  In the framework of (2+1)-dimensional compact lattice QED with light
fermions, we investigate the phase diagram in the $(\beta, N)$ plane. The
approximations involved are related to an expansion of the effective fermionic
action as a power series of the flavor number $N$. We also develop a new
mechanism for understanding the $N-$critical phenomenon in the full theory. Our
results for the specific heat indicate that only one phase does exist. We give
strong evidences that this qualitative result should not be changed with the
inclusion of higher order terms in the $N$ expansion.
