Reconfigurable mmWave microchips co-integrating hBN switches on GaN

Key Points:

• Au/hBN/Au switches exhibit ohmic conduction in the low resistance state (LRS) with forming voltages following a power-law relationship, and LRS resistance shows no clear dependence on the sweep rate during forming.
• Device cycling tests at room temperature and 175 °C reveal no significant differences in set voltages across different forming and testing conditions, with variability in high resistance state (HRS) mainly due to reset process fluctuations.
• Thermal scanning probe microscopy (SThM) experiments indicate that hBN has a larger lateral thermal conductivity than HfO2, resulting in a wider thermal profile in Au/hBN/Au devices under current flow.
• S-parameter measurements from multiple chips and hBN suppliers demonstrate consistent RF performance up to 50 GHz, with variability within expected limits and confirmed by BEOL-fabricated references.
• Power linearity tests show that shunt devices have better linearity and higher 1 dB compression points (P1dB) than series devices, consistent with their complementary conductive states and asymmetric set/reset voltages affecting power handling.