Effect of dopant profile on current-voltage characteristics of p+n+ In 0.53 Ga 0.47 As tunnel junctions

InGaAs tunnel FETs are now being developed for high-performance, low-power, low-subthreshold-swing logic [1]. The low bandgap and low carrier effective masses in In 0.53 Ga 0.47 As should enable high-current-density, even 200 mA/μm 2 with internal fields of 4 MV/cm created by abrupt carrier profiles at the limits of dopant solubility, 2 × 10 20 cm -3 for C [2], and 6 × 10 19 cm -3 for Si [3]. Here, molecular beam epitaxy (MBE) is used to grow heavily-doped In 0.53 Ga 0.47 As junctions. Secondary ion mass spectroscopy (SIMS) is used to measure the dopant profiles, these profiles are used to simulate the expected energy band diagrams, and current-voltage characteristics (I–V) are used to characterize the junctions.