Method and device for thin-film ablation of a substrate

US6566628B2 · kind B2 · utility

Assignee

• Siemens and Shell Solar GmbH · NL

Inventors

• Helmut Vogt · Munich, DE
• Franz Karg · Munich, DE

Key dates

• Filing date: Oct 5, 2001
• Grant date: May 20, 2003
• Expiry date: Oct 5, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F71/00
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

A method and device for thin-film ablation of a substrate of a workpiece, more particularly, for surface layer ablation of a thin-film solar cell. The device comprises a laser resonator for generating a light pulse machining beam having pulse durations smaller than 100 ns and a pulse energy density between 0.1 and 10 J/cm2, and a controllable positioner for positioning the workpiece relative to the machining beam such that an amount of energy impinging the surface to be machined is substantially constant for each unit of surface area. The device further includes an optical system arranged in a path of the machining beam, including an optical fiber cable and an optical imaging member for imaging an output of the optical fiber cable on a surface of the workpiece, the optical system being configured such that, in a plane of the surface to be machined, the power distribution is substantially homogenous.