Compositionally graded interface for passivation of HgCdTe photodiodes

Pal, R.; Malik, Amit; Srivastav, Vanya; Sharma, B. L.; Dhar, V.; Sreedhar, B.; Vyas, H. P.

doi:10.1007/s11664-006-0159-0

Cited by 6 publications

(2 citation statements)

References 10 publications

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“…It has been reported that annealing CdTe thin films on HgCdTe ranging between 125°C and 350°C has improved the interface properties of CdTe/HgCdTe, creating a graded junction. 11 A notable improvement in the lifetime was observed on all the samples, post-annealing. The plot in Fig.…”

Section: Resultsmentioning

confidence: 83%

A Novel Method to Obtain Higher Deposition Rates of CdTe Using Low Temperature LPCVD for Surface Passivation of HgCdTe

Banerjee

Dahal

Bhat

2015

Journal of Elec Materi

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The deposition rate of CdTe passivation films has been increased greatly by the implementation of a novel design of a graphite cracker cell. This cracker cell, consisting of an integrated diffuser, facilitates the efficient cracking of precursors. CdTe deposition rate has been increased from $50 nm/h (without any cracker cell) to $420 nm/h using this novel experimental set-up. H 2 flow through the main gas flow line has been increased to obtain a progressive increase in deposition rates. CdTe deposited on high aspect ratio HgCdTe samples showed adequate conformal coverage on the side walls and also on the bottom of the trenches. Microwave photoconductive decay measurements were done on planar and patterned HgCdTe substrates at 77 K to extract the minority carrier lifetimes. There was a significant improvement in the lifetime of planar HgCdTe samples after CdTe passivation, though patterned HgCdTe samples showed a minor improvement. An additional annealing step was conducted at 250°C for 20 min in the presence of H 2 after the deposition of CdTe passivation films. Minority carrier lifetimes improved further post-annealing, probably due to the formation of a graded interface between CdTe and HgCdTe.

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Section: Resultsmentioning

confidence: 83%

A Novel Method to Obtain Higher Deposition Rates of CdTe Using Low Temperature LPCVD for Surface Passivation of HgCdTe

Banerjee

Dahal

Bhat

2015

Journal of Elec Materi

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“…In this respect, MBE is the most flexible technology, as it allows for growing passivation layers with arbitrary gap grading (from a 'working' MCT layer up to CdTe on the surface) and layer thickness. A built-in electrical field provided by the presence of compositional grading ensures a number of benefits [4], and graded-gap surface layers are now widely used in MCT-based devices.…”

Section: Introductionmentioning

confidence: 99%

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

Pociask¹,

Іжнін²,

Dvoretsky³

et al. 2010

Semicond. Sci. Technol.

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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.

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