Numerical investigation of SiO<sub>2</sub> film deposition enhanced by capacitively coupled discharge plasma

Abstract

Higher requirements for the performances of thin films need to be fulfilled in the rapid development of integrated circuit technology, due to the more complicate structure and smaller size of chips. In plasma-enhanced chemical vapor deposition , high-density and high-performance thin films can be deposited at low temperature, compared with traditional chemical vapor deposition. In this work, a two-dimensional fluid/MC model coupled with the deposition module is used to describe the capacitively coupled SiH<sub>4</sub>/N<sub>2</sub>O/Ar discharges as well as the deposition processes, focusing on the influences of the radial position, gas ratio and gas pressure on the deposition of silicon oxide films. The results show that the edge effect which leads the plasma density to rise near the electrode edges gives rise to the non-uniform deposition rate along the radial direction. It is also found that the more N<sub>2</sub>O and less Ar content in the gas mixture, as well as an increased gas pressure will improve this uniformity. However, an excessive deposition rate will lead to a series of undesirable phenomena, such as “key hole structure”, vacancies and excessive impurities in films. These problems are also troublesome in the microelectronics manufacture processes. More detailed investigation into the deposition mechanism can be expected in the future .