Hynix has agreed to license innovative Z-RAM technology from ISi for use in its DRAM chips, potentially providing twice as much memory in the same chip volume. It could be the lowest-cost memory in the $30 billion-plus DRAM market.

ISi (Innovative Silicon Inc) was founded in 2002 by its current chief technology officer, Perre Fazan, and its engineering centre is in Lausanne, Switzerland. Its technology is based on the idea of making DRAM from single transistor bitcells with silicon-on-insulator (SOI) wafers.

Existing DRAM uses a combination of transistors and capacitor elements. ISi has capacitance provided through the silicon top layer of its SOI architecture. This is called the Floating Body Effect (FBE) and it makes its overall memory cell size smaller, meaning more memory cells can be built in the same space as before.

As Z-RAM takes advantage of a naturally-occurring SOI effect, it does not require process changes to build capacitors or other complex structures within the memory bitcell. Z-RAM use should also eventually lead to better yields than current DRAM technologies due to its capacitor-less design.

Mark-Eric Jones, ISi CEO, said: “Memory chips built using ISi’s Z-RAM technology will be much smaller and cheaper to manufacture. We are looking forward to working with Hynix on its next generation of DRAM chips, and to bringing tremendous performance and usability advantages to end-users.”

Hynix is one of the top ten largest silicon chip manufacturers in the world. The deal is worth in excess of $10 million in licensing fees for ISi with royalties payable as a proportion of Hynix production. Hynix may choose to make memory products with higher densities than what is currently possible with DRAM or, alternatively, make physically smaller memory chips.


ISi believes that this is the first fundamental DRAM bitcell change since the invention of DRAM in the early 1970s. It claims that Z-RAM-based DRAM can be five times as dense as embedded SRAM (static random access memory), used for CPU on-chip memory caches. It can also be used to build memories twice as dense as embedded DRAM; 1Gbit in a 512Mbit DRAM volume for example.

The technology can be used to add more memory capacity to hand-held and other intelligent devices as well as to CPU caches, PCs and servers.

AMD licensed the Z-RAM technology in December, 2005, with hopes for use in on-chip L2 or L3 cache, but nothing has been announced so far.

AMD's corporate VP for technology development, Craig Sander, said: “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.”

It can take two years or more for a licensed technology to be added to a semiconductor fabrication process before it starts producing effective yields of product.