Anisotropic Etching of Si and WSiN Using ECR Plasma of SF_6-CF_4 Gas Mixture

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概要

• 論文の詳細を見る

• The characteristics of Si etching with electron cyclotron resonance (ECR) plasma of SF_6-CF_4 are studied in order to improve anisotropy in dry etching using fluoride gases. Si undercutting is decreased by increasing the amount of CF_4. Si patterns with vertical sidewalls are obtained with an etch rate of 40 nm/min. Oxygen addition to SF_6-CF_4 increaes Si/SiO_2 etching selectivity to more than 10, but does not cause any undercutting. It is concluded that carbon (C) that decomposes from CF_4 protects the pattern sidewall from undercutting by fluorine radicals. These results are applied to the anisotropic etching of WSiN as the gate material for GaAs metal-semiconductor field effect transistors (MESFETs). WSiN patterns are more vertical when the chamber inner wall exposed to SF_6-CF_4ECR plasma is stainless steel rather than quartz. This is attributed to the reduction of the amount of CO, which possibly forms volatile tungsten-carbonyl [W(CO)_6] and, along with fluorine radicals, causes undercutting. It is confirmed that the stainless steel inner wall does not cause serious wafer contamination by metallic elements when WSiN patterns are almost vertically etched.

• 社団法人応用物理学会の論文
• 2000-06-15

著者

• TAKAHASHI Chiharu

  NTT Telecommunications Energy Laboratories

• Nishimura Kazumi

  Ntt Telecommunications Energy Laboratories

• Jin Yoshito

  Ntt Telecommunications Energy Laboratories

• Matsuo Seitaro

  Ntt Telecommunications Energy Laboratories

関連論文

• Electron Cyclotron Resonance Plasma Etching of α-Ta for X-Ray Mask Absorber Using Chlorine and Fluoride Gas Mixture
• Etching Characteristics of α-Type Ta Film Using Cl_2 Electron Cyclotron Resonance(ECR)Plasma
• Anisotropic Etching of Si and WSiN Using ECR Plasma of SF_6-CF_4 Gas Mixture
• Electron Cyclotron Resonance Plasma Etching of $\alpha$-Ta for X-Ray Mask Absorber Using Chlorine and Fluoride Gas Mixture

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