Method of manufacturing polysilicon film including recrystallization of an amorphous film
AssigneeNEC Corporation
InventorsToru Tatsumi, Akira Sakai
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Abstract
A method of fabricating a polysilicon film whose crystal grain size can be controlled in a wide range and which has a large surface area and an application thereof to a DRAM are disclosed. In polycrystallizing an amorphous silicon film having a substantially clean surface, nucleation and crystal growth are performed under different conditions. With this method, crystal grain density and crystal grain size can be controlled easily, causing a polysilicon film having finer grains to be formed concomitant with reduction of capacitor area due to increase of integration density of DRAM.
Claims7
A method of fabricating a semiconductor device, comprising the steps of:
- forming a capacitance electrode made of a polysilicon film, said polysilicon film being formed by recrystallizing an amorphous silicon film, said recrystallizing being performed by depositing said amorphous silicon film on an insulating film covering a semiconductor substrate, generating a plurality of crystal nuclei at a plurality of portions of a substantially cleaned surface of said amorphous silicon film, respectively, and growing each of said plurality of crystal nuclei into a mushroom or hemisphere shaped crystal grain to thereby convert said amorphous silicon film into said polysilicon film, said polysilicon film thereby having a concavo-convex surface caused by said mushroom or hemisphere shaped crystal grains being separated apart from one another;
- forming a dielectric film on said concavo-convex surface of said polysilicon film, said dielectric film thereby having a concavo-convex surface;
- and
- forming another capacitance electrode by forming a conductive film on said concavo-convex surface of said dielectric film.
A method of fabricating a semiconductor device, comprising the steps of:
- forming a capacitance electrode made of a polysilicon film, said polysilicon film being formed by recrystallizing an amorphous silicon film, said recrystallizing being performed by depositing said amorphous silicon film on an insulating film covering a semiconductor substrate, applying heat in vacuum or in a gas substantially chemically non-reactive to said amorphous silicon film while supplying a silicon-containing compound to produce crystal nuclei and continuing to apply said heat after terminating said supply of said compound gas to grown said crystal nuclei;
- forming a dielectric film on said polysilicon film;
- and
- forming another capacitance electrode by forming a conductive film on said dielectric film.
Dependencies are inferred from the claim text.