What is it?
The final project is a combination of a final Suprem project and the lab report on weeks 7 and 8, but it will also incorporate material from the first Suprem project and from previous lab reports.
When is it due?
The final project and your lab notebook will be due Thursday June 5, 4:30 pm.
1. Simulate YOUR process by putting in the appropriate process parameters that you used in your lab section, or measured for your wafer. Example full-process simulations are available for graphical output to the screen (fullproscreen.inp) and for postscript output (fullpropost.inp). By commenting in or out the appropriate parts of the Suprem files, obtain layer thicknesses and doping profiles for:
a. The active area.
b. The channel (with poly).
c. The field area.
Note that you will have to run the simulation 3 different times.
2. Obtain the following quantities from the output.
a. The junction depth.
b. The sheet resistance of the diffusion (the same numerical integration procedure as in lab 2, using the resistivity vs concentration graph from Sze).
c. The sheet resistance of the poly. Take an average doping concentration and use the same graph as for single crystal silicon to find the resistivity (resistivity vs concentration). Combined with the thickness this will yield the sheet resistance.
d. Final field oxide, contact oxide, and gate oxide thicknesses. You did the gate oxide for the first Suprem project, but you should include the result in the final report. The field oxide thickness may increase during the drive-in, which was not included last time (however, you did not measure the final field oxide thickness on monitor 2 because it was covered with polysilicon!) You did measure the "contact oxide" on monitor 1, where the gate oxide was run through a wet oxidation during the drive-in process.
e. Do you see penetration of boron into the channel in the Suprem simulation? Speculate on what the effect on the device would be.
Other project details:
In general, you want to compare measurements, analytical (homework type) results, and simulation results. Specific examples:
1. Compare the measured and calculated sheet resistances (you have 4 values, the measure monitor wafer Rs, the device wafer Rs from weeks 7 and 8, the sheet resistance calculated for lab report #2, and the sheet resistance computed from the Suprem simulation).
2. Compare measured, graph from text, and SUPREM simulated values for the "contact oxide."
3. Compare Suprem and measured values of poly Rs from the monitor and device wafers.
4. Same for junction depth.
Your goal is to put together a single final report incorporating what you have learned from simulating the process and comparing the simulation results with the measured results and the analytical results. It should be organized by subject rather than method. By this I mean that you should not have a section on Suprem, another on measurements, and another on analytical results. For example, when you are discussing the source/drain junctions, you will want to discuss all measurements, analysis, and simulation that go into your understanding of the junction. You will also want to discuss why the results of the different methods are different. For example, for the source/drain junction, the simple analysis probably did not include the initial phosphorus implant, and it also did not include the depth of the source/drain implant or any high-concentration diffusion effects.