Ion milling-induced conductivity-type conversion in p-type HgCdTe MBE-grown films with graded-gap surface layers

Abstract

In this paper, ion milling-induced conductivity-type conversion in p-type HgCdTe molecular beam epitaxy-grown films with graded-gap surface layers is studied. As expected, the chemical composition of the graded-gap layer strongly affects the conversion depth. At the composition of the layer on the surface, x v > 0.5, ion fluences typically used for fabricating p-n junctions in HgCdTe create only a damaged surface n + -layer with no deep conversion. With lower x v , conversion with controllable depth due to diffusion of interstitial mercury atoms Hg I can be achieved. Defect reactions in the graded-gap surface layers under the milling and post-milling ageing, which are caused by interaction of Hg I with dislocations, differ from those in the deep converted layers, where Hg I reacts with point defects. It is shown that when assessing the depth of a p-n junction fabricated with ion milling in HgCdTe with a graded-gap surface layer, it is necessary to consider the effect of the material removal from the surface.

Анализ вольт-фарадных характеристик МДП-структур с ALD Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=- на n- и p-CdHgTe, стабилизированном сверхтонким собственным оксидом

“…При температуре жидкого азота и частоте измерительного сигнала до 1 кГц все полученные МДП-структуры Основным механизмом увеличения концентрации доноров в КРТ является разрыв связей Hg−Te, диффузия межузельных атомов ртути и их взаимодействие с нейтральными дефектами/примесями кристаллической решетки, например, в результате ионной бомбардировки поверхности [29][30][31]. С другой стороны, сам по себе физико-химический процесс образования собственного оксида КРТ сопровождается разрывом связей Hg−Te.…”

Studying C-V characteristics of MIS structures with ALD Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=- on n- and p-CdHgTe stabilized with ultra-thin native oxide

“…The primary mechanism of enhancement of the donor density in MCT is the breaking of Hg−Te bonds, diffusion of interstitial mercury atoms, and their interaction with neutral defects/impurities of the crystal lattice (e.g., as a result of ion bombardment of the surface [29][30][31]). That said, the physicochemical process of formation of native MCT oxide is itself accompanied by breaking of Hg−Te bonds.…”