Estimation of boron diffusion induced residual stress in silicon by wafer curvature technique

• Deep boron diffusion in silicon (100), (110) and (111) wafers.
• Modeling of diffusion induced residual stress by wafer curvature technique.
• Estimation of the residual stress from wafer curvature data.

Heavily boron doped silicon layer is being used to control the thickness of the bulk micro-machined micro-electro-mechanical system (MEMS) based structures. Residual stress generated due to the doping may affect the functioning and reliability of the MEMS devices. This paper presents a model for estimation of the diffusion induced residual stress by wafer curvature technique. Boron diffusion induced residual stresses in the silicon (100), (110) and (111) wafers are found to be 475 MPa, 963 MPa and 957 MPa respectively.