File 2 @ IMRE: “You really want to know?”

It is already in the 11th week. Haha… But I still see Michael Essien scoring against Manchester City. Anyway, this is week 9 at school, a good time to pick up your studies and to decide whether to do honours or not, or determine you can do it or not.

My job at IMRE is to help my boss do stuff. I’m a research assistant after all. Good enough? Not really.

Basically, there are 2 parts to my job. One is to grow film; the other is to analyze the defects. To grow my required film, which is zinc oxide (ZnO), I need to thermal clean my spinel (MgAl2O4) substrates by scrubbing... Heat to 750 deg C overnight... Placed in some prepared solution... Heat to 90 deg C for 4-6 hrs... Seed layer of ZnO formed... Cleanroom (the 9pm show) for patterning (photolithography)... Photoresist spin coat... UV rays through mask... Activate the unmasked areas... Etch... Grow the Laterally Epitaxial Overgrowth film of ZnO... Place in another solution... My job is mostly to vary the parameters of this final stage of growth and to check the morphology and size of the film.



The 2nd part is a little more jiatlat. I was to use Transmission Electron Microscopy to view the samples and to analyze the defects in the films that I’ve grown. I have to cut my samples to 3mm by 3mm... Wax to stub... Polish spinel to 50-100 microns... (1 micron 1/1000 mm) Stick face-to-face + 2 similar sized silicon epoxy... (industrial superglue). Polish one side using wax and a glass slide... Wax standing on stub... Grind to flat... Polish... Fix 3mm copper grid to top... Cure... Flip... Grind to 50 microns thick... Polish... Dimpled using a dimple grinder to make a dimple... (WTF!) Ion milling for 20min to 2 days... Then, the sample can be viewed under TEM.

The long tedious steps make my sample fail every time, with a success rate of only 5-10%. Felt like a rookie oncologist. Realized that my films get delaminated under strong mechanical shear, the traditional method mentioned above is not useful. We are using Focused Ion Beam technique to get our samples done, and it is none of my business.

Can’t tell you much anyway. Yar, I purposely wrote them in long paragraphs. Read again if you do not understand. Key words: hydrothermal growth, photolithography, lateral epitaxial overgrowth, transmission electron microscopy, ion milling, focused ion beam. Haha…

Well, it is the end of the rich vs. the richer game, Essien being the only scorer. My next file would be about my bosses. (Not a good idea, eh?)

－异客拍客 @ IMRE －