Ultra clean processing of silicon surfaces v vol:92 pages:161-164
The deposition of the nano-sized SiO2 particles on substrates (nitride and silicon) is investigated and the surface density of deposited particles is found to be proportional to the volume particle concentration in the contamination solution. The particle surface density is estimated based on this proportionality. When the particle density on the surface is very big, the light point defect (LPD) signal measured by light scattering instruments does not increase with the particle density deposited. On the contrary, the haze increases proportionally to the particle density deposited on the surface. A model is developed to describe the added haze as a function of the particle size, the particle density on the surface and the refractive index of the particle material. This allows to determine the particle density for sizes smaller than the LPD size limit of the current state-of-the-art light scattering instruments.