Gerd binnig and heinrich rohrer ibm zurich created the ideas stm

• General components of SPM;
• Tip --- the probe;
• Cantilever --- the indicator of the tip;
• Tip-sample interaction --- the feedback system;• Scanner --- piezoelectric movement at x,y,z;
• Measurement artifacts: vibration must be isolated.

Basic components of SPM: tip, cantilever, sensor for tip

Tip-Sample	SPM
Electrical Current	Tip-Sample

Interaction

can be mounted with the tip or the sample stage.		Five basic components:
		1.
		2.
		3.
		4.
		5.	Feedback loop (current).
•	Tunneling current from tip to sample or vice-versa depending on bias;	5.

Tip-Sample	SPM
Electrical Current	Tip-Sample

Interaction

SPM Family

Tip-Sample	SPM	AFM + Optical Microscopy
Electrical Current		AFM + Optical Microscopy

Scanning Confocal Microscopy from NSOM

Principle of Scanning Confocal Microscope

Co-focus


STM	NSOM AFM

• AFM tip is not necessary to be conducting.

• NSOM tip should be sharp enough to get good topography resolution.• The aperture of NSOM tip should be small for better optical resolution.• The outer surface of NSOM tip should be flat to avoid artificial effects from the scanning.

Shared with Ernst Ruska (on electronic microscopy)

Brief History of Scanning Probe Microscopy (SPM): AFM

There are two ways to drive the cantilever into oscillation.

n One way is accomplished by indirect vibration, in which the cantilever is excited by high frequency acoustic vibration from a piezoelectric transducer attached to the cantilever holder. This is called the Acoustic AC mode (AAC).

Resonance frequency of the
cantilever,

requires smaller mass to keep

F: the force; k: the spring constant	the high frequency. Why high f needed? (see next slide)