Embedded DRAM is a market that hangs in there, making steady process over the last 20 years at companies such as IBM, NEC, and Toshiba. But eDRAM often has required extra masks which often sent costs beyond what is affordable for many applications.
The attraction of embedded DRAM has been on-chip density compared with SRAM, and higher bandwidth between the array and logic compared with off-chip DRAM. Now, IBM is touting a silicon-on-insulator form of embedded DRAM that is pushing against cache SRAM in terms of performance.
At the upcoming International Solid State Circuits Conference (ISSCC), which starts in San Francisco Feb. 11, IBM engineer John Barth will present an SOI-based embedded DRAM technology with a 1.5 ns latency and a 2 ns random access time. Barth, based at Essex Junctin, Vt., will present an embedded trench SOI DRAM using a one-transistor, one-capacitor SOI technology. The technology includes a new sense amplifier which utilizes a short-bit-line architecture without the area overhead associated with conventional cross-coupled sense amplifiers.
The SOI embedded DRAM offers improved bit count, standby power, soft error rates, and stability, according to an IBM
It will be interesting to see if IBM’s SOI eDRAM is employed in IBM’s cache design for the server-use Power microprocessors, which were the first MPUs to use multiple cores. Reducing the use of six-transistor SRAM with the higher density eDRAM (at 65-nm design rules, the cell size is 0.127 square microns) would be a breakthrough indeed.
The eDRAM presented by Barth also could find use on the SOI-based Cell processor. Will Sony’s PS-4 include the 1.5-ns-latency eDRAM? Will IBM license the technology to AMD for use on its Opteron processors?
The SOI eDRAM appears to be an ideal match for high-performance processors made on an SOI-process. If, as IBM contends, costs can be kept to the less-than-10 percent adder compared with SRAM, SOI eDRAM could change the high-end microprocessor competition in a big way.
About weQuest: weQuest's are written by G Dan Hutcheson, his career spans more than thirty years, in which he became a well-known as a visionary for helping companies make businesses out of technology. This includes hundreds of successful programs involving product development, positioning, and launch in Semiconductor, Technology, Medicine, Energy, Business, High Tech, Enviorntment, Electronics, healthcare and Business devisions.