| 摘要 |
<p>A substrate having a buried well is provided. The substrate may be formed by implanting ions in a surface well of a first substrate and subsequently forming a semiconductor layer, such as an epitaxial layer, over the surface well. In this manner, the surface well becomes a buried well having a semiconductor layer that is substantially undoped formed thereon. In an embodiment, a transistor is formed on the substrate. Because the epitaxial layer is substantially undoped, the transistor may be formed such that the junction capacitance between the source/drain regions and the underlying region is reduced. If desired, the epitaxial layer, or a portion thereof, may be doped to decrease the resistance between the channel region and the well contact.</p> |
