XPS data on oxidized and surface treated NPN
Katia Lyubarskaya in Alex Shestopalov’s lab has been testing different surface conditions of oxidised NPN membranes. I’ve placed her data below. (We used chips from wafer 1070)
We started by looking at chips that received different chemical/plasma/thermal processes to create an oxide layer. The thermally treated sample has a significantly higher Oxygen peak, but the samples were wrinkled. Katia chose to use the O2 plasma treatment to prep samples for the surface treatment tests.
Next are the XPS results for a variety of different surface treatments using the molecules shown below.
I’m not sure that there are any clear “winners” or “losers” from these results. The NHS-PEG2-NHS @65C has the highest C peak. This may indicate greater surface coverage. Future work will include testing thermally treated samples at lower temperatures so that wrinkling is not a problem. Katia has also acquired new molecules she will be using for different surface treatments. She will also investigate the “lifetime” of the surface treatments by measuring samples exposed to water for at least one day.