Exploration 1B: How Small is Small?

Zooming in on an IC Chip

As we zoom in from life size to 6400X magnification, compare the appearance of the integrated circuit chip with a common fly's eye. The lines on the surface are "micro"-wires formed from deposited metal, usually aluminum. The shadows underlying these wires are components in the next layer which are separated from the wires by a thin, insulative layer, usually silicon dioxide glass. The dark spots near the ends and/or corners of wires are contacts. These vertical, metal contacts form the circuitry between components in different layers. The box-like structure with 16 of these contacts, visible in the 200X and 400X frames, was probably designed for a high-current path.


Zooming in on an Accelerometer

This accelerometer is a microscopic sensor used to detect changes in velocity. As the movie zooms in from color images to black & white electron microscope images, notice the interdigitated fingers of the sensor. The polycrystalline silicon "fingers" of the sensor are 3-4 micrometers wide with gaps between "fingers" of 1 micrometer. The white spots visible at very high magnification result from slightly different orientations of the crystals. The fly in the corner shown at the same magnification as the accelerometer is to give you perspective for the extremely small dimensions of this chemically produced mechanical device.

This accelerometer provided by Berkeley Sensor and Actuator Center, Univ. of California, Berkeley.


Intel 486 Microprocessor Chip

Mass-produced microprocessor chip assemblies, such as this one named the 486 by Intel Corp., helped bring desktop computers into the lives and homes of millions of people. The integrated circuit chip containing millions of individual components is only about 1 cm square. The "fuzzy" fringe around the edges of the chip are very small wires which connect different contact pads of the chip with the rest of the computer.
As we zoom in 20 and then 80 times, what appeared to be lines on the surface of the chips are defined as layers.
These stair-stepping layers are most likely the insulating layers of silicon dioxide between each pair of layers of the circuit connections.

This microprocessor assembly was provided by Intel Corp. Photos were taken at U.C. Berkeley.

How small is small? | Computer Chip Thermochemistry | ChemConnections