B.sub.2 O.sub.3 Diffusion processes
AssigneeOwens-Illinois, Inc.
InventorJames E. Rapp
Life of this patent
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Abstract
Disclosed is a method of evolving B.sub.2 O.sub.3 from certain B.sub.2 O.sub.3 containing glass-ceramics by heating the glass-ceramic in the pressure of helium as a carrier or transport gas.
Claims4
A method of diffusing B.sub.2 O.sub.3 from the surface of a glass-ceramic consisting essentially of the following:
- ______________________________________ Component Mole Percent ______________________________________ SiO.sub.2 15-60 Al.sub.2 O.sub.3 10-30 B.sub.2 O.sub.3 20-60 RO 3-25 BaO 0-15 ______________________________________
- wherein Al.sub.2 O.sub.3 /RO=1.5-4
- wherein RO is selected from BaO, MgO, CaO, SrO and mixtures thereof;
- and
- when SiO.sub.2 is over 40, B.sub.2 O.sub.3 is not over 40, RO is not over 20, and BaO is at least 1;
- when SiO.sub.2 is not over 40, Al.sub.2 O.sub.3 is at least 15, RO is at least 5, MgO is not over 15, CaO is not over 10, SrO is not over 10, BaO is not over 15, La.sub.2 O.sub.3 is 0-5, Nb.sub.2 O.sub.3 is 0-5 and Ta.sub.2 O.sub.3 is 0-5,
- which comprises heating said glass-ceramic to a temperature of 700.degree.-1200.degree. C. while flushing the surface thereof with an inert transport or carrier gas comprising at least 60 mol percent helium.
In a process for doping a semiconductor wherein a semiconductor and a glass-ceramic dopant host for vapor phase transport of B.sub.2 O.sub.3 are maintained in vapor phase communication in the presence of a carrier gas at a temperature and for a time sufficient to effect transport and deposit of B.sub.2 O.sub.3 on said semiconductor, and wherein the glass-ceramic dopant host consists essentially of the following:
- ______________________________________ Component Mole Percent ______________________________________ SiO.sub.2 15-60 Al.sub.2 O.sub.3 10-30 B.sub.2 O.sub.3 20-60 RO 3-25 BaO 0-15 ______________________________________
- wherein Al.sub.2 O.sub.3 /RO=1.5-4,
- wherein RO is selected from BaO, MgO, CaO, SrO and mixtures thereof;
- and
- when SiO.sub.2 is over 40, B.sub.2 O.sub.3 is not over 40, RO is not over 20, and BaO is at least 1;
- when SiO.sub.2 is not over 40, Al.sub.2 O.sub.3 is at least 15, RO is at least 5, MgO is not over 15, CaO is not over 10, SrO is not over 10, BaO is not over 15, La.sub.2 O.sub.3 is 0-5, Nb.sub.2 O.sub.3 is 0-5 and Ta.sub.2 O.sub.3 is 0-5,
- the improvement which comprises employing helium as the carrier gas.
Dependencies are inferred from the claim text.