Chemistry Reference
In-Depth Information
oxides the etch rate as a function of doping concentration depends on solution dilution.
Similar findings were reported in other studies for the oxides doped with P,
451
As,
429
and B.
425
For BSG films the effect of
in the glass on etch rate also depends on
412
etchant as shown in Fig. 4.23.
In SC-1 cleaning solution, the etch rate of B- and P-
doped glasses slightly increases with increasing B and P concentrations.
1013
Solution composition has a stronger effect on the etch rate of doped oxides than
thermal oxides in BHF solutions as shown in Fig. 4.19
491
and in
115,369
solu-
tions.
Also, the etch rate difference between doped oxides and thermal oxides
depends on solution composition; in the solution the etch rate of a PSG film
is 100 to 300 times higher than thermal silicon oxide, but in the BHF solution it is only
about 10 to 30 times higher.
