IC Knowledge - Glossary

Glossary of Integrated Circuit Terminology - F

Fab - see Wafer Fabrication.
Fabless - a semiconductor company that uses foundries for all of its wafer fabrication requirements.
Fabrication - see Wafer Fabrication.
Facilities Costs - the cost to build a facility or alternately the cost of maintaining a facility, i.e., items such as facility system repair costs, insurance, ultrapure water generation, utilities, etc.
Failure Factor - utilization multiplied by the mean-time-to-repair a tool divide by the raw process time. Failure factor measures the true impact of downtime on a process.
Failure in Time - the number of failures per one billion devices hours.
Failure Rate - a rate of failures per unit time.
Farad - unit of capacitance. One farad is defined as the capacitance between two plats with 1 volt applied and charged by 1 coulomb.
Feature Size - see Minimum Geometry.
Femto - a prefix meaning one quadrillionth (x10^-15), symbol f.
Field Effect Transistor - a transistor that uses an electric field to accumulate or deplete a channel region to block or allow conduction.
Field Oxide - a thick layer of silicon dioxide that covers the area of an integrated circuit between active components.
Field Programmable Gate Array (FPGA) - a circuit made up of logic gates where the logic gate connections can be readily programmed into specific configurations.
Final Test - the test step where finished packaged devices are tested.
FIT - see Failure in Time
Flash - a type of EEPROM where data is erased in blocks. The name Flash comes from the rapid block erase operation. Flash memory requires only one transistor per memory cell versus two transistors per memory cell for EEPROMs making Flash less expensive to produce. Flash is the most popular form of nonvolatile semiconductor memory available today.
Flat Band Voltage - the voltage that when applied to a MOS Capacitor produces zero net charge in the underlying semiconductor.
Flat Zone - the region in a furnace where the temperature is controlled within some specific tolerance, for example + or - ½ degree centigrade.
Flip Flop - a latching register that maintains a consistent state until switched to a different state. The basic building block of SRAM.
Flip Chip - another name for a bumped die. Bumped die are flipped over to solder them down, hence the name flip chip.
Fluorine - atomic symbol, F, fluorine is the 9th element in the periodic table (atomic number 9) with an atomic weight of 18.998. Argon is a group VII element and is highly reactive. Flurine is used in etching gases and chemicals. Fluorine is toxic.
Forward Bias - a voltage placed across a junction in the forward direction. When a junction is forward biased to a sufficiently high voltage, current will flow.
Foundry - a wafer fabrication facility that processes wafers for other companies as a service.
Four Point Probe - a piece of metrology equipment used to measure sheet resistance. A four point probe forces a current through the two outside probes and measures the resulting voltage drop across two inside probes.
FPGA - see Field Programmable Gate Array.
Frequency - the number of times an oscillating signal goes through a complete cycle. Typically expressed as hertz.
Fringe Benefits - benefits provided in addition to salary paid wholly or in part by the employer, such as medical, dental, and or disability insurance, vacation, paid sick leave, 401k matching, pension, etc.
Fringes - abbreviation for fringe benefits.
Furnace - a type of semiconductor manufacturing equipment used to heat up groups of wafers to temperatures >200^oC and <1,300^oC, with precise temperature control. Furnaces have quartz tubes sufficiently large to hold a wafer boat and the tube is surrounded by resistance heating elements. The quartz tube has one end connected to a gas controller that allows various gases to flow through the tube, the furnace would also commonly have the ability to change temperatures in a controlled manner and insert and withdraw the wafer boat all under computer control. Computer programs may then insert the wafer boat into a controlled atmosphere, increase the temperature, make changes in the gases flowing and then reduce the temperature and withdraw the wafer boat to accomplish oxidation, diffusion, alloying or annealing. Standard furnace typically ramp-up at 5-10^oC/min. and ramp-down at 2-3^oC/min.