What does the Shower head of PECVD do?

0020-30797 Perforated Plate Shower Head

0021-35869 SHOWERHEAD

 

What does the Shower head do in the PECVD process?

As shown in the figure above, Showerhead, also translated as sprinkler head, showerhead, etc., usually fits snugly to the upper part of the reaction zone and acts as a gas inlet, injecting the reaction gas evenly into the chamber through the small holes on its surface. Of course, it is not only the function of gas distribution, some are designed to be used as part of the electrode.
Function of Shower head?

The surface of the Shower head is covered with dense pores, and after the reaction gas flows in, it is evenly divided into several parts and transferred to the top of the wafer at a consistent flow rate, so that the reaction gas evenly covers the entire wafer surface to produce a more uniform coating. When the Showerhead is part of the electrode, the RF power source generates a uniform electric field on its surface, capable of forming a homogeneous plasma.

What metal is generally used to make a shower head?

The most common is aluminum, which has a high thermal conductivity and resistance to corrosion. Quartz or ceramics can also be used to make a shower head.