A number of potential problems are caused by the high circuit element density of today's integrated circuits. For example, densely packed field-effect transistors have relatively short channel lengths, resulting in increased potential for punchthrough effects. Also, the correspondingly shallow drain and source junction depths can result in junction spiking, in which metallization layers penetrate drain and source diffusions. The short channel lengths also result in higher electric field strengths, which in turn cause deleterious hot carrier effects. Reduced device geometries increase capacitive coupling between source/drain regions and the body of the transistor, resulting in degraded device performance and signal transmission characteristics. In the case of CMOS technology, parasitic thyristors and associated latchup effects arise. These and other fundamental problems must be addressed by the circuit designer and process engineer.