Effect of dopant profile on current-voltage characteristics of p+n+ In0.53Ga0.47As tunnel junctions

摘要

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 In0.53Ga0.47As should enable high-current-density, even 200 mA/μm² with internal fields of 4 MV/cm created by abrupt carrier profiles at the limits of dopant solubility, 2 × 10²⁰ cm^-3 for C [2], and 6 × 10¹⁹ cm^-3 for Si [3]. Here, molecular beam epitaxy (MBE) is used to grow heavily-doped In0.53Ga0.47As 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.