Semiconductor device having hsg polycrystalline silicon layer

A semiconductor device comprising:

• a semiconductor substrate;
• an insulating layer formed on said semiconductor substrate, a contact hole being formed within said insulating layer;
• an undoped HSG polycrystalline silicon layer formed in said contact hole and protruding from said insulating layer;
• and
• a doped HSG polycrystalline silicon layer formed over said insulating layer and connected to said undoped HSG polycrystalline silicon layer.

A method for manufacturing a semiconductor devic, comprising the steps of:

• forming a polycrystalline silicon layer on a semiconductor substrate;
• forming an impurity-doped amorphous silicon layer on said polycrystalline silicon layer;
• and
• converting said impurity-doped amorphous silicon layer into an HSG polycrystalline silicon layer.

A method for manufacturing a semiconductor device, comprising the steps of:

• forming a first insulating layer on a semiconductor substrate:
• forming a second insulating layer on said first insulating layer:
• forming a doped amorphous silicon layer on said second insulating layer:
• forming a third insulating layer on said doped amorphous silicon layer;
• perforating a contact hole in said third insulating layer, said doped amorphous silicon layer, said second insulating layer and said first insulating layer;
• forming an undoped amorphous silicon layer in said contact hole;
• patterning said undoped amorphous silicon layer, said third insulating layer and said doped amorphous silicon layer;
• removing said third insulating layer and said second insulating layer;
• and
• converting said undoped amorphous silicon layer and said doped amorphous silicon layer into an HSG undoped polycrystalline silicon layer and an HSG doped polycrystalline silicon layer, respectively.