Patent ID: 7439595
Filing Date: 2008-10-21
Classification: H01L

Abstract:
1. A field effect transistor comprising: a first contact semiconductor layer; a gate electrode formed above the first contact semiconductor layer; an opening which penetrates the gate electrode; a channel semiconductor layer formed so that the layer penetrates the opening and the lower portion of the layer contacts the first contact semiconductor layer; a second contact semiconductor layer formed so that the layer contacts the upper portion of the channel semiconductor layer; a first source or drain electrode formed so that the electrode contacts the first contact semiconductor layer; and a second source or drain electrode formed so that the electrode contacts the second contact semiconductor layer, wherein: the carrier concentration of the channel semiconductor layer being lower than those of the first and second contact semiconductor layers, the contact area of the second contact semiconductor layer and the second source or drain electrode being larger than the area of the opening, a conductive substrate is provided below the channel semiconductor layer and the first contact semiconductor layer, a through-hole is formed between the top surface of the first contact semiconductor layer and the conductive substrate, and the first source or drain electrode, which is formed so that the electrode contacts the first contact semiconductor layer, and the conductive substrate are electrically connected with each other via the through-hole formed in the first contact semiconductor layer.