SiC ΔE-E Telescope Based on Free-Standing Epitaxial Film Fabricated by Laser Processing

The 4H-SiC detector has been widely used for detecting charged particles in a strong radiation environment due to its resistance to radiation. The ΔE-E measurement is an important method for particle identification, especially for identifying the atomic number of heavy-ions. However, the existing epitaxial SiC detector has a thick substrate, typically larger than 100 μm. This dead layer limits the application of SiC in the ΔE-E telescope. In this work, the 4H-SiC substrate was completely removed using the picosecond laser etching process. Benefiting from the stepwise power modulation strategy, the thin films can be free-standing to complete the subsequent processes. Two substrate-free detectors with thicknesses of ~17 μm and 90 μm were assembled into a ΔE-E telescope. It exhibits a good detection performance. The energy resolution is about 2.1 % for<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">241</sup>Am-<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">239</sup>Pu-<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">244</sup>Cm α source. Besides, it has been successfully used in a proton scattering experiment performed at the China Institute of Atomic Energy. This work provides a route to fabricate substrate-free 4H-SiC telescopes for detecting low-energy charged-particles.