Phosphorous doping methods of manufacturing field effect transistors having multiple stacked channels

Abstract

Integrated circuit field effect transistors are manufactured by forming a pre-active pattern on a surface of a substrate, while refraining from doping the pre-active pattern with phosphorus. The pre-active pattern includes a series of interchannel layers and channel layers stacked alternately upon each other. Source/drain regions are formed on the substrate, at opposite ends of the pre-active pattern. The interchannel layers are then selectively removed, to form tunnels passing through the pre-active pattern, thereby defining an active channel pattern including the tunnels and channels including the channel layers. The channels are doped with phosphorus after selectively removing the interchannel layers. A gate electrode is then formed in the tunnels and surrounding the channels.