3 - Packaging related technologies

The technology shown below is a technique for fabricating diaphragm closed cavities on the surface of silicon substarte. The basic concept is to etch a cavity through a tiny hole then applying uniform deposition, which will cover the structure walls and finally closing the hole. First an oxide layer is grown on a silicon substrate as the body of the cavity. Then a poly-Si diaphragm layer is deposited on top of the oxide layer and patterned, forming a hole on it. The next step is the etching of cavity in the oxide. Finally the hole is closed, using uniform deposition. As a result a diaphragm-covered closed cavity structure is produced.