The glossary section provides brief descriptions of technical terms used throughout this website.
Absolute Pressure
Pressure measured relative to zero pressure (perfect vacuum) in mass flow controllers.
Actual Flow
The gas flow as measured by an external standard in a mass flow device, not the electrical output of a mass flow meter.
Ambient Pressure
The absolute pressure of the medium surrounding the mass flow controller.
Base
The platform on which a mass flow controller's components are mounted. Contains channels that form the main flow path of the gas.
Bypass
A mass flow controller component that maintains a constant ratio of gas flow through the device's sensor and main flow path, dividing the gas stream precisely over the entire calibrated flow range. Enables the total flow to be determined by measuring just the portion of gas that passes through the sensor. Also known as the flow splitter.
Calibration Gas
The gas that flows through a mass flow device during calibration.
Calibration Temperature
The ambient temperature at which a mass flow device is calibrated.
Chamber
The portion of the process tool where actual chip processing takes place. The chamber is typically constructed of metal and operates in a vacuum.
Chip
An individual semiconductor integrated circuit or discrete device on a wafer, also commonly referred to as a die.
CMOS
Complementary metal-oxide-semiconductor; most common type of transistor structure.
Conductor
A material, such as metal, that conducts electrical current.
Control Valve
A mass flow controller component that establishes gas flow by responding to a signal that compares actual flow with the set point. Driven by actuators that are either piezoelectric, solenoid, or thermal, depending on the model.
CVD
Chemical vapor deposition is a method for depositing certain materials that function as insulating (dielectric) or conducting layers on a chip. A chemical containing atoms of the material to be deposited reacts with another chemical, liberating the desired material, which deposits on the wafer while byproducts of the reaction are removed from the reaction chamber.
Dead Time
In mass flow controller testing, the interval of time between the set point step change and the start of the resulting observable response.
Deposition
A process in which a thin film of material is placed on the surface of a wafer.
Device
A semiconductor component.
Die
An individual semiconductor integrated circuit or discrete device on a wafer; also referred to as a chip.
Differential Pressure
The difference in absolute pressure between two points of measurement in a system. The measured difference in pressures between the gas inlet and outlet fittings of a mass flow controller, typically.
DRAM
Dynamic random access memory; a common type of volatile memory chip.
Etch
Plasma etch is a dry etch process that uses reactive gases energized by a plasma field. The etch market consists of three segments: metal, polysilicon and oxide etch.
Fab
A semiconductor fabrication (manufacturing) facility.
Integrated Circuit
An electric circuit where all of the elements of the circuit (e.g., capacitors, resistors, transistors, diodes, and fuses) are integrated together on one piece of semiconductor material (e.g., typically silicon).
Logic
This is a type of semiconductor chip, which is a collection of digital circuit elements that perform logical functions; a microprocessor is a common type of logic chip.
Mass Flow Controller (MFC)
A device used to measure and control the flow of gases.
Micron
One-millionth (10-6) of a meter and often represented by a µ; typically referenced in conjunction with the linewidth of a feature on a semiconductor device. In comparison, a human hair is about 100µ thick.
Module
Refers to an arrangement of integrated components used in semiconductor or thin film substrate manufacturing equipment. Modules perform specific functions and are typically integrated with, or designed into, a process tool.
Nanometer
One-billionth (10-9) of a meter. The wavelength of light that is used in the photolithography process is measured in nanometers (nm).
Plasma
An ionized gas consisting of electrically charged particles (ionized particles).
Pressure
The force exerted on an area divided by the size of the area (i.e., force per unit of area).
Pressure Transducer
A device designed to measure pressure.
Process Tool
A piece of semiconductor manufacturing equipment. Also referred to as a “tool”.
PVD
Physical vapor deposition, also called sputtering, is a process in which molecules of conducting material (e.g., aluminum, titanium nitride, copper) are sputtered from a target of pure material, then deposited on the wafer to create the conducting circuitry on the wafer. In the dual damascene copper process, PVD is used to deposit both the barrier layer and copper seed layer.
Semiconductor
A material whose electrical conductivity is intermediate between that of metals (conductors) and insulators (dielectrics) and can be modified physically or chemically to increase or decrease its conductivity from a normal state by dopants.
Silicon
The most common element used to manufacture transistors and integrated circuits; a natural semiconductor because it can either act as a conductor or insulator of current, depending on how it is doped.
Subsystem
Refers to an arrangement of integrated components used in semiconductor or thin film substrate manufacturing equipment. Subsystems perform specific functions and are typically integrated with, or designed into, a process tool.
Torr
A pressure unit of measure. One torr is the gas pressure necessary to raise a column of mercury by 1mm at 0° C.
Transistor
A type of semiconductor that performs the core switching function in an integrated circuit. It consists of three terminals: the source, the gate and the drain.
Vacuum
A low-pressure state necessary for certain semiconductor manufacturing processes. A vacuum environment eliminates contaminating gases and provides a more uniform and controllable process.
Vacuum Gauge
A device used to measure the pressure in a vacuum.
Voltage
An electrical force causing current to flow. In the ion implantation process, this is often referred to as energy (e.g., high energy, ultra-low energy).
Wafer
A thin, circular slice of pure silicon on which semiconductors are built. Also called a substrate. The current-generation wafer size is 8 inches, or 200mm, in diameter. Next-generation wafers will be 12 inches, or 300mm, in diameter. Larger wafers allow more chips to be built per wafer.
Yield
A percentage used to measure the number of good die manufactured on a silicon wafer.