GeminiSEM 500

Description

At DTU Nanolab’s cleanroom, we have a need to upgrade our SEM capability with a high-end instrument. The instrument will be a central tool for our nanostructure qualification which is described in the detailed explanation/justification below. Lot 1: At DTU Nanolab, we have a current need to upgrade our SEM capability with a high-end instrument. A Schottky field emission (thermionic) source offering high emission at low energy spread will be necessary for providing a state of the art resolution of 0.5 nm or better at 15 kV (no immersion applied) and 1.0 nm or better at 0.5 kV (no beam deceleration or sample bias applied) using an in-lens detector. The instrument will need a beam-booster as it guarantees optimum beam conditions particularly at low acceleration voltages — a critically important mode of operation for a vast number of applications in our lab. Likewise, to ensure a high sample throughput and ideal imaging conditions free of hydrocarbon contamination, the chamber must be equipped with a fully integrated airlock system and a chamber-mounted plasma cleaner. It is our intention that the SEM cover the most challenging applications in our lab. Consequently, it should be highly versatile and host a broad selection of advanced electron detectors in addition to the standard Everhart-Thornley secondary electron (SE) detector for high vacuum conditions. Firstly, to qualify subtle material contrast differences in III-V materials, we need in-column energy selective detection of backscatter electrons (BSE's). Working in parallel, a separate annular in-lens detector will detect the in-column secondary electrons. Secondly, to provide an alternative path for differentiating the same minuscule material variations, the chamber-mounted and pneumatically retractable BSE detector should have segmented annular diode detectors each of which should have individual amplification to allow angular selection of BSE's. Thirdly, we are facing an increasing number of applications relying on the precise manufacturing of ultra-thin membranes. In this regard, we could dramatically improve our characterisation capability with an annular STEM detector for high-resolution transmission measurements. Finally, we have a strong need to upgrade our ability to characterize nano-structures defined by electron beam lithography. The world-class performance of our Jeol JBX-9500FSZ E-Beam writer is simply not matched by our current SEM characterisation capability. The situation is especially chal-lenging for line edge roughness measurements of sub 20 nanometre E-beam resist structures de-posited onto non-conducting substrates. Here, the need for charge compensation with its detrimental effects on the electron beam quality conflicts with the demand for extremely high image resolution. Clearly, we do not want to apply any kind of sample coating in order to reduce sample charging and thus suppress the high pressure requirement. The acquisition concerns a fully refurbished Carl Zeiss GeminiSEM 500 consisting of: • Basic Unit GeminiSEM 500 with airlock; • 20nA High resolution configuration for CC/VP systems; • NanoVP variable pressure imaging option; • Plasma Cleaner with integrated software control in SmartSEM; • 5-axes stepper stage with Tandem decel sample bias; • Navigation with KLA and Lasertec files for defect detection. The system is fitted with the following electron detectors: • Everhart-Thornley SE detector; • Annular Inlens SE detector; • Inlens energy selective backscatter (EsB) detector; • Pneumatically retractable 4 quadrant solid state BSE detector; • Dedicated BSE detector for NanoVP; • Annular STEM detector.