Consistent with a move towards standards in MEMS, NIST has released two reference chips that fabs can use to cross-check their measurement techniques. There are several critical parameters unique to MEMS, and five of them are captured by this 5-in-1 reference. NIST has done its own measurements, and the idea is to replicate the results they got. The chips are available for sale ($1735), along with the results for comparison.
The five tests covered are:
- Young’s modulus
- Residual strain
- Strain gradient
- Step height
- In-plane length
There are two versions of the chip: one (RM 8096) uses a CMOS process with bulk micromachining, meaning that the structures are etched out of the bulk silicon. The other (RM 8097) uses surface micromachining to build the structures out of poly.
Each chip has additional test structures for things like tensile strength and line widths.