Reactive Ion Etching in VHF Diode Reactors

摘要Murnick CTS-9419440 所提出的工作的主要目标是确定的VHF二极管反应器的有效性，在CF 4等离子体中的硅的反应离子蚀刻。 PI指出，至少在非晶硅沉积的情况下，在VHF（30-300 MHz）频率而不是在标准13.56 MHz下操作可以导致增加的沉积速率、减少的损坏和增加的膜均匀性。 PI预计，与标准100 KHz-13.56 MHz范围相比，VHF范围内的放电物理特性会有很大不同，并从他们之前的工作结果中提供了一些证据。 他们指出，VHF操作尚未应用于蚀刻，并建议确定蚀刻速率，均匀性，各向异性和损伤的CF 4等离子体中的硅蚀刻。 将采用13.56至135 MHz的频率、1至50 mTorr的压力和宽范围的施加电压。 如果可能的话，将确定优化蚀刻工艺的某些方面的等离子体条件。 对蚀刻材料的诊断将与便利地位于蒙茅斯堡的陆军研究实验室合作进行，使用标准的表面技术，包括SEM、轮廓测量法和TEM。 还将使用ARL的微波干涉仪，目前借给罗格斯大学，以测量绝对的，空间平均等离子体密度。 亚稳态氩种群也将使用视线自吸收技术进行测量。 PI还建议与科学研究协会的Meya Meyyappan博士合作，建立实验等离子体的模型。 他希望为PI提供他目前的1-D等离子体模拟代码的2-D版本，并将协助建模工作，以便为蚀刻结果的解释提供支持。

Abstract Murnick CTS-9419440 The primary objective of the proposed work is to determine the effectiveness of a VHF diode reactor for reactive ion etching of silicon in CF4 plasmas. The PI's point out that operation at VHF ( 30-300 MHz) frequencies rather than at the standard 13.56 MHz, at least in the case of amorphous silicon deposition, can result in increased deposition rates, reduced damage, and increased film uniformity. The PI's expect the discharge physics to be quite different in the VHF regime as compared to the standard 100 KHz-13.56 MHz range and provide some evidence for this from results of their previous work. They point out that VHF operation has not as yet been applied to etching, and propose to determine etch rates, uniformity, anisotropy and damage for the etching of silicon in CF4 plasmas. Frequencies from 13.56 to 135 MHz, pressures from 1 to 50 mTorr, and a wide range of applied voltages will be employed. If possible, plasma conditions which optimize certain aspects of the etch process will be identified. Diagnostics on the etched materials will be carried out in collaboration with the Army Research Laboratory conveniently located at Fort Monmouth, using standard surface techniques including SEM, profilometry, and TEM. Use will also be made of ARL's microwave interferometer, currently on loan to Rutgers, to measure absolute, spatially averaged plasma densities. Meta-stable argon populations will also be measured using a line-of sight self-absorption technique. The PI's also propose to collaborate with Dr. Meya Meyyappan of Scientific Research Associates in the modeling of the experimental plasmas. He hopes to provide the PI's with a 2-D version of his current 1-D plasma simulation code and will assist in the modeling effort in order to provide support for the interpretation of the etching results.