IBM Unveils World's Smallest SRAM Memory Cell

Traditionally, SRAM is made more dense by shrinking its basic building block, often referred to as a cell. The new IBM SRAM cell is less than half the size of the smallest experimental cell reported to date, and ten times smaller than those available today. To put this in perspective, about 50,000 of the IBM cells could fit on the circular end of a single human hair. This breakthrough demonstrates the possibility of continued system performance improvement for three additional technology generations beyond what is currently manufactured. The technology is being unveiled in December at the 2004 International Electron Devices Meeting (IEDM) in San Francisco.

"Our continued commitment to technology leadership is driven by the needs of our customers," said Dr. T.C. Chen, vice president of Science and Technology, IBM Research. "Our ability to create critical electronic components at these small scales ultimately means our systems will be able to tackle harder problems. We develop the technology and our server systems are the vehicles that put this technology to work in powerful ways."

IBM researchers optimized the SRAM cell design and circuit layout to improve stability and developed several novel fabrication processes in order to make the new SRAM cell possible. The key element was IBM's utilization of mixed electron-beam and optical lithography to print the aggressive pattern dimensions and densities. SRAM cell size is a key technology metric in the semiconductor industry, and this work demonstrates IBM's continued leadership in cutting-edge process technology.

The SRAM cell size achieved by IBM could enable on-chip memories with ten times higher capacity than the current state-of-the-art technologies. This innovative technology could pave the way for new applications, such as faster search processing, and enable the growth of on demand computational capabilities for IBM customers.

About SRAM

SRAM is a type of fast, on-chip memory that holds its data without external refresh for as long as power is supplied to the circuit. Each memory is an array of many cells. A typical SRAM cell contains six transistors and acts as a single-bit storage element. Although not as dense, SRAM is many times faster than dynamic random access memory (DRAM). SRAM is essential for storing critical data that must be quickly and frequently retrieved by the processor.