Lesker PVD75 DC/RF Sputterer

Lesker PVD75 DC/RF Sputterer

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
NEMO Designation	{{{NEMO_Designation}}}
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

Below is a list of our sputtering materials along with links to materials specs (coming soon!).

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

• Link to Google form

SOPs & troubleshooting

• SOP

• PVD-03 Open Load SOP

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	1.2 Å s-1	06/27/23
Cr (chromium)	4 mTorr	240 W	2.1 Å s-1		4 mTorr	240 W	1.6 Å s-1	04/05/23	-	-	-
Cu (copper)	4 mTorr	400 W	6.2 Å s-1		3 mTorr	400 W	3.8 Å s-1		5 mTorr	400	4.0 Å s-1	03/06/23
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		5 mTorr	300 W	0.98 Å s-1	03/06/23	6 mTorr	300 W	0.8 Å s-1
W (tungsten)	4 mTorr	350 W	2.3 Å s-1	02/02/23	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)	4 mTorr	140	3.1 Å s-1	02/24/23	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		-	-	-		4 mTorr	140 W	1.4 Å s-1	03/06/23

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	3 mTorr	120 W	0.014 Å s-1	01/03/22

Additional resources

• PVD-03 Recipes
• Sputter Yield Chart

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

• Maintenance Docs

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.