[11p-W934-1~8] Advanced ion microscopy for future nano scale materials and devices

▲ [11p-W934-5] Study on magnetoresistance and carrier localization in graphene with defects induced by helium ion microscopy

〇Takuya Iwasaki¹, Shu Nakamura², Muruganathan Manoharan², Masashi Akabori², Yoshifumi Morita³, Satoshi Moriyama¹, Shinichi Ogawa⁴, Yutaka Wakayama¹, Hiroshi Mizuta^2,5, Shu Nakaharai¹ (1.NIMS, 2.JAIST, 3.Gunma Univ., 4.AIST, 5.Hitachi Camb. Lab)

Keywords:helium ion microscope, graphene, carrier localization

Since lattice defects in graphene has attracted interest for both theory and device application, some of experimental approaches for creating defects in graphene have been studied. Among these methods, helium ion irradiation by using the helium ion microscope (HIM) is a one of valuable way to introduce defects into graphene because the irradiation area can be precisely controlled due to high spatial resolution. Moreover, the crystalline integrity of graphene is preserved due to the defects in atomistic scale thanks to the high irradiation energy and dose level control. In previous, it was reported that the on/off current ratio of the graphene device is improved by introducing the defects by the HIM. To elucidate the detailed mechanism, we investigated the carrier transport of helium-ion-irradiated graphene devices and observed the negative magnetoresistance. For the fundamental understanding of this behavior, it requires the statistical analysis of the defective graphene devices with varying some experimental parameters. Here, we show the study of the carrier transport characteristics of the helium-ion-irradiated graphene devices with different dose and the channel length.