Implantation and irradiation beamline

Personnel Responsible: José Olivares Villegas


View of the beam scanning system

Fig1. Internal view of the beam scanning system, which consists of two horizontal parallel-plates and two vertical. Due to the polishing of the plates can be seen in the image multiple reflections of light.

View of Implantation beamline

View of the Implantation and irradiation beamline under commisioning

The main aim of this beamline is to perform homogeneous implantations or irradiations in large areas, up to several cm2.  Many technological and even fundamental research studies require that the irradiated area is larger than a few mm2. In the Standard beamline by means of overfocusing the beam, using slits and wasting a significant fraction of the available beam current, a reasonable homogeneous (static) beam is readily obtained, but it is of a size just a few mm2.

Several interesting cases have been found that need a much larger homogeneous irradiated area:

In some cases, the large size requirement is imposed by the further subsequent analytical techniques to be applied to the irradiated samples, like optical measurements (like ellipsometry, reflectance, absorbance), X-Ray analysis, mechanical tests, electrical measurements, etc

In other cases, wafers of a few inches diameter (>3”) are default size for many laboratories or companies (i.e. semiconductors field) and the irradiation has to reach such a “standard” size.  This is the case in studies of damaging of electronic components under Hydrogen irradiation at high energies to simulate damage of devices occurring in outer space or in nuclear environments.

Beamline characteristics:

Beamline is located after the second high energy switching magnet (HE2), at the -20º exit port. This location allows for a large number of ions and ionic species, with reduced beam current loss. The line has a length of 6 meters.

The first key element of the irradiation beamline is a HVEE electrostatic scanner consisting of four independently polarized plates (Fig. 1), designed specifically for CMAM to address the highest energy beam available at CMAM. It is capable of scanning Hydrogen of 10 MeV energy at a size of 4 inches (100x100 mm2). This is the most restrictive case. Hydrogen with lower energies or other ions with higher charge state can be eventually scanned at larger areas if needed.

The Beamline will have a large irradiation chamber designed with the following main characteristics:

  • Compatible with ultra high vacuum operation (all flanges are built as CF).
  • Compatible with advanced optical measurements, in particular, with Andor Optical spectrometer and Woollam Ellipsometer, available at CMAM and capable of in-situ measurements (i.e. spectrum acquisition times lower than one second). Specific ports at 75º are installed for that aim.
  • Compatible with pulsed laser excitation (Nd:YAG at λ (nm) = 266, 355, 532, 1064), through glass/silica windows.
  • Compatible with load-lock loading system for transfer of 3 inches wafers between vacuum chambers (via “vacuum suitcase”) without air exposure.
  • Solid state detectors for RBS and ERD measurements.