Semiconductor device and manufacturing method thereof

A method of manufacturing a semiconductor device, comprising the steps of:

• forming a first wiring on an insulating surface;
• forming a first interlayer insulating film over said first wiring;
• forming a second interlayer insulating film on said first interlayer insulating film;
• selectively removing a part of said second interlayer insulating film;
• and
• forming a second wiring on said second interlayer insulating film that overlaps with said first wiring.

A method of manufacturing a semiconductor device including at least one TFT on an insulating surface, said method comprising:

• forming an active layer on the insulating surface;
• forming a gate insulating film on said active layer;
• introducing an n-type impurity element or a p-type impurity element into a portion of said active layer, thereby forming a source region or a drain region;
• forming a first interlayer insulating film over a gate wiring and a gate electrode;
• forming a second interlayer insulating film on said first interlayer insulating film;
• etching said second interlayer insulating film, thereby eliminating said second interlayer insulating film disposed over said source region or said drain region;
• etching said first interlayer insulating film and said gate insulating film, thereby forming a contact hole that reaches said source region or said drain region;
• and
• forming a second wiring in contact with said source region or said drain region, said second wiring disposed on said second interlayer insulating film that overlaps with said gate electrode.

A method of manufacturing a semiconductor device including at least a pixel circuit and driving circuit for controlling said pixel circuit, each disposed on a same substrate, said method comprising:

• forming an active layer on an insulating surface;
• forming a gate insulating film on said active layer;
• forming a gate wiring and a gate electrode on said gate insulating film;
• a fourth step of adding an n-type impurity element or a p-type impurity element to a part of said active layer, thereby forming an n-type impurity region or a p-type impurity region;
• forming a first interlayer insulating film over said gate wiring and said gate electrode;
• selectively forming a second interlayer insulating film on said first interlayer insulating film that overlaps with said gate electrode;
• etching said first interlayer insulating film and said gate insulating film, thereby forming a contact hole that reaches said n-type impurity region or said p-type impurity region;
• and
• forming a second wiring in contact with said n-type impurity region or said p-type impurity region, said second wiring disposed on said second interlayer insulating film that overlaps with said gate electrode.

A method of manufacturing a semiconductor device including at least a pixel circuit and driving circuit for controlling said pixel circuit, each disposed on a same substrate, said method comprising the steps of:

• forming an active layer on an insulating surface;
• forming a gate insulating film on said active layer;
• forming a gate wiring and a gate electrode on said gate insulating film;
• introducing an n-type impurity element or a p-type impurity element into a portion of said active layer, thereby forming an n-type impurity region or a p-type impurity region;
• forming a first interlayer insulating film over said gate wiring and said gate electrode;
• etching said first interlayer insulating film and said gate insulating film, thereby forming a contact hole that reaches said n-type impurity region or said p-type impurity region;
• selectively forming a second interlayer insulating film on said first interlayer insulating film;
• and
• forming a second wiring in contact with said n-type impurity region or said p-type impurity region, said second wiring disposed on said second interlayer insulating film that overlaps with said gate electrode.