Simulation for evaluation of secondary electron signals in helium ion microscope

2014 Fiscal Year Final Research Report

• Project/Area Number: 24560029
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Thin film/Surface and interfacial physical properties
• Research Institution: The University of Tokushima
• Principal Investigator: OHYA Kaoru 徳島大学, ソシオテクノサイエンス研究部, 教授 (10108855)
• Co-Investigator(Kenkyū-buntansha): YAMANAKA Takuya 徳島大学, ソシオテクノサイエンス研究部, 技術専門職員 (00546335)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: イオン顕微鏡 / 二次電子放出 / ヘリウムイオン / シミュレーション

Outline of Final Research Achievements

A simulation code based on a microscopic model for ion-solid interactions was developed for secondary electron (SE) emission of samples impacted by an ion beam. The code can calculate emission characteristics such as the SE yield and the emission energy and angle of SEs. The characteristics showed better spatial resolution and clearer material, topographic and voltage contrasts in helium ion microscope (HIM), compared with scanning electron microscope and gallium ion microscope.
Realistic sample surfaces, such as a 100 nm-high trench-structured Si surface and 10-100 nm thick SiO2 films on Si were irradiated with He ion beams to make SE profiles. The comparisons with the observation images and calculated profiles revealed the formation mechanisms of edge and charging contrasts in HIM. Channeling contrast of crystalline sample images were modeled by molecular dynamics. Sample damages by the ion irradiation were simulated by using a dynamic Monte Carlo simulation code.

Free Research Field

電子、イオン、プラズマと固体との相互作用のシミュレーション