The evolution of dense embedded memory in high performance logic technologies

Abstract

Embedded memory (eMemory) plays a key role in the performance of modern multi-core processors, and for a broad class of cache-balanced systems, can account for up to 70% of the die area. Memory is highly diagnosable and is an excellent process-learning vehicle besides pushing lithographic and process capability to the limit. Here we look at ways to increase embedded memory capacity and performance in two ways: integrating dense embedded DRAM using Deep Trench (DT) capacitors into high performance logic and using 3-dimensional integration (3Di) to integrate even larger amounts of cache close to the processing units. We also address how the DT capacitors can significantly improve overall chip performance by reducing mid-frequency power supply noise on these chips. We show that this holistic approach to embedded memory makes judicious use of SRAM, DRAM and extends to 3Di and provides the basis of “orthogonal” scaling beyond that provided by conventional lithographic scaling alone.