# Fileset

[APL_2025_sasama_SupplementalInformation.pdf](https://mdr.nims.go.jp/filesets/da3cdd2a-b8e4-423c-a1c4-9adfc71072e5/download)

## Creator

[Yosuke Sasama](https://orcid.org/0000-0002-8358-6101), [Takuya Iwasaki](https://orcid.org/0000-0002-1103-2433), [Masataka Imura](https://orcid.org/0000-0002-4236-9549), [Kenji Watanabe](https://orcid.org/0000-0003-3701-8119), [Takashi Taniguchi](https://orcid.org/0000-0002-1467-3105), [Yamaguchi Takahide](https://orcid.org/0000-0003-0208-7317)

## Rights

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Yosuke Sasama, Takuya Iwasaki, Masataka Imura, Kenji Watanabe, Takashi Taniguchi, Yamaguchi Takahide; Enhanced channel mobility of hexagonal boron nitride/hydrogen-terminated diamond heterojunction field-effect transistor. Appl. Phys. Lett. 6 October 2025; 127 (14): 143502 and may be found at https://doi.org/10.1063/5.0272041. [In Copyright](http://rightsstatements.org/vocab/InC/1.0/)

## Other metadata

[Enhanced channel mobility of hexagonal boron nitride/hydrogen-terminated diamond heterojunction field-effect transistor](https://mdr.nims.go.jp/datasets/d2f9924d-39e7-4a01-b92f-ee4209fb3779)

## Fulltext

Supplementary Information for “Enhanced channel mobility of hexagonal boronnitride/hydrogen-terminated diamond heterojunction field-effect transistor”Yosuke Sasama,1, a) Takuya Iwasaki,2 Masataka Imura,3 Kenji Watanabe,3Takashi Taniguchi,2 and Yamaguchi Takahide2, 41)International Center for Young Scientists, National Institute for Materials Science,Tsukuba 305-0044, Japan2)Research Center for Materials Nanoarchitectonics, National Institute for MaterialsScience, Tsukuba 305-0044, Japan3)Research Center for Electronic and Optical Materials,National Institute for Materials Science, Tsukuba 305-0044,Japan4)University of Tsukuba, Tsukuba 305-8571, Japana)SASAMA.Yosuke@nims.go.jp1A. Time variation of transfer characteristicsThe electrical properties of the FET fabricated in this study were maintained over along period. Figure S1 shows the transfer characteristics measured on different days. Aslight increase in sheet conductance was observed between the initial measurement andmeasurement performed 356 days later. However, no significant change in characteristicswas observed between the measurements performed 356 and 705 days later. Between themeasurements, the sample was stored in a desiccator filled with nitrogen.Figure S1: Transfer characteristics of sample B1 measured on different days. The dotted line representsthe sheet conductance measured while sweeping the gate voltage in the positive direction, and the solidline represents the sheet conductance measured while sweeping the gate voltage in the negative direction.The initial measurement (blue solid line) was performed simultaneously with the Hall-effect measurement(Figs. 2c,d). The transfer characteristics shown in Fig. 2a are the characteristics measured 356 days afterthe initial measurement.B. Calculation of Hall mobilityAs mentioned in the main text, a fringe current path is considered to exist in the regionwhere the diamond surface is hydrogen-terminated and covered by h-BN but is outside thearea under the gate electrode. To avoid overestimating mobility due to the side current path,we calculate the mobility from the sheet conductance after subtracting the conductance ofthe side current path using the following equation: µHall = (σ − σ(VGS = 0)(Wh−BN −WG)/Wh−BN)/(nHe). Here, σ is the sheet conductance, σ(VGS = 0) is the sheet conductance2at VGS = 0 V, Wh−BN is the width of h-BN, and WG is the gate width. Figure S2 depicts theHall mobility with and without the inclusion of this correction. The corrected Hall mobilityis shown in Fig. 2d of the main text.Figure S2: Gate voltage dependence of Hall mobility at 300 K with (blue) and without (black) thesubtraction of the fringe conductance effect.C. Temperature dependence of mobility at different gate voltagesFigure S3a shows the temperature dependence of mobility at VGS = −2, −4 and −6 V.The temperature dependence of mobility at different gate voltages exhibits nearly the samebehavior. Figures S3b and S3c show the results of fitting the temperature dependence ofmobility at gate voltages of −2 and −4 V with the theoretical model.3Figure S3: (a) Temperature dependence of mobility at different gate voltages for sample B1. (b)(c)Theoretical analysis of the temperature dependence of mobility at (b) VGS = −2 V and (c) −4 V. Redcircles show experimental results. Solid lines show the results of the theoretical calculation of mobility.The labels “ic,” “sr,” “ac,” and “op” indicate the calculated mobilities limited by interface charges, surfaceroughness, acoustic phonon, and optical phonon, respectively. The mobility limited by backgroundimpurity scattering is higher than the plot range. The label “tot” indicates the calculated mobilityconsidering all the above scattering mechanisms.4