Key Takeaways
- Laser lithography is a versatile laser processing technique, used to create microstructures, such as microelectromechanical systems (MEMS) and integrated circuits
- Laser lithography works similarly to photolithography, which involves the application of a photosensitive polymer to a surface with an opaque mask covering. When the polymer is exposed to light, any uncovered sections will harden, while the masked areas remain soft, so can be easily etched away. As the process repeats, more complex structures can be built
- Solid state lasers are often used in laser lithography due to their high level of stability and turn-key operation
- One of the key benefits of laser lithography is its high output power, which can be used to process robust devices in manufacturing
Contents
- What is laser lithography?
- What is photolithography?
- How laser lithography works
- The role of Novanta’s DPSS systems in laser lithography
- Laser solutions from Novanta Precision Manufacturing
What is Laser Lithography?
Laser lithography is a versatile technique for the creation of microstructures such as microelectromechanical systems (MEMS) and integrated circuits. It works on the same principles as photolithography but developments in laser technologies have meant that laser-based manufacturing has become increasingly popular.
What is Photolithography?
Photolithography involves the use of a photosensitive polymer applied to surface with an optically opaque mask covering. When the polymer exposes to light, the sections not covered by the mask will become hard. The masked areas will remain soft and can easily etch away and the process repeats to build up more complex structures.
In computer chip manufacture, photolithography has been the technique of choice as a single resist-covered layer of silicon can be easily converted to hundreds of individual chips. It is possible to create incredibly small and intricate patterns, down to a few nanometers in size.
Different wavelengths of light can be used for photolithography, with UV radiation being a common choice. Originally, lamps were used as a light source but to make the smallest structures needed for metal-oxide semiconductors lamps have been gradually replaced by lasers.
How Laser Lithography Works
High-power laser systems, such as
CO2 lasers, are excellent tools for precision cutting and machining. The minimum possible feature size that is manufactured in laser lithography is proportional to the wavelength of light. The feature sizes achievable are also dependent on the quality and availability of focusing optics and laser beam quality.
There are many technical compromises when choosing optimal wavelengths and laser types of laser lithography. While higher power systems are often desirable for faster machining, thermal load on samples can be a problem and air starts to absorb sub-193 nm wavelengths. Instabilities in beam size and shape can also cause issues during the manufacturing process.
Solid state laser systems have proved to be an excellent choice for laser lithography as they have excellent stability and typically turn-key operation. Modern systems can achieve the high output powers necessary for laser lithography in devices robust enough for manufacturing use.
The Role of Novanta's DPSS Systems in Laser Lithography
We offer three diode-pumped solid state (DPSS) with a range of output wavelengths designed for laser lithography applications. The gem series is available with 473, 532 and 660 nm output options with excellent power outputs.
By using a combination of hermetic sealing and the PowerLoQ active fast feedback system, the gem can achieve outstanding levels of stability in all output beam characteristics. All three systems have a single traverse mode. Their small, compact footprint makes them easy to integrate into larger manufacturing platforms.
Key for laser lithography, the gem series has a low M
2 value and a diffraction limited beam, so the minimum possible feature size is limited by the wavelength and not poor focusing or beam conditions. For samples where thermal load may be an issue, the current/power of the system is fully controllable to make complete optimization of the laser lithography process possible. Contact us today if you would like to learn more.
Laser Solutions from Novanta Precision Manufacturing
Novanta is a trusted technology partner to medical and industrial OEMs (original equipment manufacturers). Additionally, Novanta holds deep proprietary expertise in photonics, along with vision and precision motion technologies. We engineer mission-critical core components and subsystems that deliver extreme precision and performance in laser lithography applications.
Our highly engineered component and sub-system solutions, and deep expertise in advanced photonics, vision and precision motion make us the global technology partner of choice for medical and advanced industrial OEMs.
Contact us to find out more.
