The application discloses a TEM
sample preparation method, comprising the following steps: step one, providing a
chip sample with a
metal protective layer formed on a first surface; step two, fixing the
chip sample on a sample stage of a FIB
system; step three, performing first FIB
cutting on the
metal protective layer along a first direction to form a groove; the first direction is a width direction of the TEM sample, a second direction is perpendicular to the first direction; the groove extends along the first direction; on a section along the second direction, an inner side surface of the groove is arc-shaped, so that the thickness of the
metal protective layer in the groove area gradually changes; step four, performing second FIB
cutting along a third direction to thin the
chip sample and form a TEM sample; the third direction points from the metal protective layer to the chip sample; the thickness of the metal protective layer is used to adjust a
cutting speed, so that the width of the TEM sample gradually changes and an optimal observation area is obtained. The application can realize accurate control on the thickness of the TEM sample, thereby improving the
TEM analysis quality.