arXiv subjects

Liankai Zheng

Publications and source records attributed to Liankai Zheng.

3 recordsLinked to original sources

arXiv2026

Investigation of Hopping Conduction and Its Impact on the Subthreshold and Transition Region Transport in Oxide Semiconductor Transistors by Magneto-Transport Measurements

In this work, magneto-transport measurements, including Hall effects and magnetoresistance (MR) at various temperatures, are employed to directly probe the electron transport properties in crystalline indium oxide (In2O3) and amorphous indium-zinc oxide (IZO) transistors. For the first time, we develop a subgap density of states (DOS) extraction method based on the MR measurements at low temperature, considering both the interference and orbital shrinkage effects. The sign and magnitude of MR are used as direct evidence to distinguish the dominating transport mechanisms between hopping conduction and free-electron conduction. It is found that crystalline In2O3 exhibits a subgap DOS more than two orders of magnitude lower than that of amorphous IZO, together with a smaller localization radius of hopping sites. As a result, crystalline In2O3 not only enhances the carrier mobility but also significantly reduces the supply voltage (VDD) because of the smaller transition region enabled by the much-suppressed subgap DOS. This study reveals that structural disorder critically influences the device operation in the subthreshold and transition regions of oxide semiconductor transistors.

cond-mat.mtrl-sci↗

arXiv2026

High-Performance Scaled P-Type SnOx Transistor by Atomic Layer Deposition with CFET Integration

The development of high-performance p-type oxide semiconductors is essential for realizing complementary logic for monolithic 3D integration, yet p-type oxide semiconductors still exhibit substantially inferior performance compared with their n-type counterparts. In this work, we demonstrate high-performance p-type SnOx transistors by atomic layer deposition (ALD), as back-end-of-line compatible devices for monolithic 3D integration. The SnOx transistors exhibit high field-effect mobility of 6.9 cm2/Vs, low subthreshold swing (SS) of 185 mV/dec, decent on/off ratio (ION/IOFF) of 1.8*104 and high bias stability. By scaling the channel length down to 80 nm, a high on-current of 38.7 mA/mm at VDS of -1 V is achieved. It is understood that precursor and reaction engineering to suppress Sn4+ component in SnOx film are the key for performance enhancement. Furthermore, a complementary field-effect transistor with ALD SnOx p-FET vertically stacking on ALD In2O3 n-FET is also demonstrated, achieving maximum voltage gain of 21 V/V at VDD of 4 V. These findings suggest ALD SnOx as a promising candidate for scaled high-performance BEOL p-type transistors.

cond-mat.mtrl-sci↗

arXiv2025

Are There High-Density Deep States in AtomicLayer-Deposited IGZO Thin Film?

It has been well recognized that there exist high-density deep states in IGZO thin films. Many of the device characteristics of IGZO transistors, such as negative bias illumination stability (NBIS),were understood to be related to these deep states. However, in this work, it is found that deep state density (NtD) of atomic-layer-deposited (ALD) IGZO transistors can be an ultra-low value (2.3*10^12 /cm^3) by the proposed NBIS-free light assisted I-V measurements so that the deep states do not affect the I-V characteristics even in subthreshold region. This work also reveals that NBIS is not related to the photoexcitation of electrons in deep states. Our results suggest that the existence of deep states and the impact of deep states on ALD IGZO transistors may need to be revisited.

cond-mat.mtrl-sci↗