Oxford Plasma Technology Plasmalab 80+ Reactive Ion Etch (RIE)

Operating Instructions (cont.)

This manual is © Oxford Instruments and Oxford Plasma Technology.
Issue 5: August 99
Converted to HTML by webmaster Anders Liljeborg

5.5 Opening and closing the process chamber

The process chamber can be opened to allow access to its interior for inserting and removing wafers. Opening is achieved by a pneumatically-operated hoist which raises the chamber lid and rotates it 90 degrees. The hoist is controlled by an up/down selection switch and two hoist buttons mounted on the control panel.

The hoist buttons are located one at each end of the control panel, so that operation of the hoist requires the use of two hands. This design is a safety feature to reduce the risk of trapping the users fingers etc. in the pinch point formed between the two process chamber halves, and to prevent inadvertent chamber hoist operation.

To open the process chamber when it has fully vented, use the following procedure:

1. At the control panel, set the up/down selection switch to its Chamber Up position.
2. Press both hoist buttons simultaneously. The chamber lid will raise and rotate.
3. When the chamber lid is fully raised and rotated, release both hoist buttons.

Closing the process chamber

To close the process chamber, use the following procedure:

4. At the control panel, set the up/down selection switch to its Chamber Down position.
5. Press both hoist buttons simultaneously. The chamber lid will lower and rotate.

When the chamber lid is fully lowered and rotated, release both hoist buttons.

5.6 Operator control

This sub-section gives the procedures for operating the system.

Using the software requires the operator to be familiar with the Microsoft Windows® environment. For details, refer to the Windows on-line help and tutorials.

5.6.1 Logging on

To log on to the cluster software, proceed as follows:

5.6.2 Using PC 2000 software

The PC 2000 software facilities are access from the screen header which is displayed on all screens (pages). The screen header is shown in Diagram 5-2.

The use of the screens will be described in the relevant procedures. Remember that a full description of each screen´s features is given in the PC 2000 Reference Guide at the end of this section.

5.6.3 Pumping the system down

To pump the system down, use the following procedure:

1. Ensure that the Pump Control page is displayed (if necessary, select the System Menu, then the Pumping option).



2. Ensure that the status indicators (PSU MONITOR, Water and Gas Pod Interlock) are coloured green.
3. Ensure that the process chamber lid is in its "down" position. If you intend to carry out a manual or automatic process run, you will need to open the process chamber lid, place a wafer on the wafer holder in the process chamber, then close the process chamber lid. See sub-section 5.4 for the process chamber opening/closing procedure.
4. Select the SET BASE PRESSURE button, then enter the required process chamber base pressure if different from the default. Click OK.
5. Click on the rotary vane pump mimic to start the pump.
6. Select the Evacuate button for the process chamber. You will be prompted to enter a wafer identity; either enter the identity and click OK, or click Cancel (to pump down without a wafer in the process chamber). The relevant valves will operate and the process chamber will be pumped down.

5.6.4 Venting the system

1. Ensure that the Pump Control page is displayed (if necessary, select the System Menu, then the Pumping option).
2. Select the STOP button, then the VENT button for the process chamber. Note that the vent sequence is controlled by a timer to allow time for the turbo pumps to be purged.

When the ´Vent Time Left´ timer has decremented to zero, the process chamber has been vented.

5.6.5 Manual process run

1. Pump the system down as detailed in sub-section 5.6.3.
2. Check that the system has pumped down to base pressure. (The process chamber message panel should display ´Base Pressure reached´).
3. Select the Process Menu, then the Chamber 1 option. The Process Control page is displayed.
4. Enter the parameters required for the manual process run, e.g. Step Time, RF generator power, chiller temperature, chamber pressure, and gas demands etc.
5. Click the START button. (Note that if this button is not active, the chamber has not reached base pressure.) The process will commence.

NOTES:

1. You can pause the process at any time by selecting the PAUSE button. This will cause the Step Time and the plasma power to stop with the current step time indicated. Re-starting the process will cause the process to continue from the time it was paused. If, during the pause period, you change any of the process parameters, e.g. gas demand, pressure etc., you must press the START button for the changes made to come into effect, this will cause the step timer to continue from the time it was paused.
2. You can stop the process at any time; the message ‘Process Complete’ will be displayed, if required, you can then run the same or another process.

When the "Process Complete" message is displayed, the system can be vented (see sub-section 5.6.4), or another manual process run carried out.

