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Thermco Oxidation -Thermco1, 3, and 4
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Thermco Oxidation and Annealing Furnaces, Thermco, 3, and 4

Thermco1:

As of 8/1/23, Thermco1 is shut down and will be permanently removed from the cleanroom. It will be replaced by a new Tystar furnace in March 2024. Find the current project schedule and more information here

Thermco 3, and 4 furnaces are used for wet and dry oxidation processing and N2 annealing.

Thermco Oxidation and Annealing Furnaces, Thermco, 3, and 4

Process Capabilities

Cleanliness Standard

Training To Become a Tool User

Operating Procedures

Process Monitoring and Machine Qualification

Qual Process Overview

Procedure

Post-Process Measurements & Reported Data

Process Capabilities

Cleanliness Standard

Thermco1 and 3 are for clean work only.  The wafers processed in those furnaces are MOS clean, meaning that they have never had metal deposited on them, have been through a full KOH decontamination procedure and have not been processed in any equipment which is considered contaminated (sometimes referred to as ‘gold contaminated’).

Wafer must have undergone a full Pre-Diffusion Clean or Pre-LPCVD Clean done at wbclean1-2 within 60 mins of loading into Thermco1-3.  

Thermco4 is in the flexible cleanliness group.

 

Training To Become a Tool User

 

  1. Read all material on the SNF website concerning the specific furnace.
  2. Contact a superuser or qualified user of the furnace to arrange to ‘shadow’ them while they use the tool. The reservation option will show who will be using the tool in the near future. You are responsible to be with that labmember for the full time they are operating the tool, and ask questions and try to become as familiar as possible with the furnace during this ‘shadowing.’ You may have to shadow the superuser or qualified user more than one time.
  3. Contact the staff trainer to arrange for training on the furnace.

 

Operating Procedures

Check Tube Status

  1. Press Do key until Main Menu is reached.
  2. Use arrow keys to highlight Status Menu then press Return.
  3. Use arrows keys to highlight Tube Status then press Return.
  4. Type in Tube ID (1 for Thermco1), then press Return.

Thermco will now alternate between the Gas System screen and the Main Furnace screen.

Load Recipe

  1. Enable Tube.
  2. If tube is not in standby, press STOP button until tube is in standby.
  3. Press Do key until Main Menu is reached.
  4. Use arrow keys to highlight Recipe Menu then press Return.
  5. Use arrows keys to highlight Compile Recipe then press Return.
  6. Type in Recipe Name (1DRYOX, 2DRYOX, 1WETOX, 2WETOX, 1ANNEAL, 2ANNEAL), 3DRYO...), then press Return.
  7. For Recipe Name #2, press Return.
  8. For Parameter Table, press Return.
  9. Use arrow keys to highlight Download Only then press Return.
  10. Type in Tube ID (1 for Thermco1), then press Return.
  11. Type  Delay Time (in the HH:MM:SS format) then press Return.
  12. Enter Temp$ (example 800, 1000, 1050…) then press Return.

Thermco will flash orange Recipe Compile Succeeded once recipe is loaded.

 

Run Program

  1. Press START.  (Tube will boat out.)
  2. Load wafers.
  3. Press START.  (Tube will boat in.)
  4. Wait for tube to process wafers.
  5. Press START.  (Tube will boat out.)
  6. Unload wafers.
  7. Press START.  (Tube will boat in.)
  8. Disable tube.
  9. Fill out entries on logsheet.

 

Process Monitoring and Machine Qualification

Users may perform the specified qual process before tool use if more recent qual data is desired for reference.

 

Qual Process Overview

The tool will be reserved for 3 hours on Badger, as the run normally takes over two hours. Three freshly RCA cleaned 4" L test 100 Si wafers will be run in the WETOX recipe with a 39-minute oxidation time at 900 Celsius.

All Thermcos undergo the same WETOX process for quals. WETXOX and DRYOX processes produce comparable results, however a WETOX process is generally less time-consuming than a dry process. If off-nominal results are produced from the WETOX qual, a DRYOX process may be run to determine the source of the anomaly.

Procedure

Instructions are listed on the tool binder located in the vicinity of each corresponding tool. Once your wafers have boated in and the process starts, the remaining process run time can be monitored via the green timer numbers on the corresponding Thermco's control panel (where the Start and Stop button are located). Once the timer reaches 0 minutes remaining, the furnace must cool to 800C at all three set points before you can boat out your wafers. You can check the furnace temperature via the Tube Status screen.

Some important notes to remember are:

Wafers are to be placed in a 50-wafer spread (as shown in Figure 1 below):

 

Figure 1: Wafers should be loaded with flats up and shiny side towards the door (away from the furnace) when the boat is out.

 

Post-Process Measurements & Reported Data

A 9-point spectroscopic ellipsometry measurement will be made on the Woollam for each wafer.

 

 

Qual data may be found on the Lab Management System (LMS) comment log. Standard data findings are listed in parenthesis.