IEDM2024|Evolution and Future Directions of Logic Device Innovations Presented by TSMC

Introduction

The semiconductor industry has undergone significant transformations since its inception, fundamentally changing the landscape of computing and information processing. This article is based on a paper presented by TSMC at the 2024 International Electron Devices Meeting (IEDM) in December, discussing the historical development of transistor technology, state-of-the-art implementations, and future directions—especially focusing on innovations beyond silicon and thermal management challenges [1].

Historical Evolution of Logic Technology

The semiconductor era began in 1947 when Bardeen, Shockley, and Brattain at Bell Labs invented the point-contact transistor. Early commercialization focused mainly on germanium-based devices, but silicon quickly became the preferred material due to its larger bandgap, lower intrinsic resistivity, and more stable oxide formation properties.

The integrated circuit (IC) era began around 1959, marked by several key innovations: Jack Kilby’s germanium hybrid IC, Robert Noyce’s first planar monolithic IC made using silicon, and Jean Hoerni’s planar processing technology. These developments laid the foundation for modern semiconductor manufacturing.

Figure 1: Evolution of logic technology from bipolar to FET, eventually advancing to CMOS implementations (1960–1990).

Key Transistor Innovations in Modern CMOS Technology

Continuous innovation in transistor architecture and manufacturing processes has been central to the industry. A major milestone was the adoption of shallow trench isolation (STI) technology around 1994, which improved narrow-channel device performance and density. As transistor dimensions further shrank, a variety of technical challenges emerged, requiring innovations in channel engineering, strain enhancement, and gate stack materials.

Figure 2: Timeline of critical structural innovations in logic transistor technology, showing progression from standard silicon to high-k metal gate, FinFET, and stacked transistor architectures.

Transistor Density Scaling and Moore’s Law

The persistent pursuit of Moore’s Law has driven continual increases in transistor density and performance. Through careful optimization of device structures and manufacturing techniques, the industry has maintained steady growth in the number of transistors per chip.

Figure 3: Graph illustrating the continued rise in logic transistor density over time, showing how technological innovations have extended Moore’s Law.

Beyond Silicon: Future Channel Materials

As silicon-based technologies approach their physical limits, researchers are actively exploring alternative channel materials that may enable continued scaling and performance improvement. These include germanium, transition metal dichalcogenides (TMDs), armchair graphene nanoribbons (a-GNRs), and carbon nanotubes (CNTs).

Figure 4: Comparison of beyond-silicon semiconductor channel materials showing mobility vs. bandgap characteristics for various candidate materials

Progress in Advanced Channel Materials

Significant progress has been made in developing alternative channel materials in recent years:

Figure 5: Experimental progress of 2D TMD transistors, illustrating improvements in performance metrics over time.

Figure 6: Schematic showing the synthesis of armchair graphene nanoribbons and resulting devices, highlighting potential for atomic-precision manufacturing.

Figure 7: Graph of increasing drive current in carbon nanotube transistors, demonstrating their scaling potential.

Future Directions in Density and Thermal Management

The industry is moving toward three-dimensional (3D) integration to further enhance system performance and energy efficiency. This approach involves stacking multiple active layers and deploying new cooling solutions to address thermal challenges.

Figure 8: Projection of transistor density scaling and thermal management demands, illustrating anticipated challenges and solutions at future technology nodes.

Conclusion

The semiconductor industry continues to evolve through innovative solutions. While silicon-based CMOS technology has been foundational in digital electronics, future progress will require a combination of new materials, novel device architectures, and advanced thermal management techniques. Successful implementation of these technologies is critical to sustaining performance scaling and managing power and thermal constraints.

Future development must strengthen research in several key areas: developing reliable and scalable beyond-silicon material processes, establishing new memory technologies compatible with advanced logic processes, and creating effective thermal management solutions for 3D integrated circuits.

Reference

[1] C. H. Diaz, "Logic Technology Device Innovations," in IEEE International Electron Devices Meeting (IEDM), San Francisco, CA, USA, Dec. 2024.