Process Hierarchy

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  Boron diffusion
Process characteristics:
Diffusion depth
Diffusion depth, must be 0 .. 14 µm
0 .. 14 µm
Dopant concentration
Number of atoms per meter cubed
Dopant concentration*
Number of atoms per meter cubed, must be 1e+12 .. 1e+20 atom/cc
1e+12 .. 1e+20 atom/cc
Sides processed
Sides of the substrate affected by the process
Sides processed*
Sides of the substrate affected by the process
Ambient to which substrate is exposed during processing
oxygen, nitrogen
Excluded materials gold
Film grown
Material grown during a process
borophosphosilicate glass
Material boron
Pressure of process chamber during processing
1 atm
Temperature 1100 °C
Wafer size
Wafer size
Equipment Tylan/Tystar Furnaces (Boron diffusion)
Equipment characteristics:
Batch sizes 100 mm: 24, 150 mm: 12
MOS clean no
Wafer geometry
Types of wafers this equipment can accept
1-flat, 2-flat
Wafer holder
Device that holds the wafers during processing.
quartz boat
Wafer materials
List of wafer materials this tool can accept (not list of all materials, just the wafer itself).
Wafer thickness
List or range of wafer thicknesses the tool can accept
300 .. 600 µm
  • B2O3 ceramic wafers are used as boron solid sources.
  • Customer specifies diffusion depth and boron concentration at that depth.
  • Sample boron concentrations for different diffusion times:
    2 hr: 1e20 atom/cc at 3.0 um, 1e15 atom/cc at 5.4 um
    4 hr: 1e20 atom/cc at 3.8 um, 1e15 atom/cc at 7.1 um
    16 hr: 1e20 atom/cc at 6.4 um, 1e15 atom/cc at 13.5 um
  • The substrate wafer is prime grade N-type silicon wafer
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