Method to make interferometric taper waveguide for HAMR light delivery

US9183854B2 · kind B2 · utility

Assignee

• WESTERN DIGITAL (FREMONT), LLC · US

Inventors

• Dujiang Wan · Fremont, US
• Ge Yi · Pleasanton, US
• Lijie Zhao · San Jose, US
• Hai Sun · Milpitas, US
• Yunfei Li · Fremont, US

Key dates

• Filing date: Jun 13, 2014
• Grant date: Nov 10, 2015
• Expiry date: Jun 13, 2034

Classification

• Technology area (CPC G): Physics
• CPC primary: G11B2005/0021
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A method for making an interferometric taper waveguide (I-TWG) with high critical dimension uniformity and small line edge roughness for a heat assisted magnetic recording (HAMR) head, wherein the method includes creating an I-TWG film stack with two hard mask layers on top of an I-TWG core layer sandwiched between two cladding layers, defining a photoresist pattern over the I-TWG film stack using deep ultraviolet lithography, transferring the pattern to the first hard mask layer using reactive ion etching (RIE), forming a temporary I-TWG pattern on the second hard mask layer using RIE, transferring the temporary pattern to the I-TWG core using RIE, refilling the cladding layer, and planarizing using chemical mechanical planarization (CMP).