Self-Consistent Technique for Extracting Density of States in Amorphous InGaZnO Thin Film Transistors
Self-Consistent Technique for Extracting Density of States in Amorphous InGaZnO Thin Film Transistors
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非晶 InGaZnO 薄膜晶体管态密度提取自洽技术
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
D. Kim
中科院分区：
文献类型：
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作者：
Jun‐Hyun Park;K. Jeon;Sang Won Lee;Sangwook Kim;Sunil Kim;I. Song;Jae;Young;C. J. Kim;D. M. Kim;D. Kim
本文提出并论证了一种用于提取非晶铟镓锌氧化物（a-IGZO）薄膜晶体管态密度[DOS：g（E）]的自洽技术。关键参数是a-IGZO有源层的g（E）和本征沟道迁移率（μ ch）。当通过光子能量和栅极-源极电压（VGS）扫描来扫描能级（E）时，从电容-电压特性的光学响应提取其密度。以VGS依赖的μ ch为另一边界条件，充分考虑VGS与E的非线性关系，将一个假定VGS与E之间为线性关系的线性映射DOS转化为最终DOS.最后，通过对基于DOS的μ ch模型进行数值迭代，找到满足线性映射DOS和μ ch的实测VGS依赖性的自洽解，提取并验证最终DOS.采用指数尾态和高斯深态的计算公式，计算得到的最终态密度参数为：NTA = 1.73 × 1017 cm-3eV-1，NDA = 3.5 × 1015 cm-3eV-1，kTTA = 0.023eV，KTDGA = 1.2eV，EO = 1.7eV.
The self-consistent technique for extracting density of states [DOS: g(E)] in an amorphous indium gallium zinc oxide (a-IGZO) thin film transistor is proposed and demonstrated. The key parameters are the g(E) of the a-IGZO active layer and the intrinsic channel mobility (μ ch ). While the energy level (E) is scanned by the photon energy and gate-to-source voltage (V GS ) sweep, its density is extracted from an optical response of capacitance-voltage characteristics. Using the V GS -dependent μ ch as another boundary condition, a linearly mapped DOS assuming a linear relation between V GS and E is translated into a final DOS by fully considering a nonlinear relation between V GS and E. The final DOS is finally extracted and verified by finding the self-consistent solution satisfying both the linearly mapped DOS and the measured V GS dependence of μ ch with the numerical iteration of a DOS-based μ ch model. The extracted final DOS parameters are N TA = 1.73 × 10 17 cm -3 eV -1 , N DA = 3.5 × 10 15 cm -3 eV -1 , kT TA = 0.023 eV, KT DGA = 1.2 eV, and E O = 1.7 eV with the formula of exponential tail states and Gaussian deep states.