Enhanced columnar structure in CsI layer by substrate patterning

Conference · Tue Oct 01 04:00:00 EDT 1991

DOI:https://doi.org/10.1109/NSSMIC.1991.258889· OSTI ID:10107124

Jing, T; Cho, G; Drewery, J; Kaplan, S N; Mireshghi, A; Perez-Mendez, V; Wildermuth, D ^[1]; Fujieda, I ^[2]

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1. Lawrence Berkeley Lab., CA (United States)
2. Xerox Palo Alto Research Center, CA (United States)

Columnar structure in evaporated CsI layers can be controlled by patterning substrates as well as varying evaporation conditions. Mesh-patterned substrates with various dimensions were created by spin-coating polyimide on glass or amorphous silicon substrates and defining patterns with standard photolithography technique. CsI(Tl) layers 200--1000 {mu}m were evaporated. Scintillation properties of these evaporated layers, such as light yield and speed, were equivalent to those of the source materials. Spatial resolution of X-ray detectors consisting of these layers and a linear array of X-ray detectors consisting of these layers and a linear array of Si photodiodes was evaluated by exposing them to a 25{mu}m narrow beam of X-ray. The results obtained with 200{mu}m thick CsI layers coupled to a linear photodiode array with 20 dots/mm resolution showed that the spatial resolution of CsI(Tl) evaporated on patterned substrates was about 75 {mu}m FWHM, whereas that on CsI(Tl) on flat substrates was about 230 {mu}m FWHM. Micrographs taken by SEM revealed that these layers retained the well-defined columnar structure originating from substrate patterns. Adhesion and light transmission of CsI(Tl) were also improved by patterning the substrate.

• Research Organization: Lawrence Berkeley Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 10107124
• Report Number(s): LBL--31383; CONF-911106--44; ON: DE92004099
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601
440101
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
CESIUM IODIDES
FABRICATION
GENERAL DETECTORS OR MONITORS AND RADIOMETRIC INSTRUMENTS
LAYERS
POSITION SENSITIVE DETECTORS
PREPARATION AND MANUFACTURE
SCINTILLATOR-PHOTODIODE DETECTORS
SPATIAL RESOLUTION
SUBSTRATES
SURFACE COATING
TRANSFER FUNCTIONS
X-RAY DETECTION