Cressington 108 Auto/SE Sputter Coater Standard Operating Procedures (S.O.P) The Cressington sputter system is designed for only one purpose which is the deposition of gold onto a sample to reduce charging when analyzed in the SEM. This system is only available for reservation through a NanoFab Staff member. NanoFab staff will make the reservation and operate the system for the intended user. Here is a brief summary about film thickness from the Cressington Operations Manual. The thickness of film required to prevent charging is very dependent on the sample and the operating voltage in the SEM. A thickness of between 3nm 5nm will usually prevent charging. The film needs to be thin enough not to obscure fine detail, but thick enough to prevent charging. Operating the system: 1
1) Verify that the system is powered OFF (Fig. 1). (Fig. 1) 2) Open the UPPER LID (Fig. 2a) of the chamber, if the upper lid will not lift up easily then the chamber may not be fully vented; in this case you must press and hold the RED VENT BUTTON (Fig. 2b) located on the left side of the table until the chamber lid will lift up. (Fig. 2a) (Fig. 2b) 3) Remove the UPPER GLASS CHAMBER and the ADAPTER RING (Fig. 3) that is located underneath it and sit them off to the side. This allows for easy access to the sample table. 2
(Fig. 3) 4) Sit the sample to be coated onto the center of the SAMPLE TABLE (Fig. 3a) facing upwards. The table can be tilted if better side coverage is needed on the sample. This is done by rotating the LARGE BLACK KNOB (Fig. 3b) at the rear of the chamber. (Fig. 3a) (Fig. 3b) 5) Ensure that the CRYSTAL HOLDER (Fig. 4) is facing upwards towards the target. 3
(Fig. 4) 6) Reinstall the GLASS UPPER CHAMBER and ADAPTER RING and lower the UPPER LID (See Fig. 2a & 3). 7) Turn on the MAIN POWER SWITCH (Fig. 5). The mechanical pump will start and the chamber will begin pumping down. Within a minute the front panel gauge should begin to show a drop in vacuum pressure. (Fig. 5) 4
8) Let the system pump down to <.04 mbar as measured by the lower range of the FRONT PANEL GAUGE (Fig. 6). This should typically occur within 10 minutes of turning the system on. (Fig. 6) 9) Press the AUTO - MANUAL (FIG. 7) button to illuminate the MANUAL LED located directly above the button. (Fig. 7) 5
10) The DEPOSITION TIME is displayed in the TIMER section of the front panel. The deposition rate of this system is approximately.33 Å per second. To set the timer for the deposition thickness desired press and hold the PAUSE/TEST button (Fig. 8) and use the UP/DOWN buttons to the right of the TIME DISPLAY to adjust the deposition time. (Fig. 8) 11) Turn ON the Thickness monitor power, wait a few seconds for it to initialize and then momentarily press the ZERO button (Fig. 9). (Fig. 9) 6
12) Press the LEAK button (Fig. 10) and give the system a minute for the pressure to stabilize. Ensure that the SPUTTERING PRESSURE is set for.07 mbar -.08 mbar on the front panel gauge (See Fig. 6). If the pressure is incorrect then it will have to be adjusted, this is performed by turning the needle valve located on the back of the system (Contact NanoFab Staff for this). LEAK button (Fig. 10) 13) Now press the AUTO/MANUAL button again (See Fig. 7), the AUTO LED should now be illuminated. 14) If you need a highly uniform film on the surface of the sample then turn ON the sample table rotation by turning the SPEED SELECTION KNOB (Fig. 11) clockwise, there are 5 different rotation speeds that can be selected. (Fig. 11) 7
15) Open the shutter by turning the SHUTTER ACTUATION KNOB (Fig. 12) clockwise until it stops rotating. (Fig. 12) 16) Press the CYCLE button (Fig. 13) to start the automatic deposition cycle. Once this has been started the system will run a number of purge cycles before beginning deposition. A glow will be evident from the plasma and the timer will begin counting down once the deposition has started. The timer will reset to your preset amount when the deposition has completed. (Fig. 13) 17) Once the deposition has completed you may turn OFF the rotation (See Fig. 11). Then turn OFF both the system power (See Fig. 1) and the deposition monitor power (See Fig. 9). 18) Rotate the SHUTTER ACTUATION KNOB (See Fig. 12) counterclockwise approximately ¼ turn, back to the point it covers the target. 8
19) To vent the system you must press and hold the RED VENT BUTTON (See Fig. 2b) located to the left of the system. Once the lid lifts easily by hand you can release the RED VENT BUTTON. 20) Remove the UPPER GLASS CHAMBER and the ADAPTER RING (See Fig. 3) that is located underneath it and sit them off to the side. 21) Remove your sample and then reinstall the UPPER GLASS CHAMBER and the ADAPTER RING, then lower the UPPER LID. Leave the system in its powered down state when you are finished. 9