Specific Process Knowledge/Thin film deposition/Wordentec

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Wordentec QCL 800

Wordentec: positioned in cleanroom D-2 in the Wordentec room

The Wordentec is a machine for:

• Deposition of metals by e-beam evaporation
• Deposition of metals by thermal evaporation
• Deposition of materials by DC sputtering
• Cleaning samples before deposition by Argon RF sputter cleaning

The Wordentec is designed to deposit on 1-6 samples in sequence. Adaptors exist for deposition on 2", 4" and 6" wafers and deposition is possible on samples of almost any size and shape, as long as they do not exceed a 6" diameter. The Wordentec supports either single sample deposition for running a separate recipe on each sample or batch deposition for six wafers in sequence. It is possible to freely combine processes from the machine's different sources.

The user manual, quality control procedure and results, user APV, technical information and contact information can be found in LabManager:

Wordentec in LabManager

Process information

The metals available for E-beam evaporation and their standard deposition rates are:

Metal	Deposition rate [Å/s]
Titanium (Ti)	10
Chromium (Cr)	10
Aluminium (Al)	10
Nickel (Ni)	10
Platinum (Pt)	10
Gold (Au)	10

Temperature and roughness studies of Au deposition processes in the Wordentec

E-beam evaporation of some materials like Au and Al can affect the underlying layers and thin resists such as E-beam sensitive resists can get exposed or their topography may change. Cases of releasing bubbles of the solvent will create a crater-like surface on some materials. In most cases this only affects the areas containing resist, hence liftoff is often easier and the areas without resist will have good adhesion.

Delaminating Au film on thin E-beam resist

Thermal evaporation materials

We currently have Aluminium, Silver and Germanium available to deposit through thermal evaporation.

Sputter materials

It is possible to sputter deposit almost any material, provided that it is possible to deposit with DC sputtering. The materials available currently include:

• TiW alloy (10%/90% by weight)
• Aluminium (Al)
• Chromium (Cr)
• Silver (Ag)
• Titanium (Ti)
• Silicon (Si)
• NiV alloy

More information about deposition rates and surface roughness can be found by clicking on the different elements.

Thickness measurement

Read about how the machine measures the thickness of the growing film using a quartz crystal monitor here.

Particulates in the films

Read about some tests that we made of particulates in e-beam evaporated Al, Ni, and TiAu films made in the Wordentec and the Temescal here.

Equipment performance and process related parameters Wordentec

Purpose	Deposition of metals	E-beam evaporation Sputtering Thermal evaporation
Performance	Film thickness	~10Å - 1µm*
	Deposition rate	~2.5Å/s - 15Å/s
	Thickness uniformity	~6 % variation across a 4" wafer for thermal evaporation of 100 nm Al ** ~9 % variation across a 4" wafer for e-beam evaporation of 100 nm Ni ** ~6 % variation across a 4" wafer for e-beam evaporation of 10 nm Ti + 90 nm Au **
Process parameter range	Process Temperature	Less than 80 oC
	Process pressure	~3x10-7 - 4x10-6 mbar
Substrates	Batch size	24x2" wafers or 6x4" wafers or 6x6" wafers Deposition on one side of the substrate
	Substrate material allowed	Silicon wafers Quartz wafers Pyrex wafers
	Material allowed on the substrate	Silicon oxide Silicon (oxy)nitride Photoresist PMMA Mylar SU-8 Metals

* For e-beam evaporation and sputtering, permission is required for thicknesses above 600 nm. For thermal evaporation, permission is required for thicknesses above 120 nm. This is to ensure that there will be enough material present. Contact metal@nanolab.dtu.dk or thinfilm@nanolab.dtu.dk

** Percent variation calculated as (Max-Min)/Average. For thermally evaporated Al, the max was on one side of the wafer rather than in the middle. Measured by Rebecca Ettlinger, Nov. 2018.