| 摘要 |
PURPOSE:To protect a mask ROM against inter-bit leakage by a method wherein a parasitic channel is prevented from occurring in a manufacturing process. CONSTITUTION:A field oxide film 31, a gate oxide film 32, and a polysilicon film 33 are selectively formed on a silicon substrate 30, and then a silicon oxide film 34 is formed on the whole surface of the substrate 30. Then, the silicon oxide film 34 is etched back to enable the upside of a polysilicon film 33a on the field oxide film 31 to be exposed, and furthermore a polysilicon 35 is selectively grown. Then, ions are implanted at a certain energy level which enables ions to penetrate only the multilayered films 32, 33, and 34 through. |
