Focused ion beam repair for quartz bump defect of alternating phase-shift masks

Autor: Daichi Kakuta, Hiroichi Kawahira, Ichiro Kagami, Tooru Komizo
Rok vydání: 2001
Předmět:
Zdroj: SPIE Proceedings.
ISSN: 0277-786X
DOI: 10.1117/12.438391
Popis: An alternating phase shift mask (Alt-PSM) technique is one of the candidates to extend the KrF excimer laser lithography generation. One of the issues for practical fabrication of Alt-PSMs is a repair of quartz bump defects. A conventional focused-ion beam (FIB) repair technique has been investigated for quartz bump defect etching using (beta) -gas which has been introduced as a gas assist etching (GAE) gas for MoSi based att-PSMs. Tow kinds of software developed by Seiko Instruments are newly introduced to etch precisely quartz bump defects. We have prepared dual trench type alt-PSMs, which have programmed defects with various heights and sizes. It is confirmed that the FIB repair tool can image a quartz defect of 50nm height and 0.1micrometers size. We have optimized the parameters for quartz etching rate for each defect type. Transmittance and printability of repaired points are confirmed with AIMS. This paper describes the feasibility of FIB repair of alt-PSMs in terms of quartz etching rate repeatabiliity, and printability of repaired points.
Databáze: OpenAIRE