Study of Chemical Etching and Chemo-Mechanical Polishing on CdZnTe Nuclear Detectors

Journal Article · Tue Aug 13 00:00:00 EDT 2019 · Journal of Materials Science and Chemical Engineering

DOI:https://doi.org/10.4236/msce.2019.78005· OSTI ID:1546037

Adams, Aaron L. ^[1]; Roy, Utpal N. ^[2]; Egarievwe, Stephen U. ^[3]; Agbalagba, Ezekiel O. ^[4]; Gul, Rubi ^[3]; Hossain, Anwar ^[2]; James, Ralph B. ^[5]

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1. Alabama A&M Univ., Huntsville, AL (United States)
2. Brookhaven National Lab. (BNL), Upton, NY (United States)
3. Alabama A&M Univ., Huntsville, AL (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
4. Federal Univ. of Petroleum Resources, Delta State (Nigeria)
5. Savannah River National Lab, Aiken, SC (United States)

Cadmium zinc telluride (CdZnTe) semiconductor has applications in the detection of Xrays and gamma-rays at room temperature without having to use a cooling system. Chemical etching and chemo-mechanical polishing are processes used to smoothen CdZnTe wafer during detector device fabrication. These processes reduce surface damages left after polishing the wafers. In this paper, we compare the effects of etching and chemo-mechanical polishing on CdZnTe nuclear detectors, using a solution of hydrogen bromide in hydrogen peroxide and ethylene glycol mixture. X-ray photoelectron spectroscopy (XPS) was used to monitor TeO₂ on the wafer surfaces. Current-voltage and detector-response measurements were made to study the electrical properties and energy resolution. XPS results showed that the chemical etching process resulted in the formation of more TeO₂ on the detector surfaces compared to chemo-mechanical polishing. The electrical resistivity of the detector is of the order of 10¹⁰ Ω-cm. The chemo-mechanical polishing process increased the leakage current more that chemical etching. For freshly treated surfaces, the etching process is more detrimental to the energy resolution more than chemo-mechanically polishing. The energy resolutions of the CdZnTe wafers are expected to improve as the surfaces stabilize and result in reduced surface currents.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States); Savannah River National Lab (SRNL), Aiken, SC (United States); Savannah River Site (SRS), Aiken, SC (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation (NA-20); USDOE National Nuclear Security Administration (NNSA), Office of Nonproliferation and Verification Research and Development (NA-22); USDOE Office of Environmental Management (EM)
• Grant/Contract Number: AC09-08SR22470; SC0012704
• OSTI ID: 1546037
• Alternate ID(s): OSTI ID: 1591776
• Report Number(s): BNL--211890-2019-JAAM; SRNL-STI--2019-00466
• Journal Information: Journal of Materials Science and Chemical Engineering, Journal Name: Journal of Materials Science and Chemical Engineering Journal Issue: 08 Vol. 07; ISSN 2327-6045
• Publisher: Scientific Research Publishing, Inc.
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CdZnTe
Chemical Etching
Chemo-mechanical Polishing
Gamma Rays
Nuclear Detectors
X-ray Photoelectron Spectroscopy