Non-volatile memory devices according to embodiments of the present invention include an EEPROM transistor in a first portion of a semiconductor substrate, an access transistor in a second portion of the semiconductor substrate and an erase transistor in a third portion of the semiconductor substrate. The second portion of the semiconductor substrate extends adjacent a first side of the first portion of the semiconductor substrate and the third portion of the semiconductor substrate extends adjacent a second side of the first portion of the semiconductor substrate. The first and second sides of the first portion of the semiconductor substrate may be opposite sides of the first portion of the semiconductor substrate. The access transistor has a first source/drain terminal electrically connected to a first source/drain terminal of the EEPROM transistor and the erase transistor has a first source/drain terminal electrically connected to a second source/drain terminal of the access transistor.