Lasers for Lithography
Lithography is a technique for transferring a designed pattern directly or through an intermediate medium onto a flat surface, excluding areas of the surface that do not require a pattern.
In mask lithography, designs are printed on a substrate and exposed with a laser so that the deposited material is etched away, ready for further processing. This lithography method is widely used in the mass production of semiconductor wafers.
The ability to project sharp images of small features on a wafer is limited by the wavelength of light used. The most advanced lithography tools today use deep ultraviolet light (DUV), and in the future these wavelengths will continue to span deep ultraviolet (193 nm), vacuum ultraviolet (157 nm and 122 nm), and extreme ultraviolet (47 nm and 13 nm).
Complex products and frequent design changes for IC, MEMS, and biomedical markets -- where demand for a variety of functions and substrate sizes is growing -- have increased the cost of manufacturing these highly customized solutions while reducing production volumes. Traditional mask-based (mask) lithography solutions are not cost-effective or practical for many of these applications, where the cost and time required to design and manufacture large numbers of mask kits can increase rapidly.
However, maskless lithography applications are not hampered by the need for extremely short UV wavelengths, and instead use laser sources in the blue and UV ranges.
In maskless lithography, laser directly generates micro/nano structures on the surface of photosensitive materials. This versatile lithography method does not rely on mask consumables and layout changes can be made quickly. As a result, rapid prototyping and development becomes easier, with greater design flexibility, while retaining the advantage of large area coverage (such as 300mm semiconductor wafers, flat panel displays or PCBS).
To meet the requirements of rapid production, lasers used for maskless lithography have similar characteristics to those used for mask applications:
Continuous wave light source has long - term power and wavelength stability, narrow line width and small change of mask.
Long-life stability with little maintenance or interruption of production cycles is important for both applications.
DPSS laser has ultra-stable narrow linewidth, wavelength stability and power stability, and is suitable for two lithography methods.
We design and manufacture high-power, single-frequency lasers with unrivalled wavelength stability, narrow line width and a small footprint over the wavelength range of long dry lengths -- making them ideal for integration into existing systems.