Development of finishing methods for creation of atomically flat side-surfaces of three-dimensional nano-devices utilizing defect-site selective reactions

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H02483
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 26050:Material processing and microstructure control-related
• Research Institution: Nara Institute of Science and Technology
• Principal Investigator: HATTORI Ken 奈良先端科学技術大学院大学, 先端科学技術研究科, 准教授 (00222216)
• Co-Investigator(Kenkyū-buntansha): 服部 梓 大阪大学, 産業科学研究所, 准教授 (80464238)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 三次元立体形状試料 / 表面原子平坦化 / 側壁表面 / ファセット表面 / ウェットプロセス / 走査トンネル顕微鏡 / 電子回折

Outline of Final Research Achievements

Micro-scale three-dimensional silicon samples with atomically flat faceted surfaces (surfaces tilted from the substrate surface) were fabricated from a silicon substrate by lithography and then heating it in a vacuum.
One of the innovations for the atomically flattening is the selection of the solution in the etching process as the final step of the lithography; we promote the etching reaction from specific defect sites that can reduce the roughness of the surface. Another idea is to optimize the vacuum heating conditions to flatten the surface roughness by surface atom diffusion; we found that a temperature lower than a typical heating temperature of 150 to 200℃ is better for finishing the atomic flat surface and maintaining the three-dimensional shape.

Free Research Field

表面科学

Academic Significance and Societal Importance of the Research Achievements

立体形状をもつシリコン・デバイスの精緻な形状制御は、医療用マイクロ流路や加速度センサー等のMEMSデバイス、高密度立体トランジスタなどの最新の立体半導体デバイスなど、多くのテクノロジーを支える基盤技術の１つです。立体形状シリコンの表面は原子精度で平坦とは言えず、最先端のデバイスにおいてはパフォーマンスの劣化を招いていました。本研究の成果は、原子平坦な立体形状シリコンを創り出す技術に直結しており、デバイス・パフォーマンスの向上に寄与するものです。