Mass Spectrometry, Optical Emission Spectroscopy, and Atomic Force Microscopy Studies of Si Etch Characteristics in a Cl2 Plasma Generated by an Electron Cyclotron Resonance Source.
Mass Spectrometry, Optical Emission Spectroscopy, and Atomic Force Microscopy Studies of Si Etch Characteristics in a Cl2 Plasma Generated by an Electron Cyclotron Resonance Source.
复制标题
电子回旋共振源产生的 Cl2 等离子体中硅蚀刻特性的质谱、发射光谱和原子力显微镜研究。
DOI：
10.1143/jjap.33.7112
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
S. Pang
中科院分区：
文献类型：
--
作者：
K. Sung;S. Pang
用质谱仪、光学发射光谱(OES)和原子力显微镜(AFM)研究了多极电子回旋共振源产生的Cl2等离子体对硅的刻蚀。结果表明，硅的刻蚀速率与用质谱仪测得的SiCl6 3的强度和用OES测得的634.6 nm处的硅发射强度有关。在较高的微波或射频功率下，Si的刻蚀速率、SiCl63强度和Si发射强度增加，但Si对SiO_2的选择性降低。在Cl2中加入30%O2可获得选择性>；80。用质谱仪监测了硅刻蚀的诱导时间，随着微波功率或射频功率的增加，诱导时间减小。用原子力显微镜测量表面粗糙度，表面粗糙度随微波功率或射频功率的增大而略有增加。将优化的硅腐蚀条件应用于多晶硅栅薄到栅氧化层的腐蚀。开发了一种两步腐蚀工艺，用于0.35µm多晶硅栅刻蚀，该工艺具有垂直轮廓、光滑的形貌和对底层栅氧化层的高选择性。在100%过刻蚀的情况下，仅去除了0.5 nm的栅氧化物。多晶硅栅刻蚀的终点使用质谱仪或OES进行了清楚的监测。
Etching of Si with a Cl2 plasma generated by a multipolar electron cyclotron resonance source has been studied using mass spectrometry, optical emission spectroscopy (OES), and atomic force microscopy (AFM). It is found that the Si etch rate can be related to the SiCl63 intensity measured using mass spectrometry and the Si emission intensity at 634.6 nm using OES. At higher microwave or rf power, the Si etch rate, SiCl63 intensity, and Si emission intensity increase but the selectivity of Si over SiO2 decreases. Selectivity >80 is obtained with 30% O2 addition in Cl2. The induction time for Si etching is monitored by mass spectrometry and it decreases with microwave or rf power. Surface roughness is measured by AFM and it increases slightly with microwave or rf power. The optimized condition for Si etching was applied to the etching of polysilicon gate down to the thin gate oxide. A two-step etch process was developed for the etching of 0.35 µ m polysilicon gate with vertical profile, smooth morphology, and high selectivity to the underlying gate oxide. Only 0.5 nm of the gate oxide was removed with 100% overetch. End point for polysilicon gate etching was clearly monitored using mass spectrometry or OES.