Silicon Material Stress The Introduction Of Technology Research

The band structures will be transformed when there are strain or stress in the devices. Strained-Si technology is the one that can enhance the electron and hole mobility and improve the performance of the devices by inducing strain into them. Strained-Si technology contains two major parts:Global Strain and Local Strain. Global Strain technology includes SiGe virtual substrates, SiGe-on-Insulator and Strained-Si-on-Insulator. Local Strain technology includes Shallow Trench Isolation induced stress, Silicon Nitride Dual Stress Layers, Source/Drain Embedded SiGe or SiC and Stress Memorization Technique.This work analyzed the influence of the stress to the Si band structure, and the mechanism of mobility enhancement induced by such strain induced band transform. Then, several most used Global and Local Strain techniques are introduced.Experiments focus on Silicon Nitride cap layer induced stress and STI induced stress were carried out in this work. Firstly, in order to study the impact of deposition technique on SiN film stress and the relationship of SiN film stress and film thickness, SiN etch-stop layers with different thickness were fabricated by High-Frequency PECVD and LPCVD respectively.Then, SiN cap layers were deposted on pattened Si substrate in order to simulated the SiN cap layers above gate structure. The strain of the SiN layers samples were characterized by High-Definition X-Ray Diffraction.Secondly, STI structures with different layout parameters were experimentally fabricated, and the relationship of the strain and these layout parameters was studied. Samples were measured by Scanning Electron Microscope and HDXRD.