A capacitor structure may include a lower electrode on a substrate, a dielectric layer on the substrate, and an upper electrode on the dielectric layer. The lower electrode may include a metal nitride having a chemical formula of M1Ny (M1 is a first metal, and y is a positive real number). The dielectric layer may include a metal oxide and nitrogen (N), the metal oxide having a chemical formula of M2Ox (M2 is a second metal, and x is a positive real number). A maximum value of a detection amount of nitrogen (N) in the dielectric layer may be greater than a maximum value of a detection amount of nitrogen (N) in the lower electrode.