| Popis: |
In this paper, we present a detailed study of the effect of the interface in multi-stacked polysilicon film. In order to investigate microstructural stress characteristics, we fabricated laminated type 2 micrometers thickness of polysilicon test structures such as bridges and rotating beam pairs. Also the characteristics of the various doping and deposition method, and annealing treatment are examined through the SIMS analysis. The relative interface location was carried by changing the film thickness for each deposition step and this was compared with 2 micrometers thick film deposited at a time. We found that the interface is one of the key factors deciding the stress gradient in multi- stacked polysilicon film but the residual stress is independent of the interface location. Finally, on the basis of the result, fabricated a test pattern of the multi- stacked polysilicon microstructure with thickness of 6.5 micrometers using the symmetrical stacking and doping method has a low stress of 7.6 MPa and a low stress gradient of -0.15 MPa/micrometers . |
