Stellar mass versus star formation rate for the median values from the MAGPHYS probability distributions using the HDF-S and 3D-HST photometry. C III] emitters are color-coded according to their rest-frame EW. 6 out of 318 galaxies (1.9%) with 10⁸M_⊙ ≤ M_⋆ ≤ 10⁹M_⊙ and 1 out of 140 galaxies (0.7%) with 10⁹M_⊙ ≤ M_⋆ ≤ 10¹⁰M_⊙ in this redshift range have a combined C III] EW in excess of 5 Å.