A perfume's scent cannot be protected by copyright. The maker can protect their brand trademarks, including things like packaging design, but if someone wants to duplicate the scent of their perfumes they can. Discount copycats of popular fragrances have always been available, however they have become much more prevalent since mass spectromety became widely available. Mass spectrometry (an analytical tool useful for measuring molecules present in a sample) gave perfume companies the ability to determine the componants in a scent and more easily duplicate it. Having the molecular analysis is only the first step. A trained perfumer then adjusts the formula based on understanding of organic chemistry and how perfumes perform.
Despite the use of technology to copy scents, few "clones" smell exactly like the perfume that inspired them. There are many reasons for this involving the perfume oils and diluents (alcohol) used, the concentration of oil to alcohol, and the process used for mixing and filling bottles. Because of this, a long-time user of a fragrance may be disappointed in reformulations of the original as well as its clones. But your ability to get close to the original scent is much better now than in the past, unless the scent included ingredients that have been delisted by IFRA (International Fragrance Association).