A metal-insulator-metal (MIM) capacitor includes a lower electrode, a dielectric layer, and an upper electrode. The lower electrode includes a first conductive layer, a chemical barrier layer on the first conductive layer, and a second conductive layer on the chemical barrier layer. The chemical barrier layer is between the first and second conductive layers and is a different material than the first and second conductive layers. The dielectric layer is on the lower electrode. The upper electrode is on the dielectric layer opposite to the lower electrode. The first and second conductive layers can have the same thickness. The chemical barrier layer can be thinner than each of the first and second conductive layers. Related methods are discussed.