opposite conductivity type into the semiconductor layer for the opposite conductivity type channel transistor while using at least anyone of the gate electrode for the opposite conductivity type channel transistor and the gate insulating film therefor as a mask;
• forming a structure in which a gate insulating film for the one conductivity type channel transistor and the gate electrode for the one conductivity type channel transistor, the gate electrode having a narrower width than a width of the gate insulating film for the one conductivity type channel transistor, are stacked from bottom to top, by patterning the covering film stack;
• and
• forming predetermined source and drain regions for the one conductivity type channel transistor by introducing impurities of the one conductivity type into the semiconductor layer for the one conductivity type channel transistor while using at least anyone of the gate electrode for the one conductivity type channel transistor and the gate insulating film therefor as a mask.

A method of manufacturing a thin film transistor substrate comprising the steps of:

• forming patterns of a semiconductor layer for a one conductivity type channel transistor and a semiconductor layer for a opposite conductivity type channel transistor on or above an insulating substrate;
• forming a gate insulating film on the semiconductor layers;
• forming a conductive film, which is to be gate electrodes, on the gate insulating film;
• forming the gate electrode for the opposite conductivity type channel transistor on the semiconductor layer for the opposite conductivity type channel transistor, and forming a pattern of a covering conductive film which covers the semiconductor layer for the one conductivity type channel transistor by patterning the conductive film;
• forming a source region and a drain region for the opposite conductivity type channel transistor by introducing impurities of the opposite conductivity type into the semiconductor layer for the opposite conductivity type channel transistor through the gate insulating film while using the gate electrode for the opposite conductivity type channel transistor as a mask,;
• forming a structure in which a gate insulating film for the one conductivity type channel transistor and the gate electrode for the one conductivity type channel transistor, the gate electrode having a narrower width than a width of the gate insulating film for the one conductivity type channel transistor, are stacked from bottom to top, by patterning the covering conductive film and the gate insulating film;
• and
• forming predetermined source and drain regions for the one conductivity type channel transistor, by introducing impurities of the one conductivity type into the semiconductor layer for the one conductivity type channel transistor while using at least anyone of the gate electrode for the one conductivity type channel transistor and the gate insulating film therefor as a mask.

A method of manufacturing a thin film transistor substrate comprising the steps of:

• forming patterns of a semiconductor layer for a one conductivity type channel transistor and a semiconductor layer for a opposite conductivity type channel transistor on or above an insulating substrate;
• forming a gate insulating film on the semiconductor layers;
• forming a conductive film, which is to be gate electrodes, on the gate insulating film;
• forming a structure in which a gate insulating film for the one conductivity type channel transistor and the gate electrode for the one conductivity type channel transistor having a narrower width than a width of the gate insulating film for the one conductivity type channel transistor are stacked from bottom to top on the semiconductor layer for the one conductivity type channel transistor, and forming a pattern of a covering film stack in which a gate insulating film and a conductive film are stacked, the covering film stack covering the semiconductor layer for the opposite conductivity type channel transistor, by patterning the conductive film and the gate insulating film;
• forming a source region and a drain region for the one conductivity type channel transistor by introducing impurities of the one conductivity type into the semiconductor layer for the one conductivity type channel transistor while using at least anyone of the gate electrode for the one conductivity type channel transistor and the gate insulating film therefor as a mask;
• patterning a resist film delimiting a region for forming the gate electrode for the opposite conductivity type channel transistor on the covering film stack and covering the semiconductor layer for the one conductivity type channel transistor and the gate electrode therefor;
• forming the gate electrode for the opposite conductivity type channel transistor, the gate electrode having a predetermined width equal to or wider than a width of the resist film by etching the covering film stack while using the resist film as a mask;
• and
• forming source and drain regions for the opposite conductivity type channel transistor by introducing impurities of the opposite conductivity type into the semiconductor layer for the opposite conductivity type channel transistor while using at least anyone of the resist film and the gate electrode for the opposite conductivity type channel transistor as a mask.