Structure and Electrical Characteristics of Metal/MCT Interfaces

Ohmic metal/Hg1-xCdxTe (x ≈ 0.3) contacts

“…The lowest heats of formation were measured for Au and Pt, though even for such low values of the heat of formation, the solid-state chemical reactions take place [4,13].…”

“…From the results presented, it is clear that a model based on work functions and electron affinity is inappropriate for these semiconductors, as it was found long time ago [13]. The defect model (for the Fermi level pinning at the metal/MCT interface) predicts that, for x > 0.4, any metal contacts to n-and ptype Hg 1-x Cd x Te will give rectifying behavior and one would expect rectifying contacts for metals on p-type materials of all compositions [4,13,45].…”

“…Electrical contacts are of high importance for HgCdTe IR detectors. At the metal/HgCdTe interface, the structural and chemical defects [4] can worsen the performance of detectors and reduce their operability. To the date, there exist a certain number of materials and detectors proposed for the IR technology (see, e.g.…”

“…One of the critical points is the formation of low-temperature stable low-noise ohmic contacts (see, e.g. [4,12],) that have low degradation and surface dissociation with time and high thermal stability during packaging and using. In the present work, we will study the quality of CdTe/HgCdTe/CdZnTe heterostructures for IR detectors and will measure the characteristics of electrical contacts to n-and p-type HgCdTe layers.…”

“…Publications on contacts to MCT layers are quite numerous in the open literature (see, e.g. [4,[12][13][14][15][16][17][18][19], and earlier publications cited in them) with various heats of formation of metal/Te compounds. Several metals for contacts were used: Al, Ag, Au, Cr, Cu, Pd, Pt, Ti, Sm, and some others [13].…”