Solid diffusion sources for phosphorus doping

Abstract

Abstract New solid diffusion sources for the phosphorus doping of semiconductor silicon are made from composition preferably comprising 50-90 wt% phosphorus compounds and 10-50 wt% additives by hot-pressing or cold-pressing and sintering techniques. The phosphorus compounds are reaction products of phosphorus and silicon oxides, with compositions approximating SiO2.P2O5, and 2 SiO2.P2O5, or SiP2O7 and Si2P2O9, respectively. The additives are materials such as Al2O3, CaO, HfN, HfO2 MgO, NbN, TaN, ThO2, TiN, VN, Y2O3, ZrN, ZrO2, or Zr SiO4, which melt at temperatures above 2,000*C. The typical diffusion source developed is a thin slice, from one inch to four inches in diameter and from about 25-100 mils thick, made from a hot-pressed body composed of 70% of one of the phosphorus compounds and 30% ZrO2, the hot-pressing conditions being, typically, 1,200*C at 1,300 psi, for 5 minutes in an argon atmosphere. This source exhibits an excellent doping ability and has a long lifetime of doping effectiveness. The doping method using such a source is simple, reliable, safe, and economical compared to conventional doping methods.

Inventors

• 👤 Y Murata
• 👤 C Mcmurtry

Bibliographic Details