• 文献标题:   Wafer-scale graphene quality assessment using micro four-point probe mapping
  • 文献类型:   Article
  • 作  者:   MACKENZIE DMA, KALHAUGE KG, WHELAN PR, OSTERGAARD FW, PASTERNAK I, STRUPINSKI W, BOGGILD P, JEPSEN PU, PETERSEN DH
  • 作者关键词:   graphene, sic, conductance, micro fourpoint probe, terahertz spectroscopy, metrology, mapping
  • 出版物名称:   NANOTECHNOLOGY
  • ISSN:   0957-4484 EI 1361-6528
  • 通讯作者地址:   Tech Univ Denmark
  • 被引频次:   2
  • DOI:   10.1088/1361-6528/ab7677
  • 出版年:   2020

▎ 摘  要

Micro four-point probes (M4PP) provide rapid and automated lithography-free transport properties of planar surfaces including two-dimensional materials. We perform sheet conductance wafer maps of graphene directly grown on a 100 mm diameter SiC wafer using a multiplexed seven-point probe with minor additional measurement time compared to a four-point probe. Comparing the results of three subprobes we find that compared to a single-probe result, our measurement yield increases from 72%-84% to 97%. The additional data allows for correlation analysis between adjacent subprobes, that must measure the same values in case the sample is uniform on the scale of the electrode pitch. We observe that the relative difference in measured sheet conductance between two adjacent subprobes increase in the transition between large and low conductance regions. We mapped sheet conductance of graphene as it changed over several weeks. Terahertz time-domain spectroscopy conductivity maps both before and after M4PP mapping showed no significant change due to M4PP measurement, with both methods showing the same qualitative changes over time.