p -type arsenic doping of Hg1−xCdxTe by molecular beam epitaxy

Abstract

Growth of in situ As doped Hg1−xCdxTe by molecular beam epitaxy and activation of As at 250 °C is reported. We have used elemental arsenic, As4, as the p-type dopant source. The activation of As was observed in the 1016–1018 cm−3 range after a low temperature annealing step at 250 °C. However, for doping levels above 5×1018 cm−3, we have observed that the As activation efficiency drops. It is speculated at this time that self-compensation and formation of neutral As complexes may limit doping efficiency at very high levels. We also report our data on the structural and electrical characteristics of these As doped p-type layers using secondary ion mass spectroscopy analysis, and Hall effect measurements. An acceptor activation energy of 5.4 meV was obtained based on the dependence of the Hall coefficient on temperature. This value was attributed to singly ionized As located on a Te site (AsTe•) acting as an acceptor. A brief discussion on activation mechanism of As doped p-type HgCdTe material is also presented.

Hg(1‐x)CdxTe from short to long wave infrared on Si substrates grown by MBE

“…Similar results were obtained in all ranges of x values studied here, from x=0.2 to x=0.72. At arsenic doping levels above 10 18 cm -3 , lower activation ratios have been observed by other groups [18,19].…”

“…But in contrast to indium, which behaves very well as an n-type dopant, arsenic has amphoteric behavior and with typical MBE HgCdTe growth conditions is incorporated as an n-type dopant. This phenomenon has been seen by other groups and is still a source of discussion [15,[18][19][20][21]. One way to activate the arsenic as a p-type dopant is to anneal the layer under Hg pressure.…”

Assessment of the possibility of determination of the electrophysical characteristics of Cd x Hg1–x Te p +–n-structures using differential hall measurements

“…Figure 1 shows that the metallurgical boundary of the p-n transition is at the depth d p = 0.71 µm for the specified parameters of ion implantation. The dependence of spatial distribution of charge-carrier mobility in the implanted region was found from the approximation of the concentration dependence of electron and hole mobilities in the p-material [7,8].…”

Flexibility of p–n Junction Formation from SWIR to LWIR Using MBE-Grown Hg(1–x)Cd x Te on Si Substrates

“…This phenomenon has been seen by other groups and is still a source of discussion. 15,[18][19][20][21] One way to activate the arsenic as a p-type dopant is to anneal the layer under Hg pressure. Several works can be found in the literature modeling As activation 20,21 and detailing the procedure for annealing HgCdTe for this purpose 15,18-20 and will not be addressed in this work.…”