Application Note RSMD010
Contamination elements
MRAM elements: Lower limits of detection (LLD) [atoms/cm²]
| Mg | Al | Fe | Co | Mn | Ta | Ru | Pt | |
| TXRF-V310 | 6e8 | 9e8 | 1e7 | 1e7 | 1e7 | 1e8 | ? | ? |
| TXRF 310Fab | 6e10 | 9e10 | 1e9 | 1e9 | 1.4e9 | 1.3e10 | 1e10 | 8e9 |
After etching of MTJ layer and cap layer, those elements cause contamination on the backside of the silicon substrate.
BAC-TXRF
Backside contamination must be measured to avoid cross-contamination of the product line.
BAC-TXRF is a suitable technique for the MRAM application.
Diffusion length of Cu at various temperatures for 1 hr.
About BAC-TXRF
Frontside and backside handling with flipping robot arm
Contamination from the tunnel layer material (MgO)
The W-M excitation source is suitable to measure light-element contamination, such as Na, Mg, and Al.
Contamination from the free and pinned layer material (CoFeB)
Contamination from the Pt and Ru layers
Other detected elements
Results after cleaning
