High temperature phosphorous oxide diffusion source
AssigneeTechneglas, Inc.
InventorsGary R. Pickrell, James E. Rapp
Life of this patent
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Abstract
The present invention relates to a solid high temperature phosphorus diffusion source that is an R.sub.2 O.sub.3 /P.sub.2 O.sub.5 compound in which the ratio of R.sub.2 O.sub.3 to P.sub.2 O.sub.5 is 1 to 3 and R is La, Y, Ce, Nd, Eu, Pr, Sm, Ho, Tb, Er, Yb, Tm or Dy. The invention also relates to a method of making the diffusion source, a method of using the diffusion source to evolve P.sub.2 O.sub.5 to dope a silicon wafer, and to the doped silicon wafer.
Claims7
A method of making a doped silicon wafer using a solid diffusion source composition, the method comprising the steps of:
- A. heating R.sub.2 O.sub.3 oxide, ZrO.sub.2 and H.sub.3 PO.sub.4 to provide a R.sub.2 O.sub.3 oxide/ZrO.sub.2 /P.sub.2 O.sub.5 solid diffusion source composition consisting essentially of a R.sub.2 O.sub.3 /ZrO.sub.2 /P.sub.2 O.sub.5 compound in which the ratio of R.sub.2 O.sub.3 to P.sub.2 O.sub.5 is 1:3 and R is La, Y, Ce, Nd, Eu, Pr, Sm, Ho, Tb, Er, Tm, Yb or Dy,
- B. firing the composition to evolve P.sub.2 O.sub.5 to deposit a phosphorus containing coating on the silicon wafer at a temperature of about 950.degree. C. to 1175.degree. C. to form a glassy layer having a thickness of about 500-2500 .ANG. on the silicon wafer.
A method of using a doping source to provide a doped silicon wafer, the doping source consisting essentially of a R.sub.2 O.sub.3 /P.sub.2 O.sub.5 compound in which the ratio of R.sub.2 O.sub.3 to P.sub.2 O.sub.5 is about 1:3 and R is La, Y, Ce, or Er the method comprising:
- firing the doping source to evolve P.sub.2 O.sub.5 to deposit a phosphorus containing coating on a silicon wafer at a temperature of about 950.degree. C. to about 1200.degree. C. to form a glassy layer having a thickness of about 500-2500 .ANG. on the silicon wafer.
Dependencies are inferred from the claim text.