SILICON WAFER FOR EVALUATING LATTICE STRAIN, PRODUCTION METHOD THEREOF, AND EVALUATION METHOD FOR LATTICE STRAIN

摘要

PROBLEM TO BE SOLVED: To evaluate lattice strain in a thin film sample while taking various crystallographic effect into account by provided a wedge-shaped part where the thickness in the direction vertical to the major surface of an Si water for evaluating lattice strain varies continuously in a rage lower than a specified value thereby controlling the thickness at a part to be measured sufficiently. ;SOLUTION: The Si wafer for evaluation is machined to have a wedge-shaped part using FIB. In the FIB method, sputtering is performed using a focused Ga ion beam while observing an SIM image. The thickness the direction vertical to the major surface of the Si wafer is varied continuously in the rage from 10nm to 10μm. When the thickness exceeds 10μm, an electron beam does not transmit through the wedge-shaped part and when the thickness is less than 10nm, strain is relaxed excessively to cause difficulties in the measurement. Lattice strain is analyzed by observing variation in the HOLZ pattern obtained by CBED method. According to the method, lattice strain due to variation of film thickness can be measured accurately.;COPYRIGHT: (C)1998,JPO