Control of surface reactions in high-performance SiO2 etching
Control of surface reactions in high-performance SiO2 etching
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DOI：
10.1116/1.1305807
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发表时间：
2000-07-01
影响因子：
1.4
通讯作者：
Sekine, M
中科院分区：
文献类型：
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作者：
Tatsumi, T;Matsui, M;Sekine, M
利用多种原位测量工具，研究了双频（27 MHz和800 kHz）平行板体系中SiO2腐蚀速率与反应物质入射通量的关系。C4F8/Ar/O-2用作蚀刻气体。同时测量了刻蚀SiO2表面的氟碳聚合物层的稳态厚度TC-F。SiO2的腐蚀速率可能与总F原子通量Gamma（F-total）有关，其取决于C-F反应物质的入射通量和表面反应概率s， s是反应层净能量（V-net）的函数。该能量由入射离子能量和蚀刻表面上C-F聚合物的能量损失决定。V-net从500到1450 V的变化估计对应于s从0.01到0.1的变化。当过量的C-F物质供给蚀刻表面时，C-F聚合物TC-F的稳态厚度增加。厚的聚合物（TC-F bbb10nm）降低了离子能量，减缓或停止了细孔的蚀刻。厚度为5nm的聚合物可使离子能量降低约750 V。因此，在蚀刻高向接触孔时必须控制TC-F。(C) 2000年美国真空学会。[s0733 - 211 x(00) 05004 - 6]。
The relation between SiO2 etch rates and incident fluxes of reactive species in a dual-frequency (27 MHz and 800 kHz) parallel-plate system was evaluated by using various in situ measurements tools. C4F8/Ar/O-2 was used for etching gases. The steady-state thickness TC-F of a fluorocarbon polymer layer on the etched SiO2 surface was also measured. The SiO2 etch rate could be related to total F atom flux Gamma(F-total), which depends on both the incident fluxes of C-F reactive species and the surface reaction probability s. The s is a function of the net energy on the reactive layer (V-net). This energy is determined by the incident ion energy and the energy loss at the C-F polymer on the etched surface. A change in V-net from 500 to 1450 V was estimated to correspond to a change in s from 0.01 to 0.1. The steady-state thickness of the C-F polymer TC-F increased when excess C-F species were supplied to the etched surface. A thick polymer (TC-F>1 nm) decreases the ion energy and slows or stops the etching in fine holes. A polymer 5 nm thick can decrease the ion energy by about 750 V. The TC-F must therefore be controlled when high-aspect contact holes are etched. (C) 2000 American Vacuum Society. [S0733-211X(00)05004-6].