All-inkjet-printed thin-film transistors: manufacturing process reliability by root cause analysis

Area of Science:

• Materials Science
• Electrical Engineering
• Manufacturing Technology

Background:

• Inkjet printing offers a low-cost, ambient-condition alternative for fabricating electronic devices on flexible substrates.
• Traditional microelectronic manufacturing methods, like lithography, offer higher accuracy and yield but are more complex and costly.
• Inkjet-printed electronics, particularly thin-film transistors (TFTs), often exhibit lower manufacturing yields due to inherent process limitations.

Purpose of the Study:

• To conduct a detailed electrical investigation of all-inkjet-printed thin-film transistor (TFT) arrays.
• To identify and categorize the specific failures and their origins within these printed TFT arrays.
• To provide insights for optimizing the inkjet printing process to improve manufacturing yield.

Main Methods:

• Fabrication of TFT arrays using inkjet printing on flexible polymer substrates at a maximum temperature of 150°C in ambient conditions.
• Comprehensive electrical characterization of the manufactured TFT arrays.
• Root cause analysis of defective TFTs to develop failure categories and identify defect origins.

Main Results:

• Detailed electrical data revealing common failure modes in inkjet-printed TFTs.
• Categorization of defects based on root cause analysis, linking specific manufacturing variations to device failures.
• Identification of key factors contributing to lower yield in inkjet printing processes for TFTs.

Conclusions:

• Understanding TFT failure mechanisms is crucial for advancing inkjet printing technology.
• The developed failure categories provide a framework for targeted process optimization.
• This analysis facilitates yield improvement for flexible electronics manufactured via inkjet printing.