16-04-2013, 02:46 PM
Very large scale integration (VLSI)
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INTRODUCTION
Very-large-scale-integration (VLSI) is defined as a technology that allows the construction and interconnection of large numbers (millions) of transistors on a single integrated circuit.
Integrated circuit is a collection of one or more gates fabricated on a single silicon chip.
Wafer is a thin slice of semiconductor material on which semiconductor devices are made. Also called a slice or substrate.
Why IC?
Integration improves the design:
higher speed;
lower power;
physically smaller.
Integration reduces manufacturing cost-(almost) no manual assembly.
Applications of VLSI
Personal entertainment systems such as portable MP3 players and DVD players perform sophisticated algorithms with remarkably little energy.
• Electronic systems in cars operate stereo systems and displays; they also control fuel injection systems, adjust suspensions to varying terrain, and perform the control functions required for anti-lock braking (ABS) systems.
• Digital electronics compress and decompress video, even at high definition data rates, on-the-fly in consumer electronics.
• Low-cost terminals for Web browsing still require sophisticated electronics, despite their dedicated function.
Integrated Circuit Manufacturing
ability to manufacture huge numbers of very small devices.
Technology---Mask Driven Manufacturing
The fabrication process forms patterns on wafers that create wires and transistors.
IC manufacturing is efficient bcoz many identical chips can be produced by processing a single wafer.
Manufacturing Defects
Each chip is individually tested.
Working chips are placed in the packages familiar to digital designers.
IC manufacturing is powerful for 2 reasons:
1.All ckts can be made out of few types of transistors and wires.
2.Any combination of wires and transistors can be built by changing the mask.
Moore’s Law
The development of integration technology has followed the famous Moore’s Law. It was stated by Gordon Moore, co-founder of Intel, in the year 1965, that “the number of transistors per chip would grow exponentially (double every 18 months)”. In fact the doubling period has shortened to a mere 12 months!
Terminology
Manufacturing/Technology node: technology at a particular channel length.
Family of technologies at similar sizes can be refered as micron,submicron and deep submicron.
Deep submicron technology: 250-100 nm.
Nanometer technology: 100 nm and below.