Z-RAM gets a step closer to reality

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Z-RAM gets a step closer to reality

Santa Clara (CA) and Icheon (Korea) – Innovative Silicon (ISi) announced that it has licensed its Z-RAM technology to Hynix Semiconductor, shedding some light on a new system memory technology that could be available by 2010. The eight-figure deal ushers in the first major manufacturing change seen in the DRAM industry since CMOS.

ISi said it will work very closely with Hynix over the next two years to develop high-volume, commercial ready memory products that are compatible with today’s DRAM memory sockets. The R&D will be carried out by ISi in Lausanne, Switzerland and Santa Clara, California, as well as the Hynix’ labs in Korea. No definite schedule was given as to when commercial products will be available. Jeff Lewis, vice president of marketing at ISi, and Mark-Eric Jones, ISi’s CEO, both indicated that the ramp-up time from license to product is generally about three years. Jones also told us they also have “good confirmation their memory technology is of interest to the DRAM industry” overall. Hynix had been evaluating Z-RAM closely for about a year before licensing, we’re told.

ISi explained that Z-RAM’s advantages over traditional DRAM are its use of capacitor-less “bitcell” configuration. It’s nearly twice as dense as DRAM and about 5x as dense as SRAM. Compared to DRAM, it is promised to be faster and to consume about the same amount of power while having a smaller footprint. ISi’s design also allows for optimizations geared toward speed or power efficiencies. Lewis noted that ISi is currently running the memory at operational frequencies of around 500 MHz. While this is notably slower than most SRAM applications today, the advantages are the same die space could hold up to 5x the amount of cache.

Z-RAM requires fewer tools and manufacturing process steps to create memory devices compared to traditional capacitor-based DRAM production, we were told. This could indicate faster processing times and less chances to introduce errors. Z-RAM only works on Silicon-On-Insulator (SOI) process technologies due to SOI’s “floating body effect”: Whereas SOI isn’t generally used today, the switch could be made for Z-RAM without issue.

ISi said it holds “at least” 25 patents related to the bitcell, support circuitry and interface architectures, with about 50 more pending. Z-RAM is currently on a Gen2 iteration with validation at the 45 nm process node. Gen2 offers significantly greater power savings over Gen1, specifically on write processes. It is also faster and can hold a bit charge 25x longer than Gen1. ISi is targeting DRAM, microprocessors and SoC products for future licensing.

Hynix joins AMD as Z-RAM licensee. AMD licensed ISi’s initial Gen1 product in January, 2006. They later renewed their license with Gen2 in December of the same year. It is believed AMD will use Z-RAM for a large, embedded L3 cache in future microprocessors, though no products have been announced so far.