Development of a Method for Chemical–Mechanical Preparation of the Surface of CdZnTe Substrates for HgCdTe-Based Infrared Focal-Plane Arrays

• Published in: Journal of electronic materials Vol. 43; no. 8; pp. 3004 - 3011
• Main Authors: Pelenc, D., Merlin, J., Etcheberry, A., Ballet, P., Baudry, X., Brellier, D., Destefanis, V., Ferron, A., Fougères, P., Giotta, D., Grangier, C., Mollard, L., Perez, A., Rochette, F., Rubaldo, L., Vaux, C., Vigneron, J., Zanatta, J.-P.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Boston Springer US 01-08-2014; Springer; Springer Nature B.V
• Subjects: Applied sciences; Characterization and Evaluation of Materials; Chemistry and Materials Science; Cross-disciplinary physics: materials science; rheology; Electronics; Electronics and Microelectronics; Exact sciences and technology; Fractures; Infrared imaging systems; Instrumentation; Materials Science; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Methods of crystal growth; physics of crystal growth; Optical and Electronic Materials; Optoelectronic devices; Physics; Production techniques; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Solid State Physics; Spectrum analysis; Substrates; Surface treatment; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; CdHgTe; chemical–mechanical polishing; focal-plane array; x-ray photoelectron spectroscopy; LPE; Mechanical polishing; Photovoltaic effect; Chemical method; Background noise; Implementation; Photovoltaic cell; Planarization; Chemical preparation; Molecular beam epitaxy; Electrooptical effect; Infrared spectrum; Chemical mechanical polishing; Surface conditions; Damaging; Defect density; Focal plane arrays; Surface morphology; Epitaxial film; Photodetector; Surface treatment; chemical-mechanical polishing; Thickness; Engraving; Detector; II-VI semiconductors; Growth mechanism; X-ray photoelectron spectra
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-014-3175-5

This paper reports the first implementation in our laboratory of a chemical–mechanical polishing (CMP) process for CdZnTe (CZT) substrates prepared for growth of HgCdTe layers by liquid phase epitaxy and molecular beam epitaxy. The process enables significant reduction of the thickness of the damaged zone induced by the mechanical polishing that must be etched away before epitaxy. Resulting improvements in surface morphology, in terms of waviness and density of point defects, are reported. The chemical state of surfaces polished by CMP was characterized by x-ray photoelectron spectroscopy. The chemical state was highly homogeneous; comparison with a reference surface is reported. End use assessment of this surface processing was compared with that of reference substrates by preparation of focal-plane arrays in the medium-wavelength infrared spectral range, by using epitaxial layers grown on substrates polished by different methods. The electro-optical performance of the detectors, in terms of photovoltaic noise operability, are reported. The results reveal that the state of this CMP surface is at the level of the best commercial substrates.