LONDON — Microprocessor company Advanced Micro Devices Inc. has signed a technology license for "floating-body" silicon-on-insulator (SOI) memory developed by startup company Innovative Silicon Inc. AMD (Sunnyvale, Calif.) said it is interested in the Z-RAM (zero capacitor) technology for use in its microprocessors.
The embedded memory is a good fit with AMD, which has moved all its microprocessor production over to SOI manufacturing processes. ISi (Santa Clara, Calif.) has claimed that Z-RAM can achieve five times the density of embedded SRAM, the conventional memory choice for on-chip caches, and twice the density of embedded DRAM.
It could also provide a means to help AMD put distance between itself and PC processor rival Intel Corp. which, so far, has said it does not see a need to go to SOI technology. AMD's licensing of Z-RAM could also have implications for IBM and Chartered Semiconductor, with which AMD is aligned.
“The dramatic increase in density offered by ISi’s Z-RAM embedded memory can enable much larger on-chip microprocessor cache memories resulting in improved performance and reduced I/O power consumption,” said Craig Sander, corporate vice president of technology development at AMD.
“We’ve looked at data from Innovative Silicon and it looks very promising. We still need to assure ourselves that this will work in our own application. We need to see how it scales and we need to make our own test vehicles,” he added.
Sander said those test vehicles would probably run on 65-nanometer and 90-nanometer manufacturing processes initially and the wafers would run at AMDÂ’s Dresden, Germany wafer fabs.
However, Sander declined to say whether AMD was targeting the 65-nm manufacturing node for introduction, or how quickly AMD could deploy the technology. Sander said the introduction of Z-RAM depended not only on AMDÂ’s investigation of the technology but was also tied to product plans.
Sander did confirm that AMD is currently focused only on the microprocessor application for Z-RAM. Although other logic chips could use Z-RAM technology they would require a move to SOI wafers.
ISi has its engineering base in Lausanne, Switzerland and was founded 2002 by Pierre Fazan, chief technology officer, an experienced engineer with ideas based on developing a single-transistor DRAM using silicon-on-insulator wafers. As the technology dispenses with the conventional capacitor, using instead the body capacitance of the silicon top layer of SOI, the technology can be denser than DRAM. ISi also claims the simplicity of the technology means it should scale better than many competing technologies.
While the memory is dense it is a volatile memory, unlike flash, and it is dynamic like a DRAM.
“Working with AMD shows the increasing importance of using ultra-high density embedded memory in the semiconductor industry as embedded memory occupies larger and larger proportions of the microprocessor and embedded processor die area,” said Mark-Eric Jones, president and chief executive officer of Innovative Silicon.
Jones, an executive experienced in intellectual property licensing, also declined to comment on AMD’s timetable for introduction of Z-RAM but offered a more general perspective. “In the past it has been two years from when you sign a deal to when it is in production.”