1. Pump the system down as detailed in sub-section 5.6.3.
2. Check that the system has pumped down to base pressure. (The process chamber message panel should display "Base Pressure reached").
3. Select the Process Menu, then the Recipe option. The recipe page is displayed.
4. Select the Chamber button.
5. Select the Load button then select the required recipe from the displayed list. Click OK.
6. To run the loaded recipe, select the Run button. The recipe will be automatically run and the Chamber 1 page will be displayed to allow you to monitor its progress.

NOTES:

1. You can pause the process at any time by selecting the PAUSE button. This will cause the Step Time and the plasma power to stop with the current step time indicated. Re-starting the process will cause the process to continue from the time it was paused. If, during the pause period, you change any of the process parameters, e.g. gas demand, pressure etc., you must press the START button for the changes made to come into effect, this will cause the step timer to continue from the time it was paused.
2. You can stop the process at any time; the message "Process Complete" will be displayed, if required, you can then run the same or another process.

When the "Process Complete" message is displayed, the system can be vented (see sub-section 5.6.4), or another process run carried out.

5.7 Creating and editing recipes

This page is used to assemble and store in memory all the set points and instructions which make up a Recipe for an Automatic Mode run. These recipes consist of a sequence of process Steps. "Drag and Drop" facilities are provided to copy library steps into a recipe.

The Recipe option (accessed from the PROCESS menu) displays the recipe page for the process chamber. This page allows you to create / edit recipes and the recipe steps that they contain.

NOTE: Before creating / editing recipes, make sure that you understand the operation of key components of the system to ensure that recipes proceed as expected.

A recipe is created by adding steps from the Step Library to the Recipe Step Name fields. The recipe is then allocated a Data Log Interval and saved.

5.7.1 Working with recipe steps

Recipe steps are stored in the Step Library list. The list can contain any number of steps, depending on available hard disk space. When the displayed list is full, it becomes scrollable to allow you to view all of the list contents.

To create a new recipe step, use the following procedure:

1. In the Step Library panel, select the NEW button. The Step Edit page is displayed.
2. Enter the step parameters as required, then click on OK. The step is automatically saved.

To create a recipe step, based on an existing recipe step, use the following procedure:

1. Select a recipe step from the Step Library list, i.e. click on it to highlight it.
2. Select the COPY button. Enter a new step name.
3. Edit the step parameters as required, then click on OK. The new recipe is automatically saved.

To edit an existing recipe, use the following procedure:

1. Select a recipe step from the Step Library list, i.e. click on it to highlight it.
2. In the Step Library panel, click on the Edit button.
3. Edit the step’s process parameters as required, then click on OK. The step is automatically saved.

To delete a recipe step, use the following procedure;

1. Select the recipe step from the Step Library list, i.e. click on it to highlight it.
2. Select the DELETE button; the selected recipe step is deleted.

5.7.2 Working with recipes

Recipes are "built" using existing recipe steps, and edited as required.

Within a recipe, steps can be manipulated using the Step Commands pop-up menu (accessed by clicking on the Recipe Steps field).

To build a recipe, use the following procedure:

1. In the Recipe panel, select the NEW button.
2. Click on a recipe step in the Step Library list, hold the left mouse button down then drag the mouse pointer to the Step Name field next to the asterisk (*) then release the mouse button. The step name is displayed in the Step Name field.
3. Repeat 2) as required to add further steps to the recipe. Note that once you have filled the Step Name field, the recipe step list becomes scrollable, enabling you to add a maximum total of 1000 steps.
4. To remove a step from the list, click on it to highlight it then select the Delete step button from the Step Commands pop-up menu. Any further steps will move up the list by one place.
5. To add a step before an existing step, click on the existing step then select the Insert step button from Step Commands pop-up menu. The selected step and all those following it will move down the list by one place. You can then drag another step from the Step Library list into the now vacant field.
6. When all steps have been added, enter a time into the Data Log Interval field, then enter a name for the recipe in the Recipe Name field. Finally, select the SAVE button.

To edit a recipe, use the following procedure:

1. Select the LOAD button, then select the recipe to be edited.
2. In the Step Commands pop-up menu, click on the Edit Step button, then edit the process parameters as required. Note that editing a recipe step will not affect the associated step, i.e. a step having the same filename, in the Library of Available Steps.
3. To remove a step from the list, click on it to highlight it then select the DELETE STEP button from the Step Commands pop-up menu. Any further steps will move up the list by one place.

To add a step before an existing step, click on the existing step then select the INSERT STEP button. The selected step and all those following it will move down the list by one place. You can then drag another step from the Step Library list into the now vacant field.

Next, 5.8 Operator adjustments