Physical properties of the HCT EUV source
Physical properties of the HCT EUV source
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HCT EUV 光源的物理特性
DOI：
10.1117/12.472271
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
G. Derra
中科院分区：
文献类型：
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作者：
J. Pankert;K. Bergmann;J. Klein;W. Neff;O. Rosier;S. Seiwert;Christopher Smith;R. Apetz;J. Jonkers;Michael Loeken;G. Derra
本文介绍了用于产生极紫外辐射的空心阴极触发箍缩器件（HCT）的物理特性和最新技术进展。在之前的出版物中，我们已经证明了未触发设备在纯Xe中以1 kHz连续运行。较新一代的操作与触发设施，允许更广泛的参数空间下，稳定的操作是可能的。重复频率可达4 kHz。许多实验都是在不同长度和间隔的重复脉冲串中进行的。这也允许证明在接通和关断源时只有很少的瞬态行为。在2 p中，转换到13.5 nm附近的2%频带的转换效率约为0.4%，与其他小组报告的值相当。另一个重要参数是发光区域的尺寸。在这里，我们研究了电极几何形状和流动特性对尺寸的影响，以找到与收集光学器件要求的最佳匹配。设计完整的晶圆照明系统的主要问题是辐射的带外部分。特别是源光谱的DUV部分是一个问题，因为它也在一定程度上被Mo-Si多层镜反射。我们表明，该源具有较低的整体非EUV部分的排放。特别是，它表明，有非常少的DUV出来的可用源卷，远低于指定的水平。
The paper describes the physical properties and recent technical advances of the hollow cathode triggered pinch device (HCT) for the generation of EUV radiation. In previous publications we have demonstrated continuous operation of the untriggered device at 1 kHz in pure Xe. The newer generations operate with a triggering facility which allows a wider parameter space under which stable operation is possible. Repetition frequencies of up to 4 kHz could be demonstrated. Many of the experiments are performed in repetitive bursts of variable lengths and spacing. This allows also to demonstrate that there is only little transient behavior upon switching on and off the source. Conversion efficiencies into the 2 percent frequency band around 13.5 nm are about 0.4 percent in 2p, comparable to the values reported from other groups. Another important parameter is the size of the light emitting region. Here we have studied the influence of electrode geometry and flow properties on the size, to find a best match to the requirements of the collection optics. A major problem for the design of a complete wafer illumination system is the out-of-band portion of the radiation. Especially the DUV fraction of the source spectrum is a concern because it is also reflected to some extend by the Mo-Si multilayer mirrors. We show that the source has a low overall non-EUV part of the emission. In particular, it is demonstrated that there is very little DUV coming out of the usable source volume, well below the specified level.