|
| Technique | Observation | Mode |
|
| Optical microscopy | Stains, debris, fracture, and abnormal displacements [52]. | Nondestructive |
|
| Scanning laser microscopy | Extended depth-of-focus, abnormal vertical displacements [53]. | Nondestructive |
|
| Scanning Electron Microscopy (SEM) | Imaging defects at high magnification [54]. | Nondestructive |
|
Focused Ion Beam (FIB)
| To image structures, to cross-section elements of concern, and to cut elements free for subsequent examination [55]. | Destructive |
|
| Laser-Doppler Vibrometer | To measure out of plane motion [56]. | Nondestructive |
|
| Computed tomography (CT) | Visualizing 3D internal structures [57]. | Nondestructive |
|
| Interferometry | To detect the tilt or deflection of a sample [58]. | Nondestructive |
|
| Transmission electron microscopy (TEM) | To observe thin films deposited on MEMS [59]. | Nondestructive |
|
| Energy dispersive X-ray spectroscopy (EDS) | To analyze chemical composition of surface coating [60]. | Nondestructive |
|
| Wavelength dispersive X-ray spectroscopy (WDS) | To analyze chemical composition of surface coating [61]. | Nondestructive |
|
| Atomic force microscopy (AFM) | Topographic images and surface traces [62]. | Nondestructive |
|
| Auger electron spectroscopy (AES) | To perform qualitative and semiquantitative compositional analysis of surface of materials [63]. | Nondestructive |
|
| Secondary ion mass spectroscopy (SIMS) | Compositional analysis of the sample with sensitivities in ppm to ppb, removing material from the device [64]. | Destructive |
|
| Thermally induced voltage alteration (TIVA) | To identify electrical failure mode [65]. | Nondestructive |
|
| Resistive contrast imaging (RCI) | To identify electrical failure mode [66]. | Nondestructive |
|
| Infrared Microscopy | To construct thermal images based on the infrared radiance emitted from the structures [67]. | Nondestructive |
|
| Light emission | To observe MEMS optical devices [68]. | Nondestructive |
|
| Acoustic emission | To observe running device within package [69]. | Nondestructive |
|
| Laser cutting | To impart elements of device such as gears and links [70]. | Destructive |
|
| Lift-off technique | Accumulation of wear debris at the surfaces [71]. | Nondestructive |
|
