SJ-20 Evaporator

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< Evaporation

SJ-20 Evaporator
62040.jpg
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.

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:
    • Germanium (Ge) (4000 Å MAX, 10 Å/sec)
    • Gold (Au) (4000 Å MAX, 10 Å/sec)
    • Nickel (Ni) (2000 Å MAX, 10 Å/sec)
    • Titanium (Ti) (8000 Å MAX, 15 Å/sec)
  • Any combination of these films can be run. They are programmed 3 at a time in the XTC2 thin films controller

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.


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.

Standard Operating Procedure

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Checkout Procedure

  • Read through this page and the Standard Operating Procedure above.
  • Create a Helpdesk Ticket requesting training.
  • A tool engineer will schedule a time for initial training.
  • Practice with your mentor or 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.