Pro

Image

Low KV Imaging at high resolution and low voltage for large area imaging at highest resolution

Introduction

ProImage stands for effortless imaging with highest resolution for ultra-demanding industrial investigations, materials, and life science projects. ProImage is based on Zeiss Gemini electron optical column technology featuring a combination of surface-sensitive high detection efficiency with excellent analytical performance to achieve ~nanometer resolution even at 1 kV. Additionally, two further bricks of ProImage technology—a laser interferometer stage and write-field calibration routines—enable thousands of images to be stitched together with the highest precision in order to visualize all kinds of large-sample surface areas as a mosaic display.

For the highest demands in low kV, nm-scale imaging, and sample flexibility

Key features

Benefits for applications

Highest-efficiency surface-sensitive imaging with material contrast even at low kV

Distortion-free, high-resolution, high-efficiency imaging

Gemini technology is based on virtually magnetic-field-free electron optics (objective lens) and beam booster, which yields good imaging efficiency specifically at low kV

Detection of surface-sample information only

Imaging information comes exclusively from the uppermost sample surface layers when operated at low kV. The Inlens SE detector generates images with the real SE1 electrons emitted from the surface; the bulk sample makes only a negligible contribution to image contrast formation.

Simultaneous data acquisition for surface and compositional information

The principle of separate secondary and backscatter electron imaging by two different Inlens detectors allows f both surface and bulk information to be collected in parallel at high throughput.

Excellent material contrast even at lower kV

The detection concept of the Inlens energy-selective BSE detector (EsB detector) enables good material contrast to be achieved specifically for lower kV experiments.

Stable, crisp contrast for long-term image acquisition

Acquiring (tens of) thousands of images can be a matter of days and nights. Good long-term stability of SEM parameters such as beam current and electron energy yield constant crisp contrast over the entire data acquisition period.

How it works

Electron optics design – the key to low kV performance

The Gemini objective lens design combines electrostatic and magnetic fields to maximize optical performance, while reducing field influences at the sample to a minimum. This enables excellent imaging, even on challenging samples such as magnetic materials. Inlens—the Gemini detection concept—ensures efficient signal detection by detecting secondary (SE) and backscattered (BSE) electrons in parallel. Inlens detectors are arranged on the optical axis, which reduces the need for realignment and thus minimizes time-to-image. Gemini beam booster technology guarantees small probe sizes and high signal-to-noise ratios, right down to very low accelerating voltages. It also minimizes system sensitivity to external stray fields by keeping the beam at high voltage throughout the column until its final deceleration.

By combining Inlens EsB- (Energy selective Backscattered), SE- (Secondary Electron), or aBSD- (annular Backscattered Detector) detectors, the system delivers information about the material, topography, or crystallinity of your sample. The primary electron beam generates secondary electrons (SEs) and backscattered electrons (BSEs). The SEs escape directly from the topmost nanometers of the sample with energy of less than 50 eV and represent the topography of the surface. As a result of the unique beam booster concept, these SEs are accelerated back into the column and the Gemini objective lens directs them to the annular Inlens SE detector.

BSEs are generated below the surface and provide highly specific information about the material composition of your sample. BSEs appear conically at a ~15-degree angle to the primary electron beam. They are attracted by the beam booster of the Gemini column and directed into the column. Because of the different energies of SEs and BSEs, they follow different trajectories within the beam booster. Most of the BSEs can pass the Inlens SE detector and are collected by the EsB detector. Additionally, the Inlens EsB detector enables an energy selection of the BSEs. If the takeoff angle is greater than ~15 degrees, the BSEs cannot make their way into the column, but can be detected by an AsB (Angular selective Backscatter) detector that is integrated into the objective lens, precisely fitted into a pole piece cap below the objective lens.

Graphic of a FE-Gun which is being used for ProImage technology by RAITH

Large area SEM image of a chip acquired with the help of ProImage technology

Mosaic image viewer

Use cases

ProImage technology can be used for (large-area) image acquisition tasks as required for e.g. relocation, imaging, and metrology of nanostructures fabricated by EBL, chip design verification, process control methodologies such as defect review and SEM inspection, CAD design engineering, imaging of large biological samples, and more.
Relevant sample information, whether of topographical or compositional nature, can be accquired over very large surface areas in a fully automated fashion. ProImage technology does all this with highest efficiency and maximum sample information, due to smart detectors and excellent low kV capabilities. Calibrated write fields can be stitched together to provide a mosaic image view of the entire sample from nm to cm scale.