Hartsough Neal E, Iwanczyk Jan S, Nygard Einar, Malakhov Nail, Barber William C, Gandhi Thulasidharan
DxRay, Inc., Northridge, CA 91324 USA (telephone: 818-280-0177, e-mail:
IEEE Trans Nucl Sci. 2009 Aug 1;56(4):1810-1816. doi: 10.1109/TNS.2009.2023478.
We have created high-resolution x-ray imaging devices using polycrystalline mercuric iodide (HgI(2)) films grown directly onto CMOS readout chips using a thermal vapor transport process. Images from prototype 400x400 pixel HgI(2)-coated CMOS readout chips are presented, where the pixel grid is 30 mum x 30 mum. The devices exhibited sensitivity of 6.2 muC/Rcm(2) with corresponding dark current of approximately 2.7 nA/cm(2), and a 80 mum FWHM planar image response to a 50 mum slit aperture. X-ray CT images demonstrate a point spread function sufficient to obtain a 50 mum spatial resolution in reconstructed CT images at a substantially reduced dose compared to phosphor-coated readouts. The use of CMOS technology allows for small pixels (30 mum), fast readout speeds (8 fps for a 3200x3200 pixel array), and future design flexibility due to the use of well-developed fabrication processes.
我们利用热蒸汽传输工艺，在互补金属氧化物半导体（CMOS）读出芯片上直接生长多晶碘化汞（HgI₂）薄膜，制造出了高分辨率X射线成像设备。展示了来自400×400像素碘化汞涂层CMOS读出芯片原型的图像，其中像素网格为30μm×30μm。这些设备的灵敏度为6.2μC/Rcm²，相应的暗电流约为2.7nA/cm²，对50μm狭缝孔径的平面图像响应半高宽为80μm。X射线计算机断层扫描（CT）图像显示，与磷光体涂层读出相比，在剂量大幅降低的情况下，点扩散函数足以在重建的CT图像中获得50μm的空间分辨率。CMOS技术的使用允许采用小像素（30μm）、快速读出速度（对于3200×3200像素阵列，为8帧/秒），并且由于采用了成熟的制造工艺，未来具有设计灵活性。
