PhysAstro Research

Synthesis  parameters of the Titanium Carbide films are almost completely solved for. The C2H2 flow rate has been narrowed down to 2.70 sccm giving a composition of 43% Ti 57%C. The small working distance of 80mm proves to be very effective at giving a high deposition rate. The WDXRF provides us with a general thin film thickness of 450nm for a 30 min deposition. This was confirmed by preforming photo lithography of a pattern on to the film and then using a profilometer to test for film thickness over the bridge of Titanium Carbide. Further depositions are needed to reach the desired 1:1 ratio.

I think your enhanced carbon signal on the polymer,as measured with the WDXRF, is actually a result of the carbon in the substrate. The deposition performed on Al2O3 likely provides a reasonable measure of the composition of both films. We will need to increase the acetylene flow rate to make stoichiometric TiC.

Today I was able to make a deposit of Titanium Carbide. This deposit was done at room temperature with a sapphire substrate and a piece of flexible substrate (PETG). After a 30min deposit the samples were extracted and placed in the WDXRF for compositional testing. The Al2O3 sample came back 70% Ti and 30% Carbon, where the PETG substrate came back 46% Ti and 54% Carbon. This does mean we are able to deposit TiC onto a flexible substrate, but we need to adjust the acetylene flow rate (2.25sccm for this run) to a higher rate to achieve TiC on sapphire.

As far as the bad news the sample holder once again became lodged into the sample holder after the first fun. Therefore no other deposits were able to be completed today. To fix the issue there was a screw at the end of the retrieving rod that would catch on the sputter guard. I replaced it with a screw that does no longer have an issue with this. To stop the sample holder from getting caught under the heater I attempted to adjust the heaters position and every time the sample holder could be put in, unconnected and then reconnected the sample holder would become lodged once again. This is a reproducible issue that I would like to assume is the retrieving rod is bent.

That is it for today. The Sample TiC-97 was the only produced material for the records.

Me and James tried to deposit tonight. The sample holder can be inserted under the heater, but when the sample holder needs to be adjusted to align under the shield the extension arm can not grasp the sample holder with out pushing it past the point of no return. James and I will be in tomorrow 9/17/09 to fabricate a stop to prevent this issue from occuring.

On 9/15/2009 I took apart the “C cathode” in entirety and cleaned with methonal. We also replaced all O rings that were on the cathode. The cathode ran with a constant plasma at 200W to meet our needs. On 9/16/2009 after a complete bake out on the system via internal heater and external heater straps, the pressure was recoreded at 290 nanotorr. By cleaning this cathode and replacing all O rings I seem to have fixed a leaking issue from that specific location.

Also on a note of equipment not working properly, the Right MDX power supply is not able to lite a cathode. This was tested by switching power supplies on different cathodes.

After numerous complaints about the status of the sample holder in chamber II falling on death ears, I made progress into fixing the sample “holder holder.” Hettinger requested that the “sample holder holder” be able to hold square samples. This required me to butcher the “sample holder holder.” But after cleaning it, my and Ryan installed it into the chamber. The heater needed to be adjusted to accept the “sample holder holder.” The heater is not square to the inserting arm. This needs to adjusted. Also, i believe the thermocouple in the heater block is not in all the way. I tried to do a bake out and the heater would only get up to “340 degrees.” The heater was at 80% output and glowing uniformly. This is why I concluded the thermocouple is out of place.

I came in to deposit TiC as specified from the last varified sample. I was not able to load the sample into the “sample holder holder” with old “sample holder”. The pole that holds the “sample holder” runs into the bottom guard before the tray can be put all the way in. I was able to wiggle the arm to get it on top of the gaurd but after much time it would only get wedged in to the “sample holder holder” and not slide properly in. This heat shield for the other samples will need to be either cut down or bent downward in some fashion.