Here is the excitation and emission wavelengths for two common fluorophores for transport: rhodamine and fluoroscein. rhodamine fluoroscein max ABS 480 nm 470 nm emission 558 nm 516 nm excitation 524 nm 492 nm The protocol for finding excitation and emission wavelengths of a fluorophore with use of the Tecan can be found here. During…

Last week I showed some interesting images on the effects of annealing at a low temperature (700 C) with the susceptor.  Below are images from a wafer that was annealed at 700 C with a ramp rate of 10 C/s outside the susceptor. Immediately following RTP, I saw that the outer part of the wafer…

Last week, Dave carbonized some w501 samples for me so that I could look into discoloration with this new type of silicon stabilization. The carbonization recipe was: – 1 min 50:1 HF strip to form Si:H – Purge RTP with 100% Ar for 5 minutes – 10 min 95% Ar 5% C2H2 flush @ 200…

Last week, JP and I resurrected using TEOS as the backside pattern and experimented with using a thermal oxide as the first protective oxide layer (instead of a sputtered oxide).  The idea was to see how the reduced stress in the pattern (TEOS) would affect film morphology.  The thermal oxide on the frontside was an…

This week, Christine and I have been trying to figure out if we can measure transport in the Tecan with the transwell inserts remaining within the 24-well plates.  Here is a schematic of our idea (with sodium fluorescein, Na-F, as the model fluorescent molecule for transport studies): The left image is a side view, the…

Thanks to SiMPore’s push for TEM grids, we’ve produced a lot of amorphous material in the last month under different deposition conditions.  Below I’ve illustrated the different film structures resulting from depositing with and without substrate bias and heating. Without bias, the amorphous film exhibits clusters of thicker/denser? material (darker spots).  Intuitively, this makes sense…

Christine and I have been using the present Corning 24-well plate definition in the Tecan for our experiments so far.  Yesterday I placed a pnc-Si chip in the (approximate) middle on the bottom of 1 of the 24-wells.  I did a 500nm absorbance scan in a circular pattern (15×15 points) – to get data similar…

The last few times the spinned PDMS layers were much more uniform. The first picture below is with 1:100 diluted PDMS layer coated on it and the second one is a clean sample from the same wafer for comparison. The PDMS layer on the first picture is approximately 60nm thick. The measured thikness produced by…

Before starting my transport project with the use of the Tecan, it was important to see how the Tecan worked with the sepcon and transwell kept in the well plate. The goals from this experiment were to: 1. Test for fluorescence from the plastic. 2. See if fluorescence from the apical side has an affect…

My previous post on Electroomosis theory describes the deviation between expected and calculated zeta potential using the Smoluchowski equation. In this post I will explain another method of solving for the zeta potential and I will consider the mistakes made in the previous calculations. In a paper by Kim(Mukhtar) in J. Membrane Sci. (1996), the…