In-lens field emission scanning electron microscopy (In-Lens FESEM) provides topographical information at magnifications of 250x to 1,000,000x, with virtually unlimited depth of field.  In-lens FESEM produces clearer, less electrostatically distorted images than SEM, with spatial resolution down to 0.6 nanometers – three times better than regular FESEM and 10 times better than conventional SEM.

Other attributes of in-lens FESEM include:

• High-quality, low-voltage images with negligible electrical charging of samples (accelerating voltages ranging from 0.5 to 30 kilovolts).
• Essentially no need for placing conducting coatings on insulating materials.

Applications: Applications for in-lens FESEM include:

• Semiconductor cross-sections
• Gate widths
• Gate oxides
• Film thickness
• Construction analysis
• Advanced coatings
• Uniformity of thickness
• Uniformity of structure

Principle of Operation
A field emission cathode in the electron gun of a scanning electron microscope provides narrower probing beams at low as well as high electron energy. In conjunction with an in-lens system, this virtually eliminates aberration, resulting in optimal spatial resolution.