Thermco Oxidation and Annealing Furnaces, Thermco1 & 2
Process Capabilities (Cleanliness, Materials, Performance)
- Thermco1 and Thermco2 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 or LPCVD clean done at wbdiff within 60 mins of loading into an oxidation furnace. The pre-diffusion clean is described in these web pages; Prediffusion Cleaning at SNF.
Contact List and How To Become a User
Please follow the following procedure to become a qualified user of a tylan or thermco furnace;
Read all material on the SNF website concerning the specific furnace, including Background, Process Capabilities, Operating Procedures and Process Monitoring.
- Contact a superuser (link to superusers list) or qualified user of the furnace to arrange to ‘shadow’ them while they use the tool. The reservation option on coral 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 it would be intelligent to 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.
- The labmember you choose to follow will have a Shadow Checklist (link to check list) for the furnace and you will have to be able to understand each point on it before the labmember notifies the staff responsible for training that you are ready for training. Both of you must agree that you are ready. You may have to shadow a labmember more than once.
- Contact the staff trainer to arrange for training on the furnace.
- If there is a written test for the tool you will need to hand it in to the staff member before training commences.
- After training you will be given provisional qualification status. This allows you to use the furnace during staffed hours, 0600-1800 Mon-Fri only.
- Once a superuser or staff member has watched you and you have satisfactory demonstrated the proper use the tool you will be granted a full qualification to use the tool anytime, 24/7.
Thermco Oxide Furnace Operation (Quicksheet)
A. 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, 2 for Thermco2), then press Return.
(Thermco will now alternate between the Gas System screen and the Main Furnace screen.)
B. 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 OR 2ANNEAL), 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, 2 for Thermco2), 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.)
C. 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
To provide verification and trend of a wet oxidation program and wafer-to-wafer and within-a-wafer uniformity of etch over a 50 wafer load.
Frequency of the test:
To be completed after major maintenance such as a pull and clean or injector change, or once monthly, or as needed based on user feedback. Labmembers are encouraged to use this procedure before committing their work to critical runs to check that the furnace is operating correctly.
Documentation of results:
To be posted in the Coral equipment archive as a comment.
- From the stock room get Three wafers for each furnace, tylan1, tylan2 and tylan3. Use ‘L’ stock test wafers.
- Clean all wafers using standard pre-diffusion clean, 5:1:1 DI:H2O2:HCl last.
- Load wet program wetox into all furnaces. Time variable is 00:39:00. Oxide temperature is 900c. This should grow between 900A and 1100A oxide.
the wafers into the furnaces flats up (top) and polished sides facing
out (load direction). Arrange the wafers so that they are in the front
and back positions of two boats. See Fig. 1. This will represent a 50 wafer spread.
- Start the program and monitor the gas flows and temperature of the Load, Center and Source TC’s.
- After the program has finished (about 2hr) unload the wafers into the appropriately marked box for the furnace tested.
- Measure the wafers using the Woolam ellipsometer, Oxide program found in Staff Qual Recipes. This will set up and automatic 9 point reading for each wafer. Put the individual readings in a spreadsheet and save.
- Note the reading for thickness and standard deviations for each wafer in coral comments.