Stress development during thin film growth and its modification under ion irradiation

The paper presents the results of average stress measurements during deposition of thin copper and silver films and during ion irradiation of molybdenum thin films. Deposition chamber and ion implanter were equipped with the same optical systems for radius of curvature measurement (scanning technique). The average stress in the 92 nm total thick Cu/Ag/Cu/Ag system on 100 mum Si substrate during deposition at room temperature is reported. Deposition process was intermitted after each material. The non-continuous changes of the stress are interpreted as differences in temperature of the sample in different deposition stages. High residual stresses up to 3 GPa were evidenced in the Mo thin films deposited on Si substrate with RF sputtering. During ion implantation with Kr and Ar ions stress relaxation effect of Mo thin films was observed. Kr ion irradiation of the silicon substrate without a film was additionally performed. After the irradiation (total dose 1.4 x 10(15) ions/cm(2)), the implanted region of the silicon wafer was under compressive stress. A stress maximum was evidenced for a dose of I X 10(14) ions/cm(2). 2003 Elsevier Science Ltd. All rights reserved.