SJ-20 Evaporator
| SJ-20 Evaporator | |
|---|---|
 | |
| Equipment Details | |
| Technology | PVD |
| Materials Restriction | Metals |
| Material Processed | Ge, Au, Ni, Ti |
| Sample Size | 6", 4", 3" and 2" wafers, pieces |
| Equipment Manual | |
| Overview | System Overview |
| Operating Procedure | SOP |
| Supported Processes | Supported Processes |
| Maintenance | Maintenance |
The SJ-20 Evaporator is an electron beam evaporator used to deposit Ge, Au, Ni and Ti. It is an open loop box coater with a dome that can run multiple wafers and substrates in each run.
All the e-beam evaporators in the LNF are setup using small point sources and long throw distances that lead to very directional deposition with minimal heat transfer. The is means that evaporated films have poor gap fill but make the tool ideal to use for lift off applications. All the evaporators in the LNF use thin films controllers with quartz crystal monitor feedback to pre-heat the source materials with the shutter closed and then control power to maintain a preset deposition rate and to determine the total evaporation thickness.
Contents
Announcements
- With Sj-26 down, tool is used as a backup for ZnSe and MgF but it must be scheduled thru the tool owner.
Capabilities
- Multi-wafer lift-off evaporator
- High deposition rate (5-15 Å/sec) metal films on multiple wafers
- Designed for low heat transfer and minimal sidewall coverage for liftoff applications
- Stacks of multiple films can be run
System Overview
Hardware Details
- Cryo-pumped box coater capable of low 10-6 Torr base pressure in 1 hr of pumping
- No reactive gasses or heating run on this tool
- 4x7cc pocket E-beam gun to allow 4 different materials to be deposited in one run
- Large distance from source and curved substrate dome designed for liftoff applications
- Dome rotation and curved uniformity plate to allow for better uniformity
Substrate Requirements
- 2”, 3”, 4” and 6” wafer holders available as well as clip fixtures for smaller pieces
- Tool holds 9x4” or 4x6” fixtures.
Material Restrictions
The SJ-20 Evaporator is designated as a Metals class tool. Below is a list of approved materials for the tool. Approved means the material is allowed in the tool under normal circumstances. If a material is not listed, please create a helpdesk ticket or email info@lnf.umich.edu for any material requests or questions.
Supported Processes
- Four films available:
- Any combination of these films can be run. They are programmed 3 at a time in the XTC2 thin films controller
- In the evaporators, maximum thickness numbers are total thickness of that material per run and are determined by stress or material availible. If you run multiple layers of the same material, the total sum thickness of those layers must be below the maximum.
Each of the 4 metals has a standard XTC film program outlined on the Standard Processes page. These films can be run in any order by programming them 3 at a time in the XTC controller.
Depositing other Materials
- This tool only supports these 4 materials (and SJ-26 backup while it is down.) If you have a material deposition need that is not listed, check to see if this material is deposited on another PVD tool or see more about options for running your own private material on the LNF PVD Films page.
SJ-26 Backup - running of ZnSe, MgF and ZnS
With the loss of the control system on the SJ-26 Evaporator, the SJ-20 serves as a backup for ZnSe, MgF and ZnS films. These materials contaminate the tool and it must be thoroughly cleaned after they are run. As a result, these films can only be run through coordination of tool scheduling with LNF Staff.
Process for running ZnSe, MgF and ZnS in the SJ-20
- Submit an LNF Helpdesk Ticket requesting a run or series of runs
- Staff will respond to the ticket and coordinate a time to block off the tool for a couple of days. This time slot may take more than a week to schedule.
- Staff will block off the tool on the scheduler and you will be told when you can start and how long you have to run the tool.
- After you have completed your run, you must notify staff by updating your Helpdesk Ticket with how much tool time you used for your runs.
- The ticket will be assigned to management to coordinate charging you for the used tool time and then staff will finish cleaning the tool and restoring it for general use.
Operating Procedure
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Checkout Procedure
How to get access to this evaporator:
- Complete the online PVD Rise Training (this only needs to completed once so if you are authorized on another PVD tool or evaporator, you do not need to do it again.)
- Read through this Wiki page and the Operating Procedure above.
- Create a Helpdesk Ticket requesting training
- A tool engineer or user services member will contact you for a training session.
- Practice with another authorized user until you are comfortable with tool operation.
- Schedule a checkout session with a tool engineer via the helpdesk ticket system. If this checkout is successful, the engineer will authorize you on the tool.
Maintenance
The SJ-20 is opened for scheduled maintenance:
- Once a week and the gun area is cleaned and shutter is replaced.
- The chamber dome, sidewalls, shutters and covers are cleaned with foil replacement as needed (approximately once every 3-4 months.)
- Tool leak checks, pumping speeds and film characterization are done periodically or when major tool changes are done.
- Rough pump oil is changed once every 3 months. Cryo absorbers are replaced annually.
Tool Pumping Performance
Pumping speeds and Leak-up rates vary based on chamber sidewall deposition and outside conditions such as humidity and time tool was open.
SJ-20 pumping speed - tool crosses over to hi-vac in 5-5.5 minutes
Process Characterization
4 Films are run in the SJ-20 - Ge, Au, Ni and Ti
Power Bump Recovery
The only maintenance that users are allowed to perform is power interruption recovery.
- In the event of a power interruption, try to get the tool and cryo powered back on within 10-15 minutes. This will save 8-12 hours of down time lost to a cryo regen.
- Follow the power bump part of the SJ-20 Startup and Shutdown Procedure
- If recovery cannot be done in time this procedure will refer you to the SJ-20 Cryo Regen Procedure