Low Temperature Silicon Dioxide Thin Films Deposited Using Tetramethylsilane for Stress Control and Coverage Applications

摘要

Low temperature silicon dioxide thin films have been prepared by plasma-enhanced chemical vapor deposition (PECVD) using tetramethylsilane (TMS) as the silicon precursor at 100―200℃ in the pressure range of 2―8 Torr. PECVD TMS oxide thin films deposited at these temperatures and pressures exhibit adjustable stress. The type of stress, including tensile stress, zero stress, and compressive stress, as well as the stress level can be tailored as desired by changing the deposition conditions and film thickness. In addition, the conformality of PECVD TMS oxide thin films varies significantly with the deposition conditions. It improves when the deposition pressure is raised and the substrate temperature is reduced. The mechanisms for the variations of stress and conformality with respect to deposition conditions are discussed in this study. The adjustable stress and conformality of the PECVD TMS oxide make it a promising material for many low temperature applications, such as inter-level dielectric, micro-electro-mechanical systems (MEMs), microfabrication, and large area electronics.