College of Engineering  |  Department of Electrical Engineering and Computer Science  |  ECE Division

Contact Information:
Prof. J. Kanicki
University of Michigan
EECS Department
2307 EECS Bldg.
1301 Beal Ave
Ann Arbor, MI 48109-2122

Tel: (734) 936-0964 (Office)
Tel: (734) 936-0972 (Lab)
Fax: (734) 615-2843

Shipping Info: Click Here

Research Index

Composition Analysis of Amorphous IGZO TFT under Positive Bias Temperature Stress

Gokul Prakash and Jerzy Kanicki

research 62aAmorphous Indium Gallium Zinc oxide (a-IGZO) has been found to be a possible alternative to the already mature amorphous silicon technology used in display applications. IGZO thin film transistors (TFT) are better than their predecessors in terms of mobility (>10cm2/V-s). We have performed high resolution transmission electron microscopy, EDS analysis, SIMS analysis and Atom Probe tomography analysis of sputtered amorphous Indium Gallium Zinc Oxide TFT’s on silicon before and after Positive BTS. The effect of the positive and negative bias temperature stress on the concentrations of indium, gallium, zinc and oxygen are analyzed.

We have evaluated the changes in elemental composition of the constituent elements Indium, Gallium, Zinc and Oxygen. This data would prove to be very useful in determining the failure mechanisms of thin film transistors using a-IGZO as the active material.

Thin film transistors were fabricated with channel lengths L=100um, 150um and 200um with channel width of 300um. The TFT devices were subjected to positive bias temperature stress at 80°C and subjected to HRTEM and Energy Dispersive Spectroscopy. The concentration of oxygen in the TFT was seen to change by a drastic amount under PBTS.   

research 62b


Copyright © 2006 The Kanicki Laboratory | Site design: Academic Web Pages