Abstract: The present invention provides a method for forming a contact plug of a semiconductor device with a low contact resistance. The inventive method includes the steps of: forming a contact hole in an inter-layer insulating layer formed on a silicon substrate; removing a native oxide layer formed in the contact hole; forming a single crystal silicon layer on a surface of the silicon substrate in the contact hole, wherein the single crystal silicon layer is formed by an epitaxial growth performed at a first reaction chamber of which pressure is maintained less than approximately 10−6 Torr; and filling the contact hole with polysilicon, wherein the polysilicon layer is formed at a second reaction chamber.

Abstract: Disclosed is a semiconductor device with high-k dielectric layer. The semiconductor device has a dielectric layer including a first dielectric layer containing aluminum and a second dielectric layer containing lithium in the first dielectric layer.