Etching of mesa structures in HgCdTe

Srivastav, Vanya; Pal, R.; Sharma, B. L.; Naik, Akshay; Rawal, D. S.; Gopal, Vishnu; Vyas, H. P.

doi:10.1007/s11664-005-0203-5

Cited by 14 publications

(15 citation statements)

References 13 publications

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“…These systems induce type conversion and damages in the processed devices, particularly p-type material 1 . Ion milling of HgCdTe results in creation of extensive structural defects, type conversion of p-type HgCdTe extending to large distances (~200 µm) for short process times and produces longrange isotropic damage in n-type HgCdTe [28][29][30] .…”

Section: Electrical Propertiesmentioning

confidence: 99%

“…During the initial phases of process development, wet chemical processes were predominantly employed to fabricate HgCdTe-based detector arrays. Futuristic and current generation thermal imagers require more reliable, high performance large format detector arrays with multicolor detection and multi-task capability packed in each pixel of the arrays 1 . Fabrication of such arrays necessitated the introduction of dry processes like ion beam milling, ion implantation, reactive ion etching (RIE), high density plasma etching (HDPE) and low energy electron enhanced etching (LE4) for a number of processing steps.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Ion Beam Based Techniques for Mercury Cadmium Telluride Infrared Detectors

Pal¹,

Mittal²,

Sharma³

et al. 2009

DSJ

Self Cite

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The paper reviews the applications of ion beam-based techniques such as ion implantation and ion beam milling, for HgCdTe detector fabrication. Fabrication of large-format arrays and two-color arrays necessitate the use of dry processes. Ion irradiation causes type conversion in HgCdTe. The type conversion is far beyond the damage sites because of Hg in-diffusion to interstitial sites. The dry processes combine high anisotropy, faster etch rates, and better dimensional control, than wet etch processes, but require the damaged region to be removed.

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Section: Electrical Propertiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Ion Beam Based Techniques for Mercury Cadmium Telluride Infrared Detectors

Pal¹,

Mittal²,

Sharma³

et al. 2009

DSJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…8,9 In our study, wet etching treatments in HgCdTe technology were subdivided in two categories. In the first category, bromine was used as a direct reagent and in the second, bromine emerged as a by-product from the reaction between different bromine-based reagents.…”

Section: Different Wet Etching Mechanisms In Hgcdtementioning

confidence: 99%

Effect of Atmosphere on n-Type Hg1–x Cd x Te Surface after Different Wet Etching Treatments: An Electrical and Structural Study

Kiran

Sporken

Casselman

et al. 2008

Journal of Elec Materi

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The impact on surface recombination velocity (SRV) and minority carrier lifetime of three wet etchants are examined here. The etchants are 60DI + 10HBr + 1H 2 O 2 (by volume), 1% bromine-methanol, and 2% bromine-lactic acid. After initial etching, the HgCdTe surfaces were exposed in specific time steps to the atmosphere. At each step in the process, the effect of each etchant and of exposure to atmosphere was determined by photoconductive decay (PCD) measurements as well as by x-ray photoelectron spectroscopy (XPS). The PCD results showed that the 60DI + 10HBr + 1H 2 O 2 etchant, after exposure to atmosphere, led to a relatively small change in SRV compared to the changes that occurred for the two bromine-based etchants. In addition, XPS measurements showed that there were no neutral tellurium inclusions in the case of 60DI + 10HBr + 1H 2 O 2 and that TeO 2 formed strictly out of tellurium bonded to HgCdTe. Moreover, TeO 2 formed at a much slower rate on surfaces etched with HBr compared with those etched with the bromine-based etchants. A model is proposed in terms of band alignment at HgCdTe-Te 0 and HgCdTe-TeO 2 interfaces to explain the different surface recombination mechanisms that are due to different etchants and to atmospheric exposure.

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“…From the previous literature it becomes evident that both of these compounds get etched away in the acidic solution. 12,13 . The change in the free energy (DF) during etching is the driving force for any etching reaction, which determines the rate of etching.…”

Section: Wet Etching In Hgcdtementioning

confidence: 99%

“…13 As a result, although HgTe bond is much weaker than CdTe, CdTe becomes more unstable in etching solution resulting in a faster etching rate. 12,13 This is the basis of all HgCdTe wet etching.…”

Section: Wet Etching In Hgcdtementioning

confidence: 99%

Comparative Study of HgCdTe Etchants: An Electrical Characterization

Mallick

Kiran

Ghosh

et al. 2007

Journal of Elec Materi

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A comparative study of wet etchants for both molecular beam epitaxy (MBE) and liquid phase epitaxy (LPE) grown n-and p-type samples was performed using capacitance-voltage (C-V) characteristics and surface recombination velocity (SRV) extracted from photoconductive decay (PCD) measurements. Different wet etchants were divided in two categories, (i) where bromine is a direct reagent in the etching solution and (ii) where bromine is a byproduct after reaction among different reagents. Negative shift of the flat-band voltages were observed for both n-and p-type samples treated with second category of etchants. A decrease in minority carrier lifetimes and an increase in the surface recombination velocities were also observed for the n-type samples treated with second category of etchants.

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Etching of mesa structures in HgCdTe

Cited by 14 publications

References 13 publications

Ion Beam Based Techniques for Mercury Cadmium Telluride Infrared Detectors

Ion Beam Based Techniques for Mercury Cadmium Telluride Infrared Detectors

Effect of Atmosphere on n-Type Hg1–x Cd x Te Surface after Different Wet Etching Treatments: An Electrical and Structural Study

Comparative Study of HgCdTe Etchants: An Electrical Characterization

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