Abstract: A semiconductor device includes a photodetector having a junction at which a first conductive type first semiconductor portion and a second conductive type second semiconductor portion are joined to each other. In this photodetector, division regions are formed in part of the first semiconductor portion in such a manner as to cross the first semiconductor portion and partially enter the second semiconductor portion, so that the junction is divided into a plurality of parts by the division regions, to form a plurality of photodetector regions having the divided junction parts.

Abstract: A method of manufacturing a dynamic random access memory capacitor. To form the lower electrode of the capacitor involves using two different materials each having a different etching rate to form an alternately laid stack above a substrate. Differences in etching rates between the two materials are utilized to etch out a capacitor opening having serrated sidewalls. A polysilicon layer is next deposited into the capacitor opening. An aluminum layer and a titanium layer are sequentially formed over the polysilicon layer. An annealing operation is carried out in a nitrogen-filled atmosphere so that aluminum displaces polysilicon inside the capacitor opening. The silicon atoms in the polysilicon layer reacts with titanium atoms in the titanium layer to form a titanium silicide layer over the aluminum layer. The aluminum layer and the titanium silicide layer that cover the stacked layer are removed. The stacked layer is also removed to expose a fin-shaped aluminum lower electrode.