Double Polysilicon Dynamic Memory Cell With Polysilicon Bit Line
Original Publication Date: 1979-Feb-01
Included in the Prior Art Database: 2005-Feb-19
The overlapping double polysilicon dynamic memory cell is the most popular cell for 16 and 64 Kbit dynamic random access memories. A top and side view of this cell is shown in Fig. 1. The cell, which requires five basic lithographic masking steps, provides a diffused N+ bit line and a metal word line connected to two polysilicon gates that share a single contact hole. The second polysilicon (gate) layer overlaps the first polysilicon (capacitor plate) layer.