Computing-in-memory with thin-filmtransistors: challenges and opportunities

Abstract

Thin-film transistor (TFT) has attracted enormous interests recently for its great potential in a wide range of edge computing applications, benefitting from its large-area low-cost flexible fabrications, and well integration with sensors and displays. With the support of in-situ processing of sensor data, TFT-based edge systems show their advantages in large-scale dense sensing with real-time energy-efficient processing and interaction, and more excitingly, it provides the opportunity of eliminating the massive data transfer to the cloud servers. However, the design of high-performance processing modules based on TFT is difficult, due to large device variation, poor stability, and low mobility. Computing-in-memory (CiM), which has been proposed recently as a high-efficiency high-parallelism computing approach, is expected to improve the capacity of TFT-based edge computing systems. In this survey, various recent works on TFT-based CiM have been summarized, showing the superiority to conventional processing flow by efficient in-memory analog computation with mitigation of data transfer, and reduced ADC usage for sensor data. With both opportunities and challenges, the design space and trend of TFT-based CiM to be explored are then described. Finally, further development and co-optimization from device to system are discussed for flourishing of the next-generation intelligent TFT-based edge system.

Capacitorless Two‐Transistor Dynamic Random‐Access Memory Cells Comprising Amorphous Indium–Tin–Gallium–Zinc Oxide Thin‐Film Transistors for the Multiply–Accumulate Operation

“…[13][14][15][16][17] These cells satisfy the conditions for synaptic devices, such as low power consumption and rapid write/read operations; thus, they have attracted attention in neural networks. [18][19][20] However, MAC operation using these cells has not yet been realized. In this study, we first examined the feasibility of 2T0C DRAM cells comprising amorphous indium-tin-gallium-zinc oxide (a-ITGZO) TFTs and then demonstrated, for the first time, the MAC operation of these cells.…”