Abstract
In this work we report the surface analysis of polished p-type Hg1−xCdxTe (x ~ 0.3) epitaxial layer treated with ammonium sulfide solution (20%) for five minutes at room temperature using X-ray Photoelectron spectroscopy (XPS). XPS analysis shows sulphide signature in substantial quantity and is bonded to Cd or Hg. Quantitative estimation of sulphur by fractional coverage on the Mercury Cadmium Telluride (MCT) surface revealed 60% coverage of Hg1−xCdxTe surface by sulphur atoms. It is also observed that sulphur in elemental or oxide form is not present on the surface. The process of sulfidation results in the removal of native oxides from the Hg1−xCdxTe surface through the formation of Hg–S and Cd–S bonds as revealed during XPS studies. These bonds might act as barrier against native oxide formation when ammonium sulfide treated Hg1−xCdxTe surface is exposed to air. We further studied the effect of sulfidation on the MIS device structure fabricated using the ammonium sulfide treated Hg1−xCdxTe epitaxial layer surface with CdTe/ZnS as the passivant. The Hg1−xCdxTe—passivant interface was analyzed using C–V measurements at 77 K. To evaluate the Hg1−xCdxTe—passivant interface of the Hg1−xCdxTe surface treated with ammonium sulfide the interfacial charge were examined by fabricating a MIS structure. CdTe/ZnS layer was deposited by thermal evaporation on two polished Hg1−xCdxTe epitaxial layers with one of the layer surface treated with ammonium sulfide before CdTe/ZnS deposition. The capacitance voltage (C–V) measurement of MIS structures were carried out at 77 K and measured at a frequency of 1 MHz. A comparison of ammonium sulfide treated MIS structure shows near flat band conditions with Qss ~ 2.4 × 1010 cm−2. The density of interface traps observed is Dit ~ 1010 cm−2 eV−1 which is one order of magnitude lower than that observed for untreated MIS structures.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
W.H Chang, T.Lee, W.M. Lau, XPS study of chemical etching and CMP of HgCdTe in JAP 68(9), November 1990
R. Nokhwal et al., Surface studies on HgCdTe using non aqueous Iodine based polishing solution. JEM 46(12), 6795 (2017)
V.G. Bhide, S. Salkalachen, A.C. Rastog, C.N.R. Rao, M.S. Hegde, Depth profile composition studies of thin film CdS: Cu2S solar cells using XPS and AES. J. Phys. D Appl. Phys. 14, 1647 (1981)
V.I. Nefedov, Y.V. Salyn, P.M. Solozhenkin, G.Y. Pulatov, X-ray photoelectron study of surface compounds formed during flotation of minerals. Surf. Interf. Anal. 2, 171 (1980)
J.F. Moulder, W.F. Stickle, P.E. Sobol, K.D. Bomben, Handbook of X-ray Photoelectron spectroscopy, Perkin-Elmer corporation, Physical Electronics Division (1995)
C.D. Wagner, J.A. Taylor, Contributions to screening in the solid state by electron systems of remote atoms: Effects to photoelectron and Auger transitions. J. Electron Spectrosc. Relat. Phenom. 28, 211 (1982); B.J. Lindberg, K. Hamrin, G. Johansson, U. Gelius, A. Fahlmann, C. Nordling, K. Siegbahn, Molecular spectroscopy by means of ESCA II. Sulfur compounds: correlation of electron binding energy with structure. Phys. Scripta 1, 286 (1970)
D. Brigg’s, M.P. Seah, Practical surface analysis by 2nd edn., vol. 1, pp. 244–247
T.S. Sun, S.P. Buchner, N.E. Byer, Oxide and interface properties of anodic films on Hg1−xCdxTe. J. Vac. Sci. Technol. 17, 1067 (1980)
J.S. Hammond, S.W. Winograd, X-ray photoelectron spectroscopic studies of cadmium-and silver-oxygen surfaces. Anal. Chem. 47, 2194 (1975)
A.B. Christie, I. Sutherland, J.M. Walls, Studies of the composition, ion-induced reduction and preferential sputtering of anodic oxide films on Hg0. 8Cd0. 2Te by XPS. Surf. Sci. 135, 225 (1983)
P. Humbert, An XPS and UPS photoemission study of HgO. Solid State Commun. 60, 21 (1986)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2019 Springer Nature Switzerland AG
About this paper
Cite this paper
Manchanda, R. et al. (2019). HgCdTe Epitaxial Layer Surface Treatment Using Ammonium Sulfide Before Passivation. In: Sharma, R., Rawal, D. (eds) The Physics of Semiconductor Devices. IWPSD 2017. Springer Proceedings in Physics, vol 215. Springer, Cham. https://doi.org/10.1007/978-3-319-97604-4_71
Download citation
DOI: https://doi.org/10.1007/978-3-319-97604-4_71
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-97603-7
Online ISBN: 978-3-319-97604-4
eBook Packages: Physics and AstronomyPhysics and Astronomy (R0)