Specific Process Knowledge/Thin film deposition/Physimeca

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The Physimeca has been decomissioned and is no longer available.

Physimeca

The Physicmeca, Located in cleanroom B-1.

Physimeca is a system for deposition of metals through electron-beam evaporation.

Wafers are loaded into the system through the load lock and transferred into the deposition chamber. Physimeca allows you to deposit metals on samples up to 4 inch wafer. There are three different sample holders, one for chips (arbitrary size), one for 2" wafers and one for 4" wafers. The sample holder can be tilted during deposition, but is normally kept in a horizontal orientation.

Six different metals are present at each time in the Physimeca. The metal combination is changed if needed. A list of currently allowed metals is included in the table below; contact the ThinFilm team (Metal@nanolab.dtu.dk) if you have wishes for other metals.

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

Physimeca in LabManager

Equipment performance and process related parameters Physimeca

Purpose	Deposition of metals	E-beam evaporation of metals
Performance	Film thickness	10 Å - 5000 Å*
	Available metals and deposition rates (Å/s)	Gold (Au) 10 Chromium (Cr) 5 Platinum (Pt) 5 Titanium (Ti) 5 Nickel (Ni) 5 Germanium (Ge) 5 Palladium (Pd) 5 Silver (Ag)
Process parameter range	Process Temperature	Less then 80 oC
	Process pressure	2x10-6 mbar
	Distance between e-beam and substrate	46 cm
Substrates	Sample size	one 2" or 4" wafers Or several smaller pieces
	Substrate material allowed	III-V materials Si
	Materials allowed on the substrate	Silicon oxide Silicon (oxy)nitride Photoresist PMMA Mylar

* For thicknesses above 2000 Å special permission is required (contact thinfilm@nanolab.dtu.dk).

Calibration of Physimeca (experienced users only)

As of 16/6/2008, we will use a new system to compensate for "drift" without having to change e.g. 20 gold programs for each refilling. The power setting during deposition is a fraction of the "auto-emission current" on the genius system. In order to compensate for drift in the system the auto and max emission current on the genius is adjusted to achieve the rates at the set powers below This way it should not be necessary to adjust the programs every time, but experienced users will have to occasionally adjust the genius setting.

Reference deposition (step)	Material	Pocket	Rate (Å/s)	At power (%)	Example of max emission current (6-2008)
					mA	~mA for rate
Ti100nm-5A-cal	Ti	1	5	70	160	112
Pt100nm-5A-cal	Pt	2	5	80	460	368
Au100nm-10A-cal	Au	3	10	80	450	360
Ni100nm-5A-cal	Ni	4	5	70	250	175
Ge100nm-5A-cal	Ge	5	5	70	190	133
Cr100nm-5A-cal	Cr	6	5	70	110	77
Pd100nm-5A-cal	Pd	6	5	70	160	112

The tooling factor has been determined to ~110 for 100nm layers (lot, 6-2008). It will of course have a small dependence on material and rate.

You can use the steps above as starting point when making new programs (other thicknesses, rates, tilt etc.)

Changing Auto and Emission Current (experienced users only)

If the actual power during deposition is significantly different than the target value (e.g. off by a few % you may change the genius values).

Calculate new auto emission current: Inew="good" current during deposition / target power, e.g. 167mA/0.7 = 240mA (new max emission)

1. Use genius remote:
2. Switch to manual mode.
3. Switch to chosen material
4. Go to set data and down to auto emission and max emission .
5. Change both to the new value and note this in the user log.
6. Go to save/load and save values
7. Switch back to remote mode on genius.