Quantification of VUV photon and particle fluxes in low pressure plasmas for surface treatment

在用于表面处理的低压等离子体中，紫外线（UV），特别是真空-紫外光谱范围（VUV）的光子通量对材料表面具有决定性影响。能量分辨量化和必要时调整这些通量是优化各自等离子体过程的基本条件。因此，需要应用VUV光谱仪，其需要直接进入等离子体室，并且其复杂的强度校准需要在现场进行。因此，到目前为止，基础研究只存在于非常具体的应用或仅限于模拟。该项目旨在对用于表面处理的等离子体中的紫外和真空紫外光子通量及其与发生的粒子通量的相关性进行系统的波长分辨量化。第二步将开发一种便携式测量设备，以便在工艺等离子体中获得相关的真空紫外/紫外光子通量。调查是在一个专门的实验室实验配备了适当的诊断通量表征：强度校准发射光谱从真空紫外到近红外光谱范围，可移动的朗缪尔探针以及能量分辨质谱。的测量是由碰撞辐射建模，包括等离子体内的光子的再吸收的影响，以确定主要的影响等离子体参数上发出的辐射的协助。同时，将开发一个紧凑的测量装置的原型，以量化工艺等离子体的能量分辨真空紫外/紫外光子通量。该仪器基于VUV敏感光电二极管和可互换滤光片，可根据特定的工艺气体进行选择。实验室设置提供了一个独特的机会，以绝对校准的真空紫外光谱仪为基准的设备。为了证明其对等离子体处理的适用性，将在三个与表面处理相关的不同实验中对该设备进行最终测试。

Photon fluxes in the ultraviolet (UV) and in particular in the vacuum-ultraviolet spectral range (VUV) within low pressure plasmas for surface treatment can have a decisive impact on the material's surface. Energy resolved quantification and if necessary tuning of these fluxes is elementary for optimizing the respective plasma processes. Therefore, VUV spectrometers need to be applied, which require direct access to the plasma chamber and whose complex intensity calibration needs to be performed on-site. Hence, up to now fundamental studies exist only for very specific applications or are limited to simulations. This project aims at the systematic wavelength-resolved quantification of the UV and VUV photon fluxes in plasmas used for surface treatment and their correlation to the occurring particle fluxes. A portable measurement device is to be developed in a second step, in order to make relevant VUV/UV photon fluxes at process plasmas accessible. The investigations are conducted at a dedicated laboratory experiment equipped with the appropriate diagnostics for the flux characterization: intensity calibrated emission spectroscopy from the VUV through to the NIR spectral range, a moveable Langmuir probe as well as energy resolved mass spectrometry. The measurements are assisted by collisional-radiative modelling including the effects of reabsorption of photons within the plasma, in order to determine the main influencing plasma parameters on the emitted radiation. In parallel a prototype for a compact measurement device to quantify energy resolved VUV/UV photon fluxes at process plasmas will be developed. The instrument is based on a VUV sensitive photodiode and interchangeable filters, which are to be selected with regard to the particular process gases. The laboratory setup gives the unique opportunity to benchmark the device against the absolutely calibrated VUV spectrometer. In order to demonstrate its applicability to process plasmas the device will conclusively be tested at three different experiments related to surface treatment.