Embedded DRAM Using C-Axis-Aligned Crystalline In-Ga-Zn Oxide FET with 1.8V-Power-Supply Voltage

This paper reports the validation of our prototyped memory operating with 1.8-V power supply and low stand-by power, using 60-nm c-axis-aligned crystalline In-Ga-Zn oxide (CAAC-IGZO) field-effect transistors (FETs). Its operation evaluation verified that a reduction in driving voltage is enabled by application of a negative voltage as a low voltage (VSSL) of a word line. A negative-voltage generator uses CAAC-IGZO FETs in a comparator circuit. The total stand-by power including power consumed by the additional negative-voltage generator is as small as 120 nW, which is revealed by simulation of a 1Mb-memory operating at 100 MHz.