Method of fabricating a thin film transistor

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

• forming a substantially amorphous silicon film by LPCVD over a substrate;
• providing a selected portion of said amorphous silicon film with a metal element for promoting crystallization of said amorphous silicon film;
• heating said amorphous silicon film provided with said metal element in order to crystallize said film wherein crystals grow in a direction parallel with a surface of said substrate in a region of said silicon film adjacent to said selected portion;
• and
• forming the thin film transistor by utilizing said region of the silicon film in which crystals grew parallel with the surface of the substrate,
• wherein said amorphous silicon film is formed at a temperature not higher than 480.degree. C., and
• wherein a precursor gas used for forming said amorphous silicon film comprises silane expressed by a formula Si.sub.n H.sub.2n+2 where n.gtoreq.2.

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

• forming a substantially amorphous silicon film by LPCVD over a substrate;
• providing a selected portion of said amorphous silicon film with a metal element for promoting crystallization of said amorphous silicon film;
• heating said amorphous silicon film provided with said metal element in order to crystallize said film wherein crystals grow in a direction parallel with a surface of said substrate in a region of said silicon film adjacent to said selected portion;
• and
• forming the thin film transistor by utilizing said region of the silicon film in which crystals grew parallel with the surface of the substrate,
• wherein said amorphous silicon film is crystallized at a temperature not higher than 580.degree. C. for 4 hours, and
• wherein a precursor gas used for forming said amorphous silicon film comprises silane expressed by a formula Si.sub.n H.sub.2n+2 where n.gtoreq.2.

A method of fabricating a thin film transistor comprising the steps of:

• forming an amorphous silicon film through LPCVD method on an insulating surface, wherein a precursor gas for forming said amorphous silicon film comprises silane expressed by a formula Si.sub.n H.sub.2n+2 where n.gtoreq.2;
• forming a catalyst element in contact with a selected portion of said amorphous silicon film, said catalyst element being capable of accelerating crystallization of said amorphous silicon film;
• heating said amorphous silicon film so that a crystal growth occurs from said selected portion in a lateral direction to said insulating surface;
• forming the thin film transistor in a laterally grown portion where the crystal growth occurs in the lateral direction to said insulating surface,
• wherein branching in a crystal growth direction within a lateral growth distance of 200 .mu.m is eliminated.

A method of fabricating a thin film transistor comprising the steps of:

• forming an amorphous silicon film through LPCVD method on an insulating surface, wherein a precursor gas for forming said amorphous silicon film comprises silane expressed by a formula Si.sub.n H.sub.2n+2 where n.gtoreq.2;
• forming a catalyst element in contact with a selected portion of said amorphous silicon film, said catalyst element being capable of accelerating crystallization of said amorphous silicon film;
• heating said amorphous silicon film so that a crystal growth occurs from said selected portion in a lateral direction to said insulating surface;
• forming the thin film transistor in a laterally grown portion where the crystal growth occurs in the lateral direction to said insulating surface,
• wherein an inert gas is introduced into a chamber for forming said amorphous silicon film before forming said amorphous silicon film to suppress an oxygen concentration in the amorphous silicon film.

A method of fabricating a thin film transistor comprising the steps of:

• forming an amorphous silicon film through LPCVD method on an insulating surface, wherein a precursor gas for forming said amorphous silicon film comprises silane expressed by a formula Si.sub.n H.sub.2+2 where n.gtoreq.2;
• forming a catalyst element in contact with a selected portion of said amorphous silicon film, said catalyst element being capable of accelerating crystallization of said amorphous silicon film;
• heating said amorphous silicon film so that a crystal growth occurs from said selected portion in a lateral direction to said insulating surface;
• forming the thin film transistor in a laterally grown portion where the crystal growth occurs in the lateral direction to said insulating surface,
• wherein a chamber for forming said amorphous silicon film before forming said amorphous silicon film is at a pressure of 8.times.10.sup.-3 Pa or lower.

A method of fabricating a thin film transistor comprising the steps of:

• forming an amorphous silicon film through LPCVD method on an insulating surface, wherein a precursor gas for forming said amorphous silicon film comprises silane expressed by a formula Si.sub.n H.sub.2n+2 where n.gtoreq.2;
• forming a catalyst element in contact with a selected portion of said amorphous silicon film, said catalyst element being capable of accelerating crystallization of said amorphous silicon film;
• heating said amorphous silicon film so that a crystal growth occurs from said selected portion in a lateral direction to said insulating surface;
• forming the thin film transistor in a laterally grown portion where the crystal growth occurs in the lateral direction to said insulating surface,
• wherein said amorphous silicon film has a nucleation rate of 2.times.10.sup.8 cm.sup.-3 s.sup.-1 or lower.