Transistor of a semiconductor device having a punchthrough protection layer and methods of forming the same

摘要

According to some embodiments of the invention, transistors of a semiconductor device have a punchthrough protection layer, and methods of forming the same are provided. A channel-portion hole extends downward from a main surface of a semiconductor substrate. A punchthrough protection layer and a channel-portion layer are sequentially formed at a lower portion of the channel-portion hole. A word line pattern fills an upper portion of the channel-portion hole, and is formed on the semiconductor substrate. The word line pattern is formed to have a word line and a word line capping layer pattern stacked thereon, and the channel-portion layer is a channel region. The punchthrough protection layer can reduce a leakage current of a capacitor of the transistor embodied in a DRAM.