A novel NAND structure with a BJT contact for the high density mask ROMs

A novel NAND cell structure with a PNP BJT, which amplifies the cell current, was proposed and fabricated. Its typical current gain is around 10 and the measured cell current is about 180 /spl mu/A at 25/spl deg/C. This amount is extremely high compared to that of the conventional NAND cell structure. This structure also keeps good current driving capability regardless of temperature variation while full MOS type degrades the characteristics. This results indicate that this new structure is a strong candidate for high performance and high density mask ROMs.<>