Specific Process Knowledge/Thin film deposition/Temescal

Feedback to this page: click here

Unless otherwise stated, this page is written by DTU Nanolab internal

E-Beam Evaporator (Temescal)

The Temescal E-beam evaporator in cleanroom A-5

This system allows electron-beam evaporation of thin films (<1 μm) of metals and one semiconductor, Ge. In e-beam evaporation, the deposition is line-of-sight from the source, which means it will coat only the surface of the sample facing the source directly. This makes it useful for example for lift-off. Nanolab's current e-beam evaporators were made by Temescal, a division of FerroTec, and this particular machine was purchased by Nanolab in 2018. It is very similar to the newer e-beam evaporator, bought in 2023, called the E-beam Evaporator (10-pockets) in the LabManager system.

A special feature of the 2018 E-beam evaporator (Temescal) is that it has an ion source for argon sputtering. This can be used either for in situ sample cleaning prior to deposition or to modify the film during deposition (ion beam assisted deposition or IBAD).

In both Temescal e-beam evaporators, wafers are loaded into the top of the chamber, which acts as a loadlock as it can be separated from the rest of the chamber by a large gate valve. Deposition will happen on all loaded samples. Up to four 6" wafers /three 8" wafers may be loaded for line-of-sight deposition, or up to one 6" wafer for tilted deposition. Only one material can be deposited at a time, but layers of different metals may be deposited one after the other. The system contains 6 materials at a time which are exchanged weekly based on user requests. Please request materials well in advance.

The user manual, user APV, and contact information can be found in LabManager:

E Beam Evaporator (Temescal) in LabManager

Training videos may be found here:

Training videos on Youtube

Process information

Acceptance Test information is found here. Describes thickness uniformity, side wall deposition, sheet resistance, and use of the ion source.

Materials

Aluminium (Al)
Chromium (Cr)
Copper (Cu)
Germanium (Ge)
Gold (Au)
Molybdenum (Mo)
Nickel (Ni)
Niobium (Nb)
Palladium (Pd)
Platinum (Pt)
Silver (Ag)
Tantalum (Ta)
Tin (Sn) (we recommend using sputtering instead)
Titanium (Ti)
Tungsten (W)

If your favorite metal is not on the list you are welcome to ask if we can develop a recipe. Note that Si as well as SiO₂, Al₂O₃ and other oxides are available on the E-beam Evaporator (10-pockets).

Thickness measurement, deposition rate and process control

How the machine measures the thickness of the growing film using a quartz crystal monitor, how accurately is the control of the rate/thickness, and other useful information about e-beam deposition is found here: Thickness, rate, process control.

Particulates in the films

Read about optimizing film quality including how to minimize the number of particulates in Au films in the Temescal.

Ion source

Information on the ion source.

Equipment performance and process related parameters

Purpose	Deposition of metals	E-beam evaporation of metals Line-of-sight deposition Possible to tilt sample Possible to ion clean samples Possible to modify deposition by Ar ion bombardment
Performance	Film thickness	10Å - 1µm* (for some materials)
	Deposition rate	0.5Å/s - 10Å/s
	Thickness uniformity	up to 3 % Wafer-in-Wafer variation, Wafer-to-Wafer and Batch-to-Batch variation **
	Thickness accuracy	May vary by up to about +/- 10 % Less accurate for films below 20 nm
Process parameter range	Process Temperature	Approximately room temperature. Higher for refractive metals that require a lot of heat to evaporate, see above.
	Process pressure	Below 1*10-6 mbar before deposition starts Below 5*10-6 mbar during deposition
	Source-substrate distance	69.85 cm
Substrates	Batch size	Up to four 6" wafers per standard run Or up to three 8" wafers Up to one 6" wafer with tilt Deposition on one side of the substrate
	Substrate material allowed	Almost any that does not outgas and is approved in the cleanroom. See also the cross-contamination sheet
	Material allowed on the substrate	Almost any that does not outgas and is approved in the cleanroom. See also the cross-contamination sheet

* See table in manual with max. allowed rate and cumulative thickness. If you would like to deposit more than the limit in the table, please request permission from metal@nanolab.dtu.dk no matter if it is a single layer or a number of deposition runs adding up to a total thickness exceeding the limit. This is so we can ensure that enough material will be present and that the the machine can be cleaned up as needed as thick layers can cause flaking.

** Defined as the ratio of the standard deviation to the average of the measurement made using the DektakXT. For further details see the acceptance test.