| 摘要 |
PROBLEM TO BE SOLVED: To realize memory cells effective for a highly integrated device by reducing the energy difference between the valence band top end of a second semiconductor layer and vacuum level below that between the valence band top end of a first and third semiconductor layers and vacuum level. SOLUTION: A main surface of a p-type Si substrate 1 is provided with a first p-type Si semiconductor layer 3 through a silicon oxide layer 2. On element-forming regions 21 on this layer 3 a second p-type SiGe semiconductor layer 4 and third p-type Si semiconductor layer 5 are formed. The energy difference between the valence band top end of the second semiconductor layer 4 and vacuum level is reduced below that between the valence band top end of the first and third semiconductor layers 3, 5 and vacuum level. Thus it is possible to easily realize memory cells effective for a highly integrated device. |
