11 May 2017

AP&S tailors metal lift-off process for LED manufacturing

AP&S International GmbH of Donaueschingen, Germany says that its metal lift-off process (which was launched in 2012 and is currently running at several key customers sites in Europe) has been further developed to meet the specific requirements of LED production.

“The AP&S range already includes several wet process tools for this industry,” says Uwe Müller, director Business Unit Single Wafer. The firm can now meet the sector’s key challenges such as automated high-volume production and the prevention of substrate damage.

The AP&S metal lift-off process is a single-wafer spin process offering what is claimed to be three unique features:

• solvent performance that has no impact on the substrate and structures;
• the use of DMSO (dimethyl sulfoxide), which is non-critical in terms of the environment, health and safety in the EU and the USA; and
• an optimized process time with a positive impact on overall throughput.

Common wet chemical lift-off processes work by batch immersion or spray application, which often gives rise to critical residues and cross-contamination (e.g. metal flakes). Another commonly used technology for lift-off is based on single-wafer spin clean, which requires mandatory pre-soak and a high temperature for solvents. A further disadvantage of such equipment technologies is the use of chemicals such as NMP (n-methyl-2-pyrolidone) or acetone. NMP is an EH&S critical substance, which causes severe irritation to the skin, eye area and in the respiratory system, and carries the risk of damaging fertility and harming the unborn child. Acetone is highly flammable, and residues after processing with acetone represent a well-known problem.

By using DMSO at elevated temperatures combined with megasonic agitation, the AP&S metal lift-off process offers safety for workers, the environment and equipment, and guarantees constant solvent performance over an extended period. The process guarantees damage-free lift-off for sensitive applications and sensitive substrates. There are no residues left on the substrate after processing, and DMSO itself is easy to rinse off with deionized (DI) water or a lower solvent. This means lower chemical consumption, cost reduction in the production chain, and enhanced process capability, says the firm.

The AP&S lift-off solution is available for all types of metal layers, alloys and further protection layers used in the semiconductor industry. Interested parties can test the metal lift-off process in the AP&S demonstration center (an in-house application laboratory). “I look forward to welcome customers and potential partners in our demo center and to demonstrate them our unique metal lift-off process.

Tags: Epitaxial lift-off Wet processing systems

Visit:  www.ap-s.de