Method for laser-processing semiconductor device

A method of manufacturing a display device having an active matrix circuit and a driver circuit both formed over a same substrate, said driver circuit including at least one CMOS device comprising an N-channel type thin film transistor and a P-channel type thin film transistor, said method comprising the steps of:

• forming a semiconductor film comprising amorphous silicon over said substrate;
• crystallizing said semiconductor film by heating;
• irradiating said semiconductor film with a laser light after said crystallizing step wherein an irradiation area of said laser light on said semiconductor film is elongated in one direction;
• etching the crystallized semiconductor film after the irradiating step into at least one semiconductor island;
• and
• introducing an N-type impurity into portions of said semiconductor island to form source and drain regions and at least one lightly doped region for said N-channel type thin film transistor,
• wherein said lightly doped region is formed only in said N-channel type thin film transistor.

A method of manufacturing a display device having an active matrix circuit and a driver circuit both formed over a same substrate, said driver circuit including at least one CMOS device comprising an N-channel type thin film transistor and a P-channel type thin film transistor, said method comprising the steps of:

• forming a semiconductor film comprising amorphous silicon over said substrate;
• crystallizing said semiconductor film by heating;
• irradiating said semiconductor film with a laser light after said crystallizing step wherein an irradiation area of said laser light on said semiconductor film is elongated in one direction;
• etching the crystallized semiconductor film after the irradiating step into at least one semiconductor island;
• introducing an N-type impurity into portions of said semiconductor island to form source and drain regions and at least one lightly doped region for said N-channel type thin film transistor;
• and
• forming an interlayer insulating film over said semiconductor island,
• wherein said P-channel type thin film transistor has no lightly doped region.

A method of manufacturing a display device having an active matrix circuit and a driver circuit both formed over a same substrate, said driver circuit including at least one CMOS device comprising an N-channel type thin film transistor and a P-channel type thin film transistor, said method comprising the steps of:

• forming a semiconductor film comprising silicon over said substrate;
• irradiating said semiconductor film with a laser light wherein an irradiation area of said laser light on said semiconductor film is elongated in one direction;
• etching the semiconductor film after the irradiating step into at least one semiconductor island;
• and
• introducing an N-type impurity into portions of said semiconductor island to form source and drain regions and at least one lightly doped region for said N-channel type thin film transistor,
• wherein said P-channel type thin film transistor has no lightly doped region.

A method of manufacturing a display device having an active matrix circuit and a driver circuit both formed over a same substrate, said driver circuit including at least one CMOS device comprising an N-channel type thin film transistor and a P-channel type thin film transistor, said method comprising the steps of:

• forming a semiconductor film comprising silicon over said substrate;
• irradiating said semiconductor film with a laser light wherein an irradiation area of said laser light on said semiconductor film is elongated in one direction;
• etching the semiconductor film after the irradiating step into at least one semiconductor island;
• and
• introducing an N-type impurity into portions of said semiconductor island to form source and drain regions and at least one lightly doped region for said N-channel type thin film transistor,
• wherein said lightly doped region is formed only in said N-channel type thin film transistor.

A method of manufacturing a display device having an active matrix circuit and a driver circuit both formed over a same substrate, said driver circuit including at least one CMOS device comprising an N-channel type thin film transistor and a P-channel type thin film transistor, said method comprising the steps of:

• forming a semiconductor film comprising silicon over said substrate;
• irradiating said semiconductor film with a laser light wherein an irradiation area of said laser light on said semiconductor film is elongated in one direction;
• etching the semiconductor film after the irradiating step into at least one semiconductor island;
• introducing an N-type impurity into portions of said semiconductor island to form source and drain regions and at least one lightly doped region for said N-channel type thin film transistor;
• and
• forming an interlayer insulating film over said semiconductor island,
• wherein said P-channel type thin film transistor has no lightly doped region.