| 摘要 |
PURPOSE:To improve a diode which functions as a voltage limiter in reliability by a method wherein ions are implanted into the PN junction section of the diode so as to develop the defect in it. CONSTITUTION:A mask is formed, which is composed of a connecting hole 21B of a diode D2 provided to a region A that is annealed at high temperature of 900 deg.C-1000 deg.C and a resist film of a pattern where a part of a memory cell M1 that the information of a mask ROM is to be written in is opened. Next, P-type impurity, for instance, boron is introduced for the formation of a damaged region 24 in a region A and a P-type semiconductor region 14 in a channel region of the memory cell M1 in a region C. Then, wirings 22A, 22B, and 22C, a data line DL, and other aluminum wirings are successively formed. A mask of a resist film is removed after patterning is performed. Thereafter, H2 annealing is performed at temperature of 450 deg.C, more or less. The annealing performed at about 450 deg.C after the formation of the aluminum wirings 22A, 22B, 22C, and the data line DL does not cure the defect, which is developed in the damaged region 24 formed on the diode D2, so that the diode D2 can be improved in property. |
