Semiconductor Glossary

Tape Automated Bonding: An automated process for electrically attaching LSI chip’s connectors to a substrate using a tape (i.e., film carrier). Packaging of LSIs using TAB is called tape carrier package (TCP).

Thin Film Transistor: A transistor based on a thin film of amorphous and/or multi-crystalline silicon. It is typically used in liquid crystal displays (LCDs). TFT LCD, which uses active matrix thin film transistors, is the mainstream technology for LCDs.

Thin Film: A film with a thickness of several thousand angstroms (1 angstrom = 1/100,000,000 cm) or less. Resistors and capacitors are made by depositing a thin film of metal or a dielectric material on a ceramic or glass substrate, using processes such as chemical vapor deposition and sputtering.

Transistor: A small and lightweight three-terminal semiconductor device, often used in electronic circuits of oscillators and amplifiers. It was invented in 1948 by William Shockley, who received the Nobel Prize in Physics for this achievement in 1956 along with two others. ICs and LSIs are devices in which large numbers of transistors are integrated. There are a few theories about the etymology of the word “transistor,” one of which argues that it is an abbreviated combination of “trans-“ (as in transfer) and “resistor.”

Thin Small Outline Package: A type of thin IC package made of plastic, typically used for a memory (DRAM) module. It is a kind of small outline package (SOP) characterized by two parallel rows of electrical connecting pins, except that TSOP has to be 1.27 mm or less in height when mounted on the substrate, with a resin component of 1 mm in thickness.

Tunnel Effect (also called Tunneling or Quantum Tunneling): A phenomenon at the quantum scale in which a particle tunnels through a barrier that should be insurmountable in terms of classical physics. This quantum effect, also known as tunneling or quantum tunneling, can be explained by the uncertainty principle.

Tunnel Magneto-Resistance (TMR) Effect: A magneto-resistance effect that occurs in a magnetic tunnel junction (MTJ). When a voltage is applied to the junction, electrons tunnel through the insulator and change the electrical resistance of the junction. The effect is being applied to the MRAM device, and is also expected to radically enhance the storage density of hard disk drives, as the memory cells using the TMR effect will be far smaller than those that depend on electromagnetic induction.

Ultra-Pure Water: Water that has been purified to attain extremely low levels of conductivity, particles, bacteria, total organic carbon (TOC), etc. In LSI manufacturing processes, ultra-pure water is used to cleanse wafers. As the semiconductor integration level rises, so does the required level of water purity.

Ultra-Thin Substrate: An interposer that substitutes a lead frame to carry a chip. Chips for mobile phones and thin digital signal controllers (DSCs) require a low profile package consisting of a very thin chip combined with a substrate of less than 100μm in core thickness.

Ultra-Thin Wafer: Chip size packages (CSPs) and multi-chip packages (MCPs) found in advanced digital appliances are made possible by ultra-thin wafers of less than 100 μm in thickness. Development of 50μm-thick wafers is ongoing, but the issue of their delicate handling still needs to be addressed.

UV Lithography: A photolithography process used in semiconductor fabrication that uses ultraviolet (UV) light as the source. The process typically uses a light source producing the spectral line at 436 nm (g-line) or at an even shorter wavelength of 365 nm (i-line).

Wafer: A thin and circular slice of semiconductor material used for manufacturing ICs. Wafers are typically 0.6-0.8 mm in thickness, and the diameter can be as large as 450 mm, although the most common wafer diameter seen in mass production is 300 mm, followed by 200 mm. A large number of semiconductor devices are formed on a wafer, which are then cut into IC chips using a machine called dicer or scriber.

Wire Bonding: A process of connecting an IC chip contact pad with lead frame connectors by means of metal wire. Typically, gold wire with a diameter of 30 microns is used for this purpose in a fully automated process.

Wafer Level Chip Size Package: A type of chip size package (CSP) that uses an advanced technology to encase an IC device in resin while it is still part of the wafer. Because WLCSP’s package size is virtually the same as a bare chip and finer bump pitch can be easily achieved, it is widely used for mobile phone IC chips.

X-Ray Lithography: A lithography technology that uses as the light source soft X-rays (wavelengths: about 0.5 nm - 1.5 nm) emitted from synchrotron orbital radiation (SOR) facilities.

Zinc Oxide-Based Light Emitting Diode: An LED that uses zinc oxide (ZnO) for an epitaxial layer. It emits blue and ultraviolet light just as a GaN LED does. ZnO LEDs have several advantages over GaN LEDs: they cost less to produce, can use a lower wavelength range to broaden the choice of fluorescent materials, and emit light at higher temperatures.