Patent ID: 6750501
Filing Date: 2004-06-15
Classification: H01L

Abstract:
A transistor type ferroelectric body nonvolatile storage element, comprising:a semiconductor substrate defining a source region, a drain region and a channel region between the source region and the drain region, a channel length direction being defined as a direction along a length of the channel region from the source region to the drain region; a gate structure including an insulating film, a first conductor film, a ferroelectric body film and a second conductor film successively laminated on the semiconductor substrate; a low dielectric constant layer restraining layer formed at an interface between the insulating film and the semiconductor substrate, and formed only over the channel region; a first thick silicon oxide film covering the source region and having a boundary with the channel region, a thickness of the first silicon oxide film increasing with distance from the boundary between the first silicon oxide film and the channel region; and a second thick silicon oxide film covering the drain region and having a boundary with the channel region, a thickness of the second silicon oxide film increasing with distance from the boundary between the second silicon oxide film and the channel region, the insulating film and the first conductor film being arranged above the channel region of the semiconductor substrate and above and only partially covering the first and second silicon oxide films such that lengths of the first conductor film and the insulating film in the channel length direction are longer than a length of the channel region, the lengths of the first conductor film and the insulating thin film in the channel length direction being longer than a length of the ferroelectric body film in the channel length direction and the length of the ferroelectric body film in the channel length direction being longer than a length of the second conductor film in the channel length direction.