Unaxis solutions for plasma-enhanced chemical vapor deposition (PECVD) silicon nitride (SiNx) are used extensively in the production of GaAs devices. PECVD is compatible with the low temperature constraints required for GaAs device manufac- turing. With this technique, high quality SiNx can be deposited at temperatures less than 400°C. PECVD SiNx is used in many different GaAs-based devices such as MESFETs, HBTs, and HEMTs. In these devices, PECVD SiNx is typically used for passivation, encapsulation, and as a capping layer. In addition, the large dielectric constant of SiNx makes it attractive for use as the intermetallic dielectric in MIM capacitors.
