Method of making semiconductor memory device
US5336630A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1992 |
| Grant date | Aug 9, 1994 |
| Priority date | — |
| Expiry date | Nov 13, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/943
- WIPO fieldOptics
- WIPO sectorInstruments
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 .ANG. to 6,000 .ANG. 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 .ANG. 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.degree. the semiconductor substrate, to form a check-board photoresist pattern, and patterning the polysilicon film using the photoresist pattern as a mask. The formed s…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.