Specific Process Knowledge/Lithography/EBeamLithography

The JEOL JBX-9500 electron beam lithography system is a spot electron beam type lithography system designed for writing patterns with dimensions from nanometers to sub-micrometers. The maximum field-size without stitching is 1 mm x 1 mm. The machine is located in a class 10 cleanroom with tight temperature and moisture control. The room must only be entered when the machines or equipment inside the room is intended to be used.

Overview of the performance of the e-beam writer

Purpose	pattern an electron sensitive resist	Mainly for pattering structures with minimum feature size between 1 µm to 20nm
Performance	Resolution	Minimum e-beam size: 12 nm
Performance	Max. e-beamed area without stitching	1mm x 1mm
Process parameter range	E-beam voltage	100kV
	Scanning speed	100MHz
	Min. electron beam size	10nm
	Min. step size	1nm
	Beam current range	0.1nA to 20nA in normal conditions (see available condition files here)
	Dose range	0.001µC/cm² to 100000µC/cm²
Samples	Batch size	Wafer cassettes: 6 x 2" wafers 2 x 4" wafers 1 x 6" wafer Special wafer cassette with slit openings of 20 mm (position A), 12 mm (position B), 8 mm (position C) and 4 mm (position D).
Samples	Substrate material allowed	Silicon wafers Wafers with layers of silicon oxide or silicon (oxy)nitride Wafers with layers of metal III-V materials Quartz wafers Pyrex wafers

Getting started

To request a training session or a time-slot for the e-beam, contact the e-beam team via this link: e-beam@danchip.dtu.dk'

You need 3-4 training sessions before being allowed to use the e-beam writer. You can get training in loading and unloading samples into a cassette, to optically pre-align the samples, to calibrate the writer, to perform 2nd alignment and start exposure. For safety reasons, the costumer is however not allowed to load or unload cassettes to or from the e-beam writer.

Before you request for a training, it is crucial to have your pattern ready in either tdb-format or GDSII format. Also, check your pattern in e.g. CleWin before requesting. In order to reach the files from the computers inside the cleanroom, it is recommended to either dropbox them or send them per email to yourself.

It is also recommended to gather as much knowledge about your e-beam run from your colleagues, i.e. which e-beam current, aperture and dose to use, which shot pitch (e.g. SHOT A,10). In order to get an overview of what an e-beam process requires, it is recommended to a assist a fully trained colleague of yours when she or he e-beam writes. Furthermore, please read the e-beam manual for more information on which parameters to use.

On the L-drive, a logbook for the e-beam writer can be found. Sheet 1 gives you an overview of which condition files (currents and apertures) have been in use recently by which user on which type of resist. On sheet 2 in this logbook you can find a writing time estimation program; please use this prior to requesting e-beam sessions. If in doubt how to use it, contact the e-beam team.