关键词: 硅外延, 重掺磷衬底, 失配位错, 几何参数

Abstract: When growing high-resistivity epitaxial layers on heavily phosphorus-doped substrates, lattice mismatch and thermal expansion coefficient mismatch between the substrate and epitaxial layer cause misfit dislocations to form as the epitaxial layer exceeds a critical thickness during growth, thereby releasing stress. These misfit dislocations propagate outward, severely compromising the electrical properties and reliability of the epitaxial material while also degrading the geometric parameters of the epitaxial wafer. The misfit dislocation density in the epitaxial layer is quantified using the Surfscan SP1 surface inspection system. By adjusting the epitaxial growth rate, control over the misfit dislocation density is achieved. The impact of misfit dislocation density on epitaxial geometric parameters is analyzed. As the misfit dislocation density increases, warp increases from 65 μm to 90 μm, and bow increases from 31 μm to 42 μm.

Key words: silicon epitaxy, heavily phosphorus-doped substrate, misfit dislocation, geometric parameters