The document discusses the history and development of VLSI (Very Large Scale Integration) technology and Moore's Law over time. It describes how transistors have gotten smaller through scaling, allowing more to fit on chips. This doubling of transistors every couple years is known as Moore's Law. 3D VLSI is presented as a potential solution to continue following Moore's Law by building chips in three dimensions rather than just two. Key challenges of 3D integration are also outlined.
2. The beginning Microprocessors are essential to many of the products we use every day such as TVs, cars, radios, home appliances and of course, computers. Transistors are the main components of microprocessors. At their most basic level, transistors may seem simple. But their development actually required many years of painstaking research. Before transistors, computers relied on slow, inefficient vacuum tubes and mechanical switches to process information. In 1958, engineers managed to put two transistors onto a Silicon crystal and create the first integrated circuit, which subsequently led to the first microprocessor.
3. Transistor Size Scaling MOSFET performance improves as size is decreased: shorter switching time, lower power consumption. 2 orders of magnitude reduction in transistor size in 30 years.
4. Significant Breakthroughs Transistor size : Intel’s research labs have recently shown the world’s smallest transistor, with a gate length of 15nm. We continue to build smaller and smaller transistors that are faster and faster. We've reduced the size from 70 nanometer to 30 nanometer to 20 nanometer, and now to 15 nanometer gates. Manufacturing process : A new manufacturing process called 130 nanometer process technology (a nanometer is a billionth of a meter) allows Intel today to manufacture chips with circuitry so small it would take almost 1,000 of these "wires" placed side-by-side to equal the width of a human hair. This new 130-nanometer process has 60nm gate-length transistors and six layers of copper interconnect. This process is producing microprocessors today with millions of transistors and running at multi-gigahertz clock speeds. Wafer size : Wafers, which are round polished disks made of silicon, provide the base on which chips are manufactured. Use a bigger wafer and you can reduce manufacturing costs. Intel has begun using a 300 millimeter (about 12 inches) diameter silicon wafer size, up from the previous wafer size of 200mm (about 8 inches).
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11. Ever since the invention of integrated circuit, the smallest feature size has been reducing every year. Currently (2002) the smallest feature size is about 0.13 micron. At the same time the number transistors per chip is increasing due to feature size reduction and increase in chip area. Classic example is the case of memory chips: Gordon Moore of Intel in early 1970s found that: “density” (bits per chip) growing at the rate of four times in 3 to 4 years - often referred to as Moore’s Law. In subsequent years, the pace slowed down a bit, data density has doubled approximately every 18 months – current definition of Moore’s Law .
18. Die Size Growth Die size grows by 14% to satisfy Moore’s Law Courtesy, Intel 4004 8008 8080 8085 8086 286 386 486 Pentium ® proc P6 1 10 100 1970 1980 1990 2000 2010 Year Die size (mm) ~7% growth per year ~2X growth in 10 years
19. Clock Frequency Lead microprocessors frequency doubles every 2 years P6 Pentium ® proc 486 386 286 8086 8085 8080 8008 4004 0.1 1 10 100 1000 10000 1970 1980 1990 2000 2010 Year Frequency (Mhz) 2X every 2 years Courtesy, Intel
Staffing costs computed at $150K/staff year (in 1997 dollars)
While the cost of producing a single transistor has dropped exponentially over the past few decades, the basic cost equation hasn’t changed. Cost of a circuit is dependent upon the chip area. Alpha depends upon the complexity of the manufacturing process (and is roughly proportional to the number of masks). A good estimate for today’s complex CMOS process is alpha = 3. Defects per unit area is a measure of the material and process-induced faults. A value between 0.5 and 1 defects/cm**2 is typical today but strongly depends upon the maturity of the process.
While the cost of producing a single transistor has dropped exponentially over the past few decades, the basic cost equation hasn’t changed. Cost of a circuit is dependent upon the chip area. Alpha depends upon the complexity of the manufacturing process (and is roughly proportional to the number of masks). A good estimate for today’s complex CMOS process is alpha = 3. Defects per unit area is a measure of the material and process-induced faults. A value between 0.5 and 1 defects/cm**2 is typical today but strongly depends upon the maturity of the process.