The straightforward Erica is a Norse feminization that was long associated with the complex, mega-popular character Erica Kane, played by Susan Lucci for decades on the soap opera All My Children. Used in Scandinavia since the early eighteenth century, where it was usually spelled Erika, it was in the Top 50 girls' list in the USA in the 1970s and eighties. In 2014, Erica ranked Number 657, declining more than 100 positions since 2013.
It is worth noting that Erica is also a flower name, in which sense it is its own name, rather than a feminisation.
The most prominent bearer of the name in recent times is novelist Erica Jong, author of the influential Fear of Flying.