Ion Beam Nanostructuring of HgCdTe Ternary Compound

Area of Science:

• Materials Science
• Nanotechnology
• Semiconductor Physics

Background:

• Mercury cadmium telluride (HgCdTe) is a crucial semiconductor alloy for infrared optoelectronics.
• Surface modification techniques are essential for tailoring semiconductor properties for advanced applications.
• Ion beam irradiation offers precise control over material composition and nanostructure formation.

Purpose of the Study:

• To investigate the effects of 100 keV Boron (B+) and Silver (Ag+) ion beam bombardment on (111) Hg1-x Cdx Te epilayers.
• To characterize the resulting surface morphology, chemical composition, and structural properties.
• To evaluate the charge transport characteristics and radiation sensitivity of the modified HgCdTe structures.

Main Methods:

• Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) for surface morphology analysis.
• X-ray Photoelectron Spectroscopy (XPS) and X-ray Diffraction (XRD) for chemical and structural characterization.
• Non-stationary impedance spectroscopy to study charge transport properties.

Main Results:

• Fabrication of nanoscale arrays of holes and mounds on the HgCdTe surface.
• Formation of a polycrystalline HgCdTe cubic phase with altered composition (x ≈ 0.20) via ion irradiation.
• Boron-implanted structures exhibited capacity-type impedance, while silver-implanted structures showed inductive-type impedance.
• A hybrid metal-oxide-semiconductor structure with Ag2O inclusions was created, demonstrating sub-THz radiation sensitivity (NEP ≈ 4.5 × 10^-8 W/Hz^1/2 at 140 GHz).

Conclusions:

• 100 keV B+ and Ag+ ion beam irradiation effectively modifies the surface morphology and structural properties of HgCdTe epilayers.
• Ion implantation induces distinct electrical impedance behaviors, with potential for novel device functionalities.
• The fabricated Ag-implanted HgCdTe hybrid system shows promising performance for unamplified sub-terahertz radiation detection.