Influence of process parameters on the properties of TEOS–PECVD-grown SiO2 films

The influence of chamber pressure, substrate temperature and mass flow ratio on growth rate, refractive index and stress of plasma-enhanced chemical vapor deposition (PECVD) grown SiO2 films has been investigated. In this study, the silicon dioxide films were grown by homemade PECVD system by carrying three different sets of processes for variation in chamber pressure (70–240 Pa), substrate temperature in the range of 523–673 K and flow rate ratio (O2/TEOS) of 2–10. In these processes, liquid tetraethoxysilane (TEOS) has been used as a source of Si instead of SiH4 to avoid difficult handling of SiH4. The growth rate (by measuring thickness for specified time process), refractive index and stress of the deposited SiO2 films have been determined by ellipsometry technique. The present study reveals that, in order to grow good quality SiO2 films for their microelectronics applications, where stress is of prime importance, deposition processes of TEOS–PECVD should be carried out with substrate temperature and flow ratio variations. However, for optoelectronics applications, the growth processes carried out with varying chamber pressure are believed to be highly desirable, they allow precise control of the refractive index and a higher thickness.