Growth and properties of chemical-vapor-deposited Ti–P–O films grown under the CO2- and H2-existing conditions

Abstract Amorphous titanium phosphate (Ti–P–O) films are prepared by low-pressure chemical vapor deposition (CVD) using a mixture of titanium tetrachloride (TiCl 4 ) and trimethyl phosphite (P(O–CH 3 ) 3 ). Two systems are studied: one is the TiCl 4 /P(O–CH 3 ) 3 /CO 2 or the CO 2 system and the other is the TiCl 4 /P(O–CH 3 ) 3 /H 2 or the H 2 system. Growth and properties of the CVD Ti–P–O films are functions of deposition temperature and the CO 2 and H 2 inputs. The films have a higher growth rate and a lower Ti content at higher deposition temperature. A high CO 2 input favors for film growth, but a high H 2 flow rate is detrimental. Variations of growth rate and film composition with the CO 2 and H 2 inputs are rationalized by the proposed growth mechanisms. The changes in internal stress with deposition temperature and the CO 2 and H 2 inputs are mainly attributed to film thickness. The large difference in electrical resistivity of films of the two systems deposited at 500 °C can be related to the drift of defect protons on the oxygen sites under an electric field.