Pooja Pheiroijam, Chien Chun Che, Chin Albert
Department of Electronics Engineering, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan.
Nanomaterials (Basel). 2023 Jun 20;13(12):1892. doi: 10.3390/nano13121892.
This work reports the first nanocrystalline SnON (7.6% nitrogen content) nanosheet n-type Field-Effect Transistor (nFET) with the transistor's effective mobility (µ) as high as 357 and 325 cm/V-s at electron density (Q) of 5 × 10 cm and an ultra-thin body thickness (T) of 7 nm and 5 nm, respectively. At the same T and Q, these µ values are significantly higher than those of single-crystalline Si, InGaAs, thin-body Si-on-Insulator (SOI), two-dimensional (2D) MoS and WS. The new discovery of a slower µ decay rate at high Q than that of the SiO/bulk-Si universal curve was found, owing to a one order of magnitude lower effective field (E) by more than 10 times higher dielectric constant (κ) in the channel material, which keeps the electron wave-function away from the gate-oxide/semiconductor interface and lowers the gate-oxide surface scattering. In addition, the high µ is also due to the overlapped large radius s-orbitals, low 0.29 m effective mass (m*) and low polar optical phonon scattering. SnON nFETs with record-breaking µ and quasi-2D thickness enable a potential monolithic three-dimensional (3D) integrated circuit (IC) and embedded memory for 3D biological brain-mimicking structures.
这项工作报道了首个具有高达357和325 cm²/V-s有效迁移率（µ）的纳米晶SnON（氮含量7.6%）纳米片n型场效应晶体管（nFET），其电子密度（Q）为5×10¹² cm⁻²，超薄体厚度（T）分别为7 nm和5 nm。在相同的T和Q下，这些µ值显著高于单晶硅、铟镓砷、绝缘体上硅（SOI）薄膜、二维（2D）二硫化钼和二硫化钨。研究发现，在高Q时µ衰减率比SiO/体硅通用曲线慢，这是由于沟道材料中有效场（E）低一个数量级，而介电常数（κ）高10倍以上，这使得电子波函数远离栅极氧化物/半导体界面并降低了栅极氧化物表面散射。此外，高µ还归因于重叠的大半径s轨道、低至0.29 m⁺的有效质量（m*）和低极性光学声子散射。具有破纪录µ和准二维厚度的SnON nFET为潜在的单片三维（3D）集成电路（IC）和用于3D生物脑模拟结构的嵌入式存储器提供了可能。
