高分辨X射线衍射元件的研制

Fabrication of the High Resolution X-Ray Diffractive Element

X射线波带片是纳米X射线成像系统的核心元件之一,为了研制高分辨率X射线波带片,对纳米结构的电子束光刻和高精度电镀进行了实验研究。首先,通过对电子束曝光工艺版图进行优化设计,平衡了邻近效应对纳米结构的影响,有效地控制了光刻胶的扭曲和坍塌。实验结果表明,采用校正的工艺版图,用线曝光方式在800 pC/cm2剂量下可以研制出厚度为270 nm、最外环宽度为50 nm的高分辨率X射线波带片光刻胶结构。然后,在配制的柠檬酸金钾电镀液中,优化了电镀工艺参数。采用金含量为10%的柠檬酸金钾电镀液,各电镀参数pH值为4.2,电镀温度为50℃,电流密度为0.2 A/dm2电镀出高分辨率X射线波带片。

The X-ray zone plate is the core diffraction element in the high-resolution X-ray imaging system. The resolution of the X-ray imaging system depends on the outer zone width of the zone plate. We carried on experimental researches of the electron beam lithography and high precision plating of the nanostructures. First,via the optimization of the layout of the electron beam lithography process,it reduced the influence on the nanostructures of the proximity effect and controlled the distortion or collapse of the photoresist efficiently. The result indicated that it is capable to fabricate the high resolution X-ray zone plate photoresist masks with the thickness of 270 nm and the outmost zone width of 50 nm using the calibration layout by the electron beam lithography in line exposure with the dose of 800 pC/cm2 . Second,we chose appropriate plating parameters of the precision electroplating experiments in the solution of potassium citric monohydrate. The high resolution X-ray zone plates were electroplating with the elec-troplating solution（10% in gold）,pH value of 4. 2,temperature of 50 ℃ and the electric current of 0. 2 A/dm2.