Denton Sputtering System
Denton Vacuum Explorer 14 Sputtering System is used to deposit the thin films of dielectric material or metals by using magnetron gun. Sputtering Definition Sputtering is a vacuum process in which a very thin film is deposited on substrates. By applying a high voltage across a low-pressure gas (usually argon at about 5 mtorr), a plasma can be created. This plasma consists of electrons and gas ions in a high-energy state. During sputtering, these highly energized plasma ions will strike the target which is composed of the desired coating material. This collision causes the atoms from the target to sputter off and fall onto the substrate. The thickness of the deposited films can range from 100Å to 200µm. Generally, the thicknesses are around 2000Å-5000Å. Main Chamber and Cathode
Common Sputtering Rate: 50 nm/min @ 300W
100°C Ti-W Sputtering rate: 160A/min
Au Sputtering rate: 600A/min
Green button means it is ON Red button means it is OFF Screen Buttons
OVERVIEW: Access to overview screen.
PUMPS & VALVES: Access to controls for all pumps and valves.
GAUGES: Access to gauge controls.
DC 1 SPUTTER CONTROL: Access to DC 1 power supply, cathode selection, shutter control, and rotation control in the manual mode.
RF SPUTTER CONTROL: Access to RF power supply, RF igniter, gas control, cathode selection, shutter control, and rotation in the manual mode.
RF BIAS CONTROL: Access to RF power supply, RF igniter, gas control, and rotation control in the manual mode.
TIMED SPUTTER: Access to Semi-Auto process set-up and control.
HEAT CONTROL: Access to the heat power on/off, heat setpoint in manual mode.
ROTATION: Access to rotation controls
GAS: Access to the Gas Valve controls
AUTO: Access to AutoPump and AutoVent semi-auto processes.
SERVICE: Access to service mode Start Up Procedure Turn ON the power breaker (Should be on already) Push the Green Power switch ON (Should be on already) Power up the DC power supply and RF power supply Make sure the argon gas in the pump room is ON. Turn ON the cooling water system System Pumping and Venting (Automatic Mode) Automatic System Pumping Make sure the system is NOT in Service mode. Select the "Auto Pump/Vent" screen indicator.
- When click Overview, you will see the first screen.
- Select the "Auto Pump" indicator button.
- System Status will display Auto Mode. System will safely pump from atmosphere to high vacuum. Process in the Picture Rough Valve turns on
- Rough Valve shuts off
- Backing Valve turns on
- High Vac Valve turns on
- Chamber pressure starts decreasing
- The chamber pressure should be around 1E-6 torr. The pressure indicated on the left should be around 198 mtorr.
- Auto Pump can be started with the Turbo Pump ON or OFF. Auto Pump process will start the Turbo Pump if it is OFF. Automatic System Venting (Pump Down) Insure that the system is not in the service mode position. Turn off all internal sources of energy (RF power, DC power). Turn off all Gas Controls. Select the "Auto Control" screen. Select the "Auto Vent" indicator button indicator button.
Auto Pump can be started with the Turbo Pump ON or OFF. Auto Pump process will start the Turbo Pump if it is OFF. System Status will display Auto Mode. Chamber will safely vent to atmospheric pressure. System Pumping and Venting (Manual Mode) Manual System Pumping Abort any Automatic process to switch to Manual mode. Turn the Mechanical Pump ON and wait one minute. Open the Backing Valve and wait one minute. Turn on the Turbo Pump and wait for the Turbo Speed interlock to be satisfied. Close the Backing Valve. Close the chamber door and open the Roughing Valve. Wait until chamber Vacuum is less than 1.5 x 101 Torr (crossover pressure). Close the Roughing Valve, wait 15 seconds Open the Backing Valve and wait 15 seconds. Open the Hi-Vac Valve. Manual System Venting (Pump Down) Abort any Automatic process to switch to Manual mode. Turn off all internal sources of energy (RF power, DC power). Turn off all Gas Controls. Select the "Pumping Control" screen. Close (if open) the hi-vac valve. Close (if open) the chamber rough valve. Close (if open) the gas #1 and t2 isolation valves. Open the chamber vent valve. When chamber is fully vented and the chamber door seal is broken, close the chamber vent valve. Cathode Selection Cathode 1: Si3N4 Cathode 2: SiO2 Cathode 3: Metal (See Table for Available Metal Table) Process Gas Coming Soon Sputtering Procedure Auto RF Sputtering Procedure Auto RF Sputtering is the easiest and fastest procedure overall. However, note that the "Heat Set Point", "Pre Sputter Time", and "Sputter Time vary with different sputtering material and output power. On the screen, select "RF 1 Cathode Select".
- On the screen, select "RF Sputter Control".
