Heterogeneously integrated program voltage generator for 1.0V operation NAND flash with best mix & match of standard CMOS process and NAND flash process

Abstract

For 1.0V operation NAND flash memory, heterogeneously integrated voltage generator is proposed and experimentally demonstrated. The proposed 2-stage boost converter uses high voltage (HV) transistors of standard CMOS process as the 1st stage and HV transistors of NAND flash process as the 2nd stage. The intermediate load capacitance is adaptively adjusted according to the number of NAND flash chips operating simultaneously. As a result, 89% ramp-up time decrease and about 15% chip cost reduction is achieved.