Method for fabrication of high aspect ratio trenches and formation of nanoscale features therefrom

US9653309B2 · kind B2 · utility

Assignee

• The Regents of the University of California · US

Inventors

• Robert C. Dynes · Village of La Jolla, US
• Peter Roediger · San Diego, US
• Travis Joseph Wong · Village of La Jolla, US
• Shane A. Cybart · Corona, US

Key dates

• Filing date: May 24, 2013
• Grant date: May 16, 2017
• Expiry date: Jun 29, 2033

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/31138
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A process for forming trenches in a target material includes forming a masking layer onto the target material, where the masking layer comprises a material having high selectivity to a plasma etch gas adapted for etching the target material. A pattern is formed in the masking layer to expose portions of the target material and the sample is placed on an angle mount at a pre-determined angle relative to a cathode of a reactive ion etcher so that the target material is within a plasma dark space of the plasma etch gas. Ballistic ions within the plasma dark space form a trench structure within the target material. The process may further include repeating the steps of positioning the sample and etching the exposed portions of the target material with the substrate at a different angle to define a triangular structure.