Mechanism for anisotropic etching of photoresist-masked, polycrystalline silicon in HBr plasmas
Mechanism for anisotropic etching of photoresist-masked, polycrystalline silicon in HBr plasmas
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DOI：
10.1116/1.588439
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发表时间：
1996-01-01
影响因子：
1.4
通讯作者：
Donnelly, VM
中科院分区：
文献类型：
--
作者：
Cheng, CC;Guinn, KV;Donnelly, VM
在螺旋谐振器HBr等离子体中蚀刻后，多晶硅（poly-Si）的微米尺寸的功能掩模与光致抗蚀剂（PR）进行了研究，角度分辨X射线光电子能谱和扫描电子显微镜，空间分辨表面化学成分。多晶硅侧壁和沟槽底部以及PR侧壁覆盖有一至两个SiBr和SiBr 2单层。PR表面顶部不存在SiBrx物质。在多晶硅侧壁上没有检测到碳或氧，这表明没有发生来自PR的拐角和侧面的溅射侵蚀的碳的视线沉积。由于Br原子与多晶硅反应非常缓慢，相对于离子辅助蚀刻速率，各向异性蚀刻不需要PR侵蚀产物的侧壁钝化。但是，SiBrx层确实在PR侧壁上形成，并且可以在抑制掩模的横向腐蚀和改善用HBr相对于Cl-2等离子体蚀刻的轮廓控制方面发挥作用。(C)1996年美国真空学会。
After etching in a helical resonator HBr plasma, polysilicon (poly-Si) micron-size features masked with photoresist (PR) were investigated with angle-resolved x-ray photoelectron spectroscopy and scanning electron microscopy to spatially resolve surface chemical compositions. The poly-Si sidewalls and trench bottoms, and the PR sidewalls are covered with one to two monolayers of SiBr and SiBr2. No SiBrx species are present on top of the PR surfaces. No carbon or oxygen were detected on the poly-Si sidewalls, suggesting that line-of-sight deposition of carbon from sputter erosion of the corners and sides of the PR does not occur. Because Br atoms react very slowly with poly-Si, relative to the ion-assisted etch rates, anisotropic etching does not require sidewall passivation from products of PR erosion. A SiBrx layer does form on the PR sidewall, however, and could play a role in suppressing lateral erosion of the mask and improving profile control with HBr versus Cl-2 plasma etching. (C) 1996 American Vacuum Society.