Role of Hg in junction formation in ion-implanted HgCdTe

The present work clarifies the role of Hg diffusion in forming ion-implanted junctions in HgCdTe. Two experiments indicate that displaced Hg acts as a limited diffusion source. The first experiment contrasts n/p junction electrical profiles in two HgCdTe wafers, one p doped primarily by cation vacancies and the other primarily by the addition of As in the liquid phase epitaxy melt. The second experiment compares the carrier concentration near the junction with the residual net background doping of the sample. The results indicate that Hg released from the implant region operates as a limited diffusion source in the post-implant anneal process. Adjusting these material and process parameters allows n-on-p junctions to be formed with a controllable electrical profile.