Patent ID: 7992108
Filing Date: 2011-08-02
Classification: H01L

Abstract:
1. A method of predicting an impurity concentration distribution comprising: preparing a first evaluation substrate made of a single crystal, an angle between a direction perpendicular to a surface of the first evaluation substrate and a direction defined by first Miller indices of the first evaluation substrate being equal to or smaller than a first angle, and a second evaluation substrate made of a same single crystal as the first evaluation substrate, the direction defined by the first Miller indices of the second evaluation substrate being inclined by an angle larger than the first angle from a normal direction of a surface of the second evaluation substrate; implanting impurities into the first evaluation substrate by using an ion beam propagating in a first direction, an angle between the first direction and the direction defined by the first Miller indices of the first evaluation substrate being equal to or smaller than a second angle; implanting impurities into the second evaluation substrate by using an ion beam propagating in a second direction, an angle between the second direction and the direction defined by the first Miller indices of the second evaluation substrate being equal to or smaller than a third angle; measuring impurity concentration distributions in a depth direction of the first and second evaluation substrates into which the impurities are implanted; and predicting a first impurity concentration distribution on an extension line of the ion beam and a second impurity concentration distribution in a direction perpendicular to the extension line by using a computer, in accordance with an impurity concentration distribution of the first evaluation substrate and an impurity concentration distribution of the second evaluation substrate, respectively being measured, wherein: the first and second angles are selected so that there is substantially a negligible difference between a third impurity concentration distribution and a fourth impurity concentration distribution, the third impurity concentration distribution being an impurity distribution in a depth direction of a third evaluation substrate that is made of a same single crystal as the first evaluation substrate, into which an impurity is implanted in a vertical direction, a direction defined by the first Miller indices of the third evaluation substrate being perpendicular to a surface of the third evaluation substrate, the fourth impurity concentration distribution being an impurity distribution in a depth direction of the first evaluation substrate into which the impurities are implanted; and the third angle is selected so that there is substantially a negligible difference between a fifth impurity concentration distributions and a sixth impurity concentration distributions, the fifth impurity concentration distributions being impurity concentration distributions of the second evaluation substrate when an impurity is implanted using ion beam propagating in a direction parallel to the direction defined by the first Miller indices of the second evaluation substrate, the fifth impurity concentration distributions being a distribution on an extension line of the ion beam and a distribution in a direction perpendicular to the extension line, the sixth impurity concentration distributions being impurity concentration distributions of the second evaluation substrate when an impurity is implanted using ion beam propagating in a direction tilted by the third angle from the direction defined by the first Miller indices of the second evaluation substrate, the sixth impurity concentration distributions being a distribution on an extension line of the ion beam and a distribution in a direction perpendicular to the extension line.