- Set "Heat Set Point" for specific heat (In general, it is 100°C)
- Set "Pre Sputter Time"
- Set "Sputter Time"
- Select "Timed Sputter Enable"
Semi-Auto RF Sputtering Procedure Program a Process Pressure setpoint Select desired process options, RF, DC and cathode number to be run. Set power level by depressing the RF (or DC) Set point Display. Use numeric keypad, as normal. Enter a power value. Press Enter. Set Pre-sputter time (sputter time) by depressing the Presputter Time display (Sputter Time display). Use numeric keypad, as normal. Enter the desired time. Press Enter. Enter Heat Setpoint if desired. Enter RF Bias Setpoint if RF Bias is desired. Depress the "Timed sputter Enable" button. System will pump down to reach the programmed Process Setpoint. Substrate Rotation will turn ON. Substrate heat will activate to reach the Heat Setpoint. When the Process and Heat Setpoints are satisfied: The rotation will turn on, the selected power supplies will turn on, the targets will preclean to the set time, and the shutter(s) will open. The deposition will continue until the sputter time is complete and the shutter (s) will close. The RF Bias power supply will start when the sputter power supplies start. The RE Igniter sequence will be activated automatically if RF Setpoint is a non-zero value and a cathode is selected Manual RF Sputtering Procedure Insure that main chamber has been pumped to high vacuum. Abort any Automatic process to switch to Manual mode. Turn on rotation. Activate the HiVac Intermediate position (if equipped). Open Gas Control. Establish 0.0050 (5 mtorr) of gas as indicated on the screen. Select the desired cathode. Select set points by depressing the RF Setpoint button. A keypad will appear. Enter a power value (Watts) of 0-300. Press Enter. Use the RF Ignitor feature or manually start the RF plasma by the following procedure: Close the Hivac valve until the chamber pressure rise to about 5O mtorr. Turn on "Power" to source. Open the Hivac valve. Pre-sputter target to clean any contaminants. Open shutter(s) to begin deposition. When desired deposition is obtained, close shutter(s) and turn off the power supply that was selected. Turn off the rotation power. Close the Gas Valves. Allow the substrate to cool under vacuum before exposure to atmospheric pressure. This step is necessary to insure that the freshly deposited film will not be oxidized. Manual DC Sputtering Procedure Abort any Automatic process to switch to Manual mode. Pump system down to less than 1E-5 torr. If this is the first time you have run system (or sputterhead), allow at least a two-hour period to pump out contaminants from the sputterhead. Open gas valve. Allow thirty seconds for a pulse of gas to work its way through system, and for pressure to stabilize. Adjust mass flow controller and HiVac Intermediate position (if equipped) to bring pressure to desired setting (generally 5 mtorr). The sputterhead is capable of sputtering between .6 and 10 mtorr. (The lower the pressure, the less scattering losses there will be. The higher the pressure, the easier it is to develop a plasma.) A recommended starting pressure is 10 mtorr. Select the desired Cathode. After ensuring that water flow to the sputterhead is on, turn on sputter power and bring up to desired power setting. 300 mA is sufficient to sputter Al, Cr, Ta, W, Ni and any other DC Magnetron sputterable material. After a suitable pre-sputter, open the shutter to deposit the coatings. Power Supply must be in power or current regulation. Final deposition rate will be dependent on material being sputtered, power setting, pressure, distance and time. When you have reached the desired thickness on your substrate, the power should be turned off the shutter should be closed, the argon turned off and the chamber vented.
- Open the Main Chamber door
- Take off the aluminium foil
- Put the shutter in and install on the top Picture of the shutter
- Picture of the shutter lead
- Install the shutter along with the lead
- Put the aluminum foil back on the shutter
- Try to cover as much as possible
Shut Down Instructions
1. Make sure that the Main Chamber Door is closed.
2. Run the Automatic System Pumping Procedure to pump down the chamber.
Cathode 1: Si3N4 Cathode 2: SiO2 Cathode 3: Metal (See Table for Available Metal Table) Tungsten(W) Sputtering Time: 300s DC Power: 500mA Process Set Point: 5X10-6 Torr Pressure: 4-5 mTorr Titanium-Tungsten(Ti-W) Gases available: Ar DC sputtering power source: 2 x 600V - 500mA RF sputtering power source: 600W at 13.56MHz Chamber pressure: 5x10-7 torr Substrate size: 4" wafer
Cleaning the System
To clean the System, spray IPA(Isopropanol) on a cleanroom towel and wipe out the inside of the Main Chamber.
Calculation for Thickness Non-UniformityThickness Non-Uniformity = (((Tmax-Tmin)/Tavg)/2)*100 Tmax = Maximum thickness recorded within measurement area Tmin = Minimum thickness recorded within measurement area Tavg = Average thickness recorded within measurement area
Sputtering 100nm of Tungsten(W) Change Tungsten Target. Press Auto Vent to Pump Up. Open the Door and put the wafer into the Sputtering Machine. Press Auto Pump to Pump Down. Set the Process Set poiont to be 5X10-6 Torr. Set Pre-Sputtering Time to be 60 s. Set Sputtering Time to be 300 s. Set DC power to be 500 mA. Wait until it pumps down to the process set point. Two light on the top right hand corner of the screen will be changed from red to green. Go to Timed Sputter menu. Press "Sputter Enable". It will start the automatic process. You should see some light through the chamber door. Once it is done, Auto Vent the machine and take the wafer out. Change the target back to the normal one.
Check Interlock Status Skins(SK) That means on the left door on the bottom (with Emergency button) is not closed completely. Try to open and close the door completely again. The Interlock should change back to "All Satisfied" For questions about the Sputtering System, please email the student contact on the top of the page.
Automatic Mode Automatic Pumping Up Make sure the system is NOT in Service mode. Select the "Auto Control" screen indicator. Select the "Auto Pump" indicator button. System Status will display Auto Mode. System will safely pump from atmosphere to high vacuum. Auto Pump can be started with the Turbo Pump ON or OFF. Auto Pump process will start the Turbo Pump if it is OFF. Automatic Pumping Down (Venting) Insure that the system is not in the service mode position. Turn off all internal sources of energy (RF power, DC power). Turn off all Gas Controls. Select the "Auto Control" screen. Select the "AutoVent" indicator button. System Status will display Auto Mode. Chamber will safely vent to atmospheric pressure. Cathode Selection Cathode 1: Si3N4 Cathode 2: SiO2 Cathode 3: Metal (See Table for Available Metal Table)