Patterning of thick electroplated CoPt magnets using SU-8 micromoulds

Micro & nano letters

article

Yuzheng Wang¹  Renuka Bowrothu¹  Yong-Kyu Yoon¹  David P. Arnold¹ 

[1] Interdisciplinary Microsystems Group (IMG), Department of Electrical and Computer Engineering, University of Florida

关键词: photoresists;    moulding;    metallic thin films;    cobalt alloys;    microfabrication;    scanning electron microscopy;    electroplating;    platinum alloys;    magnetic thin films;    electromagnets;    CoPt;    size 25.0 nm;    time 4.0 hour;    size 100.0 mum;    vibrating sample magnetometer;    scanning electron microscope;    optical profilometer;    electrodeposition;    hydrofluoric acid;    sacrificial layer;    silicon wafers;    film patterning;    complete process flow;    high-energy-density permanent-magnet microstructures;    ultra-thick patterned cobalt platinum magnets;    sputtered titanium layer;    constant magnetic performance;    pattern definition;    SU-8 2050 electroplating moulds;    thick-film photoresist mould materials;    aggressive electroplating conditions;    electroplated cobalt platinum magnetic films;    SU-8 micromoulds;   

DOI  :  10.1049/mnl.2019.0287

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

Recently, electroplated cobalt platinum (CoPt) magnetic films have been developed that afford thick (up to ∼100 μm), high-energy-density (up to ∼100 kJ/m 3 ) permanent-magnet microstructures. However, the aggressive electroplating conditions have shown to be incompatible with most thick-film photoresist mould materials, making patterning these films an unanswered technical challenge. In this work, it is reported a complete process flow of fabricating and removing SU-8 photoresist moulds to enable the ultra-thick patterned CoPt magnets on silicon wafers. The implementation of thick SU-8 2050 electroplating moulds makes it feasible to deposit 100 µm thick CoPt magnets in 4 h. A 25 nm thick sputtered titanium layer is used as a sacrificial layer to completely release the SU-8 mould in hydrofluoric acid after electrodeposition. Compared to prior research, significantly improved pattern definition and constant magnetic performance are observed and characterised by optical profilometer, scanning electron microscope, and vibrating sample magnetometer.

【 授权许可】

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