Linearity optimization of atomic layer deposited ZrO_2 metal-insulator-metal capacitors by inserting interfacial Zr-doped chromia layers

摘要

In order to improve the electrical behaviour of metal-insulator-metal capacitors with ZrO_2 insulator grown by Atomic Layer Deposition, the influence of the insertion of interfacial Cr layers between Pt electrodes and the zirconia is investigated. An improvement of the α-voltage coefficient of capacitance as low as 567 ppm/V~2 is achieved for a single layer of Cr while maintaining a high capacitance density of 10.7 fF/μn~2 and a leakage current of less than 1.2 x 10~(-8)A/cm~2 at +1 V. The role of the interface is discussed by means of X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy showing the formation of Zr stabilized chromia oxide phase with a dielectric constant of 16.