7/5/13 (Tran)

Update from Tran (I was out of lab on Friday)

1. Imaged our last sample with PMMA (from Wednesday). Unfortunately, I didn't see any line or any pattern at all. So I think there are few possibilities: 

- We can't get the pattern with PMMA (I'm not sure if we got it before with Gabe; I can't remember) 

- The layer of SiO2 is too thin  

- The spot size 1 (this is least likely since we used the same spot size with EL6 and were able to see part of the pattern) 

- I might have missed the pattern ( I almost exposed the whole chip to find the pattern but it's still one possibility) 

2. I think I should do another NPGS with PMMA with spot size 3 to see if there is any different and try to find what the reasons why we didn't get it 

- I ended up doing 2 NPGS runs. One with spot size 3 and one with spot size 1 (on the same chip with PMMA) 

- After the NPGS I put on 15 drops CNT and imaged 

- I still can't find any lines for both spot size 1 and 3 ( Again I think I exposed the whole chip but still found nothing)

- On the other hand, I noticed that with PMMA, a lot more CNTs stick on the surface. While searching for the lines, I saw many CNTs all over the place (much more that what we see on EL6). So I would think EL6 would be a little bit better, since we don't really want CNTs on the surface but on the lines. This part I'm not 100% sure since I might misunderstand the reason why we used PMMA or EL6.

- One more thing I notice, if we want to use different spot size, we probably want to change the spot size on the NPGS menu also, just right above where we enter the picoammeter current, we didn't do that last time when we change from spot size 3 to spot size 1. I think it makes a difference, the time was so much faster but I'm not sure if we're supposed to change it or not.