Thin film transistor device and method of manufacturing the same

A thin film transistor device manufacturing method comprising the steps of:

• forming a semiconductor film in a first conductivity type thin film transistor forming region and a second conductivity type thin film transistor forming region on a substrate respectively;
• forming a gate insulating film and a gate electrode on the semiconductor film;
• forming first conductivity type source/drain regions by introducing a first conductivity type impurity into the semiconductor film;
• forming a first interlayer insulating film on an overall upper surface of the substrate;
• forming a first conductive film on the first interlayer insulating film;
• forming a resist film, which covers the first conductivity type thin film transistor forming region and a display electrode forming region, on the first conductive film;
• forming second conductivity type source/drain regions by introducing a second conductivity type impurity into the semiconductor film in the second conductivity type thin film transistor forming region;
• removing the resist film on the first conductivity type thin film transistor forming region to leave the resist film only on the display electrode forming region;
• forming a display electrode by etching the first conductive film while using the resist film as a mask;
• removing the resist film from the display electrode forming region;
• forming a second interlayer insulating film on an overall upper surface of the substrate;
• forming contact holes that reach source/drain regions of the thin film transistor from a surface of the second interlayer insulating film;
• forming a second conductive film on the overall upper surface of the substrate;
• and
• processing the second conductive film into a predetermined pattern.

A thin film transistor device manufacturing method comprising the steps of:

• forming a semiconductor film in a first conductivity type thin film transistor forming region and a second conductivity type thin film transistor forming region on a substrate respectively;
• forming a gate insulating film and a gate electrode on the semiconductor film;
• forming first conductivity type source/drain regions by introducing a first conductivity type impurity into the semiconductor film;
• forming a first interlayer insulating film on an overall upper surface of the substrate;
• forming a first conductive film on the first interlayer insulating film;
• forming a resist film thin in the first conductivity type thin film transistor forming region on the first conductive film and thick in the display electrode forming region;
• removing the first conductive film in the second conductivity type thin film transistor forming region while using the resist film as a mask;
• forming second conductivity type source/drain regions by introducing a second conductivity type impurity into the semiconductor film in the second conductivity type thin film transistor forming region;
• removing the resist film on the first conductivity type thin film transistor forming region to leave the resist film only on the display electrode forming region;
• forming a display electrode by etching the first conductive film while using the resist film as a mask;
• removing the resist film from the display electrode forming region;
• forming a second interlayer insulating film on an overall upper surface of the substrate;
• forming contact holes that reach source/drain regions of the thin film transistor from a surface of the second interlayer insulating film;
• forming a second conductive film on the overall upper surface of the substrate;
• and
• processing the second conductive film into a predetermined pattern.

A thin film transistor device manufacturing method comprising the steps of:

• forming a semiconductor film in a thin film transistor forming region on a substrate;
• forming a gate insulating film and a gate electrode on the semiconductor film;
• forming an interlayer insulating film on an overall upper surface of the substrate;
• forming a first conductive film as a display electrode on the interlayer insulating film;
• forming contact holes, which reach the semiconductor film from a surface of the first conductive film, by a photolithography method;
• forming a second conductive film on the overall upper surface of the substrate;
• forming a resist film, which covers a wiring forming region and a display electrode forming region, on the second conductive film;
• etching the second conductive film and the first conductive film while using the resist film as a mask;
• removing the resist film in the display electrode forming region to leave the resist film in the wiring forming region;
• and
• removing the second conductive film on the display electrode forming region by an etching using the resist film as a mask.

A thin film transistor device manufacturing method comprising the steps of:

• forming a semiconductor film in a thin film transistor forming region on a substrate;
• forming a gate insulating film and a gate electrode on the semiconductor film;
• forming an interlayer insulating film on an overall upper surface of the substrate;
• forming a first conductive film as a display electrode on the interlayer insulating film;
• forming a resist film, in which contact hole forming regions are opened, on the first conductive film;
• forming contact holes, which reach the semiconductor film from a surface of the first conductive film, by executing an etching while using the resist film as a mask;
• removing the resist film to leave only on the display electrode forming region;
• etching the first conductive film while using the resist film remaining on the display electrode forming region as a mask;
• removing the resist film on the display electrode forming region;
• forming a second conductive film on the overall upper surface of the substrate;
• and
• processing the second conductive film into a predetermined shape.

A thin film transistor device comprising:

• a substrate;
• a semiconductor film formed on the substrate and having source/drain regions of an LDD structure;
• a first insulating film formed on the substrate and the semiconductor film;
• a gate electrode constructed by a first conductive film, which is formed on the first insulating film over the semiconductor film, and a second conductive film, which is formed on the first conductive film to have a width narrower than the first conductive film;
• a display electrode formed on the first insulating film and made of a same material as the first conductive film;
• a second insulating film formed on the first insulating film to cover the gate electrode;
• contact holes that reach the semiconductor film from a surface of the second insulating film;
• and
• a wiring formed on the second insulating film, one end of which is connected electrically to the semiconductor film via the contact hole and other end of which is connected electrically to the display electrode.

A thin film transistor device manufacturing method comprising the steps of:

• forming a semiconductor film in a thin film transistor forming region on a substrate;
• forming sequentially a first insulating film, a first conductive film, and a second conductive film on an overall upper surface of the substrate;
• forming a resist film in a display electrode forming region and a gate electrode forming region on the second conductive film;
• forming a display electrode and a gate electrode having a terrace structure by applying an isotropic etching to the second conductive film and by applying an anisotropic etching to the first conductive film while using the resist film as a mask;
• removing the resist film on the display electrode forming region to leave the resist film on the gate electrode forming region;
• removing the second conductive film remaining on the display electrode;
• removing the resist film from the gate electrode forming region;
• forming source/drain regions by introducing an impurity into the semiconductor film;
• forming a second interlayer insulating film on the overall upper surface of the substrate;
• patterning the second interlayer insulating film to expose the display electrode and to form contact holes that reach the semiconductor film from a surface of the second interlayer insulating film;
• forming a third conductive film on the overall upper surface of the substrate;
• and
• forming a wiring, which connects electrically the semiconductor film and the display electrode, by patterning the third conductive film.