AccuThermo RTA

AccuThermo RTA

Essentials
Full name	AccuThermo AW 610
Manufacturer	Allwin21 Corp.
Description	Rapid thermal annealer
Location	03.2.213
Responsibility
Primary	Nader
Secondary	Shiv

RTP AW610

Short description

Startup Procedure

If this is your first time using the machine, consult the Czar for training. You can use the computer to create a recipe without powering on the machine, so there is no reason not to do it first. Refer to Creating a recipe

If your recipe is already created:

1. Sign up the sheet..
2. Make sure the Lamp Power is set to OFF
3. Make sure the power switch on the wall is set to ON.
4. Check that the emergency button is not engaged( is pulled out ).
5. Load your sample into the susceptor.
6. Open oven door approx. 10cm out. This will prevent any potential overpressure from shattering the quartz isolation chamber
7. Load the susceptor inside the chamber and close the door.
8. Open up for Air cooling valves(5.5 bar).
9. Open up the process gas/gasses on the cylinders that you need by opening the main valves on the cylinders. Pressure of the regulator on secondary manometer should be set to 1.5 bar ( Check them also during the run ).
10. Turn the blue valve on the blue tube to open for air cooling line. The pressure should be around 2.5 bar and the flow rate of above 280.
11. Turn the Lamp Power ON in front.
12. Choose and load your recipe.
13. Run the proces.
14. Check that the water flow is between 500-700 lph during your run( Flowmeter is below Scriber ).

Power Down Procedure

After the system has cooled down and the sample was removed:

1. Make sure the Lamp Power is set to OFF
2. Open the oven door and unload the susceptor.
3. Put the wafer back in the oven and close the door.
4. Turn the blue knob on the blue tube the line to Close position.
5. Close the main valves for the process gasses that have been used.
6. Close the Air cooling valves.
7. On the computer press ESC until the main menu appears.
8. Leave AC power at ON position at the wall

For recipe creation and sample handling refer to the wiki.

Creating a recipe

For managing the annealing process the RTP AW610 uses a custom software suite. Before creating a recipe consider if you will be using a susceptor(refer to Sample loading).

To create a recipe:

• First navigate to Process for Engineer tab in the main menu
• click on the NEW recipe in the recipe list
• click on Edit Recipe
• Write a new name for your recipe in the respective field and click on Save. This creates a new recipe in the list that you can now freely edit.
• Check Sensor type to be set to Thermocouple and Wafer Type to be set to either Susceptor or Wafer depending on what you will be using.(consult Sample loading section)

Other parameters should be left as they are unless you know what you are doing and want something different.

You can now proceed with creating the recipe sequence itself. The available parameters are step number, function, time for a given step, temperature, init factor and gas flow for each connected process gas. Ignore the initiation factor.

Main available functions are:

• Delay - keeps the lamp power off while maintaining other parametes, such as gas flow rates. Used for purging the chamber of air as an initial step and is a good option for cooling.

• Ramp - ramps the temperature up or down to a desired value. The ramping rate is calculated by time/target temperature. Note: when using a susceptor, maximum ramp up rates should not exceed 15C/s

• Steady - keeps the lamps turned on and the temperature at a set value. The ideal step for baking the sample at a particular temperatures for a longer time.

Important

The total flow rate through the chamber should never exceed 15slpm.

At the temperatures above 600C the thermocouple begins to melt with the susceptor or a silicon wafer.

Tips for creating a good recipe:

A good initial step is to displace the normal atmosphere by Nitrogen. The total volume of the quartz chamber is 0.84l, therefore it is a good idea to start the process by letting Nitrogen flow into the chamber at around 5slpm for 15-20 seconds. After this initial step is complete, add or replace Nitrogen with a desired process gas.

During Ramping and Steady step, the maximum total flow rate should be 5slpm

It takes between 10-15 seconds for the machine to stabilize the temperature. Consider this when creating a multistep recipe.

Sample loading

The first rule: Dont touch anything behind the front door without gloves!

The sample holder is a quartz tray. Be gentle when putting down your sample!

Thermocouple

The temperature measurement in the RTP is obtained with a thermocouple which is connected to the oven door. When placing a sample(a wafer or a susceptor) onto the quartz loading tray make sure that:

• the thermocople is still in one piece
• the tip of the thermocouple is in contact with your sample
• the two wires of the thermocouple are not in contact with eachother or the sample at any point
• when closing the door ensure that the thermocouple will not be bent

If not set correctly, the temperature readout will not be accurate and might lead to the destruction of the sample or the machine. Use your fingers of tweezers to gently shape the thermocople wires in a sort of a bow shaped spring. If broken, contact the Czar or refer to the Service Manual to replace it.

Susceptor

When using a small sample or if your sample is transparent to the radiation spectrum emitted by the lamps(like GaAs) you'd want to use a susceptor. The susceptor is a SiC coated graphite piece that will evenly heat the sample that is placed inside.

• The inside of the susceptor should not be exposed outside of the cleanroom
• Before loading your sample into the susceptor, examine the latter for cracks and scratches. If any deep scratches or cracks are present - use another one and report the issue to a Czar
• With flow rates of around 5 slpm, the process gasses should have no problem reaching the inside of the susceptor
• Be careful not to scratch the susceptor when placing your sample inside it
• When using a susceptor the maximum heating rate should not exceed 15C/s!
• Do not heat the susceptor without a sample inside it
• Store the susceptor in a designated spot. Do not leave it in the oven.

RTP log

List of avalable spare parts and maintenance log