Measurement Principle |
Resolution |
Speed |
Advantages/Disadvantages |
Horizontal |
Vertical |
Laser Triangulation |
|
5um |
2um |
Fast |
Measurement by laser triangulation
Fast measurement speed
Long measurement range
Low measurement resolution
Specular surface hard to measure
Shaded area exists
|
Moire
(Phase Measuring Profilometry Moire) |
|
5um |
0.2um |
Fast |
Phase measurement by grid transfer
Fast measurement speed
Short measurement range
Limited measurement resolution
Specular surface hard to measure
Shaded area exists |
Confocal System
(Confocal Scanning Microscope)
|
|
0.2um |
10nm |
Slow |
Measurement by focus
Slow measurement speed
High measurement resolution
No shaded area
Translucent or specular mirror surface measurable |
White Light Interferometry
(White Spectrum Interferometer) |
|
0.2um |
10nm |
Slow |
Measurement by multiple wave length light interference
Slow measurement speed
High measurement resolution
No shaded area
Vulnerable to vibration |