| 摘要 |
<p>A semiconductor device composed of a high voltage transistor is provided to maintain a high voltage of a transistor by removing a field stopper that used to be formed in a conventional technique. A plurality of first transistors are formed on a semiconductor substrate of a first conductivity type. Each one of the first transistor includes a first gate electrode, a first diffusion layer of a second conductivity type constituting one of a source or a drain region, and a second diffusion layer of the second conductivity type constituting the other of the source or the drain region. The first gate electrode is shared by the plurality of the first transistors. An isolation layer is formed in the semiconductor substrate, isolating the plurality of first transistors. An impurity region of the first conductivity type is formed in a region of the semiconductor substrate in which the plurality of first transistors are formed. The impurity region of the first conductivity type is deeper than the first and the second diffusion layers of the first transistor, determining the critical voltage of the first transistor. A higher voltage than that applied to the second diffusion layer and the first gate electrode can be applied to the first diffusion layer.</p> |
