Sub-fin doping method

US10002793B1 · kind B1 · utility

Assignee

• GlobalFoundries Inc. · KY

Inventors

• Jiehui Shu · Clifton Park, US
• David Paul Brunco · Latham, US
• Jinping Liu · Ballston Lake, US
• Baofu Zhu · Clifton Park, US
• Shesh Mani Pandey · Saratoga Springs, US

Key dates

• Filing date: Mar 21, 2017
• Grant date: Jun 19, 2018
• Expiry date: Mar 21, 2037

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D84/0156
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A gap fill method for sub-fin doping includes forming semiconductor fin arrays over a semiconductor substrate, forming a first dopant source layer over a first fin array and filling intra fin gaps within the first array, and forming a second dopant source layer over a second fin array and filling intra fin gaps within the second array. The first and second dopant source layers are recessed to expose a channel region of the fins. Thereafter, an annealing step is used to drive dopants from the dopant source layers locally into sub-fin regions of the fins below the channel regions.