Grown-in and Annealed Beryllium

DESCRIPTION

The input file for this simulation is in the "examples/exam14" directory, in the file example14.in.

option quiet
set echo

mode one.dim
line x loc=0.0 spacing=0.01 tag=top
line x loc=1.0 spacing=0.01
line x loc=20 spacing=0.25 tag=bottom

region gaas       xlo=top  xhi=bottom
boundary exposed  xlo=top  xhi=top
boundary backside xlo=bottom xhi=bottom

init beryllium conc=1e15
deposit gaas thick=.5 divisions=100 beryllium conc=5e18
deposit gaas thick=.5 divisions=100 beryllium conc=1e15
deposit nitride thick=.3

    select z=log10(beryllium)
    plot.1d x.min=-1 x.ma=1 y.mi=14 y.max=20 line.type=4

method fermi init=1e-5
method full.fac
diffuse time=15 temp=800 argon
    select z=log10(beryllium)
    plot.1d x.min=-1 x.ma=1 y.mi=14 y.max=20 cle=f axi=f line.type=2

quit

Here, Be is grown into the GaAs by using the deposit statements

deposit gaas thick=.5 divisions=100 beryllium conc=5e18
deposit gaas thick=.5 divisions=100 beryllium conc=1e15

instead of an implant statement. In this case, SUPREM-IV.GS uses the lower "as-grown" diffusivities for beryllium since no implanted beryllium is present. The as-grown and diffused profiles are shown in Figure 1. The extent of beryllium diffusion is seen to be much less in this case compared to the implanted case (Example 13), even though the same anneal conditions are used and the beryllium peak concentrations are comparable (the diffusion is hole, or concentration, dependent).