CdTe-based detectors for digital mammography

Sri International, Menlo Park CA

Investigators

Abstract

[unreadable] DESCRIPTION (provided by applicant): [unreadable] The long-term objective of this proposal is to develop and test a cadmium-telluride (CdTe)-based, directconversion X-ray detector for application in the field of digital mammography. Digital mammography offers a number of advantages over current photographic film mammography, including improved image quality, lower radiation dosages, greater availability to a larger population of women, and better performance in the detection and diagnosis of breast cancer, particularly in women with dense breasts. In addition, the related use of telemammography will make high-quality mammography available to many women who are currently underserved because they live in areas where expert mammographic radiologists are not available to interpret their examination results. This work is to be undertaken as a collaboration between two companies: SRI International and NOVA R&D, Inc., both based in California. [unreadable] [unreadable] SRI's CdTe deposition process and the X-ray detector already under development at NOVA will find immediate application in the field of digital mammography. The detector's principal of operation is the direct conversion of X-ray energy into an electrical signal, with no intermediate generation of light. Furthermore, the X-ray absorbing phase, CdTe, is grown directly onto the readout chip, thereby avoiding the need for mechanical attachment of a wafer slice to the absorber. [unreadable] [unreadable] In the first phase of this project, an existing process will be further developed for the direct deposition of CdTe and cadmium zinc telluride (CdZnTe) onto a fully configured readout chip, using metal organic chemical vapor deposition, such that the resulting X-ray detector chip can be employed with a minimum of further processing. Specifically, the first phase will focus on determining the optimum combination of deposition temperature, as it determines the crystal quality of the CdTe and hence its electrical characteristics, and CdTe thickness. The resulting detector chips will be characterized directly for their X-ray detection and imaging properties. [unreadable] [unreadable] The readout chip to be used for deposition studies is an existing design that is not fully optimized for direct conversion with CdTe. In the second phase of this project, an optimized readout chip will be designed and manufactured. The CdTe deposition process will be applied to this new chip and the resulting detector characterized. If warranted, a set of detector chips will be assembled into a detector panel for incorporation into an existing commercial digital mammography system. [unreadable] [unreadable]