High Sensitivity Scanning Probe System

Tuck Wah Ng (Inventor), Hui Tong Chua (Inventor), Osami Sasaki (Inventor)

Research output: Patentpeer-review


The present invention provides a hybrid optical and interferometric atomic force microscope system ( 40 ) for monitoring a cantilever probe ( 46 ). A light source ( 42 ) provides a light beam which is focussed on the back of the cantilever probe ( 46 ). The light reflected off the probe is split into two beams of different path lengths and are recombined to form an interference beam ( 58 ). This interference beam ( 58 ) is passed through a grating ( 102 ) having substantially the same period and orientation as the interference beam pattern. The light transmitted through the grating ( 102 ) illuminates a photodetector ( 122 ) to give a signal according to the intensity of the light falling on the photodetector. The photodetector output signal is sent to a positioning system ( 126 ), which in turn gives a signal to the piezoelectric system ( 54 ) so that the probe ( 46 ) follows the sample ( 50 ) surface. This signal is integrated as a function of position across the scanned area to represent a characteristic of the sample surface. An array of light beams, cantilever probes and photodetectors are also provided, and a plurality of characteristics may be obtained by performing a single scan on the sample surface. Actuators are also provided on the grating ( 102 ) and mirrors in the interferometer ( 60, 60 a , 60 b) to modulate the fringes of the interference beam ( 58 ) and cancel out noise in the microscope system ( 40 ).
Original languageEnglish
Patent numberUS 7230719 B2
Priority date2/12/03
Publication statusPublished - 12 Jun 2007
Externally publishedYes


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