Evaluation of the Effect of Impurities in Hexagonal Boron Nitride Single Crystals on Insulation Properties

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K14559
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 28020:Nanostructural physics-related
• Research Institution: The University of Tokyo
• Principal Investigator: Onodera Momoko 東京大学, 生産技術研究所, 特任助教 (10907819)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: 六方晶窒化ホウ素 / 二次元層状物質

Outline of Final Research Achievements

To evaluate the effect of impurities in hexagonal boron nitride (h-BN) on voltage holding capability, carbon annealed and unannealed crystals were used. The flakes were then fabricated on a SiO2 substrate by a mechanical cleavage method using adhesive tape. The flakes were placed on the metal electrode on the SIO2 substrate using PVC. The devices were fabricated by sandwiching h-BN between the top and bottom electrodes, and measurements were performed at room temperature and at cryogenic temperatures. Measurements were performed at room temperature and cryogenic temperatures. The behavior of the withstand voltage curve changed between the cases with and without carbon atoms doped.

Free Research Field

二次元材料

Academic Significance and Societal Importance of the Research Achievements

炭素ドープ結晶とドープしていない結晶において耐電圧曲線の振る舞いが異なることが確かめられたが、この振る舞いの違いに関しては一つのフレーク内でもばらつきがある。このばらつきの要因としては転写時にh-BN層にあかるひずみによるh-BNへの欠陥の導入、あるいは転写時にh-BNと接触したPVCから付着したポリマー残渣の影響が考えられる。そこで、これらの転写による原子層へのダメージを極力少なくするため、PVC転写の開発に取り組んできた。その結果として、PVCの膜厚制御による持ち上げ温度変化や転写効率の向上に成功している。