" Small-Scale Integration " ( SSI ), were the first integrated circuits, which contained only a few transistors. They consisted of circuits, containing transistors numbering in the tens.
SSI circuits were vital to early aerospace projects. The Minuteman missile and the Apollo program both needed lightweight digital computers for their inertial guidance systems. the integrated-circuit technology development was led by the Apollo guidance computer, while the Minuteman missile bolstered it into mass-production.
The purchase of almost all of the available integrated circuits from 1960 through 1963, was from these programs, and basically almost provided the demand that funded the production improvements. In turn this got the production costs from $1000 per circuit (in 1960 dollars) to a mere $25 per circuit (in 1963 dollars). They began to become used in consumer products at the turn of the decade, for example in FM inter-carrier sound processing in television receivers.
The next step in the development of integrated circuits (in the later part of 1960s), was that of " Medium-Scale Integration " ( MSI ), this saw devices which contained hundreds of transistors on each chip. Also, these cost little more to produce than SSI devices, and also allowed more complex systems to be produced, using smaller circuit boards and less assembly work (due to fewer individual components).
Developments, were further driven by economic factors, thus led to " Large-Scale Integration " ( LSI ) by the mid 1970s. Chips now were developed with tens of thousands of transistors.
Integrated circuits such as 1K-bit RAMs, calculator chips, and the very first microprocessors had under 4000 transistors and saw a moderate quantity of manufacture in the early part of 1970. True LSI circuits, were approaching 10000 transistors and began to be produced for computer main memories and second-generation microprocessors in around 1974.
Starting in the 1980s and continuing through to this day, was "Very Large-Scale Integration" (VLSI). This starts with hundreds of thousands of transistors in the early 1980s, and continues beyond several billion transistors as of 2007.
No single breakthrough allowed the increase in complexity. Manufacturing moved to cleaner fabs and smaller rules, which allowed them to produce chips with more transistors with adequate yield, (summarized by the International Technology Roadmap for Semiconductors). Design tools also saw much improvement, this was enough to make it practical to finish the designs in reasonable times. Energy efficient CMOS replaced NMOS and PMOS, which avoided a prohibitive increase in power consumption. Many other factors helped also.
By 1986 the first one megabit RAM chips were introduced, these contained more than a million transistors. 2005 saw microprocessor chips passing the billion transistor mark. The trend continues largely unabated, with chips introduced in 2007 containing tens of billions of memory transistors.
The term ULSI that stands for " Ultra-Large Scale Integration ", this was proposed for chips of complexity of more than 1 million transistors.
Wafer-scale integration (WSI) is a system of building extremely large integrated circuits that uses a whole silicon wafer to produce a single "super-chip". Through a combination of large size and reduced packaging, WSI could lead to dramatically reduced costs for some systems, notably in massively parallel supercomputers. The name is taken from the term Very-Large-Scale Integration, the current state of the art during the development time of WSI.
System-on-a-Chip (SoC or SOC) is an integrated circuit where all the components needed for a computer (or other system), are included on a single chip. The design of this device can be costly and extremely complex, and also building disparate components on a single piece of silicon, could compromise the efficiency of some of its' elements. Nevertheless these drawbacks are offset by low manufacturing and assembly costs, and by a vastly reduced power budget (as the signals among the components are kept on-die, much less power is required).
Three Dimensional Integrated Circuit (3D-IC) has two or more layers of active electronic components, these are integrated both horizontally and vertically into a single circuit. Communication between the layers relies on on-die signaling, so the power consumption is lower than that of equivalent separate circuits. Sensible use of short vertical wires can substantially reduce the total wire length, for faster operation and efficiency.
>> go to page 1, 2, 3, 4, 5 <<