TABLE OF CONTENTS M. Suezawa
February 1997
Nitrogen is an important impurity in crystalline silicon and its properties have been extensively studied. This Datareview summarises values for solubility and segregation (Section B), diffusion (Section C), IR absorption (Section D) and interactions with defects and oxygen (Section E).
There are four methods of doping silicon with nitrogen: melting of silicon with Si 3N 4, melting silicon in an atmosphere which includes nitrogen or ammonia, annealing silicon in nitrogen gas, and ion-implantation.
The solubility of nitrogen in silicon has mainly been studied with the first two methods. It was first studied by Kaiser and Thurmond [1] by melting silicon in an atmosphere which included nitrogen or ammonia. They determined the solubility of nitrogen to be about 10 19 cm -3 in molten silicon by vacuum fusion gas analysis. Yatsurugi et al [2] determined it using the floating zone method of hemicylindrical silicon rods sandwiching Si 3N 4. The solubility of nitrogen in the melt silicon was determined to be about 6 l0 18 cm -3 by charged particle analysis.
The solid solubility of nitrogen at the melting point depended on the zone-travelling velocity. This is due to solute trapping caused by a very small segregation coefficient, about 7 10 -4, which is defined as the equilibrium concentration ratio between solid and liquid. The solid solubility at the melting point was determined to be (4.5 1.0)10 15
