A new patented hot trap has been launched by Edwards to address pumping challenges in depositing transparent conductive oxide (TCO) films for solar manufacturing.
The hot trap is developed for thermal decomposition of liquid diethyl zinc, a material used to deposit TCO films in thin films solar production. During the deposition process, the unreacted liquid diethyl zinc goes into the vacuum pumps and gets decomposed. This in turn coats the surface of the pump and considerably reduces the pump’s working lifetimes. Edwards’ solution overcomes this problem by extending the pump maintenance intervals, increasing productivity and providing the lowest cost of ownership.
Earlier, solar cell manufacturers have been using TCO film produced from indium tin oxide. A plasma vapor deposition process was used to deposit the films. But now, they are shifting towards a zinc oxide film that is deposited by a CVD process. TCO films made of zinc oxide enhance the light capturing technique.
Edwards offers a two-pronged method to address the challenges in depositing TCO films. The patented hot trap is the first prong, which prevents the entry of liquid diethyl zinc into the process pump. The second prong is the iXH harsh process pump that has minimum internal operating temperature, which helps in reducing the thermal decomposition rate.
The hot trap consists of replaceable cartridges through which gases from the process chamber passes before entering into the vacuum pump. The replaceable cartridges are heated to a temperature for optimizing the decomposition of liquid diethyl zinc. These cartridges can be replaced once in 30 days and they are easy to reuse and clean. Edwards’ patented hot trap can expand the vacuum pump maintenance cycle from a week to nearly six months.