New Semiconducting Photoresist Enables High-Density Organic Transistor Integration on Full-Frame Chip
TapTechNews July 8th news, TapTechNews learned from the Department of Polymer Science of Fudan University that the research team of this school has designed a new type of semiconducting photoresist, and integrated 27 million organic transistors on a full-frame size chip using lithography technology and achieved interconnection, and the integration degree reaches the level of ultra-large-scale integration (ULSI).
On July 4, 2024, this result was published in Nature Nanotechnology under the title of High-Performance Large-Scale Integrated Organic Phototransistors Based on Photovoltaic Nanounits.
The degree of chip integration can be divided into small-scale integration (SSI), medium-scale integration (MSI), large-scale integration (LSI), very large-scale integration (VLSI), and ultra-large-scale integration (ULSI). Previously, the manufacturing methods of organic chips mainly include screen printing, inkjet printing, vacuum evaporation, lithography processing, etc., and the integration degree usually can only reach the level of large-scale integration (LSI).
The photoresist, also known as a photoresist, plays a key role in chip manufacturing. Through processes such as exposure and development, the required fine pattern can be transferred from the mask to the substrate to be processed, which is a basic material for a lithography process.
The Fudan team designed a new type of functional photoresist composed of a photoinitiator, a cross-linking monomer, and a conductive polymer. After photo-crosslinking, a nano-scale interpenetrating network structure is formed, which has both good semiconductor performance, lithography processing performance and process stability. This photoresist can not only achieve reliable manufacturing of sub-micrometer-scale feature-sized patterns, and this pattern itself is a semiconductor, thus simplifying the chip manufacturing process.
The interconnected array of organic transistors fabricated by lithography contains 4500×6000 pixels, and the integration density reaches 3.1×106 units per square centimeter, that is, 27 million devices are integrated on a full-frame size chip, reaching the level of ultra-large-scale integration (ULSI), and its light responsivity reaches 6.8×106 amperes per watt. The high-density array can be transferred to a flexible substrate, realizing bionic retinal applications.
The paper address: https://www.nature.com/articles/s41565-024-01707-0