AN OPTICAL METHOD TO DETECT AMOUNT OF PARTICLES DEPOSITED OM A SUBSTRATE

It is examined whether the principle of reflectometry, developed to me asure the thickness of a thin layer oh a surface, is applicable to det ecting quantitatively the amount of fine particles deposited on a subs trate, It is found that the relative difference of parallel and perpen dicular components of the laser beam reflected on the surface is propo rtional to the particle coverage if experimental conditions are suitab ly selected, and that this principle is able to be used to detect with high sensitivity in-situ the amount of particles.