DC Magnetron Sputtering System: Introduction

Components Information

And

How to operate ?

Main Components:

Vacuum Chamber

209mm diameter and 400mm length

Water Cooling Coils

Two View Ports

Magnetrone setup

Hydraulic Lift

For Top Plate Movement Controlled by “Hoist Up/Down” Key.

Magnetrone Source

On Top Plate with DC Power supply

Water Cooled Supply

Gas Feedthrough

By Needle Valve on Top of Chamber

Inert Gas Argon Flow

Water Cooled Substrate Holder

Cum Heater

Water Cooling System

Heater Power Supply 230 V

Temperature between 0 to 400 degree

Celsius (temperature Indicator)

Source Shutter

Manually Operated to Cover/ Uncover

the Cathode

Vacuum Pumping System:

Rotary Vacuum Pump:

Vacuum Up to 10-3 mbar

Effective Pumping Speed

250 lit/min

Diffusion Pump:

Vacuum Up to 10-7 mbar

Base Pressure of 10-2 mbar is

Required

Effective Pumping Speed 250 lit/s

Liquid Nitrogen Trap

Between Diffusion Pump and

Hi Vacuum Valve

To Condense the condensable

vapour and as well as back

streaming of oil vapour emitted in

diffusion pump

High vacuum Valve

Between Diffusion Pump and

Chamber

• Vacuum Measuring Gauges

• Pirani Gauge :- Atm. Pressure to 10-3 mbar

• Penning Gauge :- 10-3 mbar to 10-6 mbar

• Control Panel

1. Magnetron Power Supply

2. Pirani gauge

3. Substrate Temperature Indicator

4. Substrate Heater Control Knob

5. Rotary Pump “On” and “Off” Push Button

6. Selector Switch for DP and SH

7. Switch for Hydraulic Lift

8. Penning Gauge

9. Indication Lamps

Basics Theory:-

• Sputtering is the removal of atomised material from a solid due to

energetic bombardment of its surface layers by ions or neutral

particles.

• Uses target as cathode and

substrate as anode. The ion in

plamsa will be accelerated toward

cathode, hit the target and transfer

the energy sputtering the target to

substrate surface. Target must be a

conductive material (metal). It

can't sputter dielectric material

target. DC sputtering is also

known as diode or cathodic

sputtering.

• Magnetron sputtering - powerful and flexible technique used to coat

virtually any workpiece with a wide range of materials and it is low-

cost and easy control method for film growth, especially suitable for

large-scale film deposition.

• Prior to the sputtering procedure a vacuum of less than one ten

millionth of an atmosphere must be achieved. From this point a

closely controlled flow of an inert gas such as argon is introduced.

This raises the pressure to the minimum needed to operate the

magnetrons.

• Planar magnetron sputtering is the one with parallel target and anode

electrode surfaces.

• E and B fields are perpendicular to one another, electrons are forced to

drift in a cycloidal hopping motion along the tunnel track length.

Magnetic fields of about ~ 0.5 G on the target front surface.

• Important implications of the magnetron sputtering are higher

deposition rates due to higher ionization of Argon atoms or

alternatively, lower voltage operation than for simple DC sputtering.

Another important advantage is reduced operating pressures.

Schematic Diagram of the System:

Sputtering Gas Argon

Venting Valve

• Open the chamber.

• Lift the chamber by selecting Rotary switch to “Hoist-Up” position.

• Load the substrate and fix the required target, which is to be coated.

• Close the chamber by selecting Rotary switch to “Hoist-Down” position.

• Close the air admittance valve, needle valve and hi vacuum valve.

• Switch ON main circuit breaker.

• Switch ON the Rotary pump by pressing the green start button on the front

panel.

• Open the roughing valve by moving the combination valve to roughing position.

Operating Procedure:

• Switch ON Pirani gauge and select the GH2 position in Pirani to measure the

roughing vacuum (wait until gauge reading is less then 0.05 mbar, best is to wait

for 0.02 mbar)

• Close the roughing valve and open the backing valve using combination valve.

• Select the GH1 position in Pirani gauge to measure the backing vacuum. (wait

until gauge reading is less then 0.05 mbar, best is to wait for 0.02 mbar)

• Switch On the diffusion pump by selecting the rotary switch to DP position.

• Switch ON the chiller and motor, make sure that water is flowing through

cooling lines of DP.

• Wait for 45 minutes.

• Pour liquid nitrogen in liquid nitrogen tank (3 to 5 lit).

• Open the hi vacuum valve.

• After five minutes switch ON the penning gauge to read the high vacuum in the

chamber (5×10-6 mbar).

• After reaching the required vacuum, switch on the substrate heater by selecting

the rotary switch to DP&SH position.

• Switch ON the temperature indicator and set the required temperature.

• Slowly turn the SH control knob and keep the required position.

For Doing the Sputtering

• Close the hi vacuum valve totally.

• Switch OFF the penning gauge.

• Insert the Argon gas by opening the needle valve by using the mass flow

controller slowly and maintain the chamber vacuum level between 0.05 to 0.02

mbar.

• Open HV valve slowly to mid (between open and close) position.

• Adjust needle valve to get correct pressure.

• Switch on DC magnetron power supply, after make sure that all interlocks are

satisfied.

• Switch ON mains (red LED is ON), then push green button.

• Open source shutter.

• Keep DC power for required time duration.

• Tune the current control knob to control current (if current is high then plasma

density is high and as a result deposition rate is high).

• After switching ON the Dc power, at particular current we can see the plasma

through the view ports. It might be violet-lavender while the ends are blue-

violet-lavender.

Shutting Down the System

• Slowly turn OFF the current control

• Switch OFF red button.

• Switch OFF the mains.

• Switch OFF DC magnetron power supply.

• Close the Argon gas flow using needle valve.

• Close the high vacuum valve.

• Switch OFF the substrate heater and temperature indicator.

• Switch OFF diffusion pump.

• Keeping the backing valve open, run the Rotary pump for the period of 30-45

minutes and then close the backing valve.

• Switch OFF the Rotary pump on control panel.

• Switch OFF the chiller and motor of water supply.

• Switch OFF the mains circuit breaker.

• Open the air admittance valve and vent the chamber by air or liquid nitrogen.

• Open the chamber and lift the chamber by selecting Rotary switch to “Hoist-

UP” position.

• Remove target and samples.

To Keep the Chamber In High Vacuum

• Close the chamber by selecting rotary switch to Hoist-Down position.

• Close the air admittance valve.

• Switch ON mains circuit breaker.

• Switch ON the rotary pump and open the roughing valve.

• Switch ON Pirani guage and wait for the vacuum level 0.02 mbar.

• Close the roughing valve.

• Switch OFF rotary pump.

• Switch OFF the mains circuit breaker.

Cautions:

• All manually operated valves should be closed before starting.

• All switches on the control panel should be OFF.

• All cabinet doors should be properly closed.

• The top plate is tighten properly to make sure of no leakage.

• Do not touch the system with bare hand when plasma is ON.

• Make sure that there is proper cooled-water supply to magnetron, diffusion

pump and main chamber.

• Always keep the chamber in vacuum the system is not in use.

Power Cut During Deposition

• Close the high vacuum valve.

• Make all the switches OFF.

• Release the backing tube using venting valve.

• Switch OFF mains.