Method for annealing by a high energy beam to form a single-crystal film
AssigneeFujitsu Limited
InventorSeiichiro Kawamura
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Abstract
A large single-crystalline film on an amorphous insulator is formed by high energy beam annealing. The crystal growth of a molten polycrystalline or amorphous film on the insulator is controlled to occur from the central region toward the outer edge of the molten zone. This control is accomplished by using, for example, a doughnut-shaped laser beam.
Claims12
A method for forming a single-crystalline semiconductor film on an amorphous insulator, comprising the steps of:
- depositing a polycrystalline or amorphous semiconductor film on the amorphous insulator;
- and
- scanning a high-energy beam over the polycrystalline or amorphous semiconductor film, the high energy beam having a thermal profile such that a region of the polycrystalline or amorphous semiconductor film irradiated by the high energy beam is melted and then cooled so as to crystallize in the direction from a central region toward an outer edge of a trailing edge of an area exposed to the high-energy beam, whereby a continuous single-crystalline film is formed.
A method for forming a single-crystalline semiconductor film on an amorphous insulator layer, comprising the steps of:
- forming the amorphous insulator layer on a semiconductor substrate, the amorphous insulator layer having a cross-sectional thickness which is thinner in the central portion than in the outer portions;
- forming a polycrystalline or amorphous semiconductor film on the amorphous insulator layer;
- and
- scanning a high energy beam over the polycrystalline or amorphous semiconductor film in a direction perpendicular to the amorphous insulator, whereby a continuous single-crystalline film is formed.
A method for forming a single-crystalline semiconductor film on an amorphous insulator layer, comprising the steps of:
- forming a polycrystalline or amorphous semiconductor film on the amorphous insulator;
- covering only the peripheral region of the polycrystalline or amorphous semiconductor film with a nonreflective film;
- and
- scanning a high energy beam over the polycrystalline or amorphous semiconductor film formed on the amorphous insulator, whereby a continuous single-crystalline film is formed.
Dependencies are inferred from the claim text.