Film growth and mechanism of LICVD of chromium films from Cr(CO)6 at 248 nm

The probe-beam transmission method was used to study the chemical vapor deposition of chromium films due to photodecomposition of Cr(CO)₆ by pulsed excimer laser radiation at 248 nm in a reversed-substrate configuration, where the film forms on the quartz entrance window of the deposition cell. The dependence of the deposition rate and the film formation time on the laser pulse intensity and repetition rate as well as on the Ar buffer gas pressure was determined for different stages of the deposition process. The experiments were performed at room temperature, on a deposition area of about 0.15 cm², with laser fluences up to 100mJ cm^–2, pulse repetition rates between 5 and 80 pps and buffer gas pressures between 10 and 700 mbar. The results are discussed within the framework of a simple model for LICVD. They reveal the dominant role of gas-phase photodissociation and diffusion in chromium film deposition under the conditions employed. Some results concerning the morphology and the depth distribution of Cr, O, and C in films deposited in the reversed-substrate configuration are also presented.