Alan Freedman -- The Computer Language Company - Computer Desktop Encyclopedia
Computer Desktop Encyclopedia
Longest-Running Tech Reference on the Planet

A CDE Definition

You'll love The Computer Desktop Encyclopedia (CDE) for Tech Term of the Day (TTOD)

LOOK UP ANOTHER TERM


wafer

(1) A small continuous-loop magnetic tape cartridge that was used from time to time for data storage. See Stringy Floppy.

(2) The base unit of chip making. A wafer is a slice taken from a salami-like silicon crystal ingot up to 450 mm (17.7") in diameter. The larger the wafer, the more chips produced in a single production pass, which comprises a series of photomasking, etching and implantation steps. Wafers are approximately 1/30th of an inch thick; however, the actual layers of transistors that make up the active circuitry are only a few microns deep.

Wafers started out being very small from one to three inches in diameter. Then came 100mm ingots (3.9"), followed by 125, 150, 200 and 300mm. Various wafer sizes are used today depending on the type of chip being made. See chip and wafer scale integration.




The Boule Is Sliced
The silicon ingot, which is known as a "boule," is sliced into wafers. (Image courtesy of IBM.)











Different Sizes
The person at the top is holding 150mm wafers; in the middle 200mm; and 300mm at the bottom. (Images courtesy of Texas Instruments, Inc., Advanced Micro Devices, Inc. and Intel Corporation, respectively).







Heating the Wafers
The red glow comes from a furnace that reaches 1000 degrees centigrade. The semiconductor wafers are baked in the oven to prepare them for the chip-making process. (Image courtesy of Intel Corporation.)






Personal Use Only

Before/After Your Search Term
BeforeAfter
W3wafer scale integration
W3Cwaffle
W3C SchemaWAFL
W3C XML SchemaWAIS
WAwait state
WAAWake-on-LAN
WAASwalkie talkie
Wabiwalking 1s test
WACWalkman
WADLwalkthrough

Terms By Topic
Click any of the following categories for a list of fundamental terms.
Computer Words You Gotta KnowSystem design
Job categoriesUnix/Linux
Interesting stuffPersonal computers
InternetIndustrial Automation/Process Control
Communications & networkingAssociations/Standards organizations
HistoryDesktop publishing
Audio/VideoGraphics
MainframesSecurity
ProgrammingHealthcare IT
System design