Toxic arsenic vapor may be generated during evaporation of GaAs.

1. STARTUP

a. Turn on the cooling water by setting the wall toggle switch to "RTA" position.

b. Open manual valve #1 to start nitrogen flowing (for lamps cooling.

c. Set the process nitrogen flow to 35 sccm, using the flow meter button and manual gas valve #2.

d. Set Meter Select switch on the heating chamber control panel to"TEMP" position.

e. Set PYRO/TC switch to "TC" position.

f. Set Lamp Control switch to "AUTO" position

g. "POWER" switch should be OFF.

NOTE: If the heating chamber POWER switch is ON when the computer is turned on, the lamps on the heating chamber may come on.

h. Open the oven door (if a wafer is present, remove it.) Completely close the oven door. An interlock switch will prevent the lamps from firing if the door is not completely closed.

i. Turn on the computer after its display has turned on. Press F1 key on computer keyboard and P-CAT logo will appear on display.

NOTE: Be sure the "POWER" switch is off when you turn on the computer.

j. Turn on the "POWER" switch on the heating chamber control panel. You will hear a strong clunk-like noise, as the contactor is engaged. The rta35 is now ready for operation.

2. SET THE OPERATING PARAMETERS

a. From MAIN menu of PCAT software/DOS , choose the desired recipe. The program maintains only one recipe in its memory at a time; it is called "Current Recipe."

b. Load the recipe by selecting the "Read recipe from..." line from MAIN menu, using arrow keys or type R and press ENTER. Select the recipe from the list of recipes on the screen using the arrow keys.
This will be the Current Recipe. Check if this is the process which you want to run, by reading the Steady State(SS), Ramp and Delay(Dly) step's parameters. The recipe name is listed at the bottom of Process
Cycle Display screen.

3. PLACE THE WAFER IN THE PROCESSING CHAMBER

a. Open the door, remove the square quartz lid and place the samples face down on the silicon support wafer. Cover the sample(s) with the quartz lid, and slowly close the door.

b. Purge the chamber/wafer with nitrogen for at least 3 minutes. Oxygen from the atmosphere could de-calibrate and shorten the K-type thermocouple's life.

4. RUN THE PROCESS

a. From "Process Cycle Display" screen, press F10 key to go back to MAIN menu.

To execute the Loaded recipe, select "Execute recipe" line from MAIN menu, or type E. The system will display the Process Cycle Display screen. Press F1 (Run) to run the selected recipe. Run could be monitored on the computer.

b. At the end of process, wait until the temperature reaches 150C, on the heating chamber control panel display, before opening the chamber door. The temperature displayed on the computer screen is valid only as long as the recipe is running.

During the cool down step, the reactor should be purged with nitrogen, so any possible toxic gas accumulation should have evacuated prior to opening the chamber.

c. With the door fully open, wait until the temperature is below 70C, before removing the square quartz lid and unloading the sample(s).

d. Return to the MAIN menu after you are done.

5. SHUTDOWN

a. Wait until the chamber temperature is lower than 150C.

b. Turn off the controller "POWER" switch.

c. Turn off the computer and the display.

d. Switch off the cooling water flow/bypass using the three valves.

e. Turn off the heating lamps cooling nitrogen.

f. Flow process N2 through the chamber.

g. End "Operate Machine" in CAFE