Semiconductor device including capacitorless RAM

A semiconductor device comprising:

• a field effect transistor having a floating body structure, comprising:
• a first region comprising a first semiconductor having a given band gap;
• a second region comprising a second semiconductor having a larger band gap than that of the first semiconductor;
• a channel body region being disposed in said first region;
• a source region;
• a drain region, and
• wherein each of said source and drain region has a high density dopant region and a low density dopant region;
• and
• each said low density dopant region is disposed at least between said channel body region and said high density dopant region of said source or said drain region;
• said semiconductor device further comprising an insulating layer underlying said field effect transistor.

A semiconductor device comprising:

• a field effect transistor having a floating body structure, wherein said field effect transistor comprises:
• a first region comprising a first semiconductor having a given band gap;
• a second region comprising a second semiconductor having a larger band gap than that of the first semiconductor;
• and
• wherein a channel body region of said field effect transistor is disposed in said first region,
• wherein the field effect transistor including the floating body structure is arranged at respective intersections of a plurality of word lines and a plurality of bit lines, and one of the source and drain regions of the field effect transistor is electrically connected to the bit line, and the other of the source and drain regions of the field effect transistor is electrically connected to a source line, and the plurality of bit lines are connected via a selecting switch to a sense amplifier, and the sense amplifier is connected to a line to supply a current having an intermediate value between ON current and OFF current of the field effect transistor.