1. Electronic elements that amplify or switch electrical signals
2. A circuit in which many transistors are integrated and wired together

The semiconductor chip manufacturing process can be broadly divided into three processes.

1. The design process, in which the wiring circuits are designed
2. The front-end process, in which electronic circuit patterns such as transistors and wiring are transferred to a semiconductor wafer through exposure
3. The back-end process, in which wafers with electronic circuits formed on them are divided into individual chips and assembled

Semiconductor lithography equipment has mainly been used in front-end processes.
However, the performance improvement of semiconductors through the miniaturization of circuit patterns in the front-end process is approaching its limit. Instead, using semiconductor lithography equipment in the back-end process as well, efforts are being made to connect multiple semiconductor chips with high-density wiring into a single large-scale semiconductor using what is called 3D integration technology.

Semiconductor lithography equipment projects fine circuit patterns onto wafers.

The equipment consists of an illuminator that produces bright and uniform light suitable for exposure, a reticle stage on which a reticle is placed, a projection optical system consisting of many lenses, a wafer stage on which a wafer is placed for exposure, and an alignment scope that measures the wafer mounting position.

Semiconductor lithography equipment transfers circuit patterns to wafers through the following process.

1. First, the wafer is placed on the wafer stage. The alignment scope is used to correctly position the wafer.
2. A reticle with a circuit pattern is placed on the reticle stage.
3. Ultraviolet (UV) light is illuminated from above.
4. The UV light passing through the reticle passes through the projection optical system to project the circuit pattern of the reticle onto the wafer placed on the wafer stage.

A resin, called the "photoresist," has been applied to the surface of the wafer in advance. This photoresist changes when it is exposed to UV light, so the electronic circuit pattern on the reticle is transferred.

In general, the types of semiconductor lithography equipment are categorized by the light source: i-line, KrF, ArF, and EUV.
In addition to ArF, the ArF immersion method, which can form a finer circuit pattern by filling the space between the lens and wafer with pure water, which has a higher refractive index than air, is categorized separately.
Canon's nanoimprint semiconductor lithography equipment, on the other hand, cannot be classified by light source, as it uses a completely different mechanism than conventional lithography equipment. The line width of the circuit that can be formed is very narrow, so it can also be adapted to state-of-the-art semiconductor manufacturing.

※1 Circuits are formed using a simple principle that involves transferring a circuit pattern mask (mold) onto the coated photoresist on the surface of the wafer.
See "Nanoimprint Lithography" for details.
※2 nm = nanometer, or 1/1,000,000,000 of a meter
※3 X-rays of longer wavelength

The following three performance characteristics have the greatest impact on the performance of semiconductor lithography equipment.

1. Resolution

Resolution is a measure of how fine the circuit patterns that are transferred (via exposure) to the wafer can be. Generally speaking, the finer the circuit pattern, the more compact the resulting semiconductor chip and the greater its performance. This in turn improves the performance of the products containing the semiconductor chips.

2. Overlay accuracy

Each wafer is exposed multiple times to create numerous circuit patterns. Overlay accuracy indicates how precisely wafers and reticle circuit patterns can be overlaid. This characteristic is directly linked to semiconductor chip yield rates.

3. Throughput

This refers to the speed with which wafers can be processed, and is an indicator of production efficiency. It is an important indicator for mass production intended to manufacture as many semiconductor chips as possible within a given amount of time.