The inventions of paper, pen and printing technologies around two thousand years ago upgraded human civilization. Today we use our fingers to write on electronic displays some messages which are transferred and stored in semiconductor memories. Civilization has been modernized by electronic storage and communication due to the big inventions of SRAM, DRAM and flash memories in silicon IC productions.
In 2013 these memories created business revenues of over 72 billion dollars, which is about 23% of the total semiconductor revenues. In the near future, the impact generated by semiconductor memories will be huge, but more disruptive innovations in designs and technologies are needed.
The newest flash memories have displayed a single 3D NAND cell-array die by stacking every individual nonvolatile cell into 32 layers, respectively, with three bits stored in each cell. Smart circuit designs have achieved fast access to total memory bits of 128Gb and have used only 30nm lithography, resulting in an “effective Moore’s Law scaling” equivalent to using 10nm. Building this “Empire State Building” in the nanometer scale will not only become a major trend for NAND flash development but should also trigger development of more chips with a variety of functions. This will facilitate the trend of a “Virtual Moore’s Law”.
With DRAM, we have already used 3D cell structures by either stacking capacitors or drilling deep trench capacitors, which has increased chip density to up to 8Gb today. By using 3D technologies, a total of 16 layers of DRAM dies are connected to reach a total capacity of over 64Gb. We also use novel circuit techniques to make the most advanced LPDDR4 DRAM, which enables extremely high data rates for 4G cell phones today. Still, how we can make smarter, lower-power DRAM in 1Xnm remains a challenge and requires innovation.
There are yet to be perfect memories with both DRAM’s high performance and NAND’s large storage for the emerging 4C, Big Data, IoT and wearable applications. Some disruptive inventions regarding new kinds of memories with novel cell structures and intelligent designs are still waiting for top engineers. In this presentation I’ll show some genuine inventions in memories and hope to stimulate the interest of Future ISSCC attendees to make big innovations in this new century!
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Post time: Oct-18-2017