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N-Doping Tystar Diffusion Furnace Instructions
- Log onto access controller. Go to the tube computer located right next to the access controller. Press menu then DS (Display Status) next press the enter key. Check the upper left corner of screen to see if machine is in idle mode. If machine is not in idle mode wait until process has completed before proceeding. N-Doping Tube Computer
- The N-Doping Tube is used to deposit N-Doping material onto substrates through the use of solid sources that emit at 1000c.
- There is only 1 programs for N-Doping. NDOPING.001. This process only gives you the ability to change your process time. If you would like to change gas flows, or temperature contact MIRC staff and we will create a program for you to do so.
- Your time limit will depend on the thickness desired. Which would be entered on the Tystar tube computer in hours, minutes and then seconds. Which would be 1 hour and 20 minutes and 33 seconds (01:20:33).
- Run all samples through the CMOS wet bench prior to placing in the furnace. This includes new wafers. Make sure the pirana and the SC2 tank are used!
- The Tystar is made up into 4 sections. Loading Zone: Where the 4 tube computers are located and the place where loading and unloading of wafers take place. Loading Zone. Heater Cabinet: Where the 3 zones are located. L-Zone for boat loader, C-Zone for center heater zone and S-Zone for source heater zone. Heater Cabinet Source Cabinet: Where the mass flow controllers are located. Source Cabinet Host Computer: Located on the adjustable arm next to the Source Cabinet. Host computer is used to download recipes and configurations to the tube computer. The Host is used to calibrate the furnace. The Host computer is also used to collect data from all process runs. When processes are finished you can view the data from each run. The information is stored under the date and time stored into the archive of tube 1. Host Computer
- Loading a recipe. Press menu. Press RL (for Recipe Load). Then press enter. A display of recipes appears. Use the arrow keys to highlight the desire recipe. Once recipe is selected press enter 2 times to load. A menu appears that ask you to end your process time limit. The display is in hours, minutes and seconds (HH:MM:SS).You must enter every digit including the colon or the computer will reject it. Enter your time and press enter. The screen will tell you 0 errors and alarm. Press acknowledge button to silence alarm. Press menu to continue. Press DS enter (to go to the display status screen).
- Running a recipe. Once you are in the display status menu make sure that the machine is in the idle mode. Indicator is in the top left section of the screen. Press the run button from the tube computer. The process begins to vent the tube and enter the loading step. You can load 4 inch silicon or quartz wafers. Use only uncontaminated Teflon tweezers in the tube or the provided wafer wand located on tube 4. Wafer Wand
- Loading. The furnace load arm is now coming out to the outer loading position. Once the arm is stopped and in the load position. Place your wafers on the quartz plate located on the load end of the furnace. Use the vacuum wand to load wafers into the furnace boats. Place your wafers with the process side facing the boat loader door. Place your samples in front of the white solid doping sources in the vacant slots. One wafer per source. Process side of wafer must face the doping source for proper doping. Do not use metal tweezers. Use the vacuum wand or uncontaminated teflon tweezers. Once your wafers are in place you can wait for your load timer to elapse and the door will close automatically then jump to the next step once the door is closed. You can also skip to the next step and bypass that timer by pressing event on the tube computer. The door will close immediately and the process will continue to run the next step of the process. Loading Steps Unloading Step
- The tube will first purge and the tube then heats up to the 900c process temperature with 5000sccm of nitrogen flowing into the tube on step # 7and # 8. If the tube displays SHLD this is a special hold mode. This generally occurs when the tube doesn’t heat up before the tolerance time limits expire, could also mean gas flow tolerance went out of range or the tube door isn’t fully closed or you didn’t log on to the access controller. The special hold mode just pauses the run it does not abort it. Call MIRC staff if you get a special hold. Your run will be able to be resumed from the point it stopped once the problem is corrected.
- Step # 10 the tube begins to ramp from 900c to 1000c as the tube continues to purge with 3000sccm of nitrogen. Step 15 is the stabilization step to stabilize temperature and gas flows. The next step is the Doping step # 20. The tube is held at a constant temperature of 1000c and gas flow of 3000sccm of nitrogen for your process time. After the process step is done the tube will purge 4000sccm of nitrogen in. The tube will cool down with a nitrogen purge. After the tube is cooled the tube should be at a temperature of 600c. The step on the tube computer now will display BTOT (Boat Out). The system will be alarming. Press the acknowledge button on the tube computer to silence alarm. You must press event to go from BTOT to the next step.
- The tube will now open the boat loader The boat loader will come out slowly. Once the boat loader is fully opened and stopped Remove wafers from the Tystar boats with the provided wafer wand located beside the tube computer. Make sure you use the quartz plate provided to unload your wafer. Do not place wafers on the aluminum decking of the Tystar. The boat loader will go back in automatically when the timer elapses. You can press event to bypass the timer and the door will begin to close. Your process is now complete.
Keep objects such as sample holders and wafer boxes out of the way of the boat loader. Load area where the door opens must remain clear. Keeps hands and loose clothing out of the boat loader area while the door is opening and closing. Hands and clothing could get caught on the moving parts of the boat loader. Do not ever open the center heater cabinet doors. There is a high voltage and a severe burn danger. Do not lean up against the heater cabinet doors. Doors are hot to the touch. When placing your wafers inside and removing from the tube never touch the boat loader or quartz ware. Quartz ware is extremely hot. Never put your hand into the doors of the source cabinet while tube is running. Everything connected directly to the tube is to hot to touch. Do not wipe the furnace tube down with solvents. Tubes are hot and could cause a fire.
Never Open Heater Doors. Never Touch Quartz Ware With Hands