MEMC Glossary - MEMC Electronic Materials, Inc.

KKerf: The notch left by a saw cut; the width of a saw cut.Kerf Loss: The amount of material lost while slicing wafers. The kerf is the cut and swarf is the chips and fillings from the kerf.LLapping: Process to remove controlled amounts of silicon from the slice using a lapping compound. This process removes sawdamage and positively impacts the slice’s flatness.Laser mark: Method of identification required by some customers. Series of letters and numbers inscribed onto the wafer by laser.Lifetime: The average time a free-electron or hole can exist in a crystal, measured in seconds. Lifetime may vary within a crystal:bulk lifetime within the crystal and surface lifetime at, of course, the surface.Linear Thickness Variation: Thickness variation within a slice whose front and back surfaces can be represented by two, nonparallelplanes.Local or Site Flatness: Flatness of specifically defined areas on the slice.Lot: Group of wafers going to the same area with the same identities and are to be processed together.Low Temperature Oxide (LTO): Sealant to keep the dopant in the wafer when it goes through the Epi process. It is applied inFurnace/Enhanced Gettering Area.LPCVD: Low Pressure CVD, deposits a layer of polysilicon to the wafer, later removed by polishing. A backside layer can act as agettering agent.LPD: Light Particle Defect, sometimes known as particles.MMelt: The pure, molten silicon from which single crystal silicon is grown in a crystal pulling furnace during the Czochralski process.Meltdown: Changing a polysilicon charge from a solid to a liquid state by heating it in the crystal puller.Micron: A unit of length, 1/1,000,000 (one millionth) of a meter.MOScap: Test structure used for Bvox, GOI, VTW, and Zerbst tests. Capacitor structure: silicon wafer/gate oxide/polysilicon gate.NNanotopology: Surface variations over a small areaN-Type: Property of the silicon semiconductor material. Doping with donor atoms increases the density of negative charge carriers(electrons) in the conduction band and produces an N-type semiconductor.Neck: Portion of the crystal below the seed and above the taper. The first growth step in a crystal.OOhm: Unit of electrical resistance.Oi: Interstitial Oxygen.Opposite End (OE): End of the grown crystal rod. Known more formally as the ‘tang’ portion of the rod.Optical Comparator: Instrument held close to the wafer’s edge for evaluation of the edge grinding process.Optical Precipitation Profiler (OPP): Non-destructive measurement of bulk defects.