Thin film semiconductor device and liquid crystal display unit, and fabrication methods thereof

In a liquid crystal display unit comprising:

• a pair of substrates jointed to each other with a specific gap held therebetween, and liquid crystal held in said gap;
• wherein one substrate has a plurality of signal interconnections and a plurality of gate interconnections crossing said signal interconnections, and pixels disposed at crossing points between said signal and gate interconnections, and the other substrate has an electrode facing to respective pixels;
• each of said pixels includes at least a pixel electrode, a thin film transistor for driving said pixel electrode, and a light shield band for shielding said thin film transistor from external light;
• and
• a source of said thin film transistor is connected to one of said signal interconnections, a drain of said thin film transistor is connected to said pixel electrode, and a gate electrode of said thin film transistor is connected to one of said gate interconnections;
• the improvement wherein
• said light shield band is formed of a first conductive layer, and at least part of said light shield band is used as said gate interconnection;
• said gate electrode is formed of a second conductive layer different from said first conductive layer;
• and
• said first conductive layer used for said gate interconnection is electrically connected to said second conductive layer forming said gate electrode within each pixel region.

In a method of fabricating a thin film semiconductor device, said semiconductor device comprising:

• a plurality of signal interconnections and a plurality of gate interconnections crossing said signal interconnections, and pixels disposed at crossing points between said signal and gate interconnections, said signal and gate interconnections and said pixels being provided on an insulating substrate;
• wherein each of said pixels includes at least a pixel electrode, a thin film transistor for driving said pixel electrode, and a light shield band for shielding said thin film transistor from external light;
• and a source of said thin film transistor is connected to one of said signal interconnections, a drain of said thin film transistor is connected to said pixel electrode, and a gate electrode of said thin film transistor is connected to one of said gate interconnections;
• the improvement wherein
• said light shield band is formed of a first conductive layer, and at least part of said light shield band is used as said gate interconnection;
• said gate electrode is formed of a second conductive layer different from said first conductive layer;
• and
• said first conductive layer used for said gate interconnection is electrically connected to said second conductive layer forming said gate electrode within each pixel region.

A method of fabricating a liquid crystal display unit, said liquid crystal display unit comprising:

• a pair of substrates jointed to each other with a specific gap held therebetween, and liquid crystal held in said gap;
• wherein one substrate has a plurality of signal interconnections and a plurality of gate interconnections crossing said signal interconnections, and pixels disposed at crossing points between said signal and gate interconnections, and the other substrate has an electrode facing to respective pixels;
• each of said pixels includes at least a pixel electrode, a thin film transistor for driving said pixel electrode, and a light shield band for shielding said thin film transistor from external light;
• and a source of said thin film transistor is connected to one of said signal interconnections, a drain of said thin film transistor is connected to said pixel electrode, and a gate electrode of said thin film transistor is connected to one of said gate interconnections;
• the improvement wherein
• said light shield band is formed of a first conductive layer, and at least part of said light shield band is used as said gate interconnection;
• said gate electrode is formed of a second conductive layer different from said first conductive layer;
• and
• said first conductive layer used for said gate interconnection is electrically connected to said second conductive layer forming said gate electrode within each pixel region.