MASK ROM CELL, CODING METHOD OF THE SAME, AND MASK ROM

摘要

PURPOSE: A mask ROM(Read Only Memory) cell, a coding method of the same, and a mask ROM are provided to apply user code to the mask ROM cell by transforming the second conductive type of the second region into the first conductive type using counter doping. CONSTITUTION: A mask ROM cell includes the first region and the second region. The first region(110) is formed on a semiconductor substrate. The first region is doped with the first conductive type impurities. The second region(120) is formed on the first region. The second region is doped with the second conductive type impurities. The second region is transformed into the first conductive type region by performing counter doping using the first conductive impurities according to user code.