Thermal Oxide on Silicon
We provide thermal oxide wafer with/without Ti layer/Pt layer in diameter from 2″ to 6″,now we give examples as follows:
1) 4 inch,silicon prime/test wafer,deposited with 5000 Angstroms of silicon oxide
2) Pt layer+Ti layer+thermal oxide layer deposit on silicon wafer:
4 inch Prime grade silicon,1-20 ohm cm,500 um thick ,Single side polished
+ 3000 Angstroms of thermal oxide
+ 500 Angstroms of Ti
+1500 Angstroms of Pt
Thermal Oxide is normally grown in a diffusion furnace (either vertical or horizontal) or it can also be grown in a Rapid Thermal Processor. RTP systems are normally used for thin dry Thermal Oxides or Implant annealing on devices where tight thermal budgets are an issue. Large Horizontal or Vertical diffusion furnaces are usually the tool of choice when growing most Thermal Oxides.
Growth methods: Thermal oxide is grown at high temperatures from 800°C – 1100°C using either a “Wet” or “Dry” growth method.
1) for dry oxidation: Si (solid) + O2 (vapor) –> SiO2 (solid); and
2) for wet oxidation: Si (solid) + 2H2O (vapor) –> SiO2 (solid) + 2H2 (vapor).
Today’s Wet Oxides are grown pyrogenically using Hydrogen and Oxygen gases in a internal or external torch. Most large IC manufactures use external torch technology, this is where H2 & O2 gases are combined in a quartz torch unit outside of the quartz furnace tube. This torch unit is housed in it’s own small high temperature furnace element (separate from the main furnace) that is heated to a temperature >800°C. At this temperature the gases will ignite and burn on their own without an outside ignition source. The flame produced is blue in color and usually contained in a secondary quartz vessel called a steam chamber, the result of this blue flame is pure steam.