Atom trapping chips with vacuum feedthroughs and double layer of metal wire patterns

This invention relates to the atom trapping chips with vacuum feedthroughs and double layer of metal wire patterns and the fabrication process. The characteristic of the device is to use the vacuum feedthroughs located in the substrate of the atom trapping chips. The purpose of vacuum feedthroughs is to conduct the electrical current from the backside to the front side of the atom chips via the feedthroughs in the substrate. Thus, the front surface of the atom chip could be anodically bonded to a Pyrex vacuum chamber and the usable front surface area of the atom chips could also be increased. In addition, an electroplated micro copper pillar has chosen as the vacuum feedthrough conducting material to connect the metal wires on two sides of the atom chips. The electroplated micro copper pillar is not only good for being the electrical conductor but also has the low outgassing rate after baking in the ultra-high vacuum environment. Therefore, the outside electrical current could be conducted to the metal wires