Observer™

Scanning Probe Microscope For Scanning Electron Microscopes

Observer™ scanning probe microscope (SPM) is designed to complement the imaging capability of a scanning electron microscope (SEM). It provides high Z contrast on flat samples and quantitative 3-dimensional data at atomic levels that can be obtained only by an SPM. These features are excellent counterparts to the field-of-view and high scan rate capabilities of a scanning electron microscope.

Near-Contact Image of Alumina Silica Glass

For many years, SEMs have been used to image a wide range of materials at the sub-micron level and over areas as large as several millimeters. But the resolution of a SEM is limited to a fraction of a micron for most samples. This is adequate for many, but not all, of today's experiments and process investigations. An atomic-resolution SPM, built to operate within the SEM, permits combining the best features of both instruments into a single system.

Clay Crystal on Paper

The SEM's field-of-view of several millimeters provides greater operating convenience than the relatively small field-of-view of the SPM. This advantage, coupled with the SEM's high scan rate and long depth of field, simplifies the survey process required to locate specific surface features for analysis by the SPM. Also, the SEM's excellent depth-of-field characteristic eliminates the need for an optical microscope to monitor the SPM probe approach to the sample.

Contact Image Single Fiber Surface

Observer™ SPM was developed to operate inside the SEM vacuum chamber. It incorporates integral vibration isolation, an essential feature to perform high-resolution data acquisition. It includes a computer-controlled X-Y sample positioner with 6 x 6mm travel range so various areas of the sample can be scanned. This stage is mounted at a 45° incident angle to the SEM electron beam. An 11 x 11 mm translation stage holds the entire SPM assembly in place. Computer control of this stage permits positioning the SPM probe relative to the SEM electron beam from outside the vacuum chamber. This combined stage arrangement provides direct visual access to the probe and sample, and permits simultaneous imaging with the SEM and SPM.

GaAs Atomic Steps

Because Observer™ SPM makes direct vertical (Z) measurements, there is no need to cross-section the sample to obtain height data, as is required in SEM imaging. With a SEM, Observer™ can easily bring the SPM probe to a sub-micron scale feature that is not resolvable be an optical microscope.

Niobium Thin Film by Observer™

System Configuration

Observer™ can be configured to operate in both AFM and STM modes. The AFM sensor head features a light lever design. This permits operating in the lateral force (LFM), force modulation, magnetic force and electrical force (MFM/EFM), and non-contact AFM modes. For STM imaging, the AFM cantilever holder is replaced with an STM probe holder. The STM pickup amplifier is mounted directly on the SPM stage.

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Hitachi S-4100 FESEM with OBSERVER™

Observer™ comes complete with a load-lock chamber and isolation valve. These are used to move the SPM stage in and out of the SEM vacuum chamber without affecting vacuum integrity. It is a convenient way to change samples and SPM probes. System electronics and a Pentium 133 MHz control and data processing computer workstation are also provided.

Observer™ meets all of the requirements of an SPM for SEM use. It is a perfect companion instrument that substantially improves image resolution capability at a very affordable price.

Observer™ was designed, developed, tested and built to be compatible with most large chamber SEM systems. For specifics on system configurations, please contact the factory.

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