Physikalisch-Technische Bundesanstalt, Braunschweig und Berlin Working group 5.22 in cooperation with Surface Imaging Systems Nanostation 300: System for scanning probe metrology on larger objects Travel range: 300 mm x 550 mm; el.-magnetic linear direct drives Feedback control by encoder systems with < 10 nm resolution Position deviations after correction of reproducible errors: < 1 μm Objectives: - System for SPM metrology on 300 mm objects - Sample navigation: opt. microscopes and SPM - Automatic measurement incl. tip reconstruction - Use of air bearing x-y-stage and stable granite base - Flexibility with respect to different SPM modi - System upgradeable: 6 axis piezo scanning stage - System upgradeable: x-y-laser interferometry Nanostation 300 in PTB clean room centre Nanostation 300: SPM z-stability SPM tip reconstruction Microscopic structure localisation SPM contact mode measurements on etched Si (111) faces Use of non-contact SPM mode with EBD C-needle cantilever: Control paramater setting influences obtainable edge resolution Wrong setting of control parameters can damage sensitive tips Edge measurement requires application of dedicated scanning modi Different microscopes for structure localization: Coarse ( and fine microscope (0.7 High resolution microscope: 85 μm x 65 μm, 117 nm pixelsize Optical feature localisation to define batch AFM measurements 4 mm x 3 mm) mm x 0.5 mm) Stage characteristics Straightness deviation in y-direction: 1.2´´, hysteresis of 0.4´´ Straightness deviation in x-direction: 4´´, no hysteresis Stage positioning noise at target position currently 70 nm (2s) Further decrease possible by controlled reduction of air gap yaw vs. position along y-axis -0,8 -0,4 0 0,4 0,8 -0,3 -0,15 0 0,15 0,3 y position [m] yaw [arc sec] yaw vs. position along x-axis -4 -2 0 2 -0,15 -0,1 -0,05 0 0,05 0,1 0,15 x position [m] yaw [arcsec] Profile through atomic Si steps -0,2 -0,1 0 0,1 0,2 0 1000 2000 3000 4000 5000 x position [nm] height [nm] sensor noise in z -0.06 -0.04 -0.02 0 0.02 0.04 0.06 0 0.2 0.4 0.6 0.8 1 position [nm] height [nm] SPM measurement in contact: z- noise < 0.06 nm spot mode Edge detection and control parameters X Position [nm] -20 -10 0 10 20 Z [nm] 0 2 4 6 8 10 SPM tip reconstruction method by use of Au nanospheres: Reconstruct the 3D tip shape from several 1D profiles Scanning probe microscope Reference samples Optical microscope Mask object Object frame Air bearing x-y-stage 26,7° 24,1° 26,7° 24,1° 49,2° 46,9° 49,2° 46,9° 59,3° 61,7° artefact 59,3° 61,7° artefact Use of carbon-needle cantilever, variation of damping parameters: above: 60% remaining amplitude => low resolution middle: 53% => optimum resolution bottom: 50% => severe tip wear