Specific Process Knowledge/Thin film deposition/PECVD

PECVD Plasma Enhanced Chemical Vapor Deposition

PECVD1 (part of cluster1) - positioned in cleanroom2

PECVD3 - positioned in cleanroom1

We have three PECVD's here at DANCHIP. They can all be used to deposit Silicon oxides and Silicon nitrides with or without dopants of Boron, Phosphorus and Germanium. PECVD1 and PECVD3 are used for silicon based processing where as PECVD2 is dedicated deposition on III-V materials. PECVD1 is the cleanest system where as PECVD3 is allowed to use with substrates with small abouts of metal on. See the precise rules in the equipment manuals which are uploaded in LabManager.

PECVD is a chemical vapor deposition process that applies a plasma to enhance chemical reaction rates of reactive spices. PECVD processing allows deposition at lower temperatures, which is often critical in the manufacture of semiconductors.

All though PECVD1, 2 and 3 are very similar you should not expect to transfer a recipe between the systems and get the same exact same result.

Recipes on PECVD1 and PECVD3

• Recipes on PECVD1 for deposition of silicon oxides
• Recipes on PECVD1 for deposition of silicon nitride and silicon oxynitride
• Recipes on PECVD3 for deposition of silicon oxides
• Recipes on PECVD3 for deposition of silicon nitride and silicon oxynitride

A rough overview of the performance of PECVD thin films and some process related parameters

Purpose	Deposition of dielectrica |	Silicon oxide Silicon nitride Silicon oxynitride PBSG (Phosphorous Boron doped Silica Glass) Silicon oxide doped with Germanium
Performance	Film thickness	~10nm - 30µm
.	Index of refraction	~1.4-2.1
.	Step coverage	In general: Not so good PBSG: Floats at 1000oC
.	Film quality	Not so dense film Hydrogen will be incorporated in the films
Process parameter range	Process Temperature	300 oC
.	Process pressure	~200-900 mTorr
.	Gas flows	SiH$_{4}$:0-60 sccm N$_{2}$O:0-3000 sccm NH$_{3}$:0-1000 sccm N$_{2}$:0-3000 sccm GeH$_{4}$:0-6.00 sccm 5%PH$_{3}$:0-99 sccm 5%B$_{2}$H$_{6}$:0-1000 sccm
Substrates	Batch size	1-3 4" wafer per run 1 6" wafer per run Or several smaler pieces Deposition on one side of the substrate
.	Substrate material allowed	Silicon wafers with layers of silicon oxide or silicon (oxy)nitride Quartz wafers
.	Material allowed on the substrate	Aluminium All metals < 5% of the substrate coverage (ONLY PECVD3!)