5 Irradiation Facility and Setup

The heavy-ion species used for the SEE studies on this product were provided and delivered by the TAMU Cyclotron Radiation Effects Facility using a superconducting cyclotron and an advanced electron cyclotron resonance (ECR) ion source. At the fluxes used, ion beams had good flux stability and high irradiation uniformity over a 1-in diameter circular cross-sectional area for the in-air station. Uniformity is achieved by magnetic defocusing. The flux of the beam is regulated over a broad range spanning several orders of magnitude. For the bulk of these studies, ion flux of 10⁴ and 10⁵ ions/cm²·s were used to provide heavy-ion fluences of ≈ 3 × 10⁶ and 10⁷ ions/cm².

For the experiments conducted in this report the following ions and corresponding angles were used in order to provide a range of LET_EFF of 1.33 to 43 MeV·cm2 /mg.

• Krypton (⁸⁴Kr) at 44.3° for an LET_EFF = 43 MeV

  • Range_EFF = 77.7 µm

  • Total Kinetic Energy = 2.081 GeV (25 MeV/nucleon)

• Krypton (⁸⁴Kr) at 42.7° for an LET_EFF = 43.1 MeV

  • Range_EFF = 73.6 µm

  • Total Kinetic Energy = 1.259 GeV (15 MeV/nucleon)

• Krypton (⁸⁴Kr) at 0° for an LET_EFF = 29.7 MeV

  • Range_EFF = 118.2 µm

  • Total Kinetic Energy = 1.259 GeV (15 MeV/nucleon)

• Copper (⁶³Cu) at 41.6° for an LET_EFF = 28.1 MeV

  • Range_EFF = 80.1 µm

  • Total Kinetic Energy = 0.944 GeV (15 MeV/nucleon)

• Copper (⁶³Cu) at 0° for an LET_EFF = 19.7 MeV

  • Range_EFF = 124.1 µm

  • Total Kinetic Energy = 0.944 GeV (15 MeV/nucleon)

• Argon (⁴⁰Ar) at 42.3° for an LET_EFF = 12 MeV

  • Range_EFF = 120.8 µm

  • Total Kinetic Energy = 0.599 GeV (15 MeV/nucleon)

• Argon (⁴⁰Ar) at 0° for an LET_EFF = 8.44 MeV

  • Range_EFF = 180.9 µm

  • Total Kinetic Energy = 0.599 GeV (15 MeV/nucleon)

• Neon (²⁰Ne) at 43.1° for an LET_EFF = 3.89 MeV

  • Range_EFF = 177 µm

  • Total Kinetic Energy = 0.300 GeV (15 MeV/nucleon)

• Neon (²⁰Ne) at 0° for an LET_EFF = 2.74 MeV

  • Range_EFF = 261.3 µm

  • Total Kinetic Energy = 0.300 GeV (15 MeV/nucleon)

• Nitrogen (¹⁴N) at 0° for an LET_EFF = 1.33 MeV

  • Range_EFF = 371.8 µm

  • Total Kinetic Energy = 0.210 GeV (15 MeV/nucleon)

Ion uniformity for these experiments was between 88 and 98%.

Figure 5-1 shows the TPS7H4010-SEP test board used for the experiments at the TAMU facility. Although not visible in this photo, the beam port has a 1-mil Aramica window to allow in-air testing while maintaining the vacuum within the accelerator with only minor ion energy loss. All through-hole test points were soldered backwards for easy access of the signals while having enough room to change the angle of incidence and maintaining the 40-mm distance to the die. The in-air gap between the device and the ion beam port window was maintained at 40 mm for all runs.