Instructions for Tylan Oxidation Process Qualification
Purpose: to provide verification and trend of a wet oxidation
program and wafer-to-wafer and within-a-wafer uniformity of etch over a 50
of the test: to be completed after
major maintenance such as a pull and clean or injector change, or once monthly,
or as needed based on user feedback.
Labmembers are encouraged to use this procedure before committing their
work to critical runs to check that the furnace is operating correctly.
of results: to be posted on the log
sheet located in the assigned book at the tool, posted in the equipment archive
for each of the four tylan oxidation furnaces on the SNF website and in a file
or webpage available to users in data or chart format.
- From the stock room get four wafers for each furnace,
tylan1, tylan2 and tylan3. Get two
wafers for tylan4. Use ‘L’ stock
- Clean all wafers using standard pre-diffusion clean,
5:1:1 DI:H2O2:HCl last.
- Load wet program WET900 into all furnaces. Time variable is 00:39:00. This should grow between 900A and 1100A
- Load the wafers into the furnaces flats up (top) and
polished sides facing out (load direction). Arrange the wafers so that they are in the front and back positions
of two boats. See Fig. 1. Tylan4
will have one wafer in the front position of the first boat and one wafer
in the back position of the second boat.
This will represent a 50 wafer spread. See Fig. 2.
- Start the program and monitor the gas flows and
temperature of the Load, Center and Source TC’s.
- After the program has finished (about 2hr) unload the
wafers into the appropriately marked box for the furnace tested.
- Measure the wafers using either Nanospec or Nanospec,
program 1. Be sure to reference the instrument using the standard
wafer. Take readings for the
Center, Flat, Bottom, Right and Left positions of the wafer. Readings should be taken about 15mm
from the edge. See Fig. 3.
- Note the reading for thickness and in the Oxide
Figure 1: Wafer placement in tylan1-3 boats
Figure 2: Wafer placement in tylan4 boats
Figure 3: Reading placement. Note that the flat is “up”.