High step coverage tungsten deposition

US12002679B2 · kind B2 · utility

Assignee

• Lam Research Corporation · US

Inventors

• Michael J. Bowes · Mammoth Lakes, US
• Tsung-Han Yang · San Jose, US
• Anand Chandrashekar · Sunnyvale, US
• Xing Zhang · Hefei, CN

Key dates

• Filing date: Apr 7, 2020
• Grant date: Jun 4, 2024
• Expiry date: Jun 10, 2040

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76877
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Methods of depositing a tungsten nucleation layers that achieve very good step coverage are provided. The methods involve a sequence of alternating pulses of a tungsten-containing precursor and a boron-containing reducing agent, while co-flowing hydrogen (H2) with the boron-containing reducing agent. The H2 flow is stopped prior to the tungsten-containing precursor flow. By co-flowing H2 with the boron-containing reducing agent but not with the tungsten-containing precursor flow, a parasitic CVD component is reduced, resulting in a more self-limiting process. This in turn improves step coverage and conformality of the nucleation layer. Related apparatuses are also provided.