DEEP LEVELS OF CHROMIUM-HYDROGEN COMPLEXES IN SILICON

Deep levels related to chromium m n-type silicon have been investigate d using deep level transient spectroscopy (DLTS) and concentration pro file measurements. The DLTS measurement reveals four electron traps of E(C)-0.22, E(C)-0.28, E(C)-0.45, and E(C)-0.54 eV in chromium-doped s amples. The trap of E(C)-0.22 eV is a donor due to interstitial chromi um. The other three traps are observed near the surface region of samp les etched with an acid mixture containing HF and HNO3 and annihilate after annealing at 175-degrees-C for 30 min. The origin of these traps has been studied by isochronal annealing and various chemical treatme nts. It is demonstrated that the three electron traps are due to compl exes of interstitial chromium and hydrogen.