Ion etching of HgCdTe: Properties, patterns and use as a method for defect studies

Ultra-thin uncooled integrable-on-chip detector to measure wide infrared radiation residue in lithography exposure and metrology inspection tools

“…The n/n + interface, marked in blue in Figure 3, has n-type conductivity; n denotes light donor-doping and n + -heavy donor-doping occurring in the vicinity of the surface area defected by ion milling. The latter is used to convert the conduction type from p to n [19]. The P + interface, marked in red, is the contact for the holes and is heavily acceptor-doped.…”

Photoluminescence in Mercury Cadmium Telluride – a Historical Retrospective. Part II: 2004–2022

“…Therefore, the rest of the shift (29 meV) was attributed to the BM effect, with calculations of the Fermi level shift as a result of heavy electron doping confirming its exact value. The authors of this review would like to note, though, that the shift observed by Zha et al [26,27] should not be, in fact, permanent, as electron concentration in ion-milling-induced n-type material is prone to relaxation and gradually decreases with time [29,31].…”

“…Modulated PL spectroscopy with a step-scan FTIR spectrometer was used for the study of the so-called blue-shift in PL and photoconductivity (PC) spectra of the n-on-p MCT photodiodes fabricated with ion milling [26,27]. Ion milling or ion (plasma) etching are used in MCT technology for fabrication of n-on-p photodiode structures, as lowenergy (1 to 5 keV) ion or plasma treatment causes controllable p-to-n conductivity type conversion in p-type material [28,29]. Zha et al [26,27] reported that a sequence of PL spectra measured across a square p-n junction fabricated with ion milling showed luminescence peaks of the milled area shifting strongly to shorter wavelengths in comparison to the spectra of the initial LPE-grown p-type material.…”

“…The main investigation tool used in that study was electrical measurements (those of the Hall coefficient and conductivity) in combination with ion etching. This etching releases HgI atoms that actively interact with existing defects and change the properties of the material [28,29,31,32]. By measuring the parameters of the material before and after the etching, as well as during the relaxation, when etching-induced defects gradually disintegrate, it is possible to obtain a considerably larger body of information about the defect structure of the material, compared with the 'standard' electrical measurements [29].…”

“…showed that it was possible to use this technique to determine the concentration of residual donors, an important parameter of the material that could not be measured using the conventional Hall-effect measurements due to electrical compensation [81]. Moreover, by creating a HgI concentration exceeding the equilibrium value by six to seven orders of magnitude, the etching can somehow activate even neutral defects in MCT [29]. In the case of Ref.…”