Method of making semiconductor memory device

Abstract

Abstract A method of making a semiconductor memory device wherein a storage node having a plurality of pillars, capable of increasing the storage node surface area and thus the cell capacitance. The storage node is formed by depositing a storage node polysilicon film to have a thickness of 5,000 Å to 6,000 Å over a semiconductor substrate, forming a photoresist pattern over the polysilicon film in a direct electron beam writing manner, and etching the polysilicon film up to a depth of 1,000 Å from the upper surfaces of a gate and a bit line by using the photoresist pattern. The formed storage node has a plurality of uniformly spaced pillars. Alternatively, the storage node is formed by forming a smoothing insulating film over the semiconductor substrate depositing a storage node polysilicon film over the smoothing insulating film, primarily photo exposing the semiconductor substrate using a glass mask having phase shifters, secondarily photo exposing the semiconductor substrate under the condition of rotating 90° the semiconductor substrate, to form a check-board photoresist pattern, and patterning the polysilicon film using the photoresist pattern as a mask. The formed storage node has a plurality of pillars arranged independently or intersectionally.

Inventors

• 👤 Kwang H. Yun
• 👤 Hee G. Lee
• 👤 Seong J. Jang
• 👤 Young K. Jun

Bibliographic Details