integrated circuits

Definition History Fabrication process Advantages Disadvantages Applications

Definition History Fabrication process Advantages Disadvantages Applications

INTEGRATED CIRCUIT:

Integrated circuit is a microscopic array of electronic circuits and components that are diffused or implanted onto the surface of a single crystal, or chip, of semiconducting material such as silicon.

Definition History Fabrication process Advantages Disadvantages Applications

First integrated circuit was proposed by G.W.A .Dummer in 1952.

First functional integrated circuit was demonstrated and patented by Jack Kilby in 1959. Robert noyce also patented the first integrated circuit in the year 1959.

The number of transistors in an IC doubles for every 18 months.

Analog IC’sEx: op-Amps, voltage regulators

Digital IC’sEx: Micro processors,Multiplexers,decoders

Mixed signal IC’sEx: ADC,DAC

Small scale integration(SSI) Medium scale integration(MSI) Large scale integration(LSI) Very large scale integration(VLSI)Ultra large scale integration(ULSI)

System-on-a-Chip (SOC) All the components needed for a system are included on a single chip.

Three Dimensional Integrated Circuit (3D-IC)It has two or more layers of active electronic components.

Wafer-scale integration (WSI) It uses an entire silicon wafer to produce a single "super-chip".

The first microprocessor was developed by Intel Corporation in 1969.

It went into commercial production in 1971 as the Intel 4004.

Intel introduced their 8088 chip in 1979.

Definition History Fabrication process Advantages Disadvantages Applications

The construction & design plans for the chip are prepared on a computer-aided drafting machine

From the construction plans image is made into a mask.

Under precisely monitored conditions, a pure silicon crystal is grown.Heated to its melting point of about 2550°F (1400°C).Diameter is about 1.5 to 4.0 inches (3.8 to 10.2 cm) .

•A thin, round wafer of silicon is cut off the ingot using a precise cutting machine called a wafer slicer.

•Each slice is about 0.01 to 0.025 inches (0.004 to 0.01 cm) thick.

steps involved1.Wafer cleaning2.Barrier layer formation3.Photoresist application4.Soft baking5.Mask alignment6.Exposure and development 7.Hard-baking

Photolithography is the process of transferring geometric shapes on a mask to the surface of a silicon wafer.

DryDryEtch, PR strip, or clean

Rinse

•The surfaces of the wafer are coated with a layer of silicon dioxide.

A covering film of protective material is put on top of the insulating silicon dioxide.

UV-light is shown through a mask and onto the chip.

The wafer is developed, rinsed and baked.

The wafer is treated with chemicals in a process called "etching."

Horizontal Furnace

Center Zone

Flat Zone

Distance

Temperature

Heating Coils

Quartz Tube

Gas flow

Wafers

Silicon substrate

Diffusion of reactants

Metal is added to connect the components to each other in a process called metallization.

Photoresist application Imparting patterns

Development

Etching removes the metal not protected by photo resist.

This leaves a pattern of metal that is the same as the one described by the mask.

Formation of multiple layers

When the final layer of connecting metal wires have been added, the chips on the silicon wafer are tested.

The chips on the wafer are separated with a diamond saw to form individual integrated circuits.

Finally, each chip is packed into the protective casing and subjected to another series of tests.

Pins

Chip

BondingPad

1. Low cost2. High reliability 3. Low power requirements 4. High processing speeds 5. Low power dissipation6. Less weight7. Less space

Cannot be modified.Cannot be repaired.