Specific Process Knowledge/Thin film deposition/Temescal: Difference between revisions

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==E-Beam Evaporator (Temescal)==
==E-Beam Evaporator (Temescal)==
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[[File:Temescal.JPG|400px|right|thumb|The Temescal E-beam evaporator in cleanroom A-5]]
[[File:Temescal.JPG|400px|right|thumb|The Temescal E-beam evaporator in cleanroom A-5]]


The Temescal is a system for depositing metals by electron-beam evaporation. In e-beam evaporation, the deposition is line-of-sight directed from the source, which means it will coat only the surface of the sample facing directly towards the source. This makes it very useful for example for metals for lift-off. The system also has an ion source for in-situ Argon sputtering that can be used either for cleaning samples prior to deposition or to modify the film during deposition.  
The E-beam evaporator (Temescal) is a system for depositing metals by electron-beam evaporation. In e-beam evaporation, the deposition is line-of-sight directed from the source, which means it will coat only the surface of the sample facing directly towards the source. This makes it very useful for example for [[Specific Process Knowledge/Lithography/LiftOff|lift-off]]. This particular machine is made by Temescal, a division of FerroTec, and was purchased by Nanolab in 2018. It is very similar to the newer e-beam evaporator we have from the same manufacturer, bought in 2023, which we call [[Specific Process Knowledge/Thin film deposition/10-pocket_e-beam_evaporator|E-beam Evaporator (10-pockets)]] in the LabManager system.  


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 samples that are loaded together. You can load up to four 6" wafers or three 8" wafers for deposition on surfaces facing the evaporation source, or on up to one 6" wafer for tilted deposition (smaller samples may be tilted more). By using sample holder inserts, you can deposit metals on samples of different sizes and shapes. Only one metal can be deposited at a time, but you can deposit many layers of different metals one after the other. The system contains 6 metals at a time and the metals are exchanged based on user requests, so please request the metals you wish well in advance.  
A special feature of the older machine - the E-beam evaporator (Temescal) - is that it has an ion source for in-situ Argon sputtering that can be used either for cleaning samples prior to deposition or to modify the film during deposition.
 
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 samples that are loaded together. You can load up to four 6" wafers or three 8" wafers for deposition on surfaces facing the evaporation source, or on up to one 6" wafer for tilted deposition. By using sample holder inserts, you can deposit metals on samples of different sizes and shapes. Only one metal can be deposited at a time, but you can deposit many layers of different metals one after the other. The system contains 6 metals at a time and the metals are exchanged based on user requests, so please request the metals you wish well in advance.  


'''The user manual, user APV, and contact information can be found in LabManager:'''  
'''The user manual, user APV, and contact information can be found in LabManager:'''  
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[http://labmanager.danchip.dtu.dk/function.php?module=Machine&view=view&mach=429 E Beam Evaporator (Temescal) in LabManager]
[http://labmanager.dtu.dk/function.php?module=Machine&view=view&mach=429 E Beam Evaporator (Temescal) in LabManager]


'''Training videos may be found here:'''  
'''Training videos may be found here:'''  
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==Deposition rate and thickness measurement accuracy==
== Process information ==
The machine measures the thickness of the growing film with a Quartz Crystal Microbalance or QCM. The machine calls it the Xtal (crystal). This is a very thin piece of quartz that resonates at about 5-6 MHz when a voltage is applied across it. The resonance frequency varies with the mass of the crystal, and when material is deposited on one side of it, the frequency changes. This is measured by the crystal monitor, which can then calculate the deposited thickness.
[[File:Sell_quartz_crystal_microbalance.jpg|100px|right|thumb|Quartz crystal microbalance with gold electrode. Image from RLC on EC21.com]]


The thickness calculation depends on the material density as well as other physical factors. A ''tooling factor'' is used to adjust the calculation based on the geometry of the setup, since the crystal is not in the same place as the wafers so the thickness deposited on the crystal is lower than on the samples.
*[[/Acceptance Test|Acceptance Test]]. Describes '''thickness uniformity''' tests, '''side wall deposition''' tests, '''sheet resistance''' tests and tests of the '''ion source''' for substrate cleaning.


The tooling factor is calibrated for a particular deposition rate. It may not be perfectly accurate for other deposition rates, but should easily be within the 10 % accuracy that we test for in our quality control measurements.
====Materials for e-beam evaporation====
For very thin films the thickness measurement will be less accurate than for thicker films.
 
The machine gives a rough number for the crystal lifetime simply based on how thick a layer it calculates has been deposited on it. If many layers have been deposited and there is stress in the layers (e.g., in Cr or Ni), there may be partial delamination, which can make the thickness measurement inaccurate. In this case the lifetime estimate given by the machine will be inaccurate. If you think the crystal is not measuring correctly, please let us know. We exchange the crystals usually around 20 % lifetime use.
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== Heating during the deposition ==
If the material you are depositing requires a lot of heat to evaporate, the substrates may get warm during the deposition.
 
A temperature test of a 100 nm Al deposition at 10 Å/s showed that the back of the wafer stays below 37 <sup>o</sup>C. The same is true for 10 nm Ti plus 90 nm Au at 10 Å/s. In contrast, deposition of 100 nm Nb at 2 Å/s heated the substrate to above 104 <sup>o</sup>C (but the back of the wafer stayed at less than 110 <sup>o</sup>C). Deposition of 60 nm W at about 1 Å/s heated the substrate to more than 110 <sup>o</sup>C.
 
You may get some idea of how much the substrate will be heated by looking at the temperature required to give a reasonable vapor pressure for the evaporation. You can find a collection of Honig's vapor pressure curves at the bottom of [https://old.mcallister.com/vacuum.html this page (external link)].
 
Please contact us if you would like to test the heating of the substrates (write to [mailto:thinfilm@danchip.dtu.dk thinfilm@danchip.dtu.dk]).
 
==The e-beam and the Cu hearth==
[[File:Cu hearth 2.jpg|100px|left|thumb|Empty 6-pocket copper hearth (from Fil-Tech)]]
 
[[File:Cu hearth.jpg|200px|right|thumb|E-beam impinging on the target from the filament and a 6-pocket Temescal copper hearth and filament assembly enclosed by shields (from Scotech)]]
 
At the start of the deposition and for every 100 nm, please check that the e-beam hits the target material rather than the hearth next to the pocket or the bottom of the pocket.
 
1) Check that the e-beam sweep has not shifted away from the material onto the hearth. This could happen if the filament assembly has been distorted by heat for example.
 
2) Check that there is enough material in the pocket, so that the beam does not hit the bottom of the pocket. If you burn a hole in the bottom of the pocket, cooling water can leak into the chamber and it may flood!
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== Process information ==
[[Specific Process Knowledge/Thin film deposition/Deposition of Aluminium|Aluminium (Al)]]
,[[Specific Process Knowledge/Thin film deposition/Deposition of Chromium|Chromium (Cr)]]
,[[Specific Process Knowledge/Thin film deposition/Deposition of Copper|Copper (Cu)]]
,[[Specific Process Knowledge/Thin film deposition/Deposition of Germanium|Germanium (Ge)]]
,[[Specific Process Knowledge/Thin film deposition/Deposition of Gold|Gold (Au)]]
,[[Specific Process Knowledge/Thin film deposition/Deposition of Molybdenum|Molybdenum (Mo)]]
,[[Specific Process Knowledge/Thin film deposition/Deposition of Nickel|Nickel (Ni)]]
,[[Specific Process Knowledge/Thin film deposition/Deposition of Niobium|Niobium (Nb)]]
,[[Specific Process Knowledge/Thin film deposition/Deposition of Palladium|Palladium (Pd)]]
,[[Specific Process Knowledge/Thin film deposition/Deposition of Platinum|Platinum (Pt)]]
,[[Specific Process Knowledge/Thin film deposition/Deposition of Silver|Silver (Ag)]]
,[[Specific Process Knowledge/Thin film deposition/Deposition of Tantalum|Tantalum (Ta)]]
,[[Specific Process Knowledge/Thin film deposition/Deposition of Tin|Tin (Sn)]]
,[[Specific Process Knowledge/Thin film deposition/Deposition of Titanium|Titanium (Ti)]] 
,[[Specific Process Knowledge/Thin film deposition/Deposition of Tungsten|Tungsten (W)]] - thinner layers


*[[/Acceptance Test|Acceptance Test]]. Describes thickness uniformity tests, side wall deposition tests, sheet resistance tests and tests of the ion source for substrate cleaning.
Note that to date (May 2022) we have processes available for deposition of Al, Cr, Cu, Ge, Au, Ni, Nb, Pd, Pt, Ag, Ti, W and Ta as well as Ru. If your favorite metal is not available we may be able to buy a target and develop a recipe, just ask.


====Materials for e-beam evaporation====
===Thickness measurement, deposition rate and process control===
Read about how the machine measures the thickness of the growing film using a quartz crystal monitor, how accurately you can control the rate/thickness, and other useful information about e-beam deposition here: [[/Good to know about the Temescal#Deposition rate and thickness measurement accuracy|Thickness, rate, process control]].


*[[Specific Process Knowledge/Thin film deposition/Deposition of Aluminium|Aluminium (Al)]]
===Particulates in the films===
*[[Specific Process Knowledge/Thin film deposition/Deposition of Chromium|Chromium (Cr)]]
Read about optimizing film quality including how to minimize the number of [[/Particulates in Temescal Au films|particulates in Au films in the Temescal]].
*[[Specific Process Knowledge/Thin film deposition/Deposition of Copper|Copper (Cu)]]
*[[Specific Process Knowledge/Thin film deposition/Deposition of Gold|Gold (Au)]]
*[[Specific Process Knowledge/Thin film deposition/Deposition of Molybdenum|Molybdenum (Mo)]]
*[[Specific Process Knowledge/Thin film deposition/Deposition of Nickel|Nickel (Ni)]]
*[[Specific Process Knowledge/Thin film deposition/Deposition of Niobium|Niobium (Nb)]]
*[[Specific Process Knowledge/Thin film deposition/Deposition of Palladium|Palladium (Pd)]]
*[[Specific Process Knowledge/Thin film deposition/Deposition of Platinum|Platinum (Pt)]]
*[[Specific Process Knowledge/Thin film deposition/Deposition of Silver|Silver (Ag)]]
*[[Specific Process Knowledge/Thin film deposition/Deposition of Tantalum|Tantalum (Ta)]]
*[[Specific Process Knowledge/Thin film deposition/Deposition of Tin|Tin (Sn)]]
*[[Specific Process Knowledge/Thin film deposition/Deposition of Titanium|Titanium (Ti)]] 
*[[Specific Process Knowledge/Thin film deposition/Deposition of Tungsten|Tungsten (W)]] - thinner layers
 
Note that to date (Dec 2018) we have processes available for deposition of Al, Cr, Au, Ge, Nb, Ni, Pd, Pt, Ag, Ti, and W as well as Ru. More will be available as they are requested.


==Equipment performance and process related parameters for the Temescal E-beam evaporator==
==Equipment performance and process related parameters for the Temescal E-beam evaporator==
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'''**''' ''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.''
'''**''' ''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.''
==Quality control (QC) for the Temescal==
We are still developing the QC procedure for the Temescal (September 2018).

Latest revision as of 13:24, 16 May 2024

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

The E-beam evaporator (Temescal) is a system for depositing metals by electron-beam evaporation. In e-beam evaporation, the deposition is line-of-sight directed from the source, which means it will coat only the surface of the sample facing directly towards the source. This makes it very useful for example for lift-off. This particular machine is made by Temescal, a division of FerroTec, and was purchased by Nanolab in 2018. It is very similar to the newer e-beam evaporator we have from the same manufacturer, bought in 2023, which we call E-beam Evaporator (10-pockets) in the LabManager system.

A special feature of the older machine - the E-beam evaporator (Temescal) - is that it has an ion source for in-situ Argon sputtering that can be used either for cleaning samples prior to deposition or to modify the film during deposition.

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 samples that are loaded together. You can load up to four 6" wafers or three 8" wafers for deposition on surfaces facing the evaporation source, or on up to one 6" wafer for tilted deposition. By using sample holder inserts, you can deposit metals on samples of different sizes and shapes. Only one metal can be deposited at a time, but you can deposit many layers of different metals one after the other. The system contains 6 metals at a time and the metals are exchanged based on user requests, so please request the metals you wish 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. Describes thickness uniformity tests, side wall deposition tests, sheet resistance tests and tests of the ion source for substrate cleaning.

Materials for e-beam evaporation

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) ,Titanium (Ti) ,Tungsten (W) - thinner layers

Note that to date (May 2022) we have processes available for deposition of Al, Cr, Cu, Ge, Au, Ni, Nb, Pd, Pt, Ag, Ti, W and Ta as well as Ru. If your favorite metal is not available we may be able to buy a target and develop a recipe, just ask.

Thickness measurement, deposition rate and process control

Read about how the machine measures the thickness of the growing film using a quartz crystal monitor, how accurately you can control the rate/thickness, and other useful information about e-beam deposition 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.

Equipment performance and process related parameters for the Temescal E-beam evaporator

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
Material allowed on the substrate

* For thicknesses above 600 nm please request permission so we can ensure that enough material will be present.

** 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.