Measurements of electron density and electron temperature with plasma absorption probe and its application to deposited plasmas

近年来，为了提高性能、运算速度和功耗，人们对高性能大规模集成电路电子器件进行了研究。为了解决这个问题，已经开发了特征尺寸小于~100 nm的微细加工和用于改善分配线路上的信号延迟的低k材料。等离子体技术已被广泛应用于微细加工和低k薄膜的制备，但仍有许多问题需要解决。在这项工作中，我们对等离子体吸收探头进行了改进，使其即使在绝缘聚合物沉积的污秽条件下也能测量电子密度，以测量电子温度的重要参数，以表征等离子体。将该探头应用于化学气相沉积等离子体低k膜的诊断，获得了改进材料工艺的基础数据。探头天线周围的护套a…对用探头测量的吸收频率有更多的影响，并且鞘厚度是作为电子密度和电子温度的函数的德拜长度的几倍。因此，当测量吸收频率时，可以同时获得电子密度和电子温度这两个不同于鞘层厚度的表面波吸收探针。探头天线直径对电子密度与电子温度的关系有显著影响，随着天线直径的增大，满足测量吸收频率的电子密度与电子温度无关。两种探头的满意密度对温度的依赖关系不同，更适合于准确测定密度和温度。因此，天线直径相差较大的探头更适合实现准确的测量。最后，获得了与传统朗缪尔探头几乎相同的电子密度和电子密度。探头揭示了用于低k薄膜沉积的窄能隙CVD等离子体系统的以下特征。(1)电子密度及其径向分布在很大程度上取决于诸如放电功率和工作压力等条件，以及电子密度的径向分布与12英寸直径上的沉积速率之间的相关性。硅片。(2)电子温度随总工作压力和母体气体分数的增加而降低。Xe的加入也有效地降低了电子温度。作为派生结果，该探头系统也被应用于其他等离子体系统的材料加工，并对其等离子体诊断有用。较少

Recently, high performance LSI electronic devices has been studied to improve capability, calculation speed and power consumption. To achieve this issue, microfabrication with a feature size less than 〜100 nm and low-k materials for improvement of signal delay at distribution lines have been developed. Plasma processing has been widely used for the microfabrication and the low-k film formation, however there are still various problems to be solved. Understanding of plasma properties and precise control of the plasma suitable for desired process have been requred.In this work, plasma absorption probes which enable us to measure electron density even under soiled conditions of insulated polymer deposition were improved to measure electron temperature of important parameters to characterize the plasma. We also applied the probe to diagnostics of CVD plasmas for the low-k film formation, and fundamental data to improve the materials process were obtained.A sheath around the probe antenna a … More ffects on an absorption frequency measured with the probe, and sheath thickness is given by a several times of Debye length as a function of electron density and electron temperature. Therefore, when absorption frequencies are measured two surface wave absorption probes having different dependence on the sheath thickness, both of electron density and electron temperature can be simultaneously obtained. An antenna diameter of the probe significantly affected on the relation between the electron density and electron temperature, and the electron density satisfying the measured absorption frequency became independent of electron temperature as the antenna diameter increased. The different temperature dependence of the satisfying density between the two probes was preferable to accurately determine the density and the temperature. Therefore, the probes with much different antenna diameter were preferable to achieve accurate measurements. Finally, electron density and electron was available with the almost same accuracy of a conventional Langmuir probe.The probe revealed the following characteristics of a narrow gap CVD plasma system for low-k film deposition. (1)An electron density as well as its radial profile significantly depended on conditions such as discharge powers and operating pressures, and a correlation between radial profiles of the electron density and a deposition rate over a 12-inch-diam. silicon wafer. (2)An electron temperature decreased with an increase in the total operating pressure as well as a fraction of parent material gases. Xe addition was also effective for reduction of the electron temperature. However significant radial profile was not clearly observed.As derivative results, the probe system was also applied to other plasma systems for materials processing, and useful for their plasma diagnostics. Less