Contact & Support

Semiconductor Structures with Large Differences in Hardness - Sample Preparation for SEM

Application Note for Leica EM RES102 - Industrial Manufacturing

In most cases, multi-layer structures or material combinations with large differences in hardness cannot be processed with conventional polishing techniques, or can only be very poorly processed. Due to the large differences in hardness, blurring or edge-rounding occurs, which distorts the original structure. Above all, this also affects the preparation result of angled and cross-sectional polishing.

In the application example shown, we are dealing with a solder ball structure. The goal was to determine the solder structure. The use of conventional grinding and polishing techniques was not possible due to the large differences in hardness between the solder ball and other materials in the sample.

Authors

Topics & Tags

Table of Content

Preparation Conditions
Mechanical pre-preparation with the Leica EM TXP:
Diamond foil 9 µm at 2000 rpm to approach the area of interest.
Process has been stopped when the solder ball appeared.
This is roughly 50 µm before the center of the solder ball.

Ion milling

Sample holder:90°-slope cutting holder
Acceleration voltage:7 kV
Milling time:4 h
Sample movement:Oscillation (60°)

 

Results
With the help of the slope-cut procedure, cross sections could be produced without destroying the original layer structure. The structure of the solder ball is easily recognizable. There is no damage caused by the preparation process.