New applications and challenges of dielectric films at 14nm FinFET technology and beyond

With technology scaling towards 14nm and beyond, it becomes extremely difficult for conventional planar Field Effect Transistors (FETs) to suppress a short channel effect (SCE). FinFET technology is a promising candidate for further generation to overcome those issues. The gate of a FinFET wraps around the channel without heavy doping offers an improved electrostatic control to yield a tighter distribution and optimized CMOS circuit performance. Although a large part of well-established conventional CMOS processes can be used for FinFET fabrication, there are still a lot of new processes, applications and challenges that need to address, in order to meet stringent requirements of FinFET. In this paper, some new processes and applications of dielectric films at 14nm FinFET technology and beyond will be discussed, such as ALD BSG and PSG films for solid-state doping (SSD), flowable CVD (FCVD) film applied for STI and ILD gapfill, nitride films for self-aligned contact (SAC), etc. Furthermore, the preliminary evaluation result of those processes will also be discussed. Then, some challenges of those applications will be illustrated in details. Their improvement approaches of those dielectric films for different applications will be explored to address those challenges in order to meet fabrication requirements.