CMOS Diodes under Cryogenic Temperature and High Magnetic Field Environment

This paper describes the DC characteristics of three CMOS diodes (PN junction diode, STI separated SBD (Schottky Barrier Diode) and Poly-gate separated SBD) under cryogenic temperature and high magnetic field environment. The temperature dependences of the devices were measured at the ambient temperatures of 300 K, 150 K, 77 K and 4.2 K. To understand the magnetic field dependence of the CMOS diodes at the temperatures, measurements were also performed under magnetic fields of 0 T, 2 T, 4 T and 6 T. The parameters including ideality factors, Schottky barrier heights, turn-on voltages and magnetoresistances (MR) of the diodes are analyzed under the various conditions. No abnormal behaviors are observed at the temperatures down to 4.2 K. The measured MRs vary depending on the diode current level. The maximum magnetoresistance of 35% is observed in the PN junction diode under the temperature of 4.2 K and horizontal magnetic field of 6 T. The MR quadratically increases as the magnetic field increases in the high injection region. The diodes show a higher magnetoresistance under a lower temperature and higher magnetic field. The results show the feasibility of CMOS diode circuits under the cryogenic temperature and high magnetic field environment.