A 4-Mbit DRAM with half-internal-voltage bit-line precharge

A single 5-V supply 4-Mb dynamic random access memory (DRAM) was developed by using a buried-storage-electrode memory cell, a half-internal-voltage bit-line precharge method combined with a constant voltage converter, and a high signal-to-noise ratio sensing scheme. The chip was designed in a double-polycide, single-Al, epitaxial substrate NMOS technology with a 0.8-μm minimum design rule. As a result, a 4M word×1-bit DRAM with 95-ns typical access time and 99.2-mm/SUP 2/ chip area was attained by 10.58-μm/SUP 2/ storage cells.