A Two-Step Low-Temperature Process For A P-N Junction Formation Due To Hydrogen Enhanced Thermal Donor Formation In P-Type Czochralski Silicon

Abstract

ABSTRACTThe incorporation of hydrogen into standard p-type Czochralski (Cz) silicon (≥1 Ωcm) by a 110 MHz plasma treatment at 260°C leads to the formation of an n-type region due to hydrogen enhanced thermal donor (TD) formation in hydrogenated regions of the wafer, if a subsequent annealing in air is applied at 450°C. Spreading resistance probe (SRP) and light beam induced current (LBIC) measurements were used for the experimental analysis. The p-n junction depth, i. e. the counter doping by TDs, depends on the initial doping level of the p-type substrate, and therefore on the post-hydrogenation annealing time. The penetration of the n-type region into the wafer bulk is driven by a rapid hydrogen diffusion. The essential process for a TD generation is the creation of metastable hydrogen molecular species around 260°C and their decay at 450°C.