Low-cost Large-area High-Sensitivity X-ray Panel Detector for Digital Mammography

描述（由申请人提供）：在这个I期提案中，我们将开发一种具有成本效益的用于数字乳房x线摄影的大面积高灵敏度x射线板探测器。这种直接转换x射线探测器将极大地提高成本效益的高性能乳房x光检查的能力。通过将多晶CZT（碲化镉锌）薄膜直接生长到定制的CMOS读出器上，我们将创建具有高分辨率和高灵敏度的大面积面板。这些面板将为许多其他x射线成像应用提供经济高效的高性能探测器，包括普通放射照相、透视检查和x射线CT。我们将利用我们在多晶薄膜生长，固态x射线探测器物理和x射线读出ASIC设计方面的现有专业知识，生产直接在定制CMOS读出上生长的CZT（碲化镉锌）薄膜。最近，韩国和日本的学术研究小组研究了直接生长在读出器上的多晶CZT薄膜的潜力，以制造x射线成像面板探测器。这些研究表明，在薄膜生长过程中可以保持相对较低的衬底温度，从而可以直接生长到读出器件上，如薄膜晶体管阵列和CMOS器件。所制备的薄膜具有良好的x射线探测性能。我们建议在美国扩展这项工作，利用我们自己在x射线成像探测器的碘化汞多晶薄膜生长方面的经验，以及我们在设计和生产与碘化汞薄膜直接生长兼容的基于cmos的读数方面的经验。在这个第一阶段，我们将开发薄膜生长装置和在ito涂层玻璃载玻片上成功生长多晶CZT薄膜所必需的工艺，我们将测量x射线检测性能。这将大大降低第二阶段的风险。在之前的工作中，我们已经设计、制造和涂覆了与碘化汞化学兼容的大面积（10厘米× 10厘米）成像电荷集成CMOS读出芯片。在这项工作中，我们将调整它们以适应CZT薄膜的生长过程。读出具有305m像素网格，可实现高分辨率成像，8个并行输出可为10m像素设备产生每秒8帧的读出速度。在第二阶段，将测试ctt涂层CMOS读出器的x射线成像特性。大多数数字乳房x线照相术系统的空间分辨率受限于它们使用的间接探测器——与光电二极管阵列耦合的闪烁体。最近的一些系统是基于无定形硒，一种直接探测器。然而，即使这些系统也被限制在大约70-100米的像素大小。第二阶段将覆盖的CMOS读数包括30万像素网格，使乳房x光检查和其他x射线成像模式获得更高的空间分辨率。由于将CZT薄膜直接生长到读出阵列上，该器件也将具有成本效益。我们将把该设备作为OEM组件广泛销售给乳房x光检查系统制造商。

DESCRIPTION (provided by applicant): In this Phase I proposal we will develop a cost-effective large-area high-sensitivity x-ray panel detector for digital mammography. This direct-conversion x-ray detector will dramatically improve the capability for cost- effective high-performance mammography. By growing polycrystalline CZT (cadmium zinc telluride) films directly onto custom CMOS readouts, we will create large area panels with high resolution and high sensitivity. These panels will provide cost-effective, high-performance detectors for many other x-ray imaging applications including general radiography, fluoroscopy, and x-ray CT. We will leverage our existing expertise in polycrystalline film growth, solid-state x-ray detector physics, and x-ray readout ASIC design to produce CZT (cadmium zinc telluride) films grown directly onto customized CMOS readouts. Recently, academic research groups in Korea and Japan have investigated the potential for polycrystalline CZT films grown directly onto readouts to create x-ray imaging panel detectors. These studies have shown that relatively low substrate temperatures can be maintained during the film growth, enabling direct growth onto readouts such as thin-film transistor arrays and CMOS devices. The films produced have shown good x-ray detection properties. We propose to extend this work in the U.S., using our own experience in mercuric iodide polycrystalline film growth for x-ray imaging detectors and our experience in designing and producing CMOS-based readouts compatible with direct growth of mercuric iodide films. In this Phase I we will develop the film growth apparatus and processes necessary for successful polycrystalline CZT film growth on ITO-coated glass slides and we will measure the x-ray detection performance. This will substantially reduce the risk for Phase II. In previous work, we have designed, fabricated, and coated large area (10 cm x 10 cm) imaging charge-integrating CMOS readout chips which are chemically compatible with mercuric iodide. In this work, we will adapt them for compatibility with the CZT film growth process. The readouts have 30 5m pixel grids, enabling high-resolution imaging, and 8 parallel outputs which produce an 8 frames per second readout speed for the 10 Mpixel device. In Phase II, the CZT-coated CMOS readouts will be tested for x-ray imaging characteristics. Most digital mammography systems have spatial resolutions limited by their use of indirect detectors - scintillators coupled to photodiode arrays. A few recent systems are based on amorphous selenium, a direct detector. However, even these systems are limited to pixel sizes of about 70-100 5m. The CMOS readouts which will be coated in Phase II incorporate 30 5m pixel grids, giving mammography and other x-ray imaging modalities access to higher spatial resolutions. The devices will also be cost-effective due to the approach of growing CZT films directly onto readout arrays. We will widely market the device as an OEM component to mammography system manufacturers. PUBLIC HEALTH RELEVANCE: We will grow a high-sensitivity detector material, cadmium zinc telluride (CZT), directly onto CMOS technology megapixel readouts. This will achieve significant breakthroughs in x-ray imaging panel detector price and performance. Mammography will benefit due to the improved spatial resolution and reduced cost from this unique combination of detector material and readout.