CHA E-Beam Evaporator #2
Overview
General Description
General Description
- Telemark 861 deposition controller
- Six pocket e-beam evaporator
- Pockets hold 8.2 cc crucible liners
- Substrate fixture can hold 1- 6" wafer 4" wafers with adapters for a 3" wafer, 2" wafer, and fragments of wafers
- Water cooled stage
Specifications
- Source Materials: Ti, Au, Al, Ni, Ge, Ag
- Deposition rates range from 1 - 8.0 Angstroms/sec
- Quick pump down to 5x10-7 torr
RESULTS FROM TOOL CHARACTERIZATION AS OF 1/24/2020
| material deposited on clean pattered wafer | deposition rate | thickness setting | characterized result |
| using PR lift off process measured on P7 | |||
| CHA2 | |||
| Ti | 2 a/s | 50 nm | 49.9 nm |
| Au | 2 a/s | 50 nm | 49.4nm |
| Ni | 2 a/s | 50 nm | 48.3 nm |
| Pt | 2 a/s | 50 nm | 51 nm |
| Ag | 2 a/s | 50 nm | 48.8 nm |
| Ge | 2 a/s | 50 nm | 49.8 nm |
| Ti | 1 a/s | 5 nm | 5nm |
| Ti/Au | Ti 1 a/s Au 2/as | 5 nm Ti 50nm Au | 54.8nm |
Sample Requirements and Preparation
Make sure your sample has been properly Baked when using PR or PMMA.
Substrates must be solvent cleaned in the standard 3 step Toluene, Acetone, and IPA solvent clean.
Samples must be cleaned in accordance to processing needs NO FLEXIBLE SUBSTRATES OF ANY KIND ARE ALLOWED IN THIS TOOL
Standard Operating Procedure
Please Note: This instrument is billed per use based on a 2 hour reservation block
- Example: One user only uses the tool per reservation. When you vent the system and unload your sample that concludes your reservation.
- Example: If the usage is 10 minutes past the initial 2 hour reservation, you will be billed for 2 uses
Questions & Troubleshooting
I had a problem with the way the last samples turned out. It looked like there were almost pin holes or something. I am not sure if you know what may have been wrong but I can show you the samples and maybe you have an idea of what caused it.
The pinholes are most likely caused by contaminates on the substrate , below are some more comments K.S.
Harcourt Butler Technological Institute
Dear Dr. Sivagami
Deposit the film at higher vacuum than what you are using at present. For good adhesion, Degass the substrates before deposition. Make slightly thicker films. Anneal them after evaporation in vacuum at higher temperatures for getting rid of voids. See if you are able to solve the problem. Substrate cleaning can also be improved for better uniformity. Good luck.
Harcourt Butler Technological Institute
If substrates are glass plates, degassing is done by putting a heater inside the coating unit over the substrates and heat them up to 200 degree centigrade for about two hours in vacuum. The gasses absorbed comes out in this process. Switch off the heater to cool down to room temperature. Thereafter, deposit the film without exposing them to air.
Added an answer
pinholes are mainly created due to any foreign material already present in the substrate and they tries to come out through the deposited films during deposition. Clean your substrate thoroughly in piranha solution (1:1 ratio of H2O2 and H2SO4 for 20 min. ** you can search in net for details) . Thereafter rinse in DI water and preheat in oven @ 150 deg. Cent. for at least 30 min and then place in thermal chamber for deposition. Also you should heat your substrate up to 150 deg. cent. just before deposition. For better film quality high vacuum is essential
Pinholes are either caused by surface contamination remaining on the "cleaned" surface. Use the water break test to determine if the surface is residue free. You will see interference fringes as it dries. The fringes will be even as the water evaporates. Any island fringes or streaks means the surface is not clean. Any of these particles actually become nucleation sites as the coating is deposited