Semiconductor device having a display device

A method of manufacturing a semiconductor device comprising a thin film transistor and a convex portion, said method comprising:

• patterning a first conducting film on an insulating surface using a first mask to form a gate electrode of said thin film transistor and a first conducting layer;
• forming an insulating film, a semiconductor film, and an n-type semiconductor film on said first conducting layer;
• forming a second conducting film on said n-type semiconductor film;
• patterning said semiconductor film, said n-type semiconductor film, and said second conducting film using a second mask to form said convex portion comprising said first conducting layer, a semiconductor layer, an n-type semiconductor layer, and a second conducting layer;
• and
• forming a third conducting film and patterning said third conducting film using a third mask to form a pixel electrode covering said convex portion,
• wherein said pixel electrode overlaps said convex portion and has roughness, and
• wherein a channel region of said thin film transistor comprises a portion of said semiconductor film.

A method of manufacturing a semiconductor device comprising a thin film transistor and a convex portion using only three masks, said method comprising:

• a first step of patterning a first conducting film on an insulating surface using a first mask to form a gate electrode of said thin film transistor and a first conducting layer;
• a second step of forming an insulating film, a semiconductor film, and an n-type semiconductor film on said first conducting layer;
• a third step of forming a second conducting film on said n-type semiconductor film;
• a fourth step of patterning said semiconductor film, said n-type semiconductor film, and said second conducting film using a second mask to form said convex portion comprising said first conducting layer, a semiconductor layer, an n-type semiconductor layer, and a second conducting layer;
• and
• a fifth step of forming a third conducting film and patterning said third conducting film using a third mask to form a pixel electrode covering said convex portion,
• wherein said pixel electrode overlaps said convex portion and has roughness, and
• wherein a channel region of said thin film transistor comprises a portion said semiconductor film, each of source and drain regions of said thin film transistor comprises a portion of said n-type semiconductor film, and each of source and drain electrodes comprises a portion of said second conducting film.

A method of manufacturing a semiconductor device comprising a thin film transistor and a plurality of convex portions, said method comprising steps of:

• patterning a first conducting film on an insulating surface using a first mask to form a gate electrode of said thin film transistor and a first conducting layer;
• forming an insulating film, a semiconductor film, and an n-type semiconductor film on said first conducting layer;
• forming a second conducting film on said n-type semiconductor film;
• patterning said semiconductor film, said n-type semiconductor film, and said second conducting film using a second mask to form said plurality of convex portions each comprising said first conducting layer, a semiconductor layer, an n-type semiconductor layer, and a second conducting layer;
• and
• forming a third conducting film and patterning said third conducting film using a third mask to form a pixel electrode covering said plurality of convex portions,
• wherein said pixel electrode overlaps said plurality of convex portions and has roughness, and
• wherein a channel region of said thin film transistor comprises a portion of said semiconductor film.

A method of manufacturing a semiconductor device comprising a thin film transistor and a plurality of convex portions using only three masks, said method comprising:

• a first step of patterning a first conducting film on an insulating surface using a first mask to form a gate electrode of said thin film transistor and a first conducting layer;
• a second step of forming an insulating film, a semiconductor film, and an n-type semiconductor film on said first conducting layer;
• a third step of forming a second conducting film on said n-type semiconductor film;
• a fourth step of patterning said semiconductor film, said n-type semiconductor film, and said second conducting film using a second mask to form said plurality of convex portions each comprising said first conducting layer, a semiconductor layer, an n-type semiconductor layer, and a second conducting layer;
• and
• a fifth step of forming a third conducting film and patterning said third conducting film using a third mask to form a pixel electrode covering said plurality of convex portion,
• wherein said pixel electrode overlaps said plurality of convex portions and has roughness, and
• wherein a channel region of said thin film transistor comprises a portion said semiconductor film, each of source and drain regions of said thin film transistor comprises a portion of said n-type semiconductor film, and each of source and drain electrodes comprises a portion of said second conducting film.

A method of manufacturing a semiconductor device comprising:

• forming a first conductive film over a substrate;
• patterning said first conductive film using a first mask to form at least one gate electrode and at least one conductive island;
• forming an insulating film over said substrate so as to cover said gate electrode and said conductive island;
• forming a first semiconductor film over said insulating film;
• forming a second semiconductor film having one conductivity type on said first semiconductor film;
• forming a second conductive film on said second semiconductor film;
• selectively etching said first semiconductor film, said second semiconductor film and said second conductive film using a second mask to form at least a first laminate body over the gate electrode and a second laminate body over the conductive island wherein each of the first and second laminate bodies includes a portion of the first semiconductor film, a portion of the second semiconductor film and a portion of the second conductive film;
• forming a third conductive film over said substrate so as to cover said first and second laminate bodies;
• etching a portion of the third conductive film to form at least one pixel electrode and a portion of the first laminate body to form source and drain regions and a pair of electrodes on said source and drain regions wherein said portion of the third conductive film and said portion of the first laminate body are etched by a third mask,
• wherein said pixel electrode is in contact with an upper surface of one of the pair of electrodes and extends to cover said second laminate body and said pixel electrode has an uneven upper surface due to said second laminate body.

A method a manufacturing a semiconductor device comprising:

• forming a first conductive film over a substrate;
• patterning said first conductive film using a first mask to form at least one gate electrode and at least one conductive island;
• forming an insulating film over said substrate so as to cover said gate electrode and said conductive island;
• forming a first semiconductor film over said insulating film;
• forming a second semiconductor film having one conductivity type on said first semiconductor film;
• forming a second conductive film on said second semiconductor film;
• selectively etching said first semiconductor film, said second semiconductor film and said second conductive film using a second mask to form at least a first laminate body over the gate electrode, a second laminate body over the conductive island, and a third laminate body not over the conductive island, wherein each of the first, second and third laminate bodies includes a portion of the first semiconductor film, a portion of the second semiconductor film and a portion of the second conductive film;
• forming a third conductive film over said substrate so as to cover said first, second and third laminate bodies;
• etching a portion of the third conductive film to form at least one pixel electrode and a portion of the first laminate body to form source and drain regions and a pair of electrodes on said source and drain regions wherein said portion of the third conductive film and said portion of the first laminate body are etched by a third mask,
• wherein said pixel electrode is in contact with an upper surface of one of the pair of electrodes and extends to cover said second and third laminate bodies and said pixel electrode has an uneven upper surface due to said second and third laminate bodies.