Convening every December in San Francisco, the International Electron Devices Meeting (IEDM) is known as the world’s top semiconductor conference. However, due to this year’s COVID-19 pandemic, the event was held through online conferences focused on several topics, including “miniaturization of next-generation semiconductor logic technology”, “memory technology” and “quantum computing”.

▲ For the first time in its history, the 66th International Electron Devices Meeting (IEDM) was held online due to the ongoing COVID-19 pandemic.

Among the published papers submitted to IEDM, a total of 20 were selected from Taiwanese research groups, with NARLabs’ Taiwan Semiconductor Research Institute (TSRI) leading four of them and assisting seven studies published by both National Chiao Tung University and National Taiwan University. Other papers put forward by Taiwanese companies include five from TSMC and four from Macronix.

NARLabs continues to set roots in fundamental research services, by leading or assisting in publications of IEDM and other index conference papers that are in line with international development trends, turning key semiconductor technologies into service platforms, and nurturing domestic talent involved in high-level master and doctoral research. This year, NARLabs’ main IEDM achievements include the following:

1. Application of advanced Heterogeneous Complementary FETs to substrates of heterogeneous channel materials
The [Heterogeneous Complementary FETs (CFET) utilizing Low-Temperature Hetero-Layers Bonding Technique (LT-HBT)] results from novel research in collaboration with Japan’s AIST. By employing this technique, individual substrates that have different channel materials can become one single substrate, and can be used to fabricate CFET. LT-HBT enables us to accomplish multiple stacks, integrate with other channel materials, and reduce device footprints in the future. These exceptional research results, born out of international collaboration, have been reported by Japan’s well-known electronic magazine, EE Times.

2. A crystal-orientation-tolerant power gating cell allocation technique for high speed and power efficient monolithic 3D low dropout regulator (LDO)
In this research, a single-crystal-island technique with adjustable grain size and placement was demonstrated by using low thermal budget green nanosecond laser recrystallization.
Due to variations and the degradation of circuit performance caused by the orientation of the grain, a crystal-orientation-tolerant power gating cell allocation technique was further proposed to overcome such issues. It reduces the voltage ripple and the voltage droop, thereby increasing LDO response speeds. (TSRI and NCTU collaboration)

3. Wafer-scale 3D stacking of MoS2/Si co-integrated CMOS devices with embedded memory functions
3D integration of MoS2 and Si CMOS is demonstrated via the wafer-scale 2D material deposition system platform and device technologies at TSRI. This study features dual functionalities of CMOS and non-volatile memories on a single device footprint, resulting in a significant increase in the density of logic and memory devices. This work is not only capable of extending Moore’s law, but also pave the way for 3D-ICs, in-memory computing, and synaptic electronics for AI applications.

4. Ultrafast laser-enabled monolithic 3D Near-Memory-Computing (NMC) circuit

TSRI and the National Tsing Hua University research team have jointly researched and developed a number of low thermal budget process technologies. In line with the etching technology capabilities accumulated by TSRI for many years, they have developed the next generation of back-end gate-all-around (GAA-FET) and ferroelectric RAM (FRAM). This has made monolithic 3D Near-Memory-Computing (NMC) circuit possible and effectively reduces the circuit area by 50%, production costs and transmission power consumption, and can also be applied to the smart IoT industry in the future.

▲ Through its deep-rooted research capacities and advanced platform capabilities, NARLabs' Taiwan Semiconductor Research Institute (TSRI) has been able to steadily increase the quality of its published research studies.

TSRI is also establishing an open information and service platform for fields such as semiconductor manufacturing, packaging and testing, IC design, silicon intellectual property, systems integration, and more. These advances quicken the development and verification of technology within Taiwan’s spheres of industry, education and research, avoiding the duplication of resources, and fomenting the integration of high-level scientific and technological talent.