| 摘要 |
PURPOSE:To obtain an easy-to-use device and to reduce power by setting the concentration of impurity in a first region having a third region lower than the concentration of impurity in a second region thereby employing only one supply voltage for a memory device. CONSTITUTION:A burried N-type high concentration region 2 and a low concentration N-type region 3 are provided on a P-type silicon substrate 1, where P-type first and second regions 12, 9 are provided in the N-type region thus constituting a MOS transistor having the first and second regions 12, 9 as a source region or a drain region. On the other hand, an N-type high concentration third region 11 is provided in the first region 12 thus constituting a bipolar transistor having the N-type regions 2, 3 as collector regions, the first region 12 as base region and the third region 11 as emitter region. Impurity concentration in the first region is set lower than that in the second region. |
