Measurements

Materials Characterization

Atomic Force Microscopy (AFM)

CNSI has a room devoted to AFM including 2 models Asylum and NanoScope. Contact Mark Cornish <cornish@engineering.ucsb.edu> to get tips and register. The cleanroom also has a NanoScope AFM managed by Bill Mitchel <mitchell@ece.ucsb.edu>.

Asylum AFM

Asylum_AFM_MFC-3D_Procedure_v1_-_Basic_Tapping_Mode.docx

Asylum_AFM_MFC-3D_Procedure_v2_-_High_Resolution_Surface_Roughness_Scans_in_Attractive-Mode_Tapping.docx

NanoScope AFM

Bill will approve you to sign-up once someone he trusts trains you.

Analysis

Igor Pro demo: http://www.wavemetrics.com/support/demos.htm Asylum download requires a login, and to get one takes a little while. Is it possible to upload that to the wiki? Gwyddion and GTK+: http://gwyddion.net/download.php#stable-osx it recommends a specific GTK+, not sure why it matters though. If you have it from Pidgin or something I'm sure it'll work.

Focused Ion Beam

Mainly used to create/image cross sections and perform TEM lamina preparations.

[MRL Micrscopy]

Cross Sections

Needs gold coating or conducting surface.

Will mill out a trench with ion beam and image the cross section at a 52 ° tilt. Can get up to 100kX SEM images and normally create trenches up to 20μm

Best when you don't want to destroy your samples and/or your tolerance to cleaving is less than 25 µm, otherwise try cleaving

Contact Daryl Spencer to setup a session, two weeks notice is usually sufficient.

X-Ray Diffraction (XRD)

XRD qualification of wafer:

This is one scan in ~20minutes if you know the offcut and direction already.

1. Note offcut amount and direction. Draw arrow relative to wafer flats. ([110] is the direction perpendicular to the major flat)
2. ID the layer peak(s), if separated from the substrate peak, and give the strain(s) (or just peak separation)
3. ID superlattice/QW fringes. Count them (e.g. -2 to +3) and note spacing in arcseconds
4. Make note of any other strong fringe peaks or broad/mysterious layer peaks

NB: Offcut on GaAs may be up to 10degrees. (XRD person try a pole search to locate). InP offcut ~0.2degrees is standard and often not noticed during XRD.

Optical Characterization

LI curves

"Example:" This technique allows you to measure output power vs. injection current. The follwoing equipment is used:

• Keithley (link to equipment)
• Agilent powermeter (link)

The measurement can be controlled using this (link) software. A sample plot looks like this: (insert picture). More about this technique can be found in:

1. Mr.X et al., IEEE Journ. of Lightwave Technol., vol. x, pp. xxx-xxx, Aug. 2005
2. Our own uploaded description (in doc format maybe)

Electrical characterization

Analysis: http://gwyddion.net/download.php#stable-osx

Microwave measurements

Linearity measurements (OIP2, OIP3, SFDR,...)