Introduction to VLSI (Very Large Scale Integration)

Historical Background

• First transistor (1947): Invented by William B. Shockley, John Bardeen, and Walter H. Brattain at Bell Laboratories
• First IC (1958): Invented by Jack Kilby with germanium material at Texas Instruments
• First monolithic IC (1959): Invented by Robert Noyce using silicon and copper interconnects
• MOSFET transistor (1959): Invented by Mohamed M. Atalla and Dawon Kahng

What is an Integrated Circuit (IC)?

• Integrated Circuit (IC): A set of electronic circuits on one small flat piece (or "chip") of semiconductor material, normally silicon
• Integration: Process of placing multiple transistors on a single silicon wafer

Evolution of IC Technology

• 1947: First transistor invented
• 1958: First IC made with germanium
• 1959: MOSFET invented, leading to rapid IC advancement
• 2000 onward: Reduction in transistor size
  • 1999: 180 nm
  • 2002: 130 nm
  • 2005: 90 nm
  • 2008: 70 nm
  • 2011: 50 nm
  • 2014: 35 nm
  • 2016: 20 nm
  • 2019: 7 nm
  • 2021: 5 nm (ongoing research)

Classification of ICs

Based on Scale of Integration

• SSI (Small Scale Integration): <12 circuits, 1-10 transistors
• MSI (Medium Scale Integration): 12-99 circuits, 10-500 transistors
• LSI (Large Scale Integration): 100-999 circuits, 500-20,000 transistors
• VLSI (Very Large Scale Integration): 10,000-99,999 circuits, 20,000-1 million transistors
• ULSI (Ultra Large Scale Integration): 100,000-999,999 circuits, 1-100 million transistors
• GSI (Giga Scale Integration): 100 million to unlimited transistors
• WSI (Wafer Scale Integration): Entire wafer used to produce circuits
• SOC (System on Chip): All components of a system on a single chip
• 3D ICs: Multi-layer ICs

Based on Functionality

• Analog ICs/Linear ICs: Operate on analog signals
• Digital ICs: Operate on digital signals
• Mixed Signal ICs: Operate on both analog and digital signals

Based on Structure

• Monolithic ICs: Single silicon chip
• MOS ICs: Metal-Oxide-Semiconductor ICs
• Film ICs: Thin and thick film ICs

Based on Logic Families

• Bipolar ICs: Use bipolar junction transistors
  • E.g., ECL (Emitter-Coupled Logic)
• Unipolar ICs: Use field-effect transistors
  • E.g., NMOS, PMOS, CMOS

Technology Roadmap Trends

• Reduction in feature size over time has allowed more transistors per chip
• Tailored for high-speed applications and greater integration

Moore's Law

• Formulated by Gordon Moore (1960s): Co-founder of Intel
• Observation: Number of transistors on a chip doubles approximately every 18 months

Key Takeaways

• VLSI: Facilitates the creation of integrated circuits with thousands to millions of transistors
• Future Directions: Continued miniaturization and integration for advanced computing and electronics

Upcoming Topics

• Detailed study of VLSI technologies, including MOS technologies and their electrical behaviors