Atomic layer etching in continuous plasma

US9991128B2 · kind B2 · utility

Assignee

• Lam Research Corporation · US

Inventors

• Zhongkui Tan · Fremont, US
• Yiting Zhang · Fremont, US
• Ying Wu · Livermore, US
• Qing Xu · Fremont, US
• Qian Fu · Pleasanton, US
• Yoko Yamaguchi · Union City, US
• Lin Cui · Longbeilingcun, CN

Key dates

• Filing date: Jan 31, 2017
• Grant date: Jun 5, 2018
• Expiry date: Jan 31, 2037

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01J2237/334
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Methods and apparatus for etching substrates using self-limiting reactions based on removal energy thresholds determined by evaluating the material to be etched and the chemistries used to etch the material involve flow of continuous plasma. Process conditions permit controlled, self-limiting anisotropic etching without alternating between chemistries used to etch material on a substrate. A well-controlled etch front allows a synergistic effect of reactive radicals and inert ions to perform the etching, such that material is etched when the substrate is modified by reactive radicals and removed by inert ions, but not etched when material is modified by reactive radicals but no inert ions are present, or when inert ions are present but material is not modified by reactive radicals.