Atomic layer deposition (ALD) reactor, both plasma assisted and thermal. Open-load system for up to 200 mm wafers. Equipped with three precursors-inputs. Process monitoring available with in-situ spectroscopic ellipsometry, mass spectroscopy and optical emission spectroscopy during process. Has been used for instance for ALD of Al2O3, SiO2, ZnO and Al doped ZnO.