Investigation of bowing reduction in SiO2 etching taking into account radical sticking in a hole
Investigation of bowing reduction in SiO2 etching taking into account radical sticking in a hole
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DOI：
10.1143/jjap.46.7870
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发表时间：
2007-12-01
期刊：
影响因子：
--
通讯作者：
Momon, Yoshinori
中科院分区：
文献类型：
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作者：
Izawa, Masaru;Negishi, Nobuyuki;Momon, Yoshinori
研究了高深宽比接触孔（HARC）刻蚀中孔壁反应性粘附的弯曲机理。通过比较观察到的沉积轮廓与计算的自由基在侧壁上的粘附系数进行了估计。发现富C自由基和CFx自由基的系数分别为0.5和0.004，并且F自由基对氟碳聚合物的反应概率为0.07。这些系数值是由HARC腐蚀过程中孔壁上过量的O和F通量引起的。研究还表明，减少氧气流量可以抑制弯曲。利用超高频电子回旋共振（UHF-ECR）等离子体的实验结果证实了这些发现。
The bowing mechanism in high-aspect-ratio contact hole (HARC) etching was investigated by taking into account reactive sticking on the sidewall of the hole. Sticking coefficients of radicals on the sidewall have been estimated by comparing the observed deposition profile with the calculated one. It was found that the coefficients of C rich radicals and CFx radicals were 0.5 and 0.004, respectively, and that F radical reaction probability to the fluorocarbon polymer is 0.07. These coefficient values were deduced that the excessive flux of O and F onto the sidewall of a hole causes bowing during HARC etching. It was also indicated that the bowing can be suppressed by reducing of the flux of oxygen. These findings were confirmed by the results of experiments using an ultra-high frequency-electron cyclotron resonance (UHF-ECR) plasma.