Selectivity inversion in plasma processing at low temperatures

低温等离子体处理中的选择性反转

• 批准号: 04805029
• 负责人: MATSUURA Takashi
• 金额: $ 1.34万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04805029/
• 关键词: ECR Plasma; Selectivity; Plasma CVD; Etching; Epitaxy; Adsorption & Reaction; Radical; Ion Irradiation

Plasma processing at low temperatures becomes more and more important with advancement in ultrafine pattern device fabrication technology for silicon LSTs. The present investigators have developed ultraclean processing along with precise control of ion energy in order to realize ideal intrinsic reactions between materials and plasmas.In this project, we studied on plasma processing at low temperatures without substrate heating, focusing on selectivity in surface adsorption and reaction, and found a selectivity inversion between deposition and etching. We also clarified that this is due to a competitive contribution of ion irradiation induced deposition and radical etching chemistry. Also, we studied on anisotropy control and plasma transport within an ultrafine spacing under highly selective condition, and clarified basic process such that anisotropic etching features are obtained at an effective ion etching yield less than 1, that the lateral etch rate of polysilicon increases linearly with carrier concentration and the vertical one shows square root dependence, and that the radical transport in overetching is described by a flow equation in the molecular flow regime. Futhermore, we achieved self-limited atomic layr etching by adsorption of reactive gas atoms without disturbance by contaminant gases as well as by alternate irradiation of low energy ions. This can be regarded as a final selective processing, because the reaction occurs only at the adsorbed site and not at the non-adsorbed site.The success of this project supplies a key to giga-scale integration process technologies, and we continue to study the related subjects.

随着硅LSTs超细图形器件制造技术的进步，低温等离子体工艺变得越来越重要。为了实现材料和等离子体之间理想的本征反应，目前的研究人员开发了超清洁工艺和离子能量的精确控制。在本项目中，我们研究了低温等离子体工艺，重点研究了表面吸附和反应的选择性，发现了沉积和刻蚀之间的选择性反转。我们还澄清，这是由于离子辐照诱导沉积和自由基蚀刻化学的竞争贡献。此外，我们还研究了高选择性条件下的各向异性控制和超细间距内的等离子体输运，阐明了在有效离子刻蚀产额小于1的情况下获得各向异性刻蚀特征的基本工艺，多晶硅的横向刻蚀速率与载流子浓度呈线性关系，纵向刻蚀速率与载流子浓度呈平方根相关，过刻蚀过程中的自由基输运可用分子流区的流动方程来描述。此外，我们通过吸附反应气体原子而不受污染气体的干扰，以及通过交替照射低能离子来实现自限原子层蚀。由于该反应只发生在吸附位置，而不发生在非吸附位置，因此可以认为这是一种最终的选择性处理。该项目的成功为千兆级集成工艺技术提供了关键，我们将继续研究相关课题。

项目成果

T.Matsuura, T.Ohmi, J.Murota, and S.ono: "Perfectly selective directional etching technology by ultraclean ECR plasma" Surface Science Series. No.2, Chapter 9, Realize Inc.247-258 (1993)

T.Matsuura、T.Ohmi、J.Murota 和 S.ono：“通过超净 ECR 等离子体实现完美选择性定向蚀刻技术”表面科学系列。

T.Matsuura,et al.: "Layer-by-layer etching of Si by self-limited adsorption of chlorine with alternated irradiation of low enrgy Ar^+ ions" Ext.Abstr.Int.Conf.on Solid State Devices and Materials. 83-85 (1993)

T.Matsuura 等人：“通过自限吸附氯并交替照射低能 Ar 离子来对 Si 进行逐层蚀刻”《固态器件和材料》Ext.Abstr.Int.Conf.on 固态器件和材料。

T.Maatsuura, J.Murata, Y.Sawada, and T.Ohmi: "Layr-by-layr etching of Si by self-limited adsorption of chlorine with alternated irradiation of low energy Ar^+ ions" Ext. Abstr. Int. Conf. on Solid State devices and Materials. August 29 - September 1. 83-8

T.Maatsuura、J.Murata、Y.Sawada 和 T.Ohmi：“通过低能 Ar 离子的交替照射，通过氯的自限吸附来逐层蚀刻 Si”。

T.Matsuura, J.Murota, T.Ohmi, Y.Sawada, and S.Ono: "Highly selective and atomic layr controlled etching by ultraclean ECR plasmas" Proc. Int. Conf. on advanced Microelectronic Devices and Processing. March 3-5 (invited). 139-146 (1994)

T.Matsuura、J.Murota、T.Ohmi、Y.Sawada 和 S.Ono：“超净 ECR 等离子体的高选择性和原子层控制蚀刻”Proc。

T.Matsuura, J.Murota, T.Ohmi, and S.Ono: "Side etch control of n^+-polysilicon with nitrogen added chlorine plasma" Ext. Abstr. Int. Conf. on Solid State devices and Materials. August 26-28. 418-419 (1992)

T.Matsuura、J.Murota、T.Ohmi 和 S.Ono：“用氮添加氯等离子体对 n^-多晶硅进行侧面蚀刻控制”