Chemical etching and post-annealing for high performance CdZnTe strip detectors

Book · Thu Dec 31 04:00:00 EST 1998

OSTI ID:323840

Shi, Z Q ^[1]; Stahle, C M ^[2]; Shu, P ^[3]

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1. Hughes STX Corp., Greenbelt, MD (United States)
2. Orbital Sciences Corp., Greenbelt, MD (United States)
3. NASA, Greenbelt, MD (United States). Goddard Space Flight Center

One of the critical issues in CdZnTe detector fabrication is the surface treatment. This will not only affect the electrical properties, such as leakage current, but also influence the physical properties, such as smoothness and adhesion between the metal and the semiconductor. The latter will determine the wire bonding yield. Historically, there has been a problem in achieving both low leakage current and excellent wire bonding yield. In this paper, the authors report their new approach to fabricate high performance doubled sided CdZnTe strip detectors. The new surface treatments involve chemical etching and post-annealing. The leakage current, interstrip resistance and energy resolution were studied as a function of different etchants/time and post-annealing temperature. It was found that a chemical etch with bromine in ethylene glycol (Br/EG) is suitable for the double sided strip detector process. Keeping a relatively smooth surface is critical for achieving a high yield of good strips. To improve the adhesion of the metal to CdZnTe for wire bonding, the detectors were annealed from 100 to 175 C for 10 hours. It has been observed that after annealing, not only has the strip leakage current decreased, but the interstrip resistance is increased for a temperature less than 150 C.

• OSTI ID: 323840
• Report Number(s): CONF-971201--
• Country of Publication: United States
• Language: English

Related Subjects

44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
ANNEALING
CADMIUM TELLURIDES
ELECTRICAL PROPERTIES
ENERGY RESOLUTION
ETCHING
EXPERIMENTAL DATA
GAMMA DETECTION
LEAKAGE CURRENT
SEMICONDUCTOR DETECTORS
X-RAY DETECTION
ZINC TELLURIDES