Lesker PVD75 DC/RF Sputterer

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Lesker PVD75 DC/RF Sputterer
PVD-03.jpeg
Tool Name Lesker PVD75 DC/RF Sputterer
Instrument Type Deposition
Staff Manager Jason (jarohr@seas.upenn.edu)
Lab Location Bay 2
Tool Manufacturer Kurt J. Lesker
Tool Model PVD75
Iris Designation PVD-03
Lab Phone 215-898-9748
SOP Link SOP

Tool description

The Kurt J. Lesker PVD75 Sputter system is configured with 4 sputter guns in the following configuration:

Target 1: RF power, insulating/conductive target
Target 2: DC power, magnetic/non-magnetic conductive target
Target 3: DC power, non-magnetic conductive target
Target 4: DC power, magnetic/non-magnetic conductive target

The system is cryo-pumped process chamber with an automated interface, wafer platen rotation and heating up to 550°C, accepting sample sized from pieces to 150 mm diameter wafers.

When choosing between PVD-03 and PVD-05, consider the following:

  • PVD-03 is a load-locked system so base pressure will be better (~5e-8 torr vs. ~5e-6 torr) and pumpdown times will be much faster compared with PVD-05, which is an open load system.
  • PVD-03 can handle one 6" wafer or one 4" wafer (or several smaller pieces) per run. PVD-05 has a large platen and can accept about four 4" wafers with good uniformity.
  • PVD-03 is in a sputter up configuration, which means the guns point up and the sample must be attached upside down. This is usually considered cleaner, but requires greater consideration for sample mounting. PVD-05 is in sputter down configuration, so samples can just be placed on the platen.
  • Magnetic materials can only be sputtered from PVD-03. PVD-05 does not have the necessary high mag sources

Deposition sources

Metals
  • Ag - Silver (Warning! Ag target must be cooled down for more than 15 min after deposition)
  • Al - Aluminum
  • Au - Gold
  • Co - Cobalt
  • Cr - Chromium
  • Cu - Copper
  • Fe - Iron
  • Mn - Manganese
  • Mo - Molybdenum
  • Nb - Niobium
  • Ni - Nickel
  • Pd - Palladium
  • Pt - Platinum
  • Ti - Titanium
  • W - Tungsten
Semiconductors & metalloids
  • Ge - Germanium
  • Si - Silicon
  • n-Si - n-type silicon (doped)
  • p-Si - p-type silicon (doped)
Oxides, fluorides & nitrides
  • Al2O3
  • AZO (ZnO2/Al2O3; transparent conductive oxide)
  • ITO (indium-doped tin oxide; transparent conductive oxide)
  • MgF2
  • MgO
  • NbN
  • Si3N4
  • SiO2
  • Ta2O5
  • TiO2
  • TiN
Alloys & ceramics
  • Al/Si (99/1)
  • Fe/Ge (81/19 & 83/17)
  • Ni/Fe
  • Ni/Cr (80/20)
  • YSZ (Yttria-stabilized zirconia)
Other targets
  • Please consult with staff

Important resources

Target request form
SOPs & troubleshooting

DC & RF sputtering process data

DC deposition
Material Name Cathode 2 (DC; high mag) Recorded Cathode 3 (DC) Recorded Cathode 4 (DC; high mag) Recorded
Pressure Power Rate Pressure Power Rate Pressure Power Rate
Ag (silver) - - - 3 mTorr 400 W 7.6 Å s-1 3 mTorr 400 W 8 Å s-1
Al (aluminum) - - - - - - 5 mTorr 350 W 2 Å s-1
Cr (chromium) 4 mTorr 240 W 2.1 Å s-1 - - - - - -
Cu (copper) 4 mTorr 400 W 6.2 Å s-1 3 mTorr 400 W 3.8 Å s-1 - - -
ITO - - - 3 mTorr 120 W 1 Å s-1 - -
Permalloy 4 mTorr 300 W 2.7 Å s-1 - - - - - -
Ti (titanium) 6 mTorr 300 W 1.8 Å s-1 - - - 6 mTorr 300 W 0.8 Å s-1
W (tungsten) - - - 3 mTorr 400 W 1.7 Å s-1 - - -
Ni (nickel) 3 mTorr 350 W 2.5 Å s-1 - - - - - -
Mo (molybdenum) 4 mTorr 350 W 2.8 Å s-1 - - - 5 mTorr 350 W 2.9 Å s-1
FeGa (galfenol) 3 mTorr 140 W 1 Å s-1 - - - - - -
Ge (germanium) 4 mTorr 120 W 2 Å s-1 4 mTorr 120 W 1.1 Å s-1 - - -
Au (gold) - - - 3 mTorr 140 W 2.5 Å s-1 - - -
i-Si (intrinsic silicon) - - - - - - - - -
n-Si (n-type silicon) - - - 4 mTorr 280 W 1.3 Å s-1 - - -
p-Si (p-type silicon) - - - 3 mTorr 280 W 0.8 Å s-1 - - -
Pt (platinum) 4 mTorr 140 W 1.7 Å s-1 - - - - - -
RF deposition
Material Name Cathode 1 (RF) Recorded
Pressure Power Rate
TiO2 3 mTorr 120 W 0.067 Å s-1 -
Al2O3 - - - -
ZnO 3 mTorr 120 W 0.2 Å s-1 -
Si3N4 - - - -
Additional resources

Note: The sputter yield chart can be useful for estimating approximately what rate to expect from materials, but the rate given is highly dependent on tool configuration and is not directly relevant

Maintenance

The basics of magnetron sputtering

Magnetron sputtering, also simply called sputtering, is a PVD method that involves a gaseous plasma (often consisting of high-energy Ar ions) which is generated within the chamber and bombarded onto the material to be deposited, known as the target. During the bombardment, the surface of the target is eroded by the plasma and the ejected atoms travel from the surface of the target, through the vacuum environment, and deposit onto a substrate (such as a Si or quartz wafer) to form a thin film. Materials ranging from metals to dielectrics can be deposited via sputtering, and the technique is widely used within both academia and industry, with a variety of applications ranging from electronics to food packaging.

During a typical sputtering process, the chamber is evacuated to high vacuum (~ 5 x 10-8 Torr) to minimize the partial pressures of background gases (oxygen, nitrogen, water vapor, etc.) along with potential volatile contaminants (such as solvents). After high vacuum is reached, the sputtering gas that is used to form the plasma is injected into the chamber. The total pressure is subsequently regulated to the mTorr range (typically 3 to 10 mTorr). To strike the plasma, a high voltage is applied between the cathode (often located directly behind the sputtering target) and the anode (often connected to the chamber as electrical ground).

As a high voltage is applied, electrons are accelerated away from the cathode towards the anode, colliding with the nearby injected gas atoms. These collisions knock electrons off the sputtering gas atoms, causing positive ionization, hence forming the plasma. The ionized sputter gas atoms are now accelerated towards the negatively charged cathode, resulting in high energy collisions with the target. Each of these collisions can cause atoms at the surface of the target to be ejected into the vacuum environment with enough kinetic energy to reach the surface of the substrate. The overall gas pressure is typically reduced to around 3 mTorr to ensure fewer collisions between the ejected atoms and the gas atoms, as these collisions increase the diffusivity of the ejected atom stream. These collisions can give rise to a quasi-conformal coating, which can be both beneficial or detrimental for the overall application.

While sputtering is typically a slower process than evaporation, sputtering results in smoother thin-films.