
ASML is one of the world’s leading manufacturers of chip-making equipment. Headquartered in Veldhoven, the Netherlands, ASML employs more than 21,000 people.
ASML reveals its backlog once per quarter during its financial results announcements.
The book-to-bill ratio is a measure of the total orders taken or ‘booked’ over the total orders for which those same companies have received payment or ‘billed.’ For example, a book-to-bill ratio of 0.9 means that for every dollar of orders billed; only US$ 0.90 of the orders were booked.
The book-to-bill ratio is important when looking at the chipmakers – ASML’s clients -- because it gives an overall sense of supply and demand. When the number is below 1.00, it suggests that there is more supply than demand. Chipmakers typically buy new equipment when demand is high and supply is low.
Integrated circuits or chips are made in a clean room – an area virtually free of dust and other airborne particles. The air in the clean room is circulated through filters that capture any particles larger than the filter’s pore size.
If particles were to land on a wafer during processing, the chips created from that wafer would have defective structures and would not function.
Photo resist is light-sensitive material that coats a wafer so images can be etched onto the wafer’s surface. It is resistant to acid and may be a liquid spun onto wafers.
A photoresist consists of a film-forming polymer, a photosensitive material, a solvent and an additive.
Coming from sand, silicon is the material from which most semiconductors are made.
To create a wafer from silicon, purified polycrystalline silicon is heated to a molten liquid. A small piece of solid silicon is placed on the molten liquid, and as the seed is pulled from the molten liquid, it cools to form a single crystal ingot. The crystal ingot is ground to a uniform diameter and diamond saw blade cuts the ingot into thin slices of less than 1 mm thickness. This silicon wafer is then chemically polished to give it a reflective luster.
A light source, generally a laser, exposes the photoresist or the light-sensitive material that coats a wafer so images can be etched onto the wafer’s surface.
The light source emits a selected wavelength of its irradiation. The projection optics of the exposure tool are designed for this specific wavelength.
Page updated on 2016-2-22 16:55 CET