Method of fabricating sample membranes for transmission electron microscopy analysis
View Patent ↗A method of fabricating sample lamella for transmission electron microscopy (TEM) analysis is provided. A waiting-examination sample having an analysis target on the top surface of that is offered, and at least a mark around the analysis target is defined. A covering layer is covered on the top surface of waiting-examination sample. A holder is attached on the covering layer. A backside polishing process is performed to remove a portion of the waiting-examination sample until the mark is visible under the optical microscopy from the bottom surface of waiting-examination sample. An in-situ lift-out step is performed to pick up a thin membrane containing the analysis target and serve as the sample for TEM analysis.
1. A method of fabricating sample lamella for transmission electron microscopy (TEM) analysis, comprising:
providing a waiting-examination sample having an analysis target on a top surface thereof and at least a mark disposed around the analysis target;
forming a covering layer on the top surface of the waiting-examination sample;
forming a holder on the covering layer;
performing a backside polishing process to remove a portion of the waiting-examination sample until the mark is visible from the bottom surface of the waiting-examination sample under an optical microscope; and
performing an in-situ lift-out step to obtain a thin membrane containing the analysis target and the mark to serve as a sample membrane for TEM analysis.
2. The method of fabricating sample lamella for TEM analysis as claimed in claim 1 , wherein the covering layer comprises an epoxy layer, an oxide layer, a nitride layer, a silicon material layer, or a metal layer.
3. The method of fabricating sample lamella for TEM analysis as claimed in claim 2 , wherein the method of forming the covering layer on the top surface of the waiting-examination sample comprises performing a chemical vapor deposition (CVD) process or a coating process.
4. The method of fabricating sample lamella for TEM analysis as claimed in claim 1 , wherein the holder comprises a glass holder.
5. The method of fabricating sample lamella for TEM analysis as claimed in claim 4 , wherein the method of forming the holder on the covering layer comprises using an adhesive.
6. The method of fabricating sample lamella for TEM analysis as claimed in claim 5 , wherein the adhesive comprises epoxy.
7. The method of fabricating sample lamella for TEM analysis as claimed in claim 1 , wherein the process of forming the mark comprises using a dual beam FIB or laser.
8. The method of fabricating sample lamella for TEM analysis as claimed in claim 1 , wherein the mark comprises a groove.
9. The method of fabricating sample lamella for TEM analysis as claimed in claim 1 , wherein the backside polishing process comprises a mechanical polishing process.
10. The method of fabricating sample lamella for TEM analysis as claimed in claim 1 , wherein the in-situ lift-out step is performed in the dual beam FIB system.
11. The method of fabricating sample lamella for TEM analysis as claimed in claim 10 , further comprising a step of forming a protection layer on the bottom surface of the waiting-examination sample before performing the in-situ lift-out step.
12. The method of fabricating sample lamella for TEM analysis as claimed in claim 11 , wherein the passivation layer comprises platinum (Pt) or tungsten (W).
13. The method of fabricating sample lamella for TEM analysis as claimed in claim 1 , further comprising a step of performing a sample membrane thinning step after performing the in-situ lift-out step.