Cyclic Deposition/Etching Process to Etch a Bowing-Free SiO2 Contact Hole
Cyclic Deposition/Etching Process to Etch a Bowing-Free SiO2 Contact Hole
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用于蚀刻无弯曲 SiO2 接触孔的循环沉积/蚀刻工艺
DOI：
10.1149/1.3138134
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
S. Moon
中科院分区：
文献类型：
--
作者：
Jin;I. Jang;Seung;Chang;S. Moon
采用循环工艺刻蚀高深宽比的二氧化硅接触孔，采用C4F6/CH2F2/O2/Ar和C4F6/CH2F2/Ar等离子体交替刻蚀和沉积工艺，以减少孔壁弯曲。增加了CFx膜沉积步骤，以恢复掩模的侵蚀斜率，并在侧壁上沉积额外的钝化膜。沉积步骤的引入也提高了SiO_2对非晶态碳层掩膜的刻蚀选择性和接触孔的开孔率，开孔率定义为孔底直径与孔顶直径之比。通过调整循环过程中沉积和刻蚀步骤的持续时间，在直径为118 nm的2.3μm深的二氧化硅接触孔的刻蚀过程中，弯曲程度从连续刻蚀工艺时的9 nm降低到1 nm。
High aspect ratio SiO 2 contact holes were etched using a cyclic process, which consisted of alternating etching and deposition steps using C 4 F 6 /CH 2 F 2 /O 2 /Ar and C 4 F 6 /CH 2 F 2 /Ar plasmas, respectively, to minimize the sidewall bowing of the hole. A CF x -film deposition step was added to recover the eroded slope of the mask and to deposit an additional passivation film on the sidewall. The introduction of the deposition step also improved the etch selectivity of SiO 2 toward the amorphous carbon layer mask and the open ratio of the contact hole, which was defined as the ratio of the hole diameter at the bottom to that at the top of the hole. By regulating the durations of the deposition and etching steps in the cyclic process, the degree of bowing, which was 9 nm when using a continuous-etching process, was reduced to 1 nm during the etching of a 2.3 μm deep SiO 2 contact hole with a diameter of 118 nm.