摘要 |
<p>An integrated circuit formed on a substrate (101) has field effect transistors formed in relatively lightly doped (i.e., high resistivity) epitaxial layer (113), typically in a "tub" (102,103) formed therein. Operating current for the transistors is provided at least in part through a metallic layer (100) on the back side of the substrate. Surprisingly, the conductivity is sufficiently high through the epitaxial layer and the substrate that the number of power supply bondpads on the front side may be reduced, or eliminated entirely in some cases. In addition, a reduction in power supply lead inductance is obtained, reducing ringing and ground bounce problems.</p> |