Phase-shift resolving confocal microscopy with high axial resolution, wide range and reflectance disturbance resistibility.
A phase-shift resolving equation is established by combining the phase-shift interference and tomographic ability of a point detector. The theoretical measuring range of confocal microscopy is extended from the single-side linear range of an axial main lobe into the almost complete envelope of an axial main lobe, and the axial tomographic measurement is thus made resistible to the reflectance disturbance and power drift of a laser source. Experimental results indicate that the axial resolution is 0.5 nm and lateral precision for grating width measurement is 0.14 microm when NA=0.85 and lambda=632.8 nm. It can therefore be concluded that the proposed phase-shift resolving confocal microscopy can be used to achieve the high axial resolution, wide range and reflectance disturbance inhibition necessary for the measurement of microstructures made of different or hybrid material with high steps.
Liu
Jian
J
Ultra-Precision Optoelectronic Instrument Engineering Institute, Harbin Institute of Technology, No. 92, West Da-Zhi Street, Harbin 150001, Heilongjiang, China. liujian@hit.edu.cn
Tan
Jiubin
J
Zhao
Chenguang
C
Ge
Zhenggui
Z
Zhang
Daqing
D
D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods*; D018613:Microscopy, Confocal / Q000295:instrumentation* / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity