section_path: Generations/Very-large-scale integration (VLSI)
section_name: Very-large-scale integration (VLSI)
paragraph_text: Very-large-scale integration (VLSI)
  
  "Very-large-scale integration" (VLSI) is a development started with hundreds of thousands of transistors in the early 1980s, and, as of 2023, transistor counts continue to grow beyond 5.3 trillion transistors per chip.
  
  Multiple developments were required to achieve this increased density. Manufacturers moved to smaller MOSFET design rules and cleaner fabrication facilities. The path of process improvements was summarized by the International Technology Roadmap for Semiconductors (ITRS), which has since been succeeded by the International Roadmap for Devices and Systems (IRDS). Electronic design tools improved, making it practical to finish designs in a reasonable time. The more energy-efficient CMOS replaced NMOS and PMOS, avoiding a prohibitive increase in power consumption. The complexity and density of modern VLSI devices made it no longer feasible to check the masks or do the original design by hand. Instead, engineers use EDA tools to perform most functional verification work.
  
  In 1986, one-megabit random-access memory (RAM) chips were introduced, containing more than one million transistors. Microprocessor chips passed the million-transistor mark in 1989, and the billion-transistor mark in 2005. The trend continues largely unabated, with chips introduced in 2007 containing tens of billions of memory transistors.