| 摘要 |
PURPOSE:To obtain an ROM having a high reliabiliy and high density in a short time by recrystallizing partly by a laser light emission an amorphous Si as a resistor when the crossing points of a plurality of row and column lines are connected with series connecting circuits of resistors and diodes. CONSTITUTION:The crossing points of respective row lines R1, R2 and respective column lines C1, C2 are connected via diodes d11, d12, d21, d22 and resistors r11, r12, r21, r22, thereby forming a programmable ROM. In this structure, fuses which are normally used are not employed as resistors, but polycrystalline silicon injected with impurity ions in high density varying in resistance values in the order of 5 to 6 places is employed around after or before the heat treatment. That is, a series connection of an N<-> type diffused part 2 corresponding to a resistor and a polycrystalline silicon 4 is provided between the metallic wire 1 corresponding to the column lines C1, C2 and an N<+> type diffused layer 3 corresponding to the row lines R1, R2. Further, a laser light is emitted to the silicon 2 except the non-emitted region 5 and is recrystallized, thereby lowering the resistance value. |
