A GRAPHICAL ELLIPSOMETRIC DATA REDUCTION ALGORITHM AND ITS APPLICATION IN THIN SIO2 FILM MEASUREMENT

Graphical ellipsometric data reduction algorithm, based on independent analysis of both the real and imaginary parts of the ellipsometry equation, is described and compared with other established algorithms in terms of both one- and two-layer nonabsorbing film models. Issues relating to thin SiO2 film measurement are discussed, using the graphical ellipsometric data reduction algorithm. Some intrinsic properties of the ellipsometry equation, which are of practical importance, are presented for the first time using the proposed algorithm, previously impossible with other ellipsometric data reduction algorithms. In particular, it is found the imaginary part of the ellipsometry equation has considerable resistance to common measurement errors encountered in thin SiO2 film measurement. All phenomena presented are based on a nonabsorbing one-layer SiO2 film model. Similar phenomena may also be observed in the case of a nonabsorbing, two-layer SiO2 model. The special case of an absorbing one-layer film model is also examined.