| 摘要 |
PURPOSE:To obtain a MIS transistor, fundamental characteristics thereof are determined only by spatial structure and which can realize infinitesimally small size without being affected by impurity concentration in a semiconductor substrate immediately under a channel. CONSTITUTION:One conduction type semiconductor layer 17 in impurity concentration higher than a semiconductor substrate 11 is formed under a gate insulating film 14 and under a semiconductor film 19 formed between a source region 12 and a drain region 13 through an insulating film 18. In the structure, a channel can be formed in the semiconductor layer 19 because the semiconductor layer 19 is formed in low concentration close to an intrinsic semiconductor. Since the semiconductor layer 17 in impurity concentration higher than the semiconductor substrate 11 is formed under the channel, the thickness of a depletion layer 16 is determined equivalently only by structure, and does not depend upon a drain bias. |
