  We consider the corrections due to quantum fluctuations of fields on charged
black holes induced from the energy-momentum trace anomaly. Although the number
of horizons stays unchanged and their positions receive only finite
corrections, the geometry, thermodynamics and formation of RN black holes
change seriously in particular for small ones. The entropy receives a
logarithmic correction. The line $Q=M$, separating naked singularities from
physical solutions is corrected, putting a lower limit on the mass and an upper
limit on the temperature of the black hole as a function of its charge. The
modifications are highly significant in the cases of near-extremal and small
black holes. We also show that for black holes with small mass can stay in
thermal equilibrium without any constraint on the volume of the container. This
result is in contrast to the large black holes that need a finite volume
container for thermal equilibrium. The minimum of the mass lower limits occurs
at zero charge, resulting in the extremal Schwarzschild black hole with a
specific mass of the order of $M_{p}$ and zero temperature. This state which
has only gravitational interaction will be the final stage of Hawking
radiation. Stability and lack of any interaction but gravitational, makes the
extremal Schwarzschild black hole a serious candidate for dark matter particle.
