electrospray ion beam deposition (ES-IBD) source (short version)

Our experiment consists of two parts: (1) the deposition source and (2) the tunneling microscope with the sample preparation.

Here I briefly introduce the deposition source, that we use to deposit nonvolatile molecules onto surfaces in ultrahigh vacuum (UHV). It is a differentially pumped apparatus consisting of six differential pumping stages starting at 0.1 mbar and reaching to 1e-11 mbar in the UHV deposition chamber.

Scheme of the ES-IBD setup

Fig. 1: Scheme of the ES-IBD setup

everything starts with the spray source (1) at ambient pressure. Sometimes we use curtain gas (2) to dry the droplets and help the electrospray desolvation. The ions enter the vacuum trough a capillay (3). In the first and second vacuum chamber they are bundeled by RF ion optics, one ion funnel (4) and one quadrupole (5). The next quadrupole (6) in in high vacuum, so no more collimation is possible, but we use it for mass selection. Further throughout the machine we use electrostatic lenses (7) to focus the beam through the apertures (8). We have a time-of-flight (TOF) mass spectrometer (9) to measure the chemical composition and then we can deposit: in high vacuum (10) for ex situ analysis, in a vacuum suitcase (11) to transfer the sample to another UHV instrument, and finally in UHV (12) to move the sample in our own STM.

More details in the future.