Mechanisms of chemical anisotropic etching of single crystals consistently applicable throughout Micro/Meso-scopic domains

单晶化学各向异性蚀刻机制始终适用于整个微观/介观领域

基本信息

批准号：
14205016
负责人：
SATO Kazuo
金额：
$ 35.28万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14205016/
关键词：
Chemical anisotropic etching Silicon Quartz KOH TMAH Etching mechanism Surface morphology Simulation 結晶モフォロジー

项目摘要

The aim of the project is to clarify anisotropic etching mechanisms of single crystals such as silicon and quartz throughout all scales from atomistic to micrometer range. We clarified the difference in etching characteristics of two major etchants for silicon ; i.e., KOH and Tetra Methyl Ammonium Hydroxide(TMAH) solutions, in relation to those etching mechanisms. We also experimentally studied the effects of a small amount of impurities in the etchant that affect the etching rate, its anisotropy, and etched surface morphologies. We analytically verified the etching mechanism by calculating atomic removal rates at kinks and steps of a crystal surface using Monte-Carlo simulation that is based on a model considering weakening of atomic bonds caused by attachment of OH-base on the exposed surface. Etching mechanisms are well explained for silicon (111) and its vicinity. Macroscopic etching behavior is apparently dominated by the activeness of steps existing on silicon (111). This model can well explain the reverse in the anisotropy according to the difference in etching species. We recently found that the reverse in anisotropy also happens by a change in concentration of the solution. Thus the reverse in anisotropy proved not being a singular problem of the etchant, but more commonly acceptable phenomena by the change in activeness of the steps and kinks. We are further investigating the etching models for other orientations than (111).In parallel to the silicon we also characterized the anisotropic etching properties of quartz, using the same methodologies applied to silicon. We evaluated the etching rate of quartz crystal as a function of orientations. This allowed us a 3-D etching profile prediction by using a simulation. This technology is effective to design etching process of quartz for fabricating MEMS devices.

该项目的目的是阐明从原子范围到千分尺范围的所有尺度中的单晶（例如硅和石英）的各向异性蚀刻机制。我们阐明了两个硅的两个主要蚀刻剂的蚀刻特性差异。即，与这些蚀刻机制有关的KOH和四甲基氢氧化铵（TMAH）溶液。我们还通过实验研究了影响蚀刻速率，其各向异性和蚀刻表面形态的少量杂质的影响。我们通过使用蒙特卡洛模拟在扭结和晶体表面的步骤中计算原子去除速率来分析验证蚀刻机制，该模拟是基于模型，该模型考虑了由OH BASE附着在裸露表面上的原子键弱化的原子键。对于硅（111）及其附近，蚀刻机制得到了很好的解释。宏观蚀刻行为显然是由硅在硅上现有的步骤的活跃性的主导（111）。该模型可以根据蚀刻物种的差异很好地解释各向异性的相反。我们最近发现，各向异性中的反向也是由于溶液浓度的变化而发生的。因此，各向异性的逆转证明不是et鼠的一个奇异问题，而是措施和扭结的活动性的变化，更常见的现象。我们正在进一步研究其他方向的蚀刻模型（111）。在与硅平行的情况下，我们还使用应用于硅的相同方法来表征石英的各向异性蚀刻特性。我们评估了石英晶体的蚀刻速率随取向的函数。这使我们通过使用模拟进行了3-D蚀刻曲线预测。该技术可有效地设计石英蚀刻过程，用于制造MEMS设备。