Patent ID: 6313648
Filing Date: 2001-11-06
Classification: H01L

Abstract:
A method for quantitating impurity concentration comprising:introducing one kind of impurity into a plurality of semiconductor substrates;introducing another kind of impurity into said semiconductor substrates except for one semiconductor substrate;repeating said introducing said another kind of impurity into said semiconductor substrates except for n semiconductor substrates, n being a number of preceding impurity introducing steps, until introducing a last kind of impurity into a remaining one semiconductor substrate;measuring pulse CV characteristics of one semiconductor substrate selected from said semiconductor substrates every time an impurity is introduced;calculating distribution of carrier concentration in a direction of a depth of said semiconductor substrate from said pulse CV characteristics;making SIMS measurement of said semiconductor substrate at a same position as in said measuring said pulse CV characteristics to calculate SIMS profile of said impurity;calibrating said SIMS profile by a method of least squares so that a dose amount from said SIMS profile coincides with a dose amount from said distribution of carrier concentration in a range of depth where accuracy of said carrier concentration is secured, when said introduction of an impurity is the first introduction;making simulation of each step up to a next introduction of an impurity to estimate distribution of carrier concentration prior to said next introduction of an impurity;comparing said distribution of carrier concentration estimated after a last introduction of an impurity is completed with an actual value of said distribution of carrier concentration after an instant introduction of an impurity is completed, when said introduction of an impurity is not the first introduction;calculating a dose amount of said impurity introduced based on a result of said comparing;calibrating said SIMS profile by a method of least squares so that its dose amount coincides with a calculated dose amount; andmaking simulation of each step up to a next introduction of an impurity to estimate distribution of carrier concentration prior to said next introduction of an impurity.