School of Physics, Shandong University, Jinan, 250100, China.
Nanoscale Res Lett. 2012 Aug 3;7(1):434. doi: 10.1186/1556-276X-7-434.
Using measured capacitance-voltage curves with different gate lengths and current-voltage characteristics at low drain-to-source voltage for the AlGaN/AlN/GaN heterostructure field-effect transistors (HFETs) of different drain-to-source distances, we found that the dominant scattering mechanism in AlGaN/AlN/GaN HFETs is determined by the ratio of gate length to drain-to-source distance. For devices with small ratio (here, less than 1/2), polarization Coulomb field scattering dominates electron mobility. However, for devices with large ratio (here, more than 1/2), longitudinal optical (LO) phonon scattering and interface roughness scattering are dominant. The reason is closely related to polarization Coulomb field scattering.
利用不同栅长的测量电容-电压曲线和低漏源电压下的电流-电压特性，对不同漏源距离的 AlGaN/AlN/GaN 异质结构场效应晶体管（HFET）进行研究，我们发现，AlGaN/AlN/GaN HFET 中的主要散射机制由栅长与漏源距离的比值决定。对于比值较小（小于 1/2）的器件，极化库仑场散射主导电子迁移率。然而，对于比值较大（大于 1/2）的器件，长光学（LO）声子散射和界面粗糙度散射占主导地位。这一现象与极化库仑场散射密切相关。
