不同栅绝缘层工艺下a-IGZO TFT电学特性与缺陷态密度对比研究

Comparative Study on Electrical Characteristics and Defect State Density of a-IGZO TFTs under Different Gate Insulator Processes

摘要

非晶铟镓锌氧化物（a-IGZO）薄膜晶体管（TFT）因高迁移率和低温制备特性在平板显示中具有广泛应用，但由于氧空位（Vo）的存在，a-IGZO TFT易受负栅压光照应力（NBIS）影响而发生阈值电压漂移。本文对比研究了不同SiO₂栅绝缘层（GI）工艺条件下制备的顶栅a-IGZO TFT的电学特性；并通过TCAD仿真对其Vo含量进行提取与对比。实验结果显示，采用较低N₂O比例制备的栅绝缘层的顶栅a-IGZO TFT在能够具有更好器件性能且Vo含量更低。

Abstract

Amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) have been widely used in flat-panel displays due to their high mobility and low-temperature fabrication. However, a-IGZO TFTs are susceptible to threshold voltage shift under negative bias illumination stress (NBIS) caused by the presence of oxygen vacancies (Vo). This study compares the electrical characteristics of top-gate a-IGZO TFTs fabricated under different SiO₂ gate insulator (GI) process conditions, and extracts and compares their Vo content using TCAD simulation. Experimental results show that top-gate a-IGZO TFTs with gate insulators prepared using a lower N₂O ratio exhibit better device performance and lower Vo concentration.

关键词

非晶铟镓锌氧化物 / 薄膜晶体管 / 氧空位 / 栅绝缘层 / TCAD仿真

Key words

amorphous indium gallium zinc oxide / thin-film transistor / oxygen vacancy / gate insulating layer / TCAD simulation

